Powered by Deep Web Technologies
Note: This page contains sample records for the topic "optimal power flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


1

MATPOWER's Extensible Optimal Power Flow Architecture  

E-Print Network (OSTI)

of MATPOWER's extensible OPF architecture. Index Terms--Load flow analysis, Optimization methods, Power-compiled solvers. A software object is used to encapsulate the definition of the problem formulation, manage tasks. The software design has the advantage of minimizing the coupling between variables, constraints

Tesfatsion, Leigh

2

Artificial bee colony algorithm solution for optimal reactive power flow  

Science Conference Proceedings (OSTI)

Artificial bee colony (ABC) algorithm is an optimization algorithm based on the intelligent foraging behavior of honeybee swarm. Optimal reactive power flow (ORPF) based on ABC algorithm to minimize active power loss in power systems is studied in this ... Keywords: Artificial bee colony, Optimal reactive power flow, Penalty function, Power system

Kür?at Ayan; Ula? K?l?ç

2012-05-01T23:59:59.000Z

3

Natural gas and electricity optimal power flow  

E-Print Network (OSTI)

Abstract — In this paper, the combined natural gas and electric optimal power flow (GEOPF) is presented. It shows fundamental modeling of the natural gas network to be used for the GEOPF, and describes the equality constraints which describe the energy transformation between gas and electric networks at combined nodes (i.e., generators). We also present the formulation of the natural gas loadflow problem, which includes the amount of gas consumed in compressor stations. Case studies are presented to show the sensitivity of the real power generation to wellhead gas prices. Results from the simulation demonstrate that the GEOPF can provide social welfare maximizing solutions considering both gas and electric networks. I.

Seungwon An

2003-01-01T23:59:59.000Z

4

Solving Security Constrained Optimal Power Flow Problems by a ...  

E-Print Network (OSTI)

The optimal power flow (OPF) problem describes a minimum cost electricity gener- ation model that takes into account ...... Electricity Market, 2008. EEM 2008 .

5

Optimal power flow in microgrids using event-triggered optimization Pu Wan and Michael D. Lemmon  

E-Print Network (OSTI)

Optimal power flow in microgrids using event-triggered optimization Pu Wan and Michael D. Lemmon Abstract-- Microgrids are power generation and distribution systems in which users and generators-triggered distributed optimization algorithm to solve the optimal power flow (OPF) problem in microgrids. Under event

Lemmon, Michael

6

Stochastic Optimal Power Flow for Reserve Determination  

Science Conference Proceedings (OSTI)

With significant levels of renewable generation to be integrated in the future electric power systems, new balancing techniques and better forecasting are needed for system operators to maintain power system security. The impact of uncertainty and variability associated with renewable generation motivates the introduction of stochastic methods when determining reserve requirements. These methods enable operators to make better use of system flexibility in order to maintain system reliability and ...

2012-12-31T23:59:59.000Z

7

Thermal Unit Commitment Including Optimal AC Power Flow Constraints  

E-Print Network (OSTI)

Thermal Unit Commitment Including Optimal AC Power Flow Constraints Carlos Murillo{Sanchez Robert J algorithm for unit commitment that employs a Lagrange relaxation technique with a new augmentation. This framework allows the possibility of committing units that are required for the VArs that they can produce

8

Three-phase power flow analysis in sequence component frame using Hybrid Particle Swarm Optimization  

Science Conference Proceedings (OSTI)

Power flow is an important tool in power system studies. Usually, a power system is assumed to be balanced and the power flow analysis is carried out for the same. Practical power system networks are highly unbalanced and it is required to obtain load ... Keywords: Genetic algorithm, Load flow, Particle Swarm Optimization, Sequence network, Unbalanced power system

K. Gnanambal; N. S. Marimuthu; C. K. Babulal

2011-03-01T23:59:59.000Z

9

Application of Newton's optimal power flow in voltage/reactive power control  

Science Conference Proceedings (OSTI)

This paper considers an application of Newton's optimal power flow to the solution of the secondary voltage/reactive power control in transmission networks. An efficient computer program based on the latest achievements in the sparse matrix/vector techniques has been developed for this purpose. It is characterized by good robustness, accuracy and speed. A combined objective function appropriate for various system load levels with suitable constraints, for treatment of the power system security and economy is also proposed. For the real-time voltage/reactive power control, a suboptimal power flow procedure has been derived by using the reduced set of control variables. This procedure is based on the sensitivity theory applied to the determination of zones for the secondary voltage/reactive power control and corresponding reduced set of regulating sources, whose reactive outputs represent control variables in the optimal power flow program. As a result, the optimal power flow program output becomes a schedule to be used by operators in the process of the real-time voltage/reactive power control in both normal and emergency operating states.

Bjelogrlic, M.; Babic, B.S. (Electric Power Board of Serbia, Belgrade (YU)); Calovic, M.S. (Dept. of Electrical Engineering, University of Belgrade, Belgrade (YU)); Ristanovic, P. (Institute Nikola Tesla, Belgrade (YU))

1990-11-01T23:59:59.000Z

10

A Modeling and Optimization Approach for Multiple Energy Carrier Power Flow  

E-Print Network (OSTI)

Abstract — This paper presents a general power flow and optimization approach for power systems including multiple energy carriers, such as electricity, natural gas, and district heat. The model is based on a conceptual approach for the inclusion of distributed resources. Couplings between the different energy carriers are regarded explicitly, enabling investigations in power flow and marginal price interactions. Optimal demand, conversion, and transmission of multiple energy carriers within a system is formulated as a combined optimal power flow problem. A numerical example demonstrates how the method can be used for different system studies. I.

Martin Geidl; Göran Andersson

2005-01-01T23:59:59.000Z

11

Mathematical programming applied in the optimal power flow problem DC: case studies of market needs  

Science Conference Proceedings (OSTI)

This paper seeks to investigate the application of mathematical programming, considering it as a tool for optimal electrical power generation and management. Nowadays, observing signals of crisis in various countries, electrical power emerges not only ... Keywords: energy flow in electrical energy networks and markets, linear Programming, marketing theory, mathematical programming, optimum power flow DC

Emerson Eustáquio Costa; Luiz Danilo Barbosa Terra; George Leal Jamil

2008-04-01T23:59:59.000Z

12

Applying mathematical programming elements to answer market needs: case studies of optimization of electrical power flow  

Science Conference Proceedings (OSTI)

This paper seeks to investigate the application of mathematical programming, considering it as a tool for optimal electrical power generation and management. Nowadays, observing signals of crisis in various countries, electrical power emerges not only ... Keywords: energy flow in electrical energy networks and markets, linear programming, marketing theory, mathematical programming, optimum power flow DC

Emerson Eustáquio Costa; Luiz Danilo Barbosa Terra; George Leal Jamil

2008-01-01T23:59:59.000Z

13

Optimal Power Flow of Multiple Energy Carriers(Geidl and Andersson 2007) |  

Open Energy Info (EERE)

Optimal Power Flow of Multiple Energy Carriers(Geidl and Andersson 2007) Optimal Power Flow of Multiple Energy Carriers(Geidl and Andersson 2007) Home > Groups > Energy Systems Integration Qinsun's picture Submitted by Qinsun(35) Member 15 November, 2012 - 13:04 Literature Review The author proposed a linear static state model for multiple energy carriers. The optimal power flow and economic dispatch was determined. The method is a simple method of integrated system planning The methods used in the paper are linear deterministic system without control signal, optimal power flow and economic dispatch The proposed method stabilized the power grid, reduced the marginal cost of electricity, and increased the marginal cost of natural gas. The strength of the proposed method is following: 1. it is integrated; 2. it secures to converge;

14

Available transfer capability calculation with transfer based static security-constrained optimal power flow  

Science Conference Proceedings (OSTI)

In power market environment, available transfer capability (ATC) is an important index, indicating the amount of the further usable transmission capacity for commercial trading. ATC calculation is non-trivial when static security constraints are included. ... Keywords: available transfer capability (ATC), optimal power flow, power market, power system, static stability

M. Gandchi; M. Tarafdar Haque; A. Yazdanpanah

2006-03-01T23:59:59.000Z

15

Integrated Control of Active and Reactive Power Flow Controllers to Optimize Transmission System Utilization  

Science Conference Proceedings (OSTI)

Optimized power system control requires oversight of numerous control elements to efficiently and reliably transfer power across the system. The objective of this project was to minimize losses in the Consolidated Edison Electric power system via modification of control variables available to the system operator. These variables include generator voltages, transformer voltage/phase angle tap set points, and switched shunt status. System constraints include bus voltages, branch/interface flow limits, ...

2012-11-08T23:59:59.000Z

16

Synchronization-Aware and Algorithm-Efficient Chance Constrained Optimal Power Flow  

E-Print Network (OSTI)

One of the most common control decisions faced by power system operators is the question of how to dispatch generation to meet demand for power. This is a complex optimization problem that includes many nonlinear, non convex constraints as well as inherent uncertainties about future demand for power and available generation. In this paper we develop convex formulations to appropriately model crucial classes of nonlinearities and stochastic effects. We focus on solving a nonlinear optimal power flow (OPF) problem that includes loss of synchrony constraints and models wind-farm caused fluctuations. In particular, we develop (a) a convex formulation of the deterministic phase-difference nonlinear Optimum Power Flow (OPF) problem; and (b) a probabilistic chance constrained OPF for angular stability, thermal overloads and generation limits that is computationally tractable.

Bent, Russell; Chertkov, Michael

2013-01-01T23:59:59.000Z

17

Program on Technology Innovation: An Investigation of the Stability Region Concept Applied to Stability-Constrained Optimal Power Flows  

Science Conference Proceedings (OSTI)

This report presents the formulation of optimal power flow with linear dynamic stability constraints. Intensive off-line dynamic simulations were performed to capture the system instability separation modes corresponding to system disturbances and to further derive the linear coefficients for each hyperplane. Optimal power flows with and without the dynamic stability region constraints were computed, and dynamic simulations based on two sets of power flow solutions were performed. Comparison of the two s...

2009-03-31T23:59:59.000Z

18

Optimal Power Flow of Multiple Energy Carriers(Geidl and Andersson...  

Open Energy Info (EERE)

topics related to ESI Prospects for Nuclear Power(Davis 2012) A Framework for the Optimization of Integrated Energy Systems(Jain and Alleyne 2012) Energy System...

19

Centralized wind power plant voltage control with optimal power flow algorithm.  

E-Print Network (OSTI)

??This thesis presents a method of controlling the reactive power injected into a medium-voltage collection system by multiple wind turbine generators such that the voltage… (more)

Kline, Jared Andrew

2011-01-01T23:59:59.000Z

20

CHANCE CONSTRAINED OPTIMAL POWER FLOW: RISK-AWARE NETWORK CONTROL UNDER UNCERTAINTY  

E-Print Network (OSTI)

short-term demand changes locally) and are largely not of a data-driven, algorithmic and distributed. Additionally, only some real-time data is actually used by the grid to respond to evolving conditions. All Power Flow (OPF), routinely used by the electric power industry to re-dispatch hourly controllable

Bienstock, Daniel

Note: This page contains sample records for the topic "optimal power flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Contingency-Constrained Optimal Power Flow and the Community Activity Room (CC-OPF and CAR)  

Science Conference Proceedings (OSTI)

Demand for an OPF tool measuring state and recommended control actions is on the rise because of network reliability concerns as well as the expansion of LMP (Locational Marginal Pricing) markets. The two related projects brought together in this report describe a method that is secure, stable, fast, and simple to use. The first project 8212 the Contingency-Constrained Optimum Power Flow (CC-OPF) project 8212 focused on contingency analysis, revising OPF limits, developing a common data source (CDS) appl...

2006-05-03T23:59:59.000Z

22

Modified simulated annealing technique based optimal power flow with FACTS devices  

Science Conference Proceedings (OSTI)

Simulated annealing is a probabilistic method for finding the global minimum of a cost function that may possess several local minima. In this paper, a Modified Simulated Annealing (MSA) technique is proposed to minimise the generation cost in Optimal ...

Subrata Majumdar; Ajoy Kumar Chakraborty; P. K. Chattopadhyay; Tulika Bhattacharjee

2012-07-01T23:59:59.000Z

23

Bus optimization for low-power data path synthesis based on network flow method  

Science Conference Proceedings (OSTI)

Sub-micron feature sizes have resulted in a considerable portion of power to be dissipated on the buses, causing an increased attention on savings for power at the behavioral level and RT level of design. This paper addresses the problem of minimizing ...

Sungpack Hong; Taewhan Kim

2000-11-01T23:59:59.000Z

24

Holistic optimization of distribution automation network designs using survivability modeling and power flow equations  

Science Conference Proceedings (OSTI)

Smart grids are fostering a paradigm shift in the realm of power distribution systems. Whereas traditionally different components of the power distribution system have been provided and analyzed by different teams, smart grids require a unified and holistic ... Keywords: smart-grids

Anne Koziolek; Alberto Avritzer; Daniel Sadoc Menasché

2013-04-01T23:59:59.000Z

25

Optimizing Power Using Transformations  

E-Print Network (OSTI)

: The increasing demand for portable computing has elevated power consumption to be one of the most critical design parameters. A high-level synthesis system, HYPER-LP, is presented for minimizing power consumption in application specific datapath intensive CMOS circuits using a variety of architectural and computational transformations. The synthesis environment consists of high-level estimation of power consumption, a library of transformation primitives, and heuristic/probabilistic optimization search mechanisms for fast and efficient scanning of the design space. Examples with varying degree of computational complexity and structures are optimized and synthesized using the HYPER-LP system. The results indicate that more than an order of magnitude reduction in power can be achieved over current-day design methodologies while maintaining the system throughput; in some cases this can be accomplished while preserving or reducing the implementation area. 1.0 Introduction VLSI research a...

Anantha P. Chandrakasan; Miodrag Potkonjak; Renu Mehra; Jan Rabaey; Robert W. Brodersen

1995-01-01T23:59:59.000Z

26

Increased Power Flow Guidebook  

Science Conference Proceedings (OSTI)

The Increased Power Flow (IPF) Guidebook is a state-of-the-art and best practices guidebook on increasing power flow capacities of existing overhead transmission lines, underground cables, power transformers, and substation equipment without compromising safety and reliability. The Guidebook discusses power system concerns and limiting conditions to increasing capacity, reviews available technology options and methods, illustrates alternatives with case studies, and analyzes costs and benefits of differe...

2005-11-16T23:59:59.000Z

27

Particle Swarm Optimization Based Reactive Power Optimization  

E-Print Network (OSTI)

Reactive power plays an important role in supporting the real power transfer by maintaining voltage stability and system reliability. It is a critical element for a transmission operator to ensure the reliability of an electric system while minimizing the cost associated with it. The traditional objectives of reactive power dispatch are focused on the technical side of reactive support such as minimization of transmission losses. Reactive power cost compensation to a generator is based on the incurred cost of its reactive power contribution less the cost of its obligation to support the active power delivery. In this paper an efficient Particle Swarm Optimization (PSO) based reactive power optimization approach is presented. The optimal reactive power dispatch problem is a nonlinear optimization problem with several constraints. The objective of the proposed PSO is to minimize the total support cost from generators and reactive compensators. It is achieved by maintaining the whole system power loss as minimum...

Sujin, P R; Linda, M Mary

2010-01-01T23:59:59.000Z

28

Optimizing Power Factor Correction  

E-Print Network (OSTI)

The optimal investment for power factor correcting capacitors for Kansas Power and Light Company large power contract customers is studied. Since the billing capacity is determined by dividing the real demand by the power factor (the minimum billing capacity is based on 80 percent of the summer peak billing capacity) and the billing capacity is used to determine the number of kilowatt-hours billed at each pricing tier, the power factor affects both the demand and the energy charge. There is almost no information available in the literature concerning recommended power factor corrections for this situation. The general advice commonly given in the past has been that power factor should be corrected to above 0.9 if it is below that value to begin with, but that does not take into account the facts of the situation studied here. Calculations relevant to a commercial consumer of electricity were made for demands of 200, 400, 800, 1,600, 3,200, and 6,400 kW and monthly energy consumption periods of 100, 150, 200, 300, 400, and 500 hours for several capacitor purchase and installation costs. The results are displayed in a series of graphs that enable annual cost savings and payback periods to be readily determined over a range of commonly encountered parameter values. It is found that it is often economically advantageous to correct a power factor to near unity.

Phillips, R. K.; Burmeister, L. C.

1986-06-01T23:59:59.000Z

29

Differential evolution approach for optimal reactive power dispatch  

Science Conference Proceedings (OSTI)

Differential evolution based optimal reactive power dispatch for real power loss minimization in power system is presented in this paper. The proposed methodology determines control variable settings such as generator terminal voltages, tap positions ... Keywords: Differential evolution, Loss minimization, Optimal power flow, Penalty function, Reactive power dispatch

M. Varadarajan; K. S. Swarup

2008-09-01T23:59:59.000Z

30

Power Systems Operation Planning Optimization.  

E-Print Network (OSTI)

??Optimal hydrothermal power dispatch on a multi-area network is a large-scale non-linear problem. Its objective is to find the optimal generation schedule of hydro and… (more)

FRAGOMENI, UMBERTO

2013-01-01T23:59:59.000Z

31

Efficient Production Optimization Using Flow Network Models  

E-Print Network (OSTI)

Reservoir simulation is an important tool for decision making and field development management. It enables reservoir engineers to predict reservoir production performance, update an existing model to reproduce monitoring data, assess alternative field development scenarios and design robust production optimization strategies by taking into account the existing uncertainties. A big obstacle in automating model calibration and production optimization approaches is the massive computation required to predict the response of real reservoirs under proposed changes in the model inputs. To speed up reservoir response predictions without compromising accuracy, fast surrogate models have been proposed. These models are either derived by preserving the physics of the involved processes (e.g. mass balance equations) to provide reliable long-range predictions or are developed based solely on statistical relations, in which case they can only provide short-range predictions due to the absence of the physical processes that govern the long-term behavior of the reservoir. We present an alternative solution that combines the advantages of both statistics-based and physics-based methods by deriving the flow predictions in complex two-dimensional models from one-dimensional flow network models. The existing injection/production wells in the original model form the nodes or vertices of the flow network. Each pair of wells (nodes) in the flow network is connected using a one-dimensional numerical simulation model; hence, the entire reservoir is reduced to a connected network of one-dimensional simulation models where the coupling between the individual one-dimensional models is enforced at the nodes where network edges intersect. The proposed flow network model provides a useful and fast tool for characterizing inter-well connectivity, estimating drainage volume between each pair of wells, and predicting reservoir production over an extended period of time for optimization purposes. We estimate the parameters of the flow network model using a robust training approach to ensure that the flow network model reproduces the response of the original full model under a wide range of development strategies. This step helps preserve the flow network model's predictive power during the production optimization when development strategies can change at different iterations. The robust networks training and the subsequent production optimization iterations are computationally efficient as they are performed with the faster flow network model. We demonstrate the effectiveness and applicability of our proposed flow network modeling approach to rapid production optimization using two-phase waterflooding simulations in synthetic and benchmark models.

Lerlertpakdee, Pongsathorn

2012-08-01T23:59:59.000Z

32

Study on reactive power optimization problem taking the line current as state variable  

Science Conference Proceedings (OSTI)

The math model of optimization problem is established by describing the electric power network equations as the hybrid form with node voltage and line current based on ? equivalence circuit of power equipment, there the objective function is performed ... Keywords: line current, node voltage, optimal power flow, power flow, reactive power optimization

Zhang Jinsong; Wang Chengmin; Zhang Gong; Hou Zhijian

2005-10-01T23:59:59.000Z

33

Instrumentation for Increased Power Flow  

Science Conference Proceedings (OSTI)

This report is the second Technical Update of the Instrumentation for Managing Increased Power Flow project, part of EPRI's Increased Power Flow (IPF) program. The project, initiated in 2006 and expected to continue for several years, studies the feasibility of new instrumentation to support increased power flow strategies. In 2007 the work focused on two primary developments: the Backscatter Sensor for the real-time measurement of transmission line temperature and current and the Emissivity Test Instrum...

2007-12-06T23:59:59.000Z

34

Increased Power Flow Guidebook - 2012  

Science Conference Proceedings (OSTI)

The EPRI Increased Power Flow (IPF) Guidebook is a state-of-the-art and best- practices reference and guidebook on increasing the power flow capacities of existing overhead transmission lines, underground cables, power transformers, and substation equipment, without compromising safety and reliability. The Guidebook discusses power system concerns and limiting conditions to increasing capacity, reviews available technology options and methods, illustrates the alternatives with case ...

2012-12-31T23:59:59.000Z

35

Increased Power Flow Guidebook - 2013  

Science Conference Proceedings (OSTI)

The EPRI Increased Power Flow (IPF) Guidebook is a state-of-the-art and best- practices reference and guidebook on increasing the power flow capacities of existing overhead transmission lines, underground cables, power transformers, and substation equipment, without compromising safety and reliability. The Guidebook discusses power system concerns and limiting conditions to increasing capacity, reviews available technology options and methods, illustrates the alternatives with case ...

2013-11-18T23:59:59.000Z

36

Design optimization of IGCC power plants  

SciTech Connect

Integrated gasification-combined-cycle (IGCC) power plants have the potential for providing performance and cost improvements over conventional coal-fired steam power plants with flue-gas desulfurization. The major design options for IGCC power plants include the following: oxygen-blown versus air-blown gasification processes; entrained-flow, fluidized-bed, or fixed-bed gasifier; coal-slurry feed versus coal-dry feed; hot versus cold fuel-gas cleanup; gas turbine alternatives; and, design alternatives for the Heat Recovery Steam Generator (HRSG). This paper summarizes some results from these studies. The advanced thermoelectric techniques used at Tennessee Technological University (TTU) are very powerful tools for evaluating and optimizing IGCC power plants.

Tsatsaronis, G.; Lin, L.; Pisa, J.; Tawfik, T. (Tennessee Technological Univ., Cookeville, TN (United States))

1992-01-01T23:59:59.000Z

37

Power optimized programmable embedded controller  

E-Print Network (OSTI)

Now a days, power has become a primary consideration in hardware design, and is critical in computer systems especially for portable devices with high performance and more functionality. Clock-gating is the most common technique used for reducing processor's power. In this work clock gating technique is applied to optimize the power of fully programmable Embedded Controller (PEC) employing RISC architecture. The CPU designed supports i) smart instruction set, ii) I/O port, UART iii) on-chip clocking to provide a range of frequencies , iv) RISC as well as controller concepts. The whole design is captured using VHDL and is implemented on FPGA chip using Xilinx .The architecture and clock gating technique together is found to reduce the power consumption by 33.33% of total power consumed by this chip.

Kamaraju, M; Tilak, A V N; 10.5121/ijcnc.2010.2409

2010-01-01T23:59:59.000Z

38

A Conductivity Relationship for Steady-state Unsaturated Flow Processes under Optimal Flow Conditions  

SciTech Connect

Optimality principles have been used for investigating physical processes in different areas. This work attempts to apply an optimal principle (that water flow resistance is minimized on global scale) to steady-state unsaturated flow processes. Based on the calculus of variations, we show that under optimal conditions, hydraulic conductivity for steady-state unsaturated flow is proportional to a power function of the magnitude of water flux. This relationship is consistent with an intuitive expectation that for an optimal water flow system, locations where relatively large water fluxes occur should correspond to relatively small resistance (or large conductance). Similar results were also obtained for hydraulic structures in river basins and tree leaves, as reported in other studies. Consistence of this theoretical result with observed fingering-flow behavior in unsaturated soils and an existing model is also demonstrated.

Liu, H. H.

2010-09-15T23:59:59.000Z

39

Study the power flow control of a power system with unified power flow controller.  

E-Print Network (OSTI)

??Electrical power systems is a large interconnected network that requires a careful design to maintain the system with continuous power flow operation without any limitations.… (more)

Peesari, Vakula

2010-01-01T23:59:59.000Z

40

Optimization Online - Stochastic Optimization for Power System ...  

E-Print Network (OSTI)

Feb 17, 2011... for Power System Configuration with Renewable Energy in Remote ... type of problem in comparison to a state-of-the-art professional solver.

Note: This page contains sample records for the topic "optimal power flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Electric Power System Asset Optimization  

NLE Websites -- All DOE Office Websites (Extended Search)

NETL-430/061110 NETL-430/061110 March 7, 2011 430.01.03 Electric Power System Asset Optimization Disclaimer This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or

42

Power Flow Controller for Renewables: Transformer-less Unified Power Flow Controller for Wind and Solar Power Transmission  

SciTech Connect

GENI Project: MSU is developing a power flow controller to improve the routing of electricity from renewable sources through existing power lines. The fast, innovative, and lightweight circuitry that MSU is incorporating into its controller will eliminate the need for a separate heavy and expensive transformer, as well as the construction of new transmission lines. MSU’s controller is better suited to control power flows from distributed and intermittent wind and solar power systems than traditional transformer-based controllers are, so it will help to integrate more renewable energy into the grid. MSU‘s power flow controller can be installed anywhere in the existing grid to optimize energy transmission and help reduce transmission congestion.

None

2012-02-08T23:59:59.000Z

43

Power Plant Optimization Demonstration Projects Cover Photos:  

NLE Websites -- All DOE Office Websites (Extended Search)

5 SEPTEMBER 2007 5 SEPTEMBER 2007 Power Plant Optimization Demonstration Projects Cover Photos: * Top left: Coal Creek Station * Top right: Big Bend Power Station * Bottom left: Baldwin Energy Complex * Bottom right: Limestone Power Plant A report on four projects conducted under separate cooperative agreements between the U.S. Department of Energy and: * Great River Energy * Tampa Electric Company * Pegasus Technologies * NeuCo. , Inc.  Power Plant Optimization Demonstration Projects Executive Summary .......................................................................................4 Background: Power Plant Optimization ......................................................5 Lignite Fuel Enhancement Project ...............................................................8

44

Economics of Increased Power Flow  

Science Conference Proceedings (OSTI)

This report focuses on methodologies for evaluating the costs and benefits of the diverse technologies that can be used either individually or jointly to increase the flow of power through the transmission system. It begins by describing a broad slate of potential technologies and approaches for increasing transmission capacity and improving system efficiency and then provides an overall framework for assessing the benefits and costs of these technologies. Later sections cover the practical implementatio...

2010-12-21T23:59:59.000Z

45

The optimization of the stocks within coal power stations using the dynamic programming method  

Science Conference Proceedings (OSTI)

The purpose of this paper is to devise an economic and mathematical model for forecasting and optimizing the need of coal, for determining the current stock size and optimizing the supply-storage costs within a coal-fired power plant. The conditions ... Keywords: continuous flow production, dynamic programming method, energetic resources, optimization of the safety stock, power plants, stock analysis

Rascolean Ilie; Isac Claudia; Dura Codruta

2009-12-01T23:59:59.000Z

46

Optimization neural network for solving flow problems  

Science Conference Proceedings (OSTI)

This paper describes a neural network for solving flow problems, which are of interest in many areas of application as in fuel, hydro, and electric power scheduling. The neural network consist of two layers: a hidden layer and an output layer. The hidden ...

R. Perfetti

1995-09-01T23:59:59.000Z

47

Optimal Power Grid Protection through A Defender-Attacker ...  

E-Print Network (OSTI)

DC power flow model is used to compute power ... Constraints (4) capture the active DC power flows on a ..... Board on Energy and Environmental Systems; Na -.

48

Low Power Oriented CMOS Circuit Optimization Protocol  

Science Conference Proceedings (OSTI)

Low power oriented circuit optimization consists in selecting the best alternative between gate sizing, buffer insertion and logic structure transformation, for satisfying a delay constraint at minimum area cost. In this paper we used a closed form model ...

A. Verle; X. Michel; N. Azemard; P. Maurine; D. Auvergne

2005-03-01T23:59:59.000Z

49

24 Hour Day-Ahead Reactive Power Forecasting and Optimal Scheduling  

Science Conference Proceedings (OSTI)

Reactive power management affects not only the system voltage profiles but also system efficiencies. Changes in the flow of reactive power have an influence on system losses. Reactive power forecasting and optimal scheduling of power system control elements can be conducted to efficiently and reliably transfer power across the system. The tool discussed in this report optimizes the power system to produce a security-constrained case, reduce losses, increase reactive reserve, and securely maintain ...

2013-12-29T23:59:59.000Z

50

Topology optimization of unsteady incompressible Navier-Stokes flows  

Science Conference Proceedings (OSTI)

This paper discusses the topology optimization of unsteady incompressible Navier-Stokes flows. An optimization problem is formulated by adding the artificial Darcy frictional force into the incompressible Navier-Stokes equations. The optimization procedure ... Keywords: Continuous adjoint method, Navier-Stokes equations, Topology optimization, Unsteady flow

Yongbo Deng; Zhenyu Liu; Ping Zhang; Yongshun Liu; Yihui Wu

2011-07-01T23:59:59.000Z

51

An Optimization of Electrode Energy and Power Density through...  

NLE Websites -- All DOE Office Websites (Extended Search)

An Optimization of Electrode Energy and Power Density through of Variations in Inactive Material and Electrode Porosity Title An Optimization of Electrode Energy and Power Density...

52

Tutorial on Increased Power Flow Guidebook  

Science Conference Proceedings (OSTI)

This project developed an annotated presentation of key material from the Increased Power Flow Guidebook that was published by EPRI in 2006. The presentation includes both power point and acrobat files on a CD accompanying the report.

2006-12-14T23:59:59.000Z

53

Low Power/Energy Compiler Optimizations  

E-Print Network (OSTI)

Introduction 35.2 Why compilers? 35.3 Power vs. Energy vs. Performance Power vs. Energy, Power/Energy vs. Performance, Summary 35.4 List of Optimizations Dynamic Voltage and Frequency Scaling, Resource Hibernation, Remote Task Mapping 35.5 Future Compiler Research for Power/Energy Embedded processor and SoCs are used in many devices, ranging from pace makers, sensors, phones, and PDAs, to general-purpose handheld computers and laptops. Each of these devices has their own requirements for performance, power dissipation, and energy usage, and typically implements a particular tradeo# among these entities. Allowing components of these devices to be controlled by software has opened up opportunities for compilation and operating strategies to reduce power dissipation and energy usage, at the potential cost of performance degradation. Such control includes (1) hibernation, i.e., initiating transitions of a component between a high power, active states and lower power, hibernating s

Ulrich Kremer

2004-01-01T23:59:59.000Z

54

EPRI Increased Power Flow Guidebook -- 2011  

Science Conference Proceedings (OSTI)

The EPRI Increased Power Flow (IPF) Guidebook is a state-of-the-art and best-practices reference and guidebook on increasing the power flow capacities of existing overhead transmission lines, underground cables, power transformers, and substation equipment without compromising safety and reliability. The Guidebook discusses power system concerns and limiting conditions to increasing capacity, reviews available technology options and methods, illustrates the alternatives with case studies, and analyzes th...

2011-12-12T23:59:59.000Z

55

Heuristic optimality criterion algorithm for shape design of fluid flow  

Science Conference Proceedings (OSTI)

This paper presents a heuristic optimality criterion algorithm for shape design of fluid flow. In this algorithm, the lattice Boltzmann method (LBM) is utilized to calculate the flow field of a fluid domain which is divided into elemental cells. A heuristic ... Keywords: Fluid flow, Heuristic optimality criterion, Lattice Boltzmann method, Pressure drop, Shape design

Limin Wang; Yilin Fan; Lingai Luo

2010-10-01T23:59:59.000Z

56

Optimal Power Allocation for Renewable Energy Source  

E-Print Network (OSTI)

Battery powered transmitters face energy constraint, replenishing their energy by a renewable energy source (like solar or wind power) can lead to longer lifetime. We consider here the problem of finding the optimal power allocation under random channel conditions for a wireless transmitter, such that rate of information transfer is maximized. Here a rechargeable battery, which is periodically charged by renewable source, is used to power the transmitter. All of above is formulated as a Markov Decision Process. Structural properties like the monotonicity of the optimal value and policy derived in this paper will be of vital importance in understanding the kind of algorithms and approximations needed in real-life scenarios. The effect of curse of dimensionality which is prevalent in Dynamic programming problems can thus be reduced. We show our results under the most general of assumptions.

Sinha, Abhinav

2011-01-01T23:59:59.000Z

57

Distributed rate allocation for inelastic flows: Optimization frameworks, optimality conditions, and optimal algorithms  

E-Print Network (OSTI)

Abstract—A common assumption behind the recent surge in research activities on network utility maximization is that the traffic flows are elastic, which implies that the utility functions are concave and there are no hard limits on the rate allocated to each flow. These critical assumptions lead to the tractability of the analytic models of utility maximization, but also limits the applicability of the resulting rate allocation protocols. This paper focuses on inelastic flows and removes these restrictive and often invalid assumptions. We present several optimization frameworks, optimality conditions, and optimal algorithms. First we consider nonconcave utility functions, which turn utility maximization into nonconvex, constrained optimization problems that are well-known to be extremely difficult. We first show a surprising result that under certain conditions, the standard pricing algorithm for rate allocation will still converge to the globally optimal rate allocation. When the existing distributed algorithm fails, we present a new algorithm that produces the globally optimal rate allocation, with the worst case complexity being polynomial time in the number of users but exponential time in the number of links. In the second part of the paper, we provide a general problem formulation of rate allocation among time-sensitive flows from real-time and streaming applications, as well as a decomposition into subproblems coordinated by pricing. After simplifying the subproblems by leveraging the optimization structures, we highlight the difficult issues of causality and time-scale, and propose an effective pricing-based heuristics for admission control and an optimal algorithm for a special case formulation.

Mung Chiang; Shengyu Zhang; Prashanth H

2005-01-01T23:59:59.000Z

58

Wind resource evaluation at the Caltech Field Laboratory for Optimized Wind Energy (FLOWE)  

E-Print Network (OSTI)

Wind resource evaluation at the Caltech Field Laboratory for Optimized Wind Energy (FLOWE) Quinn;Caltech Field Laboratory for Optimized Wind Energy (reduced visual signature) #12;Field Study Results 6 continuous hours existing wind farms Planform Kinetic Energy Flux = U (W m-2) mean power above cut

59

Strategies in tower solar power plant optimization  

E-Print Network (OSTI)

A method for optimizing a central receiver solar thermal electric power plant is studied. We parametrize the plant design as a function of eleven design variables and reduce the problem of finding optimal designs to the numerical problem of finding the minimum of a function of several variables. This minimization problem is attacked with different algorithms both local and global in nature. We find that all algorithms find the same minimum of the objective function. The performance of each of the algorithms and the resulting designs are studied for two typical cases. We describe a method to evaluate the impact of design variables in the plant performance. This method will tell us what variables are key to the optimal plant design and which ones are less important. This information can be used to further improve the plant design and to accelerate the optimization procedure.

Ramos, A

2012-01-01T23:59:59.000Z

60

Optimization Online - The N - k Problem in Power Grids: New ...  

E-Print Network (OSTI)

Aug 1, 2008 ... Abstract: Given a power grid modeled by a network together with equations describing the power flows, power generation and consumption, ...

Note: This page contains sample records for the topic "optimal power flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Power-Flow Management - Technology Perspectives  

Science Conference Proceedings (OSTI)

The report provides a technical overview for power-flow management technologies with special emphasis on power electronic-based technologies. This includes both thyristor-based and converter-based technologies. The report thoroughly describes the fundamental relationships of alternating current (AC) power transmission at steady-state and dynamic conditions; the document also describes transmission problems and needs. This overview clearly demonstrates the role of power electronic-based Controllers and th...

2007-11-05T23:59:59.000Z

62

Optimal control for maximum power in thermal and chemical systems  

Science Conference Proceedings (OSTI)

This research treats power optimization for energy converters, such like thermal, solar and chemical engines. Thermodynamic analyses lead to converter's efficiency and limiting power. Steady and dynamic systems are investigated. Static optimization of ...

Stanislaw Sieniutycz

2009-09-01T23:59:59.000Z

63

A new structure for bidirectional power flow  

Science Conference Proceedings (OSTI)

In this paper, methods of energy recovery for electric motors in braking mode are presented. Also for motors with low and medium regenerative power, a low cost and simple structure is proposed. In this method, for converting the high voltage of DC bus ... Keywords: bidirectional power flow, energy saving, regenerative brake

Seyed Borhan Azimi; Hassan Ghafoori Fard

2005-03-01T23:59:59.000Z

64

Magnetic Amplifier for Power Flow Control  

Science Conference Proceedings (OSTI)

GENI Project: ORNL is developing an electromagnet-based, amplifier-like device that will allow for complete control over the flow of power within the electric grid. To date, complete control of power flow within the grid has been prohibitively expensive. ORNL’s controller could provide a reliable, cost-effective solution to this problem. The team is combining two types of pre-existing technologies to assist in flow control, culminating in a prototype iron-based magnetic amplifier. Ordinarily, such a device would require expensive superconductive wire, but the magnetic iron core of ORNL’s device could serve as a low-cost alternative that is equally adept at regulating power flow.

None

2012-02-24T23:59:59.000Z

65

Proceedings: EPRI/ESEERCO Workshop on Power Plant Optimization  

Science Conference Proceedings (OSTI)

The growing impetus to reduce costs of NOx compliance and electricity production has accelerated deployment of power plant optimization software in the utility industry. The EPRI/ESEERCO Workshop on Power Plant Optimization provided a forum for utilities to assess available power plant optimization software and review the application experience to date.

1997-08-21T23:59:59.000Z

66

Optimal monitoring and visualization of steady state power system operation  

E-Print Network (OSTI)

Power system operation requires accurate monitoring of electrical quantities and a reliable database of the power system. As the power system operation becomes more competitive, the secure operation becomes highly important and the role of state estimation becomes more critical. Recently, due to the development of new technology in high power electronics, new control and monitoring devices are becoming more popular in power systems. It is therefore necessary to investigate their models and integrate them into the existing state estimation applications. This dissertation is dedicated to exploiting the newly appeared controlling and monitoring devices, such as Flexible AC Transmission System (FACTS) devices and (Phasor Measurement Units) PMUs, and developing new algorithms to include them into power system analysis applications. Another goal is to develop a 3D visualization tool to help power system operators gain an in-depth image of the system operation state and to identify limit violations in a quick and intuitive manner. An algorithm of state estimation of a power system with embedded FACTS devices is developed first. This estimator can be used to estimate the system state quantities and Unified Power Flow Controller (UPFC) controller parameters. Furthermore, it can also to be used to determine the required controller setting to maintain a desired power flow through a given line. In the second part of this dissertation, two methods to determine the optimal locations of PMUs are derived. One is numerical and the other one is topological. The numerical method is more effective when there are very few existing measurements while the topology-based method is more applicable for a system, which has lots of measurements forming several observable islands. To guard against unexpected failures of PMUs, the numerical method is extended to account for single PMU loss. In the last part of this dissertation, a 3D graphic user interface for power system analysis is developed. It supports two basic application functions, power flow analysis and state estimation. Different visualization techniques are used to represent different kinds of system information.

Xu, Bei

2006-08-01T23:59:59.000Z

67

Free Flow Power Corporation | Open Energy Information  

Open Energy Info (EERE)

Flow Power Corporation Flow Power Corporation Jump to: navigation, search Name Free Flow Power Corporation Address 239 Causeway St Suite 300 Place Gloucester, Massachusetts Zip 1930 Sector Marine and Hydrokinetic, Ocean Product Massachusetts-based company that has developed a turbine generator designed to extract energy from tides, ocean currents, rivers, streams, canals and conduits. Free Flow has raised some initial funding and is prototype testing in rivers and tanks. Year founded 2007 Number of employees 28 Phone number 978-232-3536 Website http://www.free-flow-power.com Coordinates 37.413962°, -76.526305° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":37.413962,"lon":-76.526305,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

68

Stochastic Optimal Power Flow for Reserve Determination  

Science Conference Proceedings (OSTI)

This report uses a realistic system model to demonstrate how dynamic reserve requirements can be defined for real-time operation. Use of dynamic reserve requirements is especially beneficial for reliable and efficient integration of renewable generation. In this demonstration, the sequential dispatch process of vertically integrated utilities and energy markets was simulated using a multiple-cycle model that includes a day-ahead unit-commitment cycle with hourly intervals, an hour-ahead unit-commitment "...

2011-12-21T23:59:59.000Z

69

Increased Power Flow Guidebook - Underground Cables  

Science Conference Proceedings (OSTI)

Utilities must consider a number of factors when evaluating uprating and upgrading options for underground transmission cables. This comprehensive guidebook documents the state-of-science for increasing power flow capacities of underground transmission cables. It provides an overview of underground transmission cable ratings and uprating techniques so that the maximum utilization can be obtained from the existing underground transmission infrastructure.

2003-12-01T23:59:59.000Z

70

HRSG design method optimizes power plant efficiency  

SciTech Connect

Heat recovery steam generators (HRSGs) are widely used in cogeneration and combined-cycle power plants. simulating the performance of the HRSG system at design and off-design conditions helps the designer optimize the overall plant efficiency. It also helps in the selection of major auxiliary equipment. Conventional simulation of HRSG design and off-design performance is a tedious task, since there are several variables involved. However, with the simplified approach presented in this article, the engineer can acquire information on the performance of the HRSG without actually doing the mechanical design. The engineer does not need to size the tubes or determine the fin configuration. This paper reports that the method also can be used for heat balance studies and in the preparation of the HRSG specification.

Ganapathy, V. (ABCO (US))

1991-05-01T23:59:59.000Z

71

Optimized boundary driven flows for dynamos in a sphere  

SciTech Connect

We perform numerical optimization of the axisymmetric flows in a sphere to minimize the critical magnetic Reynolds number Rm{sub cr} required for dynamo onset. The optimization is done for the class of laminar incompressible flows of von Karman type satisfying the steady-state Navier-Stokes equation. Such flows are determined by equatorially antisymmetric profiles of driving azimuthal (toroidal) velocity specified at the spherical boundary. The model is relevant to the Madison plasma dynamo experiment, whose spherical boundary is capable of differential driving of plasma in the azimuthal direction. We show that the dynamo onset in this system depends strongly on details of the driving velocity profile and the fluid Reynolds number Re. It is found that the overall lowest Rm{sub cr} Almost-Equal-To 200 is achieved at Re Almost-Equal-To 240 for the flow, which is hydrodynamically marginally stable. We also show that the optimized flows can sustain dynamos only in the range Rm{sub cr}optimized flows and the corresponding dynamo fields are presented.

Khalzov, I. V.; Brown, B. P.; Cooper, C. M.; Weisberg, D. B.; Forest, C. B. [Center for Magnetic Self Organization in Laboratory and Astrophysical Plasmas, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706 (United States)

2012-11-15T23:59:59.000Z

72

Optimal operation of a virtual power plant with risk management  

Science Conference Proceedings (OSTI)

In the evolving smart power systems (or smart grids), distributed generators (DG) and virtual power plants (VPP) have major roles in providing electric energy for microgrids. This paper studies the optimal operation of a VPP in a microgrid considering ...

H. Taheri; A. Rahimi-Kian; H. Ghasemi; B. Alizadeh

2012-01-01T23:59:59.000Z

73

Heuristic and metaheuristic optimization techniques with application to power systems  

Science Conference Proceedings (OSTI)

The development of modern wide-area power systems, as well as recent trends towards the creation of sustainable energy systems have given birth to complex studies addressing technical, but also economical and environmental, aspects related to simple ... Keywords: efficiency, heuristic optimization, metaheuristic optimization, power systems

Mihai Gavrilas

2010-10-01T23:59:59.000Z

74

Distributed Power Flow Control: Distributed Power Flow Control using Smart Wires for Energy Routing  

Science Conference Proceedings (OSTI)

GENI Project: Smart Wire Grid is developing a solution for controlling power flow within the electric grid to better manage unused and overall transmission capacity. The 300,000 miles of high-voltage transmission line in the U.S. today are congested and inefficient, with only around 50% of all transmission capacity utilized at any given time. Increased consumer demand should be met in part with more efficient and an economical power flow. Smart Wire Grid’s devices clamp onto existing transmission lines and control the flow of power within—much like how internet routers help allocate bandwidth throughout the web. Smart wires could support greater use of renewable energy by providing more consistent control over how that energy is routed within the grid on a real-time basis. This would lessen the concerns surrounding the grid’s inability to effectively store intermittent energy from renewables for later use.

None

2012-04-24T23:59:59.000Z

75

Optimality and Conductivity for Water Flow: From Landscapes, to Unsaturated Soils, to Plant Leaves  

Science Conference Proceedings (OSTI)

Optimality principles have been widely used in many areas. Based on an optimality principle that any flow field will tend toward a minimum in the energy dissipation rate, this work shows that there exists a unified form of conductivity relationship for three different flow systems: landscapes, unsaturated soils and plant leaves. The conductivity, the ratio of water flux to energy gradient, is a power function of water flux although the power value is system dependent. This relationship indicates that to minimize energy dissipation rate for a whole system, water flow has a small resistance (or a large conductivity) at a location of large water flux. Empirical evidence supports validity of the relationship for landscape and unsaturated soils (under gravity dominated conditions). Numerical simulation results also show that the relationship can capture the key features of hydraulic structure for a plant leaf, although more studies are needed to further confirm its validity. Especially, it is of interest that according to this relationship, hydraulic conductivity for gravity-dominated unsaturated flow, unlike that defined in the classic theories, depends on not only capillary pressure (or saturation), but also the water flux. Use of the optimality principle allows for determining useful results that are applicable to a broad range of areas involving highly non-linear processes and may not be possible to obtain from classic theories describing water flow processes.

Liu, H.H.

2012-02-23T23:59:59.000Z

76

Fe/V Redox Flow Battery Electrolyte Investigation and Optimization  

Science Conference Proceedings (OSTI)

Recently invented Fe/V redox flow battery (IVBs) system has attracted more and more attentions due to its long-term cycling stability. In this paper, the factors (such as compositions, state of charge (SOC) and temperatures) influencing the stability of electrolytes in both positive and negative half-cells were investigated by an extensive matrix study. Thus an optimized electrolyte, which can be operated in the temperature ranges from -5oC to 50oC without any precipitations, was identified. The Fe/V flow cells using the optimized electrolytes and low-cost membranes exhibited satisfactory cycling performances at different temperatures. The efficiencies, capacities and energy densities of flow batteries with varying temperatures were discussed in detail.

Li, Bin; Li, Liyu; Wang, Wei; Nie, Zimin; Chen, Baowei; Wei, Xiaoliang; Luo, Qingtao; Yang, Zhenguo; Sprenkle, Vincent L.

2013-05-01T23:59:59.000Z

77

Globally Optimal Distributed Power Control for Nonconcave Utility Maximization  

E-Print Network (OSTI)

Future wireless networks are expected to operate in dense environments where the system capacity is fundamentally limited by severe co-channel interference among neighboring links. Transmit-power control has been recently explored as an important interference-mitigation technique that aims to maximize a system efficiency metric, which is often measured by a system utility function. Optimal power control is known to be difficult to achieve, mainly because the optimization problem is in general highly non-convex. This problem had eluded researchers and remained open until our recent work [11], where a centralized optimal power control algorithm, referred to as MAPEL, is developed based on a monotonic optimization framework. However, there does not yet exist a distributed power control algorithm that achieves the global optimal solution for generic utility functions, although the distributed implementation is crucial for the wireless infrastructureless networks such as ad hoc and sensor networks. This paper fill...

Qian, Li Ping; Zhang,; Chiang, Mung

2011-01-01T23:59:59.000Z

78

Optimal Scheduling of Industrial Combined Heat and Power Plants  

E-Print Network (OSTI)

Optimal Scheduling of Industrial Combined Heat and Power Plants under Time-sensitive Electricity Prices Sumit Mitra , Lige Sun , Ignacio E. Grossmann December 24, 2012 Abstract Combined heat and power companies. However, under-utilization can be a chance for tighter interaction with the power grid, which

Grossmann, Ignacio E.

79

Power-optimal pipelining in deep submicron technology  

Science Conference Proceedings (OSTI)

This paper explores the effectiveness of pipelining as a power saving tool, where the reduction in logic depth per stage is used to reduce supply voltage at a fixed clock frequency. We examine power-optimal pipelining in deep submicron technology, both ... Keywords: pipelining, power scaling, supply voltage reduction

Seongmoo Heo; Krste AsanoviC

2004-08-01T23:59:59.000Z

80

Optimal Power-Down Strategies John Augustine  

E-Print Network (OSTI)

is the power consumption rate in the sleep state and is the transition cost between the two states. The online of selecting threshold times to transition a device to low-power sleep states during an idle period. The two-state power consumption rate and transition costs. We give an algorithm that, given a system, produces

Irani, Sandy

Note: This page contains sample records for the topic "optimal power flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Optimization of the Mini-Flo flow cytometer  

SciTech Connect

A new method of collecting light scattering from a liquid flow cytometer has been proposed; this apparatus is named the Mini-Flo flow cytometer. The Mini-Flo uses a high numerical aperture collection immersed in the flow stream. The collector consists of a conically tipped fiber optic pipe and terminating optical detector. This study was performed to improve the signal/noise ration and optimize the Mini-Flo`s performance for HIV blood detection applications. Experiments were performed to gauge the effects of Raman scattering, lens/filter fluorescence, and fiber optic fluorescence on the Mini-Flo`s performance and signal/noise ratio. Results indicated that the fiber optic was a major source of fluorescence noise and reducing its length from 33 cm to 10 cm increased the signal noise ratio from 8 to 75. Therefore, one of the key issues in optimizing the Mini-Flo`s performance is a redesign of the holding structure such that the fiber optic length is minimized. Further improvements of the Mini-Flo`s performance can be achieved by studying the polish of the fiber optic, the flow over the fiber optics`s conical tip, and the optimal particle rates.

Venkatesh, M.

1996-06-01T23:59:59.000Z

82

Improving Power Density Of A Class Of Piezoelectic Power Harvesters Through Proof Mass Optimization.  

E-Print Network (OSTI)

??This thesis presents a method to optimize the proof mass of the cantilever piezoelectric power harvester. With this novel proof mass, a lower fundamental frequency… (more)

Li, Wen G.

2009-01-01T23:59:59.000Z

83

Flow control optimization in a jet engine serpentine inlet duct  

E-Print Network (OSTI)

Computational investigations were carried out on an advanced serpentine jet engine inlet duct to understand the development and propagation of secondary flow structures. Computational analysis which went in tandem with experimental investigation was required to aid secondary flow control required for enhanced pressure recovery and decreased distortion at the engine face. In the wake of earlier attempts with modular fluidic actuators used for this study, efforts were directed towards optimizing the actuator configurations. Backed by both computational and experimental resources, many variations in the interaction of fluidic actuators with the mainstream flow were attempted in the hope of best controlling secondary flow formation. Over the length of the studies, better understanding of the flow physics governing flow control for 3D curved ducts was developed. Blowing tangentially, to the wall at the bends of the S-duct, proved extremely effective in enforcing active flow control. At practical jet momentum coefficients, significant improvements characterized by an improved pressure recove ry of 37% and a decrease in distortion close to 90% were seen.

Kumar, Abhinav

2007-08-01T23:59:59.000Z

84

Cooling Tower Fan Motor Power Optimization Study  

Science Conference Proceedings (OSTI)

Cooling towers are in use at more than 200 major electric generating plants in the United States, representing approximately 800 units and a total of more than 210,000 MW. The auxiliary power consumed by cooling tower fan motors can significantly reduce the net power output of steam-cycle power plants. Cooling tower specifications are established by the economic and operational requirements of maximum unit load and the most demanding environmental conditions expected in the tower’s locale. Since power pl...

2011-11-16T23:59:59.000Z

85

Optimal control of generator resynchronisation in electric power systems  

Science Conference Proceedings (OSTI)

Optimal control techniques are discussed for the resynchronisation of a steam turbine unit in an electric power system after it has lost synchronism. A time optimal control is derived and the resulting bang-bang control law is first simulated on an analogue ...

D. Rosenfeld; F. J. Evans

1972-11-01T23:59:59.000Z

86

Optimal Energy Storage Control Policies for the Smart Power Grid  

E-Print Network (OSTI)

Optimal Energy Storage Control Policies for the Smart Power Grid Iordanis Koutsopoulos Vassiliki is to devise an energy storage control policy that minimizes long-term average grid operational cost. The cost the stored energy. We prove that the policy is asymptotically optimal as the storage capacity becomes large

Koutsopoulos, Iordanis

87

Convex Quadratic Relaxations of Nonlinear Programs in Power ...  

E-Print Network (OSTI)

Sep 30, 2013 ... Three case studies in optimal power flows, line-switching optimal power flows, and capacitor placement demonstrate the benefits of the new ...

88

Power Optimization in VLSI Layout: A Survey  

Science Conference Proceedings (OSTI)

This paper presents a survey of layout techniques for designing low power digital CMOS circuits. It describes the many issues facing designers at the physical level of design abstraction and reviews some of the techniques and tools that have been ...

Massoud Pedram; Hirendu Vaishnav

1997-03-01T23:59:59.000Z

89

Optimizing power delivery cost in datacenters  

Science Conference Proceedings (OSTI)

Our increasing reliance on Internet-centric services and information technology has led to the proliferation of datacenters. The peak power consumption of these datacenters significantly impact their sustainability: both their recurring electricity ...

Sriram Govindan / Anand Sivasubramaniam; Bhuvan Urgaonkar

2011-01-01T23:59:59.000Z

90

Minimization of voltage deviation and power losses in power networks using Pareto optimization methods  

Science Conference Proceedings (OSTI)

Voltage regulation is an important task in electrical engineering for controlling node voltages in a power network. A widely used solution for the problem of voltage regulation is based on adjusting the taps in under load tap changers (ULTCs) power transformers ... Keywords: Multi-objective optimization, Power distribution network, Power losses, Under load tap changers, Voltage regulation

Francisco G. Montoya; Raúl Baños; Consolación Gil; Antonio Espín; Alfredo Alcayde; Julio Gómez

2010-08-01T23:59:59.000Z

91

Variable selection for wind power prediction using particle swarm optimization  

Science Conference Proceedings (OSTI)

Wind energy has an increasing influence on the energy supply in many countries, but in contrast to conventional power plants it is a fluctuating energy source. For its integration in the electricity supply structure it is necessary to predict the wind ... Keywords: nearest neighbour search, neural network, particle swarm optimization, variable selection, wind power prediction

René Jursa

2007-07-01T23:59:59.000Z

92

System level optimization and design space exploration for low power  

Science Conference Proceedings (OSTI)

We present a software tool for power dissipation analysis and optimization on the algorithmic abstraction level from C/C++ and VHDL descriptions. An analysis is most efficient on such a high level since the influence of design decisions on the power ...

Ansgar Stammermann; Lars Kruse; Wolfgang Nebel; Alexander Pratsch; Eike Schmidt; Milan Schulte; Arne Schulz

2001-09-01T23:59:59.000Z

93

Optimization system for operation of gas cogeneration power plant  

Science Conference Proceedings (OSTI)

The paper presents a distributed control system for the realization of cogenerative supply of electricity and heat and, in given case, for their combination with waste heat recovery, particularly in combined (gas-steam) cycle industrial power plants. ... Keywords: cogenerative gas power plant, control of distributed parameter systems, optimization, process control

Ion Miciu

2008-09-01T23:59:59.000Z

94

Flow shop scheduling with peak power consumption constraints  

E-Print Network (OSTI)

Mar 29, 2012 ... In particular, we consider a flow shop scheduling problem with a restriction on peak power consumption, in addition to the traditional ...

95

Hybrid robust predictive optimization method of power system dispatch  

DOE Patents (OSTI)

A method of power system dispatch control solves power system dispatch problems by integrating a larger variety of generation, load and storage assets, including without limitation, combined heat and power (CHP) units, renewable generation with forecasting, controllable loads, electric, thermal and water energy storage. The method employs a predictive algorithm to dynamically schedule different assets in order to achieve global optimization and maintain the system normal operation.

Chandra, Ramu Sharat (Niskayuna, NY); Liu, Yan (Ballston Lake, NY); Bose, Sumit (Niskayuna, NY); de Bedout, Juan Manuel (West Glenville, NY)

2011-08-02T23:59:59.000Z

96

Drag reduction in pipe flow by optimal forcing  

E-Print Network (OSTI)

In most settings, from international pipelines to home water supplies, the drag caused by turbulence raises pumping costs many times higher than if the flow were laminar. Drag reduction has therefore long been an aim of high priority. In order to achieve this end, any drag reduction method must modify the turbulent mean flow. Motivated by minimization of the input energy this requires, linearly optimal forcing functions are examined. It is shown that the forcing mode leading to the greatest response of the flow is always of m=1 azimuthal symmetry. Little evidence is seen of the second peak at large m (wall modes) found in analogous optimal growth calculations, which may have implications for control strategies. The model's prediction of large response of the large length-scale modes is verified in full direct numerical simulation of turbulence ($Re=5300$, $Re_\\tau\\approx 180$). Further, drag reduction of over 12% is found for finite amplitude forcing of the largest scale mode, m=1. Significantly, the forcing ...

Willis, Ashley P; Cossu, Carlo

2009-01-01T23:59:59.000Z

97

Application Study of the Pump Water Flow Station for Building Energy Consumption Monitoring and Control Optimization  

E-Print Network (OSTI)

This paper presents a new building energy monitoring and pump speed control method. The pump speed is controlled to maintain the system resistance at an optimized value to approach the best pump efficiency and save pump power. The system resistance can be obtained by the pump head and the water flow rate calculated by the pump water-flow station (PWS), which was recently developed. The PWS measures the water flow rate using the pump head, pump speed, and pump performance curve. This method has been experimentally proved in real HVAC systems. A case study was demonstrated in this paper for application of this new method in a Continuous Commissioning (CC) practice. The case study shows that the PWS can control the pump speed to maintain the optimized system operating point. It can also measure the water flow rate and monitor energy consumption continuously with low installation and almost no maintenance cost. The results show that the new technology can save pump power and increase pump efficiency significantly.

Liu, G.; Liu, M.

2006-01-01T23:59:59.000Z

98

Power flow analysis for amplifier design and energy harvesting  

E-Print Network (OSTI)

Power flow analysis for amplifier design and energy harvesting Nikola Vujica, Donald J. Leoa strategies which will provide an electrical energy regeneration. In this case, the power is flowing from to the electrical side which may have the ability to store (regenerate) this energy. The ability of energy storage

Lindner, Douglas K.

99

Distributed control for optimal reactive power compensation in smart microgrids  

E-Print Network (OSTI)

We consider the problem of optimal reactive power compensation for the minimization of power distribution losses in a smart microgrid. We first propose an approximate model for the power distribution network, which allows us to cast the problem into the class of convex quadratic, linearly constrained, optimization problems. We also show how this model provides the tools for a distributed approach, in which agents have a partial knowledge of the problem parameters and state, and can only perform local measurements. Then, we design a randomized, gossip-like optimization algorithm, providing conditions for convergence together with an analytic characterization of the convergence speed. The analysis shows that the best performance can be achieved when we command cooperation among agents that are neighbors in the smart microgrid topology. Numerical simulations are included to validate the proposed model and to confirm the analytic results about the performance of the proposed algorithm.

Bolognani, Saverio

2011-01-01T23:59:59.000Z

100

Optimization of Piezoelectric Electrical Generators Powered by Random Vibrations  

E-Print Network (OSTI)

This paper compares the performances of a vibrationpowered electrical generators using PZT piezoelectric ceramic associated to two different power conditioning circuits. A new approach of the piezoelectric power conversion based on a nonlinear voltage processing is presented and implemented with a particular power conditioning circuit topology. Theoretical predictions and experimental results show that the nonlinear processing technique may increase the power harvested by a factor up to 4 compared to the Standard optimization technique. Properties of this new technique are analyzed in particular in the case of broadband, random vibrations, and compared to those of the Standard interface.

Lefeuvre, E; Richard, C; Petit, L; Guyomar, D

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "optimal power flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Optimal endogenous carbon taxes for electric power supply chains with power plants  

Science Conference Proceedings (OSTI)

In this paper, we develop a modeling and computational framework that allows for the determination of optimal carbon taxes applied to electric power plants in the context of electric power supply chain (generation/distribution/consumption) networks. ... Keywords: Carbon taxes, Electric power, Environmental policies, Network equilibria, Renewable energy, Supply chains, Variational inequalities

Anna Nagurney; Zugang Liu; Trisha Woolley

2006-11-01T23:59:59.000Z

102

Applications of Increased Power Flow Strategies for Underground Cables  

Science Conference Proceedings (OSTI)

In 2003, the Electric Power Research Institute (EPRI) recognized that there were no detailed resources on the topic of increased power flow (sometimes called uprating) for underground cable systems. Transmission cables were often the focus of evaluations where utilities were seeking to get the greatest improvement in load transfer for a given investment. The 2003 EPRI report, Increased Power Flow Guidebook: Underground Cables, describes basic cable rating principles and ...

2013-11-21T23:59:59.000Z

103

Market power and welfare effects in DC power flow electricity models with thermal line losses  

Science Conference Proceedings (OSTI)

A nodal electric power network with Cournot-Nash interaction among power generators is formulated as a mixed complementarity problem. The model incorporates a direct current (DC) power flow approximation with thermal line losses to model real-time flows. ... Keywords: Electricity markets, Imperfect competition, Thermal line losses, Welfare measurement

Rastislav Ivanic; Paul V. Preckel; Zuwei Yu

2005-10-01T23:59:59.000Z

104

Power Generation Loading Optimization using a Multi-Objective Constraint-Handling Method via  

E-Print Network (OSTI)

results of the power generation loading optimization based on a coal-fired power plant demonstratesPower Generation Loading Optimization using a Multi-Objective Constraint-Handling Method via PSO power industry. A major objective for the coal-fired power generation loading optimization

Li, Xiaodong

105

Fuzzy gain scheduling technique for power flow control  

Science Conference Proceedings (OSTI)

An application of fuzzy logic based control for power systems governing multiple Flexible Alternating Current Transmission System (FACTS) devices is described here. Sufficiently accurate relations have been derived to determine setpoints of FACTS ... Keywords: AC transmission, FACTS devices, Switzerland, flexible alternating current transmission system, fuzzy control, fuzzy gain scheduling, fuzzy logic, power flow control, power systems, sensitivity analysis

Alexandre Oudalov; Petr Korba; Rachid Cherkaoui; Alain J. Germond

2006-10-01T23:59:59.000Z

106

Distribution Power Flow in IRW Group Meeting  

E-Print Network (OSTI)

(PQ, SWING, PV) Maximum voltage error Busflag : HASSOURCE to indicates that this node can have.0; } Measurement: Energy, power, demand, real and reactive power 3 phase voltage and current Note: measured_demand is the watts measurement of the peak power demand of downstream objects. #12;Case study: IEEE 4 nodes test

Tesfatsion, Leigh

107

OPTIMIZATION OF COAL PARTICLE FLOW PATTERNS IN LOW NOX BURNERS  

SciTech Connect

It is well understood that the stability of axial diffusion flames is dependent on the mixing behavior of the fuel and combustion air streams. Combustion aerodynamic texts typically describe flame stability and transitions from laminar diffusion flames to fully developed turbulent flames as a function of increasing jet velocity. Turbulent diffusion flame stability is greatly influenced by recirculation eddies that transport hot combustion gases back to the burner nozzle. This recirculation enhances mixing and heats the incoming gas streams. Models describing these recirculation eddies utilize conservation of momentum and mass assumptions. Increasing the mass flow rate of either fuel or combustion air increases both the jet velocity and momentum for a fixed burner configuration. Thus, differentiating between gas velocity and momentum is important when evaluating flame stability under various operating conditions. The research efforts described herein are part of an ongoing project directed at evaluating the effect of flame aerodynamics on NO{sub x} emissions from coal fired burners in a systematic manner. This research includes both experimental and modeling efforts being performed at the University of Arizona in collaboration with Purdue University. The objective of this effort is to develop rational design tools for optimizing low NO{sub x} burners. Experimental studies include both cold-and hot-flow evaluations of the following parameters: primary and secondary inlet air velocity, coal concentration in the primary air, coal particle size distribution and flame holder geometry. Hot-flow experiments will also evaluate the effect of wall temperature on burner performance.

Jost O.L. Wendt; Gregory E. Ogden; Jennifer Sinclair; Stephanus Budilarto

2001-09-04T23:59:59.000Z

108

High Performance Vanadium Redox Flow Batteries with Optimized Electrode Configuration and Membrane Selection  

Science Conference Proceedings (OSTI)

The performance of a vanadium flow battery with no-gap architecture was significantly improved via several techniques. Specifically, gains arising from variation of the overall electrode thickness, membrane thickness, and electrode thermal treatment were studied. There is a trade-off between apparent kinetic losses, mass transfer losses, and ionic resistance as the electrode thickness is varied at the anode and cathode. Oxidative thermal pretreatment of the carbon paper electrode increased the peak power density by 16%. Results of the pretreatment in air showed greater improvement in peak power density compared to that obtained with pretreatment in an argon environment. The highest peak power density in a VRB yet published to the author s knowledge was achieved at a value of 767 mW cm 2 with optimized membrane and electrode engineering. 2012 The Electrochemical Society. [DOI: 10.1149/2.051208jes] All rights reserved.

Liu, Q. H. [University of Tennessee, Knoxville (UTK); Grim, G. M. [University of Tennessee, Knoxville (UTK); Papandrew, A [University of Tennessee, Knoxville (UTK); Turhan, A. [University of Tennessee, Knoxville (UTK); Zawodzinski, Thomas A [ORNL; Mench, Matthew M [ORNL

2012-01-01T23:59:59.000Z

109

Analyzing Optimization Techniques for Power Efficiency on Heterogeneous Platforms  

Science Conference Proceedings (OSTI)

Graphics processing units (GPUs) have become widely accepted as the computing platform of choice in many high performance computing domains. The availability of programming standards such as OpenCL are used to leverage the inherent parallelism offered ... Keywords: OpenCL, FFT, Power, Optimizations

Yash Ukidave, David R. Kaeli

2013-05-01T23:59:59.000Z

110

Optimal Bidding Strategies for Wind Power Producers with Meteorological Forecasts  

E-Print Network (OSTI)

bid is computed by exploiting the forecast energy price for the day ahead market, the historical windOptimal Bidding Strategies for Wind Power Producers with Meteorological Forecasts Antonio statistics at the plant site and the day-ahead wind speed forecasts provided by a meteorological service. We

Giannitrapani, Antonello

111

Energy Payback Optimization of Thermoelectric Power Generator Systems  

E-Print Network (OSTI)

An analytic model for optimizing thermoelectric power generation system is developed and utilized for parametric studies. This model takes into account the external thermal resistances with hot and cold reservoirs. In addition, the spreading thermal resistance in the module substrates is considered to find the impact of designing small fraction of thermo elements per unit area. Previous studies are expanded by a full optimization of the electrical and thermal circuits. The optimum condition satisfies both electrical load resistance match with the internal resistance and the thermal resistance match with the heat source and the heat sink. Thermoelectric element aspect ratio and fill factor are found to be key parameters to optimize. The optimum leg length and the maximum output power are determined by a simple formula. The output power density per mass of the thermoelectric material has a peak when thermo elements cover a fractional area of ~1%. The role of the substrate heat spreading for thermoelectric power generation is equally significant as thermoelement. For a given heat source, the co-optimization of the heat sink and the thermoelectric module should be performed. Active cooling and the design of the heat sink are customized to find the energy payback for the power generation system. The model includes both the air cooled heat sinks and the water cooled micro channels. We find that one can reduce the mass of thermoelement to around 3~10 % of that in commercial modules for the same output power, as long as the module and elements are designed properly. Also one notes that higher heat flux sources have significantly larger energy payback and reduced cost per output power.

Kazuaki Yazawa; Ali Shakouri

2010-01-01T23:59:59.000Z

112

Architecture-Level Power Optimization - What Are the Limits  

E-Print Network (OSTI)

This paper explores the limits of microprocessor power savings available via certain classes of architecture-level optimization. It classifies architectural power optimizations into three categories, three sources of waste that consume energy. The first is the execution of instructions that are unnecessary for correct program execution. The second source of wasted power is speculation waste – waste due to speculative execution of instructions that do not commit their results. The third source is architectural waste. This comes from suboptimal sizing of processor structures. This study shows that when these sources of waste are eliminated, processor energy has the potential to be reduced by 55 % and 52% for the studied SPEC 2000 integer and floating point benchmarks respectively. 1.

John S. Seng; Dean M. Tullsen

2005-01-01T23:59:59.000Z

113

Primus Power's Flow Battery Powered by $11 Million in Private Investment  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Primus Power's Flow Battery Powered by $11 Million in Private Primus Power's Flow Battery Powered by $11 Million in Private Investment Primus Power's Flow Battery Powered by $11 Million in Private Investment June 14, 2011 - 10:00am Addthis Primus Power's energy cell stack. | Photo Courtesy of Primus Power Primus Power's energy cell stack. | Photo Courtesy of Primus Power Kristina Pflanz Writer & Contractor, Advanced Research Projects Agency - Energy What does this mean for me? Will make renewable energy sources, such as solar and wind, available to more utility customers. In February, the Advanced Research Projects Agency-Energy (ARPA-E) announced that six of its projects, which initially received a total of $23.6 million in agency seed funding, had collectively generated more than $100 million in outside private capital investment. ARPA-E recently

114

Automated Synthesis Tool for Design Optimization of Power Electronic Converters  

E-Print Network (OSTI)

Designers of power electronic converters usually face the challenge of having multiple performance indices that must be simultaneously optimized, such as maximizing efficiency while minimizing mass or maximizing reliability while minimizing cost. The experienced engineer applies his or her judgment to reduce the number of possible designs to a manageable number of feasible designs for which to prototype and test; thus, the optimality of this design-space reduction is directly dependent upon the experience, and expertise and biases of the designer. The practitioner is familiar with tradeoff analysis; however, simple tradeoff studies can become difficult or even intractable if multiple metrics are considered. Hence a scientific and systematic approach is needed. In this dissertation, a multi-objective optimization framework is presented as a design tool. Optimization of power electronic converters is certainly not a new subject. However, when limited to off-the-shelf components, the resulting system is really optimized only over the set of commercially available components, which may represent only a subset of the design space; the reachable space limited by available components and technologies. While this approach is suited to cost-reduce an existing design, it offers little insight into design possibilities for greenfield projects. Instead, this work uses the Technology Characterization Methods (TCM) to broaden the reachable design space by considering fundamental component attributes. The result is the specification for the components that create the optimal design rather than an evaluation of an apriori selected set of candidate components. A unique outcome of this approach is that new technology development vectors may emerge to develop optimized components for the optimized power converter. The approach presented in this work uses a mathematical descriptive language to abstract the characteristics and attributes of the components used in a power electronic converter in a way suitable for multi-objective and constrained optimization methods. This dissertation will use Technology Characterization Methods (TCM) to bridge the gap between high-level performance attributes and low-level design attributes where direct relationship between these two does not currently exist. The loss and size models for inductors, capacitors, IGBTs, MOSFETs and heat sinks will be used to form objective functions for the multi-objective optimization problem. A single phase IGBT-based inverter is optimized for efficiency and volume based on the component models derived using TCM. Comparing the obtained designs to a design, which can be made from commercial off-the-shelf components, shows that converter design can be optimized beyond what is possible from using only off-the-shelf components. A module-integrated photovoltaic inverter is also optimized for efficiency, volume and reliability. An actual converter is constructed using commercial off-the-shelf components. The converter design is chosen as close as possible to a point obtained by optimization. Experimental results show that the converter modeling is accurate. A new approach for evaluation of efficiency in photovoltaic converter is also proposed and the front-end portion of a photovoltaic converter is optimized for this efficiency, as well as reliability and volume.

Mirjafari, Mehran

2013-05-01T23:59:59.000Z

115

Flow-optimized Cooperative Transmission for the Relay Channel  

E-Print Network (OSTI)

This paper describes an approach for half-duplex cooperative transmission to achieve cooperative diversity in a classical three-node relay channel. Assuming availability of channel state information at the source and relay, the approach makes use of this information to optimize distinct flows through the direct link from the source to the destination and the path via the relay, respectively. It is shown that such a design can effectively obtain diversity advantage of the relay channel in both high-rate and low-rate scenarios. When the rate requirement is low, the proposed design gives a second-order outage diversity performance approaching that of full-duplex relaying. When the rate requirement becomes asymptotically large, the design still gives a close-to-second-order outage diversity performance. The design also achieves the best diversity-multiplexing tradeoff possible for the relay channel.

Wong, Tan F; Shea, John M

2007-01-01T23:59:59.000Z

116

Impact of Dynamic Ratings, Major Power Flow Upgrades, and Green Power Integration on System Planning  

Science Conference Proceedings (OSTI)

Electric power utilities around the world are undergoing a major transformation, which is redefining the utilization of existing power equipment in the electric transmission network due to limited financial incentives and lengthy licensing process for new construction. Under these circumstances, the utilities are forced to find new ways of increasing power flow quickly through existing transmission corridors with minimal investments. Increased power flows of transmission circuits can be achieved by contr...

2009-12-14T23:59:59.000Z

117

Convex Quadratic Relaxations of Power Flows  

E-Print Network (OSTI)

INFORMS journal and should not be used to distribute the papers in print or online ..... Let us emphasize that although this approach may apply for general MINLPs, its automation is not ..... Using mixed-integer programming to solve power grid blackout problems. ... Smart Load and Generation Scheduling for Power System.

118

Reactive Power Management using Firefly and Spiral Optimization ...  

E-Print Network (OSTI)

Dec 2, 2013 ... Hybridized market and congestion management have been invoked in. [17-19]. Voltage ... all possible regions of the search space for information. This algorithm .... bus voltages are calculated by means of a suitable load flow analysis. The ..... Electrical Power and Energy Systems 32: 368-374. 9. Liya G ...

119

Control and Optimization Meet the Smart Power Grid - Scheduling of Power Demands for Optimal Energy Management  

E-Print Network (OSTI)

The smart power grid aims at harnessing information and communication technologies to enhance reliability and enforce sensible use of energy. Its realization is geared by the fundamental goal of effective management of demand load. In this work, we envision a scenario with real-time communication between the operator and consumers. The grid operator controller receives requests for power demands from consumers, with different power requirement, duration, and a deadline by which it is to be completed. The objective is to devise a power demand task scheduling policy that minimizes the grid operational cost over a time horizon. The operational cost is a convex function of instantaneous power consumption and reflects the fact that each additional unit of power needed to serve demands is more expensive as demand load increases.First, we study the off-line demand scheduling problem, where parameters are fixed and known. Next, we devise a stochastic model for the case when demands are generated continually and sched...

Koutsopoulos, Iordanis

2010-01-01T23:59:59.000Z

120

Domain Decomposition Methods in Optimal Flow Control for High Performance Computing.  

E-Print Network (OSTI)

??This thesis is concerned with linear and non-linear optimal flow control problems which are modeled by systems of partial differential equations. The numerical treatment of… (more)

Ketelaer, Eva

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "optimal power flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

POWER FLOW ANALYSIS OF ELECTROSTRICTIVE ACTUATORS DRIVEN BYSWITCHMODE AMPLIFIERS  

E-Print Network (OSTI)

is within the bandwidth of the amplifier. This analysis also reveals that the electrical power flow through of that energy. We adopt this view in this paper. The analysis in this paper is motivated by the smart skin being Consider the flow of energy through this smart skin. Electrical energy is supplied to the smart skin from

Lindner, Douglas K.

122

Human Factors Aspects of Power System Flow Animation  

E-Print Network (OSTI)

, engineering analysis and EMS (energy management system) software will need to be modified in a number of ways not provide a clear advantage in the visualization of transmission line flows for uncomplicated analysis tasks listings showing the exact power flows and percentage loadings can be crucial. But for medium to large

123

Floating power optimization studies for the cooling system of a geothermal power plant  

DOE Green Energy (OSTI)

The floating power concept was studied for a geothermal power plant as a method of increasing the plant efficiency and decreasing the cost of geothermal power. The stored cooling concept was studied as a method of reducing the power fluctuations of the floating power concept. The studies include parametric and optimization studies for a variety of different types of cooling systems including wet and dry cooling towers, direct and indirect cooling systems, forced and natural draft cooling towers, and cooling ponds. The studies use an indirect forced draft wet cooling tower cooling system as a base case design for comparison purposes.

Shaffer, C.J.

1977-08-01T23:59:59.000Z

124

Optimal Power Cost Management Using Stored Energy in Data Centers  

E-Print Network (OSTI)

Since the electricity bill of a data center constitutes a significant portion of its overall operational costs, reducing this has become important. We investigate cost reduction opportunities that arise by the use of uninterrupted power supply (UPS) units as energy storage devices. This represents a deviation from the usual use of these devices as mere transitional fail-over mechanisms between utility and captive sources such as diesel generators. We consider the problem of opportunistically using these devices to reduce the time average electric utility bill in a data center. Using the technique of Lyapunov optimization, we develop an online control algorithm that can optimally exploit these devices to minimize the time average cost. This algorithm operates without any knowledge of the statistics of the workload or electricity cost processes, making it attractive in the presence of workload and pricing uncertainties. An interesting feature of our algorithm is that its deviation from optimality reduces as the...

Urgaonkar, Rahul; Neely, Michael J; Sivasubramaniam, Anand

2011-01-01T23:59:59.000Z

125

Switching Surge and Lightning Impact on Increasing Power Flow  

Science Conference Proceedings (OSTI)

This report describes the effect of transient overvoltages on increasing the power flow on the electric power transmission system. The report focuses on the effect of system changes on transient recovery voltage (TRV) duties imposed on circuit breakers, and the impact of switching surges, lightning, and sustained overvoltages on transmission line upgrading.

2006-12-13T23:59:59.000Z

126

Extension and Enhancement of Increased Power Flow Guidebook  

Science Conference Proceedings (OSTI)

This project updated existing chapters in the EPRI Increased Power Flow Guidebook, developed a new chapter on economics, and prepared a Power Pointtutorial for the first edition. The first edition of the Guidebook was published by EPRI in 2006. The various components of this report will be combined with the existing guidebook in 2008, making a second edition.

2007-12-21T23:59:59.000Z

127

Optimization of a solar powered absorption cycle under Abu Dhabi's weather conditions  

SciTech Connect

In order for the solar absorption air conditioners to become a real alternative to the conventional vapour compression systems, their performance has to be improved and their total cost has to be reduced. A solar powered absorption cycle is modeled using the Transient System Simulation (TRNSYS) program and Typical Meteorological Year 2 data of Abu Dhabi. It uses evacuated tube collectors to drive a 10 kW ammonia-water absorption chiller. Firstly, the system performance and its total cost are optimized separately using single objective optimization algorithms. The design variables considered are: the collector slope, the collector mass flow rate, the collector area and the storage tank volume. The single objective optimization results show that MATLAB global optimization methods agree with the TRNSYS optimizer. Secondly, MATLAB is used to solve a multi-objective optimization problem to improve the system's performance and cost, simultaneously. The optimum designs are presented using Pareto curve and show the potential improvements of the baseline system. (author)

Al-Alili, A.; Hwang, Y.; Radermacher, R. [Department of Mechanical Engineering, University of Maryland, College Park, MD (United States); Kubo, I. [Department of Mechanical Engineering, The Petroleum Institute, Abu Dhabi (United Arab Emirates)

2010-12-15T23:59:59.000Z

128

Proceedings of the Increased Power Flow Workshop  

Science Conference Proceedings (OSTI)

This report documents the proceedings of the Electric Power Research Institute (EPRI) Increased Overhead Transmission Capacity Workshop. The workshop was held on August 13, 2013, at the offices of City Public Service in San Antonio, Texas. Participants included members of the EPRI Increased Overhead Transmission Capacity Task Force. The workshop was a joint effort of two EPRI research projects: (1) Ratings for Overhead Lines, and (2) Impact of High-Temperature Operation of Overhead ...

2013-11-20T23:59:59.000Z

129

Optimal Reactive Power Planning of Radial Distribution Systems with Distributed Generation  

Science Conference Proceedings (OSTI)

The paper analyzes reactive power optimization problem in distribution system with wind power and PV generators. Reactive power optimization mathematical model including the active power loss, reactive power compensation capacity and static voltage margin ... Keywords: Distributed generation, Distributed Generation, Immune Algorithm, Cluster Evolutionary

Li Shengqi, Zeng Lilin, Li Yongan, He Zhengping

2013-01-01T23:59:59.000Z

130

Combustion Optimization at Allegheny Energy's Armstrong Power Station  

Science Conference Proceedings (OSTI)

Individual air and coal flow measurement instruments have been installed on Allegheny Energy's Armstrong Station with a goal to balance the individual burner air to fuel ratios to minimize NOx, reduce the LOI level in the ash and improve heat rate. These signals are also being incorporated into the NOx optimization package, ULTRAMAX (R). Armstrong Station is a 180 MW front wall boiler burning a low sulfur eastern bituminous coal. Twelve Foster Wheeler IFS low NOx burners are fed by two ball mills, three ...

2000-06-21T23:59:59.000Z

131

Application of genetic algorithms for optimal reactive power planning of doubly fed induction generators  

Science Conference Proceedings (OSTI)

This paper describes optimal reactive power control of a doubly fed induction generator (DFIG), which is widely used in a distributed generating plant. Although its structure is similar to that of induction motors, its reactive power control is more ... Keywords: doubly fed induction generator, genetic algorithms, optimal reactive power planning, optimization

P. Sangsarawut; A. Oonsivilai; T. Kulworawanichpong

2010-03-01T23:59:59.000Z

132

Optimal reactive power planning of doubly fed induction generators using genetic algorithms  

Science Conference Proceedings (OSTI)

This paper describes optimal reactive power control of a doubly fed induction generator (DFIG), which is widely used in a distributed generating plant. Although its structure is similar to that of an induction motor, its reactive power control is more ... Keywords: doubly fed induction generator, genetic algorithms, optimal reactive power planning, optimization

P. Sangsarawut; A. Oonsivilai; T. Kulworawanichpong

2010-02-01T23:59:59.000Z

133

Method for controlling power flow between an electrochemical cell and a power grid  

SciTech Connect

A method is disclosed for controlling a force-commutated inverter coupled between an electrochemical cell and a power grid for adjusting the magnitude and direction of the electrical energy flowing therebetween. Both the real power component and the reactive power component of ac electrical energy flow can be independently VARied through the switching waveform presented to the intermediately coupled inverter. A VAR error signal is derived from a comparison of a var command signal with a signal proportional to the actual reactive power circulating between the inverter and the power grid. This signal is presented to a voltage controller which essentially varies only the effective magnitude of the fundamental voltage waveform out of the inverter , thereby leaving the real power component substantially unaffected. In a similar manner, a power error signal is derived by a comparison of a power command signal with a signal proportional to the actual real power flowing between the electrochemical cell and the power grid. This signal is presented to a phase controller which varies only the phase of the fundamental component of the voltage waveform out of the inverter relative to that of the power grid and changes only the real power in proportion thereto, thus leaving the reactive power component substantially unaffected.

Coleman, A. K.

1981-02-17T23:59:59.000Z

134

Time optimal software pipelining of loops with control flows  

Science Conference Proceedings (OSTI)

Software pipelining is widely used as a compiler optimization technique to achieve high performance in machines that exploit instruction-level parallelism. However, surprisingly, there have been few theoretical or empirical results on time optimal software ... Keywords: VLIW, compiler optimization, instruction-level parallelism, software pipelining

Han-Saem Yun; Jihong Kim; Soo-Mook Moon

2003-10-01T23:59:59.000Z

135

Optimal power management for a hydraulic hybrid delivery truck  

E-Print Network (OSTI)

Hydraulic hybrid propulsion and energy storage components demonstrate characteristics that are very different from their electric counterparts, thus requiring unique control strategies. This paper presents a methodology for developing a power management strategy tailored specifically to a parallel Hydraulic Hybrid Vehicle (HHV) configured for a medium-size delivery truck. The Hydraulic Hybrid Vehicle is modelled in the MATLAB/SIMULINK environment to facilitate system integration and control studies. A Dynamic Programming (DP) algorithm is used to obtain optimal control actions for gear shifting and power splitting bet ween the engine and the hydraulic motor over a representative urban driving schedule. Features of optimal trajectories are then studied to derive i mplementable rules. System behaviour demonstrates that the new control strategy takes advantage of high power density and efficiency characteristics of hydraulic components, and minimizes disadvantages of low energy density, to achieve enhanced overall efficiency. Simulation results indicate that the potential for fuel economy improvement of medium trucks with hydraulic hybrid propulsion can be as high as 48 %. 1

Bin Wu; Chan-chiao Lin; Zoran Filipi; Huei Peng

2004-01-01T23:59:59.000Z

136

Dynamic Power Flow Controller: Compact Dynamic Phase Angle Regulators for Transmission Power Routing  

SciTech Connect

GENI Project: Varentec is developing compact, low-cost transmission power controllers with fractional power rating for controlling power flow on transmission networks. The technology will enhance grid operations through improved use of current assets and by dramatically reducing the number of transmission lines that have to be built to meet increasing contributions of renewable energy sources like wind and solar. The proposed transmission controllers would allow for the dynamic control of voltage and power flow, improving the grid’s ability to dispatch power in real time to the places where it is most needed. The controllers would work as fail-safe devices whereby the grid would be restored to its present operating state in the event of a controller malfunction instead of failing outright. The ability to affordably and dynamically control power flow with adequate fail-safe switchgear could open up new competitive energy markets which are not possible under the current regulatory structure and technology base.

None

2012-01-03T23:59:59.000Z

137

A modified parallel optimization system for updating large-size time-evolving flow matrix  

Science Conference Proceedings (OSTI)

Flow matrices are widely used in many disciplines, but few methods can estimate them. This paper presents a knowledge-based system as capable of estimating and updating large-size time-evolving flow matrix. The system in this paper consists of two major ... Keywords: Data fusion, Parallel optimization, Time-evolving flow matrix

Ting Yu; Julien Ugon; Wei Yu

2012-07-01T23:59:59.000Z

138

Monitoring of energy flows and optimization of energy efficiency in a production facility  

Science Conference Proceedings (OSTI)

The present paper reports the findings of an assessment of the energy flows of a building equipped with machine tools and discusses options to optimize its energy efficiency. The energy flows in the buildings are recorded based on collected data and ... Keywords: building simulation, energy consumption, energy efficiency in production, energy flow analysis

I. Leobner; K. Ponweiser; C. Dorn; F. Bleicher

2011-07-01T23:59:59.000Z

139

A three phase load flow algorithm for Shipboard Power Systems  

E-Print Network (OSTI)

Load Flow (Power Flow) is the determination of the steady state operating conditions for the system. This is a very important tool utilized by many real time applications in power systems. Traditional load flow methods, which incorporate Gauss-Seidel and/or Newton Raphson techniques, were primarily developed for transmission system analysis. Distribution load flow analysis must incorporate its unique characteristics such as unbalanced loads, distributed loads, radial network structure, and one, two, or three phase lines. Also, there are a variety of components included in distribution systems such as switches, transformers, voltage regulators, and distributed generators. Therefore, the traditional methods cannot be directly applied to distribution systems since the assumptions made for transmission systems are not valid for the unique characteristics of distribution systems. A Shipboard Power System (SPS) is a finite inertia electric power system. The generation, transmission, and distribution systems in SPSs are tightly coupled. In reality, the transmission system consists of the lines that interconnect the generator buses in a ring configuration. The distribution system consists of lines, transformers, and loads connected in a radial configuration. When analyzing a SPS, its distinct characteristics must be taken into consideration. Therefore, just as transmission and distribution systems have unique methods of analysis, SPSs also need a unique method of analysis. A load flow algorithm for a SPS must consider its distribution system characteristics as well as the unique characteristics of SPSs. The work presented in this thesis discussed a load flow algorithm developed for Shipboard Power Systems and terrestrial wye and delta connected radial distribution systems. The issues in developing a load flow algorithm for a SPS are addressed and the solution is presented. This solution combines three methods that addressed the issues of multiple sources, ring configuration, and radial load flow. This algorithm was tested on the IEEE 37 Bus Radial Distribution Test Feeder and a simplified Shipboard Power Test System developed by researchers in the Power System Automation Laboratory. The results produced minimal percent error when compared to the actual output results.

Medina-Calder?on, M?onica M

2003-01-01T23:59:59.000Z

140

On DC. optimization algorithms for solving minmax flow problems ?  

E-Print Network (OSTI)

Jun 17, 2011 ... Email: ldmuu@math.ac.vn. Le Quang Thuy ..... programming and DCA revisited with DC models of real world nonconvex optimization problems ...

Note: This page contains sample records for the topic "optimal power flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

On DC. optimization algorithms for solving minmax flow problems  

E-Print Network (OSTI)

Jun 16, 2011 ... math.ac.vn) ... (Difference of convex functions) programming and DCA revisited with DC models of real world nonconvex optimization problems, ...

142

Power flow management of microgrid networks using model predictive control  

Science Conference Proceedings (OSTI)

In this paper, we present a power flow management method for a network of cooperating microgrids within the context of a smart grid by formulating the problem in a model predictive control framework. In order to reliably and economically provide the ... Keywords: Microgrid, Model predictive control, Renewable energy sources, Smart grid, Storage devices

A. Hooshmand; H. A. Malki; J. Mohammadpour

2012-09-01T23:59:59.000Z

143

Optimal software pipelining of loops with control flows  

Science Conference Proceedings (OSTI)

Software pipelining is widely used as a compiler optimization technique to achieve high performance in machines that exploit instruc-tion-level parallelism. However, surprisingly, there have been few theoretical or empirical results on optimal software ... Keywords: VLIW, instruction-level parallelism, software pipelining

Han-Saem Yun; Jihong Kim; Soo-Mook Moon

2002-06-01T23:59:59.000Z

144

Decentralized optimal neuro-controllers for generation and transmission devices in an electric power network  

Science Conference Proceedings (OSTI)

In this paper, the dual heuristic programming (DHP) optimization algorithm is applied for the design of two LOCAL nonlinear optimal neuro-controllers on a practical multi-machine power system. One neuro-controller is designed to replace the conventional ... Keywords: Decentralized control, Dual heuristic programming, Optimal neuro-controller, Power network, Series capacitive reactance compensator

Jung-Wook Park; Ronald G. Harley; Ganesh K. Venayagamoorthy

2005-02-01T23:59:59.000Z

145

EPRI Power Flow to CIM Interface: Development of Power Flow to Common Information Model (CIM) Converter  

Science Conference Proceedings (OSTI)

IEEE has developed a Power Systems Application Data Dictionary (PSADD) for power system data and EPRI sponsored development of a CONVERTER program to convert PTI's PSS/E's data into this format. This project will develop the common data sources (CDSs) that translate the PSADD data to/from a Common Information Model (CIM)-structured database.

2002-11-27T23:59:59.000Z

146

Mobile robot path planning algorithm by equivalent conduction heat flow topology optimization  

Science Conference Proceedings (OSTI)

This paper addresses the path planning problem for a point robot moving in a planar environment filled with obstacles. Our approach is based on the principles of thermal conduction and structural topology optimization and rests on the observation that, ... Keywords: Conduction heat flow, Mobile robot, Path planning, Topology optimization

Jae Chun Ryu; Frank Chongwoo Park; Yoon Young Kim

2012-05-01T23:59:59.000Z

147

Optimal wire sizing and buffer insertion for low power and a generalized delay model  

Science Conference Proceedings (OSTI)

We present efficient, optimal algorithms for timing optimization by discrete wire sizing and buffer insertion. Our algorithms are able to minimize dynamic power dissipation subject to given timing constraints. In addition, we compute the complete power-delay ... Keywords: Timing Optization, Elmore Delay, Dynamic Power Dissipation, Dynamic Programming, Signal Slew

John Lillis; Chung-Kuan Cheng; Ting-Ting Y. Lin

1995-12-01T23:59:59.000Z

148

Adaptive sensing and optimal power allocation for wireless video sensors with sigma-delta imager  

Science Conference Proceedings (OSTI)

We consider optimal power allocation for wireless video sensors (WVSs), including the image sensor subsystem in the system analysis. By assigning a power-rate-distortion (P-R-D) characteristic for the image sensor, we build a comprehensive P-R-D optimization ... Keywords: image sensors, power-rate-distortion (P-R-D), resource management, sigma-delta (?Delta;) modulation, wireless video

Mališa Marijan; Ilker Demirkol; Danijel Mari?i?; Gaurav Sharma; Željko Ignjatovi?

2010-10-01T23:59:59.000Z

149

Imperialist competitive algorithm for dynamic optimization of economic dispatch in power systems  

Science Conference Proceedings (OSTI)

As energy costs are expected to keep rising in the coming years, mostly due to a growing worldwide demand, optimizing power generation is of crucial importance for utilities. Economic power dispatch is a tool commonly used by electric power plant operators ... Keywords: dynamic optimization, economic dispatch, imperialist competitive algorithm, metaheuristic, microgrid

Robin Roche; Lhassane Idoumghar; Benjamin Blunier; Abdellatif Miraoui

2011-10-01T23:59:59.000Z

150

Optimization and hybridization of membrane-based oxy-combustion power plants  

E-Print Network (OSTI)

This thesis considers the optimization and hybridization of advanced zero emissions power (AZEP) cycles. More specifically, existing flowsheets for zero and partial emissions are optimized, and new integration schemes with ...

Gunasekaran, Surekha

2013-01-01T23:59:59.000Z

151

The interphase power controller: A new concept for managing power flow within AC networks  

SciTech Connect

The paper presents a new concept for controlling the flow of power within AC networks. The application is based on the series connection of impedances between different phases of the two (synchronous) subnetworks to be interconnected, hence its name: the Interphase Power Controller (IPC). The IPC acts as a current source with the following characteristics: the power flow is nearly constant (within 10%) for a wide range ([+-]25[degree]) of angle between the two subnetworks; there is no significant short-circuit contribution from one network to the other; severe contingencies on one side of the IPC have negligible impact on the voltage of the other side; no harmonics are generated (because there is no control action). Other operating conditions (reduced power, reactive power generation or absorption) are possible by switching impedance components. In all cases, the IPC comprises only conventional elements (transformer, capacitors, reactors, and circuit breakers).

Brochu, J.; Pelletier, P.; Beauregard, F.; Morin, G. (Citeq, Varennes, Quebec (Canada))

1994-04-01T23:59:59.000Z

152

Towards optimal event detection and localization in acyclic flow networks  

Science Conference Proceedings (OSTI)

Acyclic flow networks, present in many infrastructures of national importance (e.g., oil & gas and water distribution systems), have been attracting immense research interest. Existing solutions for detecting and locating attacks against these infrastructures, ...

Mahima Agumbe Suresh; Radu Stoleru; Ron Denton; Emily Zechman; Basem Shihada

2012-01-01T23:59:59.000Z

153

DC Optimal Power Flow Formulation in AMES Leigh Tesfatsion  

E-Print Network (OSTI)

23 of a user-specified maximum day. AMES includes an Independent System Operator (ISO a demand bid to the ISO for the day-ahead market for day D+1. Each demand bid consists of two parts: fixed demand (i.e., a 24-hour load profile) to be sold downstream at a regulated price r to its retail

Tesfatsion, Leigh

154

Techniques for Battery Health Conscious Power Management via Electrochemical Modeling and Optimal Control.  

E-Print Network (OSTI)

??This dissertation combines electrochemical battery models and optimal control theory to study power management in energy storage/conversion systems. This topic is motivated by the need… (more)

Moura, Scott J.

2011-01-01T23:59:59.000Z

155

Multidisciplinary Optimization of Hybrid Electric Vehicles: Component Sizing and Power Management Logic.  

E-Print Network (OSTI)

??A survey of the existing literature indicates that optimization on the power management logic of hybrid electric vehicle is mostly performed after the design of… (more)

Fan, Brian Su-Ming

2011-01-01T23:59:59.000Z

156

Optimization of a SEGS solar field for cost effective power output.  

E-Print Network (OSTI)

??This thesis presents and demonstrates procedures to model and optimize the collector field of a parabolic trough solar thermal power plant. The collector field of… (more)

Bialobrzeski, Robert Wetherill

2007-01-01T23:59:59.000Z

157

Bang-bang-type optimal constant current control of parallel ac-dc power transmission systems  

SciTech Connect

The transient stability of an ac-dc hybrid system can be improved greatly by controlling the power flow of the dc transmission line. In this study the optimal changeover curve of dc current setting value on the phase plane with a quadratic curve are approximated. The coefficients of this curve are calculated in advance taking into account the loading condition of the power system and hence the proposed control scheme can be used for emergency control of the power system. The main conclusions from this study were that: to facilitate transient stability analysis, the dc transmission line is represented by equivalent load admittances, which vary every second with the operating condition of the transmission line; the action of the speed governor increases the damping coefficient of the power system and reduces the control time which means that the admissible range of the dc current setting value can be reduced by increasing the governor gain; and the optimal change-over curve of the dc current setting value is approximated by a quadratic curve, whose coefficients can be calculated in advance taking into account the loading condition of the power system. The suboptimal changeover curve thus obtained makes it possible to change the setting value of dc current without time delay in emergency condition. While the case of three-phase short-circuit fault was specifically discussed, it is possible to extend the results obtained to the case of successful or unsuccessful reclosing. The proposed method could also be applied to multimachine systems by using equivalent network reduction methods.

Kobayashi, H.; Ichiyanagi, K.

1977-01-01T23:59:59.000Z

158

TAPO: Thermal-aware power optimization techniques for servers and data centers  

Science Conference Proceedings (OSTI)

A large portion of the power consumption of data centers can be attributed to cooling. In dynamic thermal management mechanisms for data centers and servers, thermal setpoints are typically chosen statically and conservatively, which leaves significant ... Keywords: power leakage power, TAPO, thermal aware power optimization techniques, data centers, server centers, power consumption, dynamic thermal management mechanisms, thermal setpoints, power budget, heating ventilation and air conditioning, HVAC, circuit leakage power

Wei Huang; M. Allen-Ware; J. B. Carter; E. Elnozahy; H. Hamann; T. Keller; C. Lefurgy; Jian Li; K. Rajamani; J. Rubio

2011-07-01T23:59:59.000Z

159

Probability-Based Software for Grid Optimization: Improved Power System Operations Using Advanced Stochastic Optimization  

Science Conference Proceedings (OSTI)

GENI Project: Sandia National Laboratories is working with several commercial and university partners to develop software for market management systems (MMSs) that enable greater use of renewable energy sources throughout the grid. MMSs are used to securely and optimally determine which energy resources should be used to service energy demand across the country. Contributions of electricity to the grid from renewable energy sources such as wind and solar are intermittent, introducing complications for MMSs, which have trouble accommodating the multiple sources of price and supply uncertainties associated with bringing these new types of energy into the grid. Sandia’s software will bring a new, probability-based formulation to account for these uncertainties. By factoring in various probability scenarios for electricity production from renewable energy sources in real time, Sandia’s formula can reduce the risk of inefficient electricity transmission, save ratepayers money, conserve power, and support the future use of renewable energy.

None

2012-02-24T23:59:59.000Z

160

Optimal operational planning of steam power systems using an IPSOSA algorithm  

Science Conference Proceedings (OSTI)

The operation optimization problem of steam power systems for multiperiod operation with varying demands is formulated. The objective function of the mode! is to minimize the operational cost of steam power systems for all periods, by taking into account ...

Hongchao Yin; Wenzhi Dai

2010-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "optimal power flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Total power optimization combining placement, sizing and multi-Vt through slack distribution management  

Science Conference Proceedings (OSTI)

Power dissipation is quickly becoming one of the most important limiters in nanometer IC design for leakage increases exponentially as the technology scaling down. However, power and timing are often conflicting objectives during optimization. In this ...

Tao Luo; David Newmark; David Z. Pan

2008-01-01T23:59:59.000Z

162

Research on Resource Value Flow Accounting Based on Circular Economy for Coal-fired Power Plant  

Science Conference Proceedings (OSTI)

This paper presents the methodology of resource value flow accounting developed for a study which combined material flow analysis?MFA? for the coal-fired power generation plant, in order to shed light on concepts such as resource productivity ... Keywords: Circular economy, Coal-fired power plant, Material flow analysis, Resource value flow accounting

Xie Zhiming; Yi Xuan

2010-05-01T23:59:59.000Z

163

Optimal fracture treatment design for dry gas wells maximizes well performance in the presence of non-Darcy flow effects  

E-Print Network (OSTI)

This thesis presents a methodology based on Proppant Number approach for optimal fracture treatment design of natural gas wells considering non-Darcy flow effects in the design process. Closure stress is taken into account, by default, because it is the first factor decreasing propped pack permeability at in-situ conditions. Gel damage was also considered in order to evaluate the impact of incorporating more damaging factors on ultimate well performance and optimal geometry. Effective fracture permeability and optimal fracture geometry are calculated through an iterative process. This approach was implemented in a spreadsheet. Non-Darcy flow is described by the ? factor. All ? factor correlations available in the literature were evaluated. It is recommended to use the correlation developed specifically for the given type of proppant and mesh size, if available. Otherwise, the Pursell et al. or the Martins et al. equations are recommended as across the board reliable correlations for predicting non-Darcy flow effects in the propped pack. The proposed methodology was implemented in the design of 11 fracture treatments of 3 natural tight gas wells in South Texas. Results show that optimal fracture design might increase expected production in 9.64 MMscf with respect to design that assumes Darcy flow through the propped pack. The basic finding is that for a given amount of proppant shorter and wider fractures compensate the non-Darcy and/or gel damage effect. Dynamic programming technique was implemented in design of multistage fractures for one of the wells under study for maximizing total gas production. Results show it is a powerful and simple technique for this application. It is recommended to expand its use in multistage fracture designs.

Lopez Hernandez, Henry De Jesus

2004-08-01T23:59:59.000Z

164

A Comparison of the AC and DC Power Flow Models for LMP Calculations  

E-Print Network (OSTI)

shifting transformers is often dependent upon the transformer's tap value. Last, the power flow modelsA Comparison of the AC and DC Power Flow Models for LMP Calculations Thomas J. Overbye, Xu Cheng power flow model for LMP-based market calculations. The paper first provides a general discussion

165

Atlas chamber, power flow channel, and diagnostic interface design  

DOE Green Energy (OSTI)

The Atlas pulsed-power machine, presently being designed at Los Alamos, will deliver a pulse of {approximately} 45 MA, in 4--5 {micro}sec, with energies of up to 6 MJ (from a bank of 36 MJ maximum) to a load assembly, located in vacuum. Design considerations for the vacuum vessel, power flow channel from the vessel inward, are presented. In contrast to Sandia`s PBFA II-Z, where 20 MA currents and 2--2.5 MJ of energy are delivered to ({approximately} 15 mg) loads in {approximately} 100 nsec, the Atlas structures will have to be designed for longer timescales and higher energies to drive heavy lines ({approximately} 70 g). Design issues for the chamber include materials stresses, formation of (and protection from) debris and molten jets, impulse loading, and survivability and ease of replacement of internal structures. For the power flow channel designs, issues are minimizing inductance, preventing movement of conductors during and after firing, damage mitigation, reducing the cost of materials and installation, and electrical insulation. A key issue for damage mitigation is the radius within which total destruction of material objects occurs. Choices of vessel size, insulator materials, cost and ease of manufacturing, and mechanical stability issues are presently in the conceptual design phase. Typical access requirements for diagnostics (including radial and axial X-ray backlighting, flux loops, spectroscopy, interferometry, bolometry, etc.) are provided for in the design.

Wurden, G.A.; Davis, H.A.; Taylor, A.; Bowman, D.; Ballard, E.; Ney, S.; Scudder, D.; Trainor, J.

1997-09-01T23:59:59.000Z

166

Power profile estimation and compiler-based software optimization for mobile devices  

Science Conference Proceedings (OSTI)

The complexity of mobile devices is continuously growing due to the increasing requirements on performance. In portable systems such as smart cards, not only performance is an important attribute, but also the power and energy consumed by a given application. ... Keywords: Power characterization, iterative compiling, peak reduction, power profile analysis, smart card systems, software power optimization

Matthias Grumer; Manuel Wendt; Christian Steger; Reinhold Weiss; Ulrich Neffe; Andreas Muehlberger

2009-08-01T23:59:59.000Z

167

A New Method for Power Estimation and Optimization of Combinational Circuits  

E-Print Network (OSTI)

and toggle rate of 0.5. We used a custom wire load model (CWLM) [8] to perform the power calculations. We power changes due to power transformations. REFERENCES [1] F. Najm, "Transition density, a stochastic1 A New Method for Power Estimation and Optimization of Combinational Circuits Ahmed Sammy Aldeen

Al-Asaad, Hussain

168

Modeling and optimization of geothermal power plants using the binary fluid cycle  

SciTech Connect

A computer simulation of a binary fluid cycle power plant for use with geothermal energy sources, and the subsequent optimization of this power plant type over a range of geothermal source conditions are described. The optimization technique employed for this analysis was based upon the principle of maximum use of geothermal energy.

Walter, R.A.

1976-09-01T23:59:59.000Z

169

HypoEnergy: Hybrid supercapacitor-battery power-supply optimization for Energy efficiency  

E-Print Network (OSTI)

HypoEnergy: Hybrid supercapacitor-battery power-supply optimization for Energy efficiency Azalia the hybrid battery-supercapacitor power supply life- time. HypoEnergy combines high energy density of recharge cycles of supercapacitors. The lifetime optimizations consider nonlinear battery characteristics

170

Valuation and Optimal Operation of Electric Power Plants in Competitive Markets  

Science Conference Proceedings (OSTI)

We present an algorithm for the valuation and optimal operation of hydroelectric and thermal power generators in deregulated electricity markets. Real options theory is used to derive nonlinear partial-integro-differential equations (PIDEs) for the valuation ... Keywords: dynamic programming/optimal control: application, finance/asset pricing: pricing power plants as real options, natural resources/energy: deregulated electricity markets

Matt Thompson; Matt Davison; Henning Rasmussen

2004-08-01T23:59:59.000Z

171

Brief paper: Optimal switching instants for a switched-capacitor DC/DC power converter  

Science Conference Proceedings (OSTI)

We consider a switched-capacitor DC/DC power converter with variable switching instants. The determination of optimal switching instants giving low output ripple and strong load regulation is posed as a non-smooth dynamic optimization problem. By introducing ... Keywords: Control parametrization enhancing transform, Impulsive dynamical system, Power converter, Semi-infinite programming, Switched linear system

R. C. Loxton; K. L. Teo; V. Rehbock; W. K. Ling

2009-04-01T23:59:59.000Z

172

Optimal selection and sizing of distributed energy resources for distributed power systems  

Science Conference Proceedings (OSTI)

Optimal selection and sizing of distributed energy resources is an important research problem in the development of distributed power systems. This paper presents a methodology for optimal selection and sizing of distributed energy resources in integrated microgrids using the evolutionary strategy. Integrated microgrid is an innovative architecture in distributed power systems

Thillainathan Logenthiran; Dipti Srinivasan

2012-01-01T23:59:59.000Z

173

Passive Acoustic Detection of Wind Turbine In-Flow Conditions for Active Control and Optimization  

DOE Green Energy (OSTI)

Wind is a significant source of energy; however, the human capability to produce electrical energy still has many hurdles to overcome. One of these is the unpredictability of the winds in the atmospheric boundary layer (ABL). The ABL is highly turbulent in both stable and unstable conditions (based on the vertical temperature profile) and the resulting fluctuations can have a dramatic impact on wind turbine operation. Any method by which these fluctuations could be observed, estimated, or predicted could provide a benefit to the wind energy industry as a whole. Based on the fundamental coupling of velocity fluctuations to pressure fluctuations in the nearly incompressible flow in the ABL, This work hypothesizes that a ground-based array of infrasonic pressure transducers could be employed to estimate the vertical wind profile over a height relevant for wind turbines. To analyze this hypothesis, experiments and field deployments were conducted. Wind tunnel experiments were performed for a thick turbulent boundary layer over a neutral or heated surface. Surface pressure and velocity probe measurements were acquired simultaneously. Two field deployments yielded surface pressure data from a 49 element array. The second deployment at the Reese Technology Center in Lubbock, TX, also included data from a smaller aperture, 96-element array and a 200-meter tall meteorological tower. Analysis of the data successfully demonstrated the ability to estimate the vertical velocity profile using coherence data from the pressure array. Also, dynamical systems analysis methods were successful in identifying and tracking a gust type event. In addition to the passive acoustic profiling method, this program also investigated a rapid response Doppler SODAR system, the optimization of wind turbine blades for enhanced power with reduced aeroacoustic noise production, and the implementation of a wireless health monitoring system for the wind turbine blades. Each of these other objectives was met successfully. The use of phase unwrapping applied to SODAR data was found to yield reasonable results for per-pulse measurements. A health monitoring system design analysis was able to demonstrate the ability to use a very small number of sensors to monitor blade health based on the blade's overall structural modes. Most notable was the development of a multi-objective optimization methodology that successfully yielded an aerodynamic blade design that produces greater power output with reduced aerodynamic loading noise. This optimization method could be significant for future design work.

Murray, Nathan E.

2012-03-12T23:59:59.000Z

174

Real world optimal UPFC placement and its impact on reliability  

Science Conference Proceedings (OSTI)

UPFC allows simultaneous control of active power flow, reactive power flow, and voltage magnitude at the UPFC terminals. These characteristics give UPFC the capability to enhance the performance of the power system during various operating conditions. ... Keywords: genetic algorithm (GA), optimal location, optimal setting, outage cost, reliability, unified power flow controller (UPFC)

Ahmed M. Othman; Exander Gaun; Matti Lehtonen; Mahdi El-Arini

2010-02-01T23:59:59.000Z

175

Optimization of Auxiliaries Consumption in Nuclear Power Plants  

Science Conference Proceedings (OSTI)

Operators of nuclear power plants face significant challenges to produce power more cost-effectively. One approach to producing power more cost-effectively is to reduce power consumption by auxiliary systems in the plant, leading to more power available for the grid. This report provides guidance for assessing auxiliary system performance and recommends approaches to reduce their power consumption. The report also presents results from questionnaires on auxiliary system consumption and, in some cases, ac...

2005-02-08T23:59:59.000Z

176

Optimal power generation in microgrids using agent-based technology.  

E-Print Network (OSTI)

??The existing power grids that form the basis of the respective electrical power infrastructures for various states and nations around the world, are expected to… (more)

Mahmoud, Thair

2013-01-01T23:59:59.000Z

177

New optimization techniques for power system generation scheduling.  

E-Print Network (OSTI)

??Generation scheduling in restructured electric power systems is critical to maintain the stability and security of a power system and economical operation of the electricity… (more)

Sun, Wei

2011-01-01T23:59:59.000Z

178

Abstract--A bi-objective optimization model of power and power changes generated by a wind turbine is discussed in this  

E-Print Network (OSTI)

for optimizing the power of the DFIG (Doubly Fed Induction Generator). Abdelli et al. [5] applied a multi

Kusiak, Andrew

179

An Algorithm for Unrestored Flow Optimization in Survivable Networks Based on p-Cycles  

Science Conference Proceedings (OSTI)

This paper provides compound algorithm for Unrestorable Flow Optimisation (UFO) problem formulated for computer networks protected by p-cycles, created on the base of mathematical model and solution approaches proposed in our complementary paper [1]. ... Keywords: Computer network, UFO problem, optimization, p-cycles, survivability

Adam Smutnicki

2009-05-01T23:59:59.000Z

180

Numerical simulation of turbulent flow in complex geometries used in power plants  

Science Conference Proceedings (OSTI)

Performance degradations or improvements of coal-fired power stations depend on effective functioning of pulveriser equipment and combustion efficiency of furnaces in boilers. The function of a pulveriser is to grind the lumped coal and transfer the ... Keywords: CFD, coal fired power station, flow simulation, geometrical modelling, grid generation, particle trajectories, pulveriser, roller mill, turbulent flow, two-phase flow

C. Bhasker

2002-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "optimal power flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Finding Benefits by Modeling and Optimizing Steam and Power Systems  

E-Print Network (OSTI)

A site-wide steam modeling and optimization program (Visual MESA) was implemented at the INEOS Chocolate Bayou site. This program optimizes steam production, compressor turbine extraction, pump operation (turbine/motor) operation, as well as the monitoring of the entire steam system. This is used for both day-to-day site optimization as well as long-term site planning. In this presentation, we will discuss who the main users of the program are and how they and the plant derive benefits from its use.

Jones, B.; Nelson, D.

2007-01-01T23:59:59.000Z

182

Reactive Power Management using Firefly and Spiral Optimization ...  

E-Print Network (OSTI)

Abstract—Power System planning encompasses the concept of minimization of ... and transformer taps (vertical integration). Under stable running ..... AReview”, IEEE International Journal of Power and Energy systems,. 23(2), pp 81-89, 2003.

183

Design & optimization of automotive power electronics utilizing FITMOS MOSFET technology  

E-Print Network (OSTI)

Power electronics are essential to many automotive applications, and their importance continues to grow as more vehicle functions incorporate electronic controls. MOSFETs are key elements in automotive power electronic ...

Li, Wei, Ph. D. Massachusetts Institute of Technology. Department. of Electrical Engineering and Computer Science.

2009-01-01T23:59:59.000Z

184

Power consumption optimization in multi-mode mobile relay  

E-Print Network (OSTI)

on the energy generation system (some studies have raised the power consumption of telecommunication significantly reduce power consumption when either the traffic load is below 0.4 or when short reach of power consumption- of an eventual migration from static to dynamic architecture rather than

Paris-Sud XI, Université de

185

Aerodynamic optimization of a solar powered race vehicle  

E-Print Network (OSTI)

Aerodynamic optimization was performed on Tesseract, the MIT Solar Electric Vehicle Team's 2003-2005 solar car using Wind Tunnel 8 at Jacobs/Sverdrup Drivability Test Facility in Allen Park, MI. These tests include angle ...

Augenbergs, Peteris K

2006-01-01T23:59:59.000Z

186

Optimal power capturing of multi-MW wind generation system  

Science Conference Proceedings (OSTI)

Recently, an increasing number of multi-MW (1MW and up) wind generation systems are being developed and variable speed-variable pitch (VS-VP) control technology is usually adopted to improve the fast response speed and obtain the optimal energy, which ... Keywords: adaptive fuzzy proportional integral derivative, doubly-fed induction generator, hydraulic variable pitch mechanism, optimal, variable speed-variable pitch, wind turbine

Kong Yigang; Wang Zhixin

2008-03-01T23:59:59.000Z

187

Proceedings: Second Annual EPRI Workshop on Power Plant Optimization: St. Louis, Missouri, May 12-13, 1998  

Science Conference Proceedings (OSTI)

The growing impetus to reduce costs of NOx compliance and electricity production has accelerated deployment of power plant optimization software in the utility industry. The Second Annual EPRI Workshop on Power Plant Optimization held in St. Louis on May 12-13, 1998 provided a forum for utilities to assess available power plant optimization software and review the application experience to date.

1998-09-30T23:59:59.000Z

188

Optimal Design of Fuzzy Based Power System Stabilizer Self Tuned by Robust Search Algorithm  

E-Print Network (OSTI)

In the interconnected power system network, instability problems are caused mainly by the low frequency oscillations of 0.2 to 2.5 Hz .The supplementary control signal in addition with AVR and high gain excitation systems are provided by means of Power System Stabilizer (PSS). Conventional power system stabilizers provide effective damping only on a particular operating point. But fuzzy based PSS provides good damping for a wide range of operating points. The bottlenecks faced in designing a fuzzy logic controller can be minimized by using appropriate optimization techniques like Genetic Algorithm, Particle Swam Optimization, Ant Colony Optimization etc.In this paper the membership functions of FLC are optimized by the new breed optimization technique called Genetic Algorithm. This design methodology is implemented on a Single Machine Infinite Bus (SMIB) system. Simulation results on SMIB show the effectiveness and robustness of the proposed PSS over a wide range of operating conditions and system configurati...

Linda, M Mary

2009-01-01T23:59:59.000Z

189

OPTIMAL POWER DISPATCH AND CONVERSION IN SYSTEMS WITH MULTIPLE ENERGY CARRIERS  

E-Print Network (OSTI)

This paper introduces a general optimization approach for power dispatch and conversion in power systems that include multiple energy carriers such as electricity, natural gas, and district heating. The classical Economic Dispatch method is modified in order to account for certain system properties, such as the possibility of conversion between the different energy carriers, or local overproduction and power feedback to the grid. In this work both a system model as well as an optimization approach are developed which are suitable for the integration of an arbitrary number of energy carriers. Analytical results show how the optimal conversion of power affects the marginal prices related to the different energy carriers. Finally the proposed optimization procedure is demonstrated in numerical examples.

Martin Geidl; Göran Andersson

2005-01-01T23:59:59.000Z

190

Analysis and numerical optimization of gas turbine space power systems with nuclear fission reactor heat sources  

Science Conference Proceedings (OSTI)

A new three objective optimization technique is developed and applied to find the operating conditions for fission reactor heated Closed Cycle Gas Turbine (CCGT) space power systems at which maximum efficiency, minimum radiator area, and minimum total ...

Albert J. Juhasz / Jerzy Sawicki

2005-01-01T23:59:59.000Z

191

Optimization Online - Reactive Power Management using Firefly and ...  

E-Print Network (OSTI)

Oct 4, 2013 ... Abstract: Power System planning encompasses the concept of ... variables being generator bus voltage, capacitor shunts and transformer taps.

192

Optimization Online - Reactive Power Management using Firefly and ...  

E-Print Network (OSTI)

Dec 2, 2013 ... Abstract: Power System planning encompasses the concept of ... on Generator source voltage, shunt/series injection, transformer taps etc.

193

Two-Stage Robust Power Grid Optimization Problem  

E-Print Network (OSTI)

Oct 21, 2010... plus the integration of renewable energy generation, both the supply and demand of a power grid system are volatile and under uncertainty.

194

2008 Special Issue: Optimal wide-area monitoring and nonlinear adaptive coordinating neurocontrol of a power system with wind power integration and multiple FACTS devices  

Science Conference Proceedings (OSTI)

Wide-area coordinating control is becoming an important issue and a challenging problem in the power industry. This paper proposes a novel optimal wide-area coordinating neurocontrol (WACNC), based on wide-area measurements, for a power system with power ... Keywords: Adaptive critic designs, FACTS devices, Particle swarm optimization, Radial basis function network, Wide-area control, Wind power

Wei Qiao; Ganesh K. Venayagamoorthy; Ronald G. Harley

2008-03-01T23:59:59.000Z

195

Optimal state estimation for improved power measurements and model verification: Theory  

Science Conference Proceedings (OSTI)

To improve energy efficiency in computer systems and data centers, accurate models of the power consumption are needed for analysis and advanced control algorithms. Developing models requires deep understanding not only of the components themselves but ... Keywords: system level model analysis, energy efficiency, optimal state estimation, improved power measurement, computer systems, data centers, power consumption, mathematical methods, sensor fusion, data center powering structure, cooling system, parameter identifying estimator, model parameter

T. Malkamaki; S. J. Ovaska

2011-07-01T23:59:59.000Z

196

Method and apparatus for optimizing operation of a power generating plant using artificial intelligence techniques  

DOE Patents (OSTI)

A method and apparatus for optimizing the operation of a power generating plant using artificial intelligence techniques. One or more decisions D are determined for at least one consecutive time increment, where at least one of the decisions D is associated with a discrete variable for the operation of a power plant device in the power generating plant. In an illustrated embodiment, the power plant device is a soot cleaning device associated with a boiler.

Wroblewski, David (Mentor, OH); Katrompas, Alexander M. (Concord, OH); Parikh, Neel J. (Richmond Heights, OH)

2009-09-01T23:59:59.000Z

197

A variational level set method for the topology optimization of steady-state Navier-Stokes flow  

Science Conference Proceedings (OSTI)

The smoothness of topological interfaces often largely affects the fluid optimization and sometimes makes the density-based approaches, though well established in structural designs, inadequate. This paper presents a level-set method for topology optimization ... Keywords: Level set method, Maximum permeability, Minimum energy dissipation, Navier-Stokes flow, Topology optimization, Variational method

Shiwei Zhou; Qing Li

2008-12-01T23:59:59.000Z

198

Precision control of high temperature furnaces using an auxiliary power supply and charged practice current flow  

DOE Patents (OSTI)

Two power supplies are combined to control a furnace. A main power supply heats the furnace in the traditional manner, while the power from the auxiliary supply is introduced as a current flow through charged particles existing due to ionized gas or thermionic emission. The main power supply provides the bulk heating power and the auxiliary supply provides a precise and fast power source such that the precision of the total power delivered to the furnace is improved.

Pollock, George G. (San Ramon, CA)

1997-01-01T23:59:59.000Z

199

Precision control of high temperature furnaces using an auxiliary power supply and charged particle current flow  

DOE Patents (OSTI)

Two power supplies are combined to control a furnace. A main power supply heats the furnace in the traditional manner, while the power from the auxiliary supply is introduced as a current flow through charged particles existing due to ionized gas or thermionic emission. The main power supply provides the bulk heating power and the auxiliary supply provides a precise and fast power source such that the precision of the total power delivered to the furnace is improved. 5 figs.

Pollock, G.G.

1997-01-28T23:59:59.000Z

200

MULTIOBJECTIVE OPTIMIZATION POWER GENERATION SYSTEMS INVOLVING CHEMICAL LOOPING COMBUSTION  

SciTech Connect

Integrated Gasification Combined Cycle (IGCC) system using coal gasification is an important approach for future energy options. This work focuses on understading the system operation and optimizing it in the presence of uncertain operating conditions using ASPEN Plus and CAPE-OPEN compliant stochastic simulation and multiobjective optimization capabilities developed by Vishwamitra Research Institute. The feasible operating surface for the IGCC system is generated and deterministic multiobjective optimization is performed. Since the feasible operating space is highly non-convex, heuristics based techniques that do not require gradient information are used to generate the Pareto surface. Accurate CFD models are simultaneously developed for the gasifier and chemical looping combustion system to characterize and quantify the process uncertainty in the ASPEN model.

Juan M. Salazar; Urmila M. Diwekar; Stephen E. Zitney

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "optimal power flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Use of program GEOTHM to design and optimize geothermal power cycles  

SciTech Connect

The Lawrence Berkeley Laboratory program GEOTHM has been under development for nearly two years. GEOTHM will design and optimize a wide variety of thermodynamic cycles. The most recent improvements in the GEOTHM program are included. These improvements include: a model for concentrated saline brines and a single step cycle optimization process. Geothermal power cycles are given as examples.

Pines, H.S.; Green, M.A.

1976-06-01T23:59:59.000Z

202

Optimal Power Policy for Energy Harvesting Transmitters with Inefficient Energy Storage  

E-Print Network (OSTI)

1 Optimal Power Policy for Energy Harvesting Transmitters with Inefficient Energy Storage Kaya energy is lost in the process. An optimal transmission policy maximizing the average rate within a finite; the harvested energy is variable and may be scarce, requiring tailored transmission policies to achieve

Yener, Aylin

203

Interpreting Horizontal Well Flow Profiles and Optimizing Well Performance by Downhole Temperature and Pressure Data  

E-Print Network (OSTI)

Horizontal well temperature and pressure distributions can be measured by production logging or downhole permanent sensors, such as fiber optic distributed temperature sensors (DTS). Correct interpretation of temperature and pressure data can be used to obtain downhole flow conditions, which is key information to control and optimize horizontal well production. However, the fluid flow in the reservoir is often multiphase and complex, which makes temperature and pressure interpretation very difficult. In addition, the continuous measurement provides transient temperature behavior which increases the complexity of the problem. To interpret these measured data correctly, a comprehensive model is required. In this study, an interpretation model is developed to predict flow profile of a horizontal well from downhole temperature and pressure measurement. The model consists of a wellbore model and a reservoir model. The reservoir model can handle transient, multiphase flow and it includes a flow model and a thermal model. The calculation of the reservoir flow model is based on the streamline simulation and the calculation of reservoir thermal model is based on the finite difference method. The reservoir thermal model includes thermal expansion and viscous dissipation heating which can reflect small temperature changes caused by pressure difference. We combine the reservoir model with a horizontal well flow and temperature model as the forward model. Based on this forward model, by making the forward calculated temperature and pressure match the observed data, we can inverse temperature and pressure data to downhole flow rate profiles. Two commonly used inversion methods, Levenberg- Marquardt method and Marcov chain Monte Carlo method, are discussed in the study. Field applications illustrate the feasibility of using this model to interpret the field measured data and assist production optimization. The reservoir model also reveals the relationship between temperature behavior and reservoir permeability characteristic. The measured temperature information can help us to characterize a reservoir when the reservoir modeling is done only with limited information. The transient temperature information can be used in horizontal well optimization by controlling the flow rate until favorite temperature distribution is achieved. With temperature feedback and inflow control valves (ICVs), we developed a procedure of using DTS data to optimize horizontal well performance. The synthetic examples show that this method is useful at a certain level of temperature resolution and data noise.

Li, Zhuoyi

2010-12-01T23:59:59.000Z

204

ESS 2012 Peer Review - Low Cost, High Performance and Long Life Flow Battery Electrodes - Tom Stepien, Primus Power  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

With ARPA-E we optimized With ARPA-E we optimized * Adhesion * Current density * Duration * Catalytic coatings * Voltaic performance Goals * Cost-effectiveness * High-efficiency * Uniformity EnergyPod Low Cost, High Performance and Long Life Flow Battery Electrodes TM A Breakthrough In Distributed, Grid Scale Energy Storage ARPA-E has enabled Primus Power to create an innovative and technically advanced electrode Electrode Zinc Plating This, combined with our other advances has enabled us to create a unique flow battery system with ...  Low cost electrodes  Long life  High efficiency  Flexibility For...  Ubiquitous  Dispatchable  Cost effective ... grid-scale electrical energy storage to: * Accelerate renewable

205

Computational Research Challenges and Opportunities for the Optimization of Fossil Energy Power Generation System  

Science Conference Proceedings (OSTI)

Emerging fossil energy power generation systems must operate with unprecedented efficiency and near-zero emissions, while optimizing profitably amid cost fluctuations for raw materials, finished products, and energy. To help address these challenges, the fossil energy industry will have to rely increasingly on the use advanced computational tools for modeling and simulating complex process systems. In this paper, we present the computational research challenges and opportunities for the optimization of fossil energy power generation systems across the plant lifecycle from process synthesis and design to plant operations. We also look beyond the plant gates to discuss research challenges and opportunities for enterprise-wide optimization, including planning, scheduling, and supply chain technologies.

Zitney, S.E.

2007-06-01T23:59:59.000Z

206

Hybrid Powertrain Optimization for Plug-In Microgrid Power Generation Automated Modeling Laboratory Slide 1 of 28  

E-Print Network (OSTI)

Hybrid Powertrain Optimization for Plug-In Microgrid Power Generation Automated Modeling LaboratoryPlug--InIn MicrogridMicrogrid Power GenerationPower Generation Scott J. MouraScott J. Moura DongsukDongsuk KumKum Hosam Powertrain Optimization for Plug-In Microgrid Power Generation Automated Modeling Laboratory Slide 2 of 28

Krstic, Miroslav

207

Thermal-induced leakage power optimization by redundant resource allocation  

Science Conference Proceedings (OSTI)

Traditionally, at early design stages, leakage power is associated with the number of transistors in a design. Hence, intuitively an implementation with minimum resource usage would be best for low leakage. Such an allocation would generally be followed ...

Min Ni; Seda Ogrenci Memik

2006-11-01T23:59:59.000Z

208

Optimization Online - Robust mid-term power generation management  

E-Print Network (OSTI)

Feb 23, 2011 ... Robust mid-term power generation management. Vincent Guigues(vguigues *** at*** puc-rio.br) René Aid(rene.aid ***at*** edf.fr) Papa Momar ...

209

Kansas City Power & Light- Energy Optimizer Programmable Thermostat Program  

Energy.gov (U.S. Department of Energy (DOE))

Kansas City Power and Light (KCP&L) offers a free Honeywell programmable thermostat, worth $300, and free installation to qualifying customers to manage energy usage. Only residential and small...

210

Kansas City Power and Light- Energy Optimizer Programmable Thermostat Program  

Energy.gov (U.S. Department of Energy (DOE))

Kansas City Power and Light (KCP&L) offers a free Honeywell programmable thermostat, worth $300, and free installation to qualifying customers to manage energy usage. Only residential and small...

211

Application of the interphase power controller technology for transmission line power flow control  

SciTech Connect

This paper presents an application of the IPC technology for controlling power flows while maintaining the natural synchronizing capacity of transmission lines. The benefits for transmission systems are a substantial increase in steady-state transmission capability, lower losses and voltage support. An example based on the 500 kV Mead-Phoenix Project demonstrates the effectiveness of the IPC solution: the addition of a 370 Mvar capacitor in parallel with the two 500 kV phase-shifting transformers increases their maximum capability from 1,300 to 1,910 MW. The concepts presented are the results of the first phase of work leading to the development of an IPC using power electronics.

Brochu, J.; Beauregard, F.; Lemay, J.; Morin, G.; Pelletier, P. [Center d`Innovation sur le Transport d`Energie du Quebec, Varennes, Quebec (Canada)] [Center d`Innovation sur le Transport d`Energie du Quebec, Varennes, Quebec (Canada); Thallam, R.S. [Salt River Project, Phoenix, AZ (United States)] [Salt River Project, Phoenix, AZ (United States)

1997-04-01T23:59:59.000Z

212

A Powerful Optimization Approach for the Multi Channel Dissemination Networks  

E-Print Network (OSTI)

In the wireless environment, dissemination techniques may improve data access for the users. In this paper, we show a description of dissemination architecture that fits the overall telecommunication network. This architecture is designed to provide efficient data access and power saving for the mobile units. A concurrency control approach, MCD, is suggested for data consistency and conflict checking. A performance study shows that the power consumption, space overhead, and response time associated with MCD is far less than other previous techniques.

Al-Mogren, Ahmad Saad

2010-01-01T23:59:59.000Z

213

New Technologies and Methods to Improve Computational Speed and Robustness of Power Flow Analysis  

Science Conference Proceedings (OSTI)

The power flow problem consists of determining the steady-state operating point of an electrical transmission network under specific loading conditions. This report describes the development of power flow techniques designed to improve the efficiency and reliability of an electrical power network. Leveraging advancements in computing technologies, data processing, and sophisticated computational methods can improve the performance of power system analysis tools, specifically their accuracy, speed, ...

2013-12-20T23:59:59.000Z

214

Voltage Control Optimization to Improve Transmission Efficiency  

Science Conference Proceedings (OSTI)

An optimal power flow solution is unique from a conventional power flow solution in that an objective function and user-specified constraints are enforced and satisfied to reach a valid solution. This report presents an analytical study on the optimization of power flow in order to minimize reactive power losses via the modification of generator voltage schedules and transmission switched shunt status. The study examines the potential benefits and applicability of near-real-time voltage control ...

2012-11-08T23:59:59.000Z

215

Time series power flow analysis for distribution connected PV generation.  

SciTech Connect

Distributed photovoltaic (PV) projects must go through an interconnection study process before connecting to the distribution grid. These studies are intended to identify the likely impacts and mitigation alternatives. In the majority of the cases, system impacts can be ruled out or mitigation can be identified without an involved study, through a screening process or a simple supplemental review study. For some proposed projects, expensive and time-consuming interconnection studies are required. The challenges to performing the studies are twofold. First, every study scenario is potentially unique, as the studies are often highly specific to the amount of PV generation capacity that varies greatly from feeder to feeder and is often unevenly distributed along the same feeder. This can cause location-specific impacts and mitigations. The second challenge is the inherent variability in PV power output which can interact with feeder operation in complex ways, by affecting the operation of voltage regulation and protection devices. The typical simulation tools and methods in use today for distribution system planning are often not adequate to accurately assess these potential impacts. This report demonstrates how quasi-static time series (QSTS) simulation and high time-resolution data can be used to assess the potential impacts in a more comprehensive manner. The QSTS simulations are applied to a set of sample feeders with high PV deployment to illustrate the usefulness of the approach. The report describes methods that can help determine how PV affects distribution system operations. The simulation results are focused on enhancing the understanding of the underlying technical issues. The examples also highlight the steps needed to perform QSTS simulation and describe the data needed to drive the simulations. The goal of this report is to make the methodology of time series power flow analysis readily accessible to utilities and others responsible for evaluating potential PV impacts.

Broderick, Robert Joseph; Quiroz, Jimmy Edward; Ellis, Abraham; Reno, Matthew J. [Georgia Institute of Technology, Atlanta, GA; Smith, Jeff [Electric Power Research Institute, Knoxville, TN; Dugan, Roger [Electric Power Research Institute, Knoxville, TN

2013-01-01T23:59:59.000Z

216

IEEE TRANSACTIONS ON POWER SYSTEMS (TO APPEAR) 1 Optimal Placement of Phasor Measurement  

E-Print Network (OSTI)

their deployment on every bus, which in turn motivates their strategic placement across the power grid. As state estimation is at the core of grid monitoring, PMU deployment is optimized here based on estimation concentrators. Merits of PMUs (a.k.a. synchrophasors) over conventional power meters include in- creased

Giannakis, Georgios

217

Maximal network reliability with optimal transmission line assignment for stochastic electric power networks via genetic algorithms  

Science Conference Proceedings (OSTI)

This study proposes a genetic algorithm based method integrating the minimal paths and the recursive sum of disjoint products to find maximal network reliability with optimal transmission line assignment for a stochastic electric power network. In our ... Keywords: Genetic algorithm, Maximal network reliability, Recursive sum of disjoint products, Stochastic electric power network, Transmission line assignment

Yi-Kuei Lin; Cheng-Ta Yeh

2011-03-01T23:59:59.000Z

218

Analysis and Optimization of the Power Cycle Based on the Cold Energy of Liquefied Natural Gas  

Science Conference Proceedings (OSTI)

Liquid natural gas (LNG) delivered by sea-ships contains considerable cryogenic energy which can be used for power generation before its evaporation and introduction into the system of pipe line. Electric power generation utilizing LNG cold energy is ... Keywords: liquefied natural gast, cold energy recovery, pinch analysis, exergy, optimization

Lu Yuanwei; Yang Hongchang; Ma Chongfang

2011-01-01T23:59:59.000Z

219

Combinatorial Optimization of Pulverizers for Blended-Coal-Fired Power Plant  

Science Conference Proceedings (OSTI)

Coal blending has become an important way to ease the tension of coal purchase for many Chinese power plants. Mixed by pulverizers which has been widely used, is considered the most reasonable and convenient approach of coal blending. The implementation ... Keywords: power plant, coal blending, combinatorial optimization, pulverizer, NSGA-II

Xia Ji; Peng Peng; Hua Zhigang; Lu Pan; Chen Gang

2011-02-01T23:59:59.000Z

220

Optimal control in energy conversion of small wind power systems with permanent-magnet-synchronous-generators  

Science Conference Proceedings (OSTI)

This paper presents the results of experimental investigation of a low-power wind energy conversion system (WECS), based on a permanent-magnet synchronous generator (PMSG) connected directly to the turbine. A development system was built in order to ... Keywords: hardware-in-the-loop simulation, maximum power point tracking, optimal control, permanent-magnet synchronous generator, wind system

C. Vlad; I. Munteanu; A. I. Bratcu; E. Ceanga

2008-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "optimal power flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Optimization of wind turbine energy and power factor with an evolutionary computation algorithm  

E-Print Network (OSTI)

Optimization of wind turbine energy and power factor with an evolutionary computation algorithm the energy capture from the wind and enhance the quality of the power produced by the wind turbine, and harmonic distortion. As the generation of wind energy on an industrial scale is relatively new, the area

Kusiak, Andrew

222

Simulation and optimization of cogeneration power plant operation using an Energy Optimization Program.  

E-Print Network (OSTI)

??The operation of a combined cycle cogeneration power plant system is complicated because of the complex interactions among components as well as the dynamic nature… (more)

Zhou, Jijun

2012-01-01T23:59:59.000Z

223

Optimization of a Two-Fluid Hydrodynamic Model of Churn-Turbulent Flow  

DOE Green Energy (OSTI)

A hydrodynamic model of two-phase, churn-turbulent flows is being developed using the computational multiphase fluid dynamics (CMFD) code, NPHASE-CMFD. The numerical solutions obtained by this model are compared with experimental data obtained at the TOPFLOW facility of the Institute of Safety Research at the Forschungszentrum Dresden-Rossendorf. The TOPFLOW data is a high quality experimental database of upward, co-current air-water flows in a vertical pipe suitable for validation of computational fluid dynamics (CFD) codes. A five-field CMFD model was developed for the continuous liquid phase and four bubble size groups using mechanistic closure models for the ensemble-averaged Navier-Stokes equations. Mechanistic models for the drag and non-drag interfacial forces are implemented to include the governing physics to describe the hydrodynamic forces controlling the gas distribution. The closure models provide the functional form of the interfacial forces, with user defined coefficients to adjust the force magnitude. An optimization strategy was devised for these coefficients using commercial design optimization software. This paper demonstrates an approach to optimizing CMFD model parameters using a design optimization approach. Computed radial void fraction profiles predicted by the NPHASE-CMFD code are compared to experimental data for four bubble size groups.

Donna Post Guillen

2009-07-01T23:59:59.000Z

224

Flow Measurement at Hydro Facilities: Achieving Efficiency, Compliance, and Optimal Operation (TR-113584-V5)  

Science Conference Proceedings (OSTI)

Many factors can affect the performance and profitability of hydro facilities. The basis of hydroelectric power production is founded on the quantity, availability, and effective use of water. The premise of this Hydropower Technology Roundup report is that an improvement in flow measurement techniques and applications will improve hydroelectric production.

2002-01-15T23:59:59.000Z

225

Trimode optimizes hybrid power plants. Final report: Phase 2  

DOE Green Energy (OSTI)

In the Phase 2 project, Abacus Controls Inc. did research and development of hybrid systems that combine the energy sources from photovoltaics, batteries, and diesel-generators and demonstrated that they are economically feasible for small power plants in many parts of the world. The Trimode Power Processor reduces the fuel consumption of the diesel-generator to its minimum by presenting itself as the perfect electrical load to the generator. A 30-kW three-phase unit was tested at Sandia National Laboratories to prove its worthiness in actual field conditions. The use of photovoltaics at remote locations where reliability of supply requires a diesel-generator will lower costs to operate by reducing the run time of the diesel generator. The numerous benefits include longer times between maintenance for the diesel engine and better power quality from the generator. 32 figs.

O`Sullivan, G.A.; O`Sullivan, J.A. [Abacus Controls, Inc., Somerville, NJ (United States)

1998-07-01T23:59:59.000Z

226

DRAFT STAFF PAPER EXPECTED PATH 26 POWER FLOWS  

E-Print Network (OSTI)

under varying temperature conditions. Keywords: Electricity, demand, imports, transmission flows Marshall, Marc Pryor, David Vidaver Electricity Analysis Office Electricity Supply Assessment Division a 2008 staff assessment of electricity flows over Path 26 during heat spells in the summers of 2006

227

Optimized Maximum Power Point Tracker for Fast Changing Environmental Conditions  

E-Print Network (OSTI)

working point to the optimum, following the weather (i.e. solar irradiance and temperature) conditions Tracking, Photovoltaic, Solar I. INTRODUCTION The worldwide installed PV power capacity today shows topologies, which provide high performance tracking during 'nice' weather conditions, i.e. at strong

Sera, Dezso

228

Method of optimizing performance of Rankine cycle power plants  

DOE Patents (OSTI)

A method for efficiently operating a Rankine cycle power plant (10) to maximize fuel utilization efficiency or energy conversion efficiency or minimize costs by selecting a turbine (22) fluid inlet state which is substantially in the area adjacent and including the transposed critical temperature line (46).

Pope, William L. (Walnut Creek, CA); Pines, Howard S. (El Cerrito, CA); Doyle, Padraic A. (Oakland, CA); Silvester, Lenard F. (Richmond, CA)

1982-01-01T23:59:59.000Z

229

Optimization Studies for ISOL Type High-Powered Targets  

Science Conference Proceedings (OSTI)

The research studied one-step and two-step Isotope Separation on Line (ISOL) targets for future radioactive beam facilities with high driver-beam power through advanced computer simulations. As a target material uranium carbide in the form of foils was used because of increasing demand for actinide targets in rare-isotope beam facilities and because such material was under development in ISAC at TRIUMF when this project started. Simulations of effusion were performed for one-step and two step targets and the effects of target dimensions and foil matrix were studied. Diffusion simulations were limited by availability of diffusion parameters for UCx material at reduced density; however, the viability of the combined diffusion?effusion simulation methodology was demonstrated and could be used to extract physical parameters such as diffusion coefficients and effusion delay times from experimental isotope release curves. Dissipation of the heat from the isotope-producing targets is the limiting factor for high-power beam operation both for the direct and two-step targets. Detailed target models were used to simulate proton beam interactions with the targets to obtain the fission rates and power deposition distributions, which were then applied in the heat transfer calculations to study the performance of the targets. Results indicate that a direct target, with specification matching ISAC TRIUMF target, could operate in 500-MeV proton beam at beam powers up to ~40 kW, producing ~8 1013 fission/s with maximum temperature in UCx below 2200 C. Targets with larger radius allow higher beam powers and fission rates. For the target radius in the range 9-mm to 30-mm the achievable fission rate increases almost linearly with target radius, however, the effusion delay time also increases linearly with target radius.

Remec, Igor [Oak Ridge National Laboratory] [Oak Ridge National Laboratory; Ronningen, Reginald Martin [Michigan State University] [Michigan State University

2013-09-24T23:59:59.000Z

230

Review: Multi-objective based on parallel vector evaluated particle swarm optimization for optimal steady-state performance of power systems  

Science Conference Proceedings (OSTI)

In this paper the state-of-the-art extended particle swarm optimization (PSO) methods for solving multi-objective optimization problems are represented. We emphasize in those, the co-evolution technique of the parallel vector evaluated PSO (VEPSO), analysed ... Keywords: Multi-objective optimization, Parallel VEPSO, Reactive power control

John G. Vlachogiannis; Kwang Y. Lee

2009-10-01T23:59:59.000Z

231

Trimode Power Converter optimizes PV, diesel and battery energy sources  

SciTech Connect

Conservatively, there are 100,000 localities in the world waiting for the benefits that electricity can provide, and many of these are in climates where sunshine is plentiful. With these locations in mind a prototype 30 kW hybrid system has been assembled at Sandia to prove the reliability and economics of photovoltaic, diesel and battery energy sources managed by an autonomous power converter. In the Trimode Power Converter the same power parts, four IGBT`s with an isolation transformer and filter components, serve as rectifier and charger to charge the battery from the diesel; as a stand-alone inverter to convert PV and battery energy to AC; and, as a parallel inverter with the diesel-generator to accommodate loads larger than the rating of the diesel. Whenever the diesel is supplying the load, an algorithm assures that the diesel is running at maximum efficiency by regulating the battery charger operating point. Given the profile of anticipated solar energy, the cost of transporting diesel fuel to a remote location and a five year projection of load demand, a method to size the PV array, battery and diesel for least cost is developed.

O`Sullivan, G. [Abacus Controls, Inc., Somerville, NJ (United States); Bonn, R.; Bower, W. [Sandia National Labs., Albuquerque, NM (United States)

1994-07-01T23:59:59.000Z

232

Power optimization of an irreversible Brayton heat engine  

SciTech Connect

Brayton cycles have been used extensively in gas-turbine power plants and aircraft propulsion systems. Finite-time thermodynamics is used to determine the maximum power output and the corresponding thermal efficiency for an irreversible closed-cycle Brayton heat engine. A realistic model is presented, which includes three types of irreversibilities: finite thermal conductance between the working fluid and the reservoirs, heat leaks between the reservoirs, and internal irreversibility inside the Brayton heat engine. The effects of heat leaks, hot-to-cold reservoir temperature ratios, and component efficiencies on the maximum power output and the corresponding thermal efficiency are studied. With component efficiencies less than 100%, the optimum ratio of the hot-end heat exchanger conductance to the total conductance of the two heat exchangers is found to be less than 0.5. Moreover, this ratio increases as the component efficiencies and the total conductance of the two heat exchangers are increased, and decreases as the hot-to-cold reservoir temperature ratio is increased.

Cheng, C.Y.; Chen, C.K. [National Cheng-Kung Univ., Tainan (Taiwan, Province of China). Dept. of Mechanical Engineering

1997-06-01T23:59:59.000Z

233

Combinational logic optimization for low power using implication-based transformations  

E-Print Network (OSTI)

The demand for portable equipment has increased the emphasis on low-power designs. Higher power consumption results in shorter battery-lifetime of portable electronic devices. As a result larger batteries are required for a reasonable operational time and this reduces the portability of the devices. There are several techniques which reduce power consumption during design of a it. This work presents one such technique which is applicable to a gate-level design. A combinational logic optimizer, Minpower, which reduces power consumption is presented. Heuristics and methods which help in guiding the optimization procedure towards a circuit with minimal power cost will be presented. Finally, experimental results on the ISCAS85 benchmark set and a comparision with various other techniques will be presented to demonstrate the effectiveness of the proposed technique.

Swarna, Madhukiran V.

1997-01-01T23:59:59.000Z

234

Throughput Optimal Policies for Energy Harvesting Wireless Transmitters with Non-Ideal Circuit Power  

E-Print Network (OSTI)

Characterizing the fundamental tradeoffs for maximizing energy efficiency (EE) versus spectrum efficiency (SE) is a key problem in wireless communication. In this paper, we address this problem for a point-to-point additive white Gaussian noise (AWGN) channel with the transmitter powered solely via energy harvesting from the environment. In addition, we assume a practical on-off transmitter model with non-ideal circuit power, i.e., when the transmitter is on, its consumed power is the sum of the transmit power and a constant circuit power. Under this setup, we study the optimal transmit power allocation to maximize the average throughput over a finite horizon, subject to the time-varying energy constraint and the non-ideal circuit power consumption. First, we consider the off-line optimization under the assumption that the energy arrival time and amount are a priori known at the transmitter. Although this problem is non-convex due to the non-ideal circuit power, we show an efficient optimal solution that in g...

Xu, Jie

2012-01-01T23:59:59.000Z

235

Original Articles: Experimental design and genetic algorithm optimization of a fuzzy-logic supervisor for embedded electrical power systems  

Science Conference Proceedings (OSTI)

The embedded power systems are nowadays developing at high pace. Hybrid-electric vehicles, full-electric vehicles, airplanes, ships, high-speed trains, all share a common point - the embedded electrical power system. This paper aims to present an optimization ... Keywords: Embedded electrical power system, Energy storage, Experimental design, Fuzzy logic, Genetic algorithm, Optimization

Stefan Breban, Christophe Saudemont, SéBastien Vieillard, BenoíT Robyns

2013-05-01T23:59:59.000Z

236

The effect of expansion-ratio limitations on positive-displacement, total-flow geothermal power systems  

DOE Green Energy (OSTI)

Combined steam-turbine/positive-displacement engine (PDE) geothermal power systems are analyzed thermodynamically and compared with optimized reference flash-steam plants. Three different configurations of combined systems are considered. Treated separately are the cases of self-flowing and pumped wells. Two strategies are investigated that help overcome the inherent expansion-ratio limitation of PDE's: pre-flashing and pre-mixing. Parametrically-obtained results show the required minimum PDE efficiency for the combined system to match the reference plant for various sets of design conditions.

DiPippo, R.

1982-02-01T23:59:59.000Z

237

Secured CAD Back-End Flow for Power-Analysis-Resistant Cryptoprocessors  

Science Conference Proceedings (OSTI)

This article presents a comprehensive back-end design flow that enables the realization of constant-power cryptoprocessors, natively protected against side-channel attacks exploiting the instant power consumption. The proposed methodology is based on ... Keywords: robust hardware, back-end design automation, power-constant architectures, side-channel attacks, mitigation, DFM, DFY

Sylvain Guilley; Florent Flament; Philippe Hoogvorst; Renaud Pacalet; Yves Mathieu

2007-11-01T23:59:59.000Z

238

Steady-state power flow modeling for a dynamic voltage restorer  

Science Conference Proceedings (OSTI)

This paper presents analysis, modeling and simulation of power distribution network performance incorporating with an installed dynamic voltage restorer (DVR). DVR is one of series compensators used in power distribution systems in order to maintain ... Keywords: Gauss-Seidel method, dynamic voltage restorer, modeling, power flow, simulation

T. Ratniyomchai; T. Kulworawanichpong

2006-03-01T23:59:59.000Z

239

Enhancing Cross-Correlation Analysis with Artificial Neural Networks for Nuclear Power Plant Feedwater Flow Measurement  

Science Conference Proceedings (OSTI)

One of the primary cost-saving objectives of the power plant industry, including the nuclear industry, has long been the efficient operation of plant systems. Since the maximum operating thermal power of any nuclear plant is bounded by the specific licensing ... Keywords: flow measurement, neural networks, nuclear power plant

Davide Roverso; Da Ruan

2004-05-01T23:59:59.000Z

240

Flow cytometry: A powerful technology for measuring biomarkers  

SciTech Connect

A broad definition of a biomarker is that it is a measurable characteristic of a biological system that changes upon exposure to a physical or chemical insult. While the definition can be further refined, it is sufficient for the purposes of demonstrating the advantages of flow cytometry for making quantitative measurements of biomarkers. Flow cytometry and cell sorting technologies have emerged during the past 25 years to take their place alongside other essential tools used in biology such as optical and electron microscopy. This paper describes the basics of flow cytometry technology, provides illustrative examples of applications of the technology in the field of biomarkers, describes recent developments in flow cytometry that have not yet been applied to biomarker measurements, and projects future developments of the technology. The examples of uses of flow cytometry for biomarker quantification cited in this paper are meant to be illustrative and not exhaustive in the sense of providing a review of the field.

Jett, J.H. [Los Alamos National Lab., NM (United States). Life Sciences Div.

1994-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "optimal power flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Optimal homogenization of perfusion flows in microfluidic bio-reactors; a numerical study  

E-Print Network (OSTI)

To ensure homogeneous conditions within the complete area of perfused microfluidic bio-reactors, we develop a general design of a continuously feed bio-reactor with uniform perfusion flow. This is achieved by introducing a specific type of perfusion inlet to the reaction area. The geometry of these inlets are found using the methods of topology optimization and shape optimization. The results are compared with two different analytic models, from which a general parametric description of the design is obtained and tested numerically. Such a parametric description will generally be beneficial for the design of a broad range of microfluidic bioreactors used for e.g. cell culturing and analysis, and in feeding bio-arrays.

Okkels, Fridolin; Bruus, Henrik

2009-01-01T23:59:59.000Z

242

A Novel Power Flow Method for Long Term Frequency Stability Analysis  

E-Print Network (OSTI)

This thesis presents a novel approach for a power system to find a practical power flow solution when all the generators in the system have hit their real power output limits, such as some generator units shutting down or load outages. The approach assumes the frequency of the system is unable to be kept at the rated value (usually 60 or 50 Hz) and accordingly, the generator real power outputs are affected by the system frequency deviation. The modification aims to include the system frequency deviation as a new state variable in the power flow so that the power system can be described in a more precise way when the generation limits are hit and the whole system is not operated under the normal condition. A new mathematical formulation for power flow is given by modified the conventional power flow mismatch equation and Jacobian matrix. The Newton – Raphson method is particularly chose to be modified because Newton – Raphson method is most widely used and it is a fast convergent and accurate method. The Jacobian matrix will be augmented by adding a column and a row. Matlab is used as a programming tool to implement the Power Flow for Long Term Frequency Stability (PFLTFS) method for a simple 4-bus system and the IEEE 118-bus system. And PSS/E Dynamic simulation is used to verify the steady state solution from PFLTFS is reasonable. The PSS/E Dynamic Simulation plots are used to analyze the long term frequency response. The PFLTFS method provides a technique for solving an abnormal state system power flow. From the results we can conclude that the PFLTFS method is reasonable for solving power flow of a real power unbalanced system.

Yan, Wenjin

2013-05-01T23:59:59.000Z

243

Multidisciplinary Modeling, Control, and Optimization of a Solid Oxide Fuel Cell/Gas Turbine Hybrid Power System.  

E-Print Network (OSTI)

??This thesis describes a systematical study, including multidisciplinary modeling, simulation, control, and optimization, of a fuel cell - gas turbine hybrid power system that aims… (more)

Abbassi Baharanchi, Atid

2009-01-01T23:59:59.000Z

244

Flow Shop Scheduling with Peak Power Consumption Constraints  

E-Print Network (OSTI)

enterprises; for example, many energy providers use time-of-use (TOU) tariffs ( e.g. Babu and Ashok. 2008). Peak power consumption has also received some ...

245

CONCEPTUAL DESIGN AND OPTIMAL POWER CONTROL STRATEGY FOR AN ECO?FRIENDLY HYBRID VEHICLE  

Science Conference Proceedings (OSTI)

This paper presents a new concept for a hybrid vehicle using a torque and speed splitting technique. It is implemented by the newly developed controller in combination with a two degree of freedom epicyclic gear transmission. This approach enables optimization of the power split between the less powerful electrical motor and more powerful engine while driving a car load. The power split is fundamentally a dual?energy integration mechanism as it is implemented by using the epicyclic gear transmission that has two inputs and one output for a proper power distribution. The developed power split control system manages the operation of both the inputs to have a known output with the condition of maintaining optimum operating efficiency of the internal combustion engine and electrical motor. This system has a huge potential as it is possible to integrate all the features of hybrid vehicle known to?date such as the regenerative braking system

N. Mir Nasiri; Frederick T. A. Chieng

2011-01-01T23:59:59.000Z

246

Joint optimization algorithm for network reconfiguration and reactive power control of wind farm in distribution system  

Science Conference Proceedings (OSTI)

In recent years, the number of small size wind farms used as DG sources located within the distribution system are rapidly increasing. Wind farm made up with doubly fed induction generators (DFIG) is proposed in this paper as the continuous reactive ... Keywords: DFIG wind turbine, network reconfiguration, particle swarm optimization, reactive power control, wind farm

Jingjing Zhao; Xin Li; Jiping Lu; Congli Zhang

2009-02-01T23:59:59.000Z

247

Enhanced discrete differential evolution to determine optimal coordination of directional overcurrent relays in a power system  

Science Conference Proceedings (OSTI)

This paper presents an enhanced differential evolution technique to solve the optimal coordination of directional overcurrent relays in a power system. The most vital task when installing directional relays on the system is selecting suitable current ... Keywords: directional overcurrent relays (DOCRs), enhanced discrete differential evolution algorithm (EDDEA), pickup current settings (Ip), relay coordination, time dial settings (TDS)

Joymala Moirangthem; Subranshu Sekhar Dash; Bijaya Ketan Panigrahi

2011-12-01T23:59:59.000Z

248

Optimal Power Control and SourceChannel Coding for Delay Constrained Traffic over Wireless Channels  

E-Print Network (OSTI)

problem -- the optimal power and rate allocation results in high data rates when the channel gain is high state of the Markov chain that affect the chain's transition probabilities. Each action will incur some, . probability distributions describing state transitions, . functions denoting the reward earned for each action

Goldsmith, Andrea

249

Multi-information integrated trip specific optimal power management for plug-in hybrid electric vehicles  

Science Conference Proceedings (OSTI)

Plug-in hybrid electric vehicles (PHEV) are widely received as a promising means of green mobility by utilizing more battery power. Recently, we have proposed a scheme of two-scale spatial-domain dynamic programming (DP) as a nearly global optimization ...

Yang Bin; Yaoyu Li; Qiuming Gong; Zhong-Ren Peng

2009-06-01T23:59:59.000Z

250

A STOCHASTIC OPTIMAL CONTROL APPROACH FOR POWER MANAGEMENT IN PLUG-IN HYBRID ELECTRIC VEHICLES  

E-Print Network (OSTI)

A STOCHASTIC OPTIMAL CONTROL APPROACH FOR POWER MANAGEMENT IN PLUG-IN HYBRID ELECTRIC VEHICLES.e., the engine and electric machines) in a plug-in hybrid electric vehicle (PHEV). Existing studies focus mostly. INTRODUCTION This paper examines plug-in hybrid electric vehicles (PHEVs), i.e., automobiles that can extract

Krstic, Miroslav

251

An Optimal Fuzzy Logic Power Sharing Strategy for Parallel Hybrid Electric Vehicles  

E-Print Network (OSTI)

An Optimal Fuzzy Logic Power Sharing Strategy for Parallel Hybrid Electric Vehicles F. Khoucha1 presents a fuzzy logic controller for a Parallel Hybrid Electric Vehicle (PHEV). The PHEV required driving economy, and emissions. Index Terms--Parallel Hybrid Electric Vehicle (PHEV), Internal Combustion Engine

Paris-Sud XI, Université de

252

Nonlinear controller optimization of a power system based on reduced multivariate polynomial model  

Science Conference Proceedings (OSTI)

This paper describes the design of a nonlinear controller in a power system by using the reduced multivariate polynomial (RMP) optimization algorithm with the one-shot training property. The RMP model is applied to estimate its Hessian matrix in addition ...

Seung-Mook Baek; Jung-Wook Park

2009-06-01T23:59:59.000Z

253

Optimal Power-Law Description of Oceanic Whitecap Coverage Dependence on Wind Speed  

Science Conference Proceedings (OSTI)

The optimal power-law expression for the dependence of oceanic whitecap coverage fraction W on 10 m elevation wind speed U as determined by ordinary least squares fitting applied to the combined whitecap data sets of Monahan (1971) and Toba and ...

Edward C. Monahan; IognáidÓ Muircheartaigh

1980-12-01T23:59:59.000Z

254

Simulation and Optimization on Power Plant Operation Using Sega's EOP Program  

E-Print Network (OSTI)

The operation of a cogeneration power plant is complicated. The Energy Optimization Program (EOP, software made by SEGA, Inc.) was designed to simulate and optimize the operation of TAMU power plant. All major plant components were represented by appropriate models and then structured to establish a system model. A better understanding of the complicated interaction among all energy components within the plant was achieved through systematic simulation using EOP. Overall performance of the plant operation under different conditions was investigated. Further more, (online) operational optimization is made possible by load reassignment according to EOP's calculation. Other researches on plant operation, such as the impact of utility rates on operational decision making, were also carried out with the help of this program. This paper shows how a well-designed commercial software is exploited in engineering research.

Zhou, J.; Deng, S.; Turner, W. D.; Liu, M.

2000-01-01T23:59:59.000Z

255

Simulation and Optimization on Power Plant Operation Using SEGA's EOP Program  

E-Print Network (OSTI)

The operation of a cogeneration power plant is complicated. The Energy Optimization Program (EOP, software made by SEGA, Inc.) was designed to simulate and optimize the operation of TAMU power plant. All major plant components were represented by appropriate models and then structured to establish a system model. A better understanding of the complicated interaction among all energy components within the plant was achieved through systematic simulation using EOP. Overall performance of the plant operation under different conditions was investigated. Further more, (online) operational optimization is made possible by load re-assignment according to EOP's calculation. Other researches on plant operation, such as the impact of utility rates on operational decision making, were also carried out with the help of this program. This paper shows how a well-designed commercial software is exploited in engineering research.

Zhou, J.; Deng, S.; Turner, W. D.; Liu, M.

2000-05-01T23:59:59.000Z

256

Low-Drift Flow Sensor with Zero-Offset Thermopile-Based Power Feedback  

E-Print Network (OSTI)

A thermal flow sensor has been realised consisting of freely-suspended silicon-rich silicon-nitride microchannels with an integrated Al/poly-Si++ thermopile in combination with up- and downstream Al heater resistors. The inherently zero offset of the thermopile is exploited in a feedback loop controlling the dissipated power in the heater resistors, eliminating inevitable influences of resistance drift and mismatch of the thin-film metal resistors. The control system cancels the flow-induced temperature difference across the thermopile by controlling a power difference between both heater resistors, thereby giving a measure for the flow rate. The flow sensor was characterised for power difference versus water flow rates up to 1.5 ul/min, being in good agreement with a thermal model of the sensor, and the correct low-drift operation of the temperature-balancing control system has been verified.

Dijkstra, M; De Boer, Meint; Berenschot, J W; Wiegerink, Remco; Elwenspoek, M

2008-01-01T23:59:59.000Z

257

An Optimal Power Flow (OPF) Method with Improved Power System Stability  

E-Print Network (OSTI)

Conditioning HVDC High-Voltage Direct Current IEA International Energy Agency IT Information Technology NETL Examples of software or systems Transmission enhancement Superconductors, FACTS, HVDC High-voltage direct current (HVDC). Advanced transformers: High-efficiency amorphous transformers, solid state transformers

Chen, Zhe

258

Towards Design Optimization with OpenModelica Emphasizing Parameter Optimization with Genetic Algorithms  

E-Print Network (OSTI)

. In power plants, the main steam temperature con- trol regulates the spray (attemperator) flow rate. Pre of the super heater along with the attemperator. A SQP optimizer is used to calculate the spray flow, driven

Zhao, Yuxiao

259

Sum-Rate Optimal Power Policies for Energy Harvesting Transmitters in an Interference Channel  

E-Print Network (OSTI)

This paper considers a two-user Gaussian interference channel with energy harvesting transmitters. Different than conventional battery powered wireless nodes, energy harvesting transmitters have to adapt transmission to availability of energy at a particular instant. In this setting, the optimal power allocation problem to maximize sum throughput within a given deadline is formulated. The convergence of the proposed iterative coordinate descent method for the problem is proved and the short-term throughput maximizing offline power allocation policy is found. Examples for interference regions with known sum capacities are given with directional water-filling interpretations when possible. Next, stochastic data arrivals are addressed. Finally online and/or distributed near-optimal policies are proposed. Performance of the proposed algorithms are demonstrated through simulations.

Tutuncuoglu, Kaya

2011-01-01T23:59:59.000Z

260

Interline Photovoltaic (I-PV) power system - A novel concept of power flow control and management  

E-Print Network (OSTI)

This paper presents a new system configuration for a large-scale Photovoltaic (PV) power system with multi-line transmission/distribution networks. A PV power plant is reconfigured in a way that two adjacent power system ...

Khadkikar, Vinod

Note: This page contains sample records for the topic "optimal power flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Particle Swarm Optimization and Gradient Descent Methods for Optimization of PI Controller for AGC of Multi-area Thermal-Wind-Hydro Power Plants  

Science Conference Proceedings (OSTI)

The automatic generation control (AGC) of three unequal interconnected Thermal, Wind and Hydro power plant has been designed with PI controller. Further computational intelligent technique Particle Swarm Optimization and conventional Gradient Descent ... Keywords: Automatic generation control, Particle swarm optimization, Gradient Descent method, Generation rate constraint, Area control error, Wind energy conversion system

Naresh Kumari, A N. Jha

2013-04-01T23:59:59.000Z

262

Soft computing based multi-objective optimization of steam cycle power plant using NSGA-II and ANN  

Science Conference Proceedings (OSTI)

In this paper a steam turbine power plant is thermo-economically modeled and optimized. For this purpose, the data for actual running power plant are used for modeling, verifying the results and optimization. Turbine inlet temperature, boiler pressure, ... Keywords: Artificial Neural Network, NSGA-II, Steam turbine cycle, Thermal efficiency, Total cost rate

Farzaneh Hajabdollahi; Zahra Hajabdollahi; Hassan Hajabdollahi

2012-11-01T23:59:59.000Z

263

Optimization under Uncertainty for Water Consumption in a Pulverized Coal Power Plant  

SciTech Connect

Pulverized coal (PC) power plants are widely recognized as major water consumers whose operability has started to be affected by drought conditions across some regions of the country. Water availability will further restrict the retrofitting of existing PC plants with water-expensive carbon capture technologies. Therefore, national efforts to reduce water withdrawal and consumption have been intensified. Water consumption in PC plants is strongly associated to losses from the cooling water cycle, particularly water evaporation from cooling towers. Accurate estimation of these water losses requires realistic cooling tower models, as well as the inclusion of uncertainties arising from atmospheric conditions. In this work, the cooling tower for a supercritical PC power plant was modeled as a humidification operation and used for optimization under uncertainty. Characterization of the uncertainty (air temperature and humidity) was based on available weather data. Process characteristics including boiler conditions, reactant ratios, and pressure ratios in turbines were calculated to obtain the minimum water consumption under the above mentioned uncertainties. In this study, the calculated conditions predicted up to 12% in reduction in the average water consumption for a 548 MW supercritical PC power plant simulated using Aspen Plus. Optimization under uncertainty for these large-scale PC plants cannot be solved with conventional stochastic programming algorithms because of the computational expenses involved. In this work, we discuss the use of a novel better optimization of nonlinear uncertain systems (BONUS) algorithm which dramatically decreases the computational requirements of the stochastic optimization.

Juan M. Salazar; Stephen E. Zitney; Urmila Diwekar

2009-01-01T23:59:59.000Z

264

Optimization Under Uncertainty for Water Consumption in a Pulverized Coal Power Plant  

Science Conference Proceedings (OSTI)

Pulverized coal (PC) power plants are widely recognized as major water consumers whose operability has started to be affected by drought conditions across some regions of the country. Water availability will further restrict the retrofitting of existing PC plants with water-expensive carbon capture technologies. Therefore, national efforts to reduce water withdrawal and consumption have been intensified. Water consumption in PC plants is strongly associated to losses from the cooling water cycle, particularly water evaporation from cooling towers. Accurate estimation of these water losses requires realistic cooling tower models, as well as the inclusion of uncertainties arising from atmospheric conditions. In this work, the cooling tower for a supercritical PC power plant was modeled as a humidification operation and used for optimization under uncertainty. Characterization of the uncertainty (air temperature and humidity) was based on available weather data. Process characteristics including boiler conditions, reactant ratios, and pressure ratios in turbines were calculated to obtain the minimum water consumption under the above mentioned uncertainties. In this study, the calculated conditions predicted up to 12% in reduction in the average water consumption for a 548 MW supercritical PC power plant simulated using Aspen Plus. Optimization under uncertainty for these large-scale PC plants cannot be solved with conventional stochastic programming algorithms because of the computational expenses involved. In this work, we discuss the use of a novel better optimization of nonlinear uncertain systems (BONUS) algorithm which dramatically decreases the computational requirements of the stochastic optimization.

Juan M. Salazara; Stephen E. Zitney; Urmila M. Diwekara

2009-01-01T23:59:59.000Z

265

Randomized flow model and centrality measure for electrical power transmission network analysis  

E-Print Network (OSTI)

1 Randomized flow model and centrality measure for electrical power transmission network analysis. Centrality measures can then be coherently defined. An example of application to an electrical power transmission system is presented. Acknowledgements This work has been partially funded by the Foundation pour

266

Influence of Cooling Circulating Water Flow on Back Pressure Variation of Thermal Power Plant  

Science Conference Proceedings (OSTI)

Under certain conditions, condenser pressure can be considered as back pressure of the steam turbine, which has great influence on the unit power. Based on the back pressure calculation model, influence on back pressure variation by adjusting circulating ... Keywords: Cold-end system, back pressure, cooling water flow, unit power

Nian Zhonghua, Liu Jizhen, Liu Guangjian

2013-01-01T23:59:59.000Z

267

Optimal Sizing of Energy Storage and Photovoltaic Power Systems for Demand Charge Mitigation (Poster)  

DOE Green Energy (OSTI)

Commercial facility utility bills are often a strong function of demand charges -- a fee proportional to peak power demand rather than total energy consumed. In some instances, demand charges can constitute more than 50% of a commercial customer's monthly electricity cost. While installation of behind-the-meter solar power generation decreases energy costs, its variability makes it likely to leave the peak load -- and thereby demand charges -- unaffected. This then makes demand charges an even larger fraction of remaining electricity costs. Adding controllable behind-the-meter energy storage can more predictably affect building peak demand, thus reducing electricity costs. Due to the high cost of energy storage technology, the size and operation of an energy storage system providing demand charge management (DCM) service must be optimized to yield a positive return on investment (ROI). The peak demand reduction achievable with an energy storage system depends heavily on a facility's load profile, so the optimal configuration will be specific to both the customer and the amount of installed solar power capacity. We explore the sensitivity of DCM value to the power and energy levels of installed solar power and energy storage systems. An optimal peak load reduction control algorithm for energy storage systems will be introduced and applied to historic solar power data and meter load data from multiple facilities for a broad range of energy storage system configurations. For each scenario, the peak load reduction and electricity cost savings will be computed. From this, we will identify a favorable energy storage system configuration that maximizes ROI.

Neubauer, J.; Simpson, M.

2013-10-01T23:59:59.000Z

268

Optimal power consumption in a central heating system with geothermal heat pump  

E-Print Network (OSTI)

Abstract: A ground source heat pump connected to a domestic hydronic heating network is studied to be driven with the minimum electric power. The hypothesis is to decrease the forward temperature to the extent that one of the hydronic heaters work at full capacity. A less forward temperature would result in a dramatic temperature drop in the room with saturated actuator. The optimization hypothesis is inspired by the fact that, the consumed electric power by the heat pump has a strong positive correlation with the generated forward temperature. A model predictive control scheme is proposed in the current study to achieve the optimal forward temperature. At the lower hierarchy level, local PI controllers seek the corresponding room temperature setpoint. Simulation results for a multi-room house case study show considerable energy savings compared to the heat pump’s traditional control scheme.

F. Tahersima; J. Stoustrup; H. Rasmussen

2011-01-01T23:59:59.000Z

269

Code Size Effects of Power Optimizing Code Transformations for Embedded Multimedia Applications  

E-Print Network (OSTI)

A systematic methodology has been developed for the reduction of the data transfers and storage related power consumption in realizations of multimedia applications on programmable multimedia processors. The methodology is based on the application of code transformations that move the main part of the memory accesses from the large (off-chip) memories to smaller ones (on-chip). Performance (in number of cycles) which is the overriding constraint for multimedia applications is improved in most cases by the application of the power optimizing code transformations as well. The main focus of this paper is on the effect of these power optimizing code transformations on the code size, an important design parameter that implicitly affects both the total system power consumption and the performance. Experimental results from real-life applications demonstrate that contrary to earlier conjectures, if applied well our methodology introduces only small code size penalties that do not offset the significant gains in both performance and power consumption achieved by its application.

K. Masselos; F. Catthoor; C. E. Goutis; H. Deman

1999-01-01T23:59:59.000Z

270

An Integrated Approach for Optimal Coordination of Wind Power and Hydro Pumping Storage  

E-Print Network (OSTI)

The increasing wind power penetration in power systems represents a techno-economic challenge for power producers and system operators. Due to the variability and uncertainty of wind power, system operators require new solutions in order to increase the controllability of wind farm output. On the other hand, producers that include wind farms in their portfolio need to find new ways to boost their profits in electricity markets. This can be done by optimizing the combination of wind farms and storage so as to make larger profits when selling power (trading) and reduce penalties from imbalances in the operation. The present work describes a new integrated approach for analyzing wind-storage solutions that make use of probabilistic forecasts and optimization techniques to aid decision-making on operating such systems. The approach includes a set of three complementary functions suitable for use in current systems. A reallife system is studied, comprising two wind farms and a large hydro station with pumping capacity. Economic profits and better operational features can be obtained from the proposed cooperation between the wind farms and storage. The revenues are function of the type of hydro storage used and the market characteristics and several options are compared in this study. The results show that the use of a storage device can lead to a significant increase in revenue, up to 11 % (2010 data, Iberian market). Also, the

Edgardo D. Castronuovo; Julio Usaola; Ricardo Bessa; Manuel Matos; I. C. Costa; L. Bremermann; Jesus Lugaro; George Kariniotakis; Sophia Antipolis France

2013-01-01T23:59:59.000Z

271

Optimal Power Procurement and Demand Response with Quality-of-Usage Guarantees  

E-Print Network (OSTI)

In this paper, we propose a general operating scheme which allows the utility company to jointly perform power procurement and demand response so as to maximize the social welfare. Our model takes into consideration the effect of the renewable energy and the multi-stage feature of the power procurement process. It also enables the utility company to provide quality-of-usage (QoU) guarantee to the power consumers, which ensures that the average power usage level meets the target value for each user. To maximize the social welfare, we develop a low-complexity algorithm called the \\emph{welfare maximization algorithm} (WMA), which performs joint power procurement and dynamic pricing. WMA is constructed based on a two-timescale Lyapunov optimization technique. We prove that WMA achieves a close-to-optimal utility and ensures that the QoU requirement is met with bounded deficit. WMA can be implemented in a distributed manner and is robust with respect to system dynamics uncertainty.

Huang, Longbo; Ramchandran, Kannan

2011-01-01T23:59:59.000Z

272

Development of an entrained flow gasifier model for process optimization study  

SciTech Connect

Coal gasification is a versatile process to convert a solid fuel in syngas, which can be further converted and separated in hydrogen, which is a valuable and environmentally acceptable energy carrier. Different technologies (fixed beds, fluidized beds, entrained flow reactors) are used, operating under different conditions of temperature, pressure, and residence time. Process studies should be performed for defining the best plant configurations and operating conditions. Although 'gasification models' can be found in the literature simulating equilibrium reactors, a more detailed approach is required for process analysis and optimization procedures. In this work, a gasifier model is developed by using AspenPlus as a tool to be implemented in a comprehensive process model for the production of hydrogen via coal gasification. It is developed as a multizonal model by interconnecting each step of gasification (preheating, devolatilization, combustion, gasification, quench) according to the reactor configuration, that is in entrained flow reactor. The model removes the hypothesis of equilibrium by introducing the kinetics of all steps and solves the heat balance by relating the gasification temperature to the operating conditions. The model allows to predict the syngas composition as well as quantity the heat recovery (for calculating the plant efficiency), 'byproducts', and residual char. Finally, in view of future works, the development of a 'gasifier model' instead of a 'gasification model' will allow different reactor configurations to be compared.

Biagini, E.; Bardi, A.; Pannocchia, G.; Tognotti, L. [Consorzio Pisa Ric, Pisa (Italy). Div Energia Ambiente

2009-10-15T23:59:59.000Z

273

Reactive Power Management to Address Short-Term Voltage Stability Using Optimal Reactive Power Allocation Method  

Science Conference Proceedings (OSTI)

Voltage stability has attracted attention recently because power systems are increasingly operated under heavy loads and subjected to high levels of dynamic fast acting loads. Voltage instability under these conditions can be manifested as depressed voltage profiles, delayed voltage recovery at load buses following a major disturbance, and even fast voltage collapse. Single-phase, low-inertia induction motors can have adverse effect on voltage stability as they decelerate in the event of voltage ...

2012-11-28T23:59:59.000Z

274

Thermoeconomic design optimization of a KRW-based IGCC power plant. Final report  

SciTech Connect

This report discussed the cost and efficiency optimization of an integrated gasification-combined-cycle (IGCC) power plant design and the effects of important design options and parameters. Advanced thermoeconomic techniques were used to evaluate and optimize a given IGCC concept which uses Illinois No. 6 bituminous coal, air-blown KRW coal gasifiers, a hot gas cleanup system, and GE MS7001F gas turbines. Three optimal design concepts are presented and discussed in the report. Two of the concepts are characterized by minimum cost of electricity at two different values of the steam high pressure. The third concept represents the thermodynamic optimum. This study identified several differences between the original design and the design of the optimized cases. Compared with the original concept, significant annual savings are achieved in the cost optimal cases. Comparisons were made between results obtained using both the old and the new performance data for the MS7001F gas turbine. This report discusses the effects of gasification temperature, steam high pressure, coal moisture, and various design options on the overall plant efficiency and cost of electricity. Cost sensitivity studies were conducted and recommendations for future studies were made.

Tsatsaronis, G.; Lin, L.; Pisa, J.; Tawfik, T. [Tennessee Technological Univ., Cookeville, TN (United States). Center for Electric Power

1991-11-01T23:59:59.000Z

275

Thermoeconomic design optimization of a KRW-based IGCC power plant  

SciTech Connect

This report discussed the cost and efficiency optimization of an integrated gasification-combined-cycle (IGCC) power plant design and the effects of important design options and parameters. Advanced thermoeconomic techniques were used to evaluate and optimize a given IGCC concept which uses Illinois No. 6 bituminous coal, air-blown KRW coal gasifiers, a hot gas cleanup system, and GE MS7001F gas turbines. Three optimal design concepts are presented and discussed in the report. Two of the concepts are characterized by minimum cost of electricity at two different values of the steam high pressure. The third concept represents the thermodynamic optimum. This study identified several differences between the original design and the design of the optimized cases. Compared with the original concept, significant annual savings are achieved in the cost optimal cases. Comparisons were made between results obtained using both the old and the new performance data for the MS7001F gas turbine. This report discusses the effects of gasification temperature, steam high pressure, coal moisture, and various design options on the overall plant efficiency and cost of electricity. Cost sensitivity studies were conducted and recommendations for future studies were made.

Tsatsaronis, G.; Lin, L.; Pisa, J.; Tawfik, T. (Tennessee Technological Univ., Cookeville, TN (United States). Center for Electric Power)

1991-11-01T23:59:59.000Z

276

Distributed control of reactive power flow in a radial distribution circuit with high photovoltaic penetration  

E-Print Network (OSTI)

We show how distributed control of reactive power can serve to regulate voltage and minimize resistive losses in a distribution circuit that includes a significant level of photovoltaic (PV) generation. To demonstrate the technique, we consider a radial distribution circuit with a single branch consisting of sequentially-arranged residential-scale loads that consume both real and reactive power. In parallel, some loads also have PV generation capability. We postulate that the inverters associated with each PV system are also capable of limited reactive power generation or consumption, and we seek to find the optimal dispatch of each inverter's reactive power to both maintain the voltage within an acceptable range and minimize the resistive losses over the entire circuit. We assume the complex impedance of the distribution circuit links and the instantaneous load and PV generation at each load are known. We compare the results of the optimal dispatch with a suboptimal local scheme that does not require any com...

Turitsyn, Konstantin; Backhaus, Scott; Chertkov, Michael

2009-01-01T23:59:59.000Z

277

Optimal Design of Integration of Intelligent, Adaptive Solar (PV) Power Generator with Grid for Domestic Energy Management System  

Science Conference Proceedings (OSTI)

This paper introduces a novel system based on integration of solar power generator with grid for optimal utilization of energy by minimizing the power drawn from grid. A prototype grid integrated PV system comprising of PV module (2*75Wp), battery bank ... Keywords: Solar power Generator (SPG), Domestic Energy Management, Bi-directional Inverter, Photovoltaic(PV), Total Harmonic Distortion (THD)

S. N. Singh; Pooja Singh; Swati Kumari; Swati

2010-03-01T23:59:59.000Z

278

Evaluation and Optimization of a Supercritical Carbon Dioxide Power Conversion Cycle for Nuclear Applications  

Science Conference Proceedings (OSTI)

There have been a number of studies involving the use of gases operating in the supercritical mode for power production and process heat applications. Supercritical carbon dioxide (CO2) is particularly attractive because it is capable of achieving relatively high power conversion cycle efficiencies in the temperature range between 550°C and 750°C. Therefore, it has the potential for use with any type of high-temperature nuclear reactor concept, assuming reactor core outlet temperatures of at least 550°C. The particular power cycle investigated in this paper is a supercritical CO2 Recompression Brayton Cycle. The CO2 Recompression Brayton Cycle can be used as either a direct or indirect power conversion cycle, depending on the reactor type and reactor outlet temperature. The advantage of this cycle when compared to the helium Brayton Cycle is the lower required operating temperature; 550°C versus 850°C. However, the supercritical CO2 Recompression Brayton Cycle requires an operating pressure in the range of 20 MPa, which is considerably higher than the required helium Brayton cycle operating pressure of 8 MPa. This paper presents results of analyses performed using the UniSim process analyses software to evaluate the performance of the supercritical CO2 Brayton Recompression Cycle for different reactor outlet temperatures. The UniSim model assumed a 600 MWt reactor power source, which provides heat to the power cycle at a maximum temperature of between 550°C and 750°C. The UniSim model used realistic component parameters and operating conditions to model the complete power conversion system. CO2 properties were evaluated, and the operating range for the cycle was adjusted to take advantage of the rapidly changing conditions near the critical point. The UniSim model was then optimized to maximize the power cycle thermal efficiency at the different maximum power cycle operating temperatures. The results of the analyses showed that power cycle thermal efficiencies in the range of 40 to 50% can be achieved.

Edwin A. Harvego; Michael G. McKellar

2011-05-01T23:59:59.000Z

279

220 kV SSSC device for power flow control (Smart Grid Project) | Open  

Open Energy Info (EERE)

kV SSSC device for power flow control (Smart Grid Project) kV SSSC device for power flow control (Smart Grid Project) Jump to: navigation, search Project Name 220 kV SSSC device for power flow control Country Spain Headquarters Location Catalonia, Spain Coordinates 41.59116°, 1.520862° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":41.59116,"lon":1.520862,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

280

Optimization and preconceptual design of a 5 MWe salt-gradient solar pond power plant at Great Salt Lake  

DOE Green Energy (OSTI)

The techniques used to optimize and design a solar salt-gradient pond (SSP) power plant for installation at the Great Salt Lake are described. The method and results of the site selection study are described as well as the characteristics of the selected site. The figure of merit used as well as the characteristics of the selected site. The figure of merit used in the optimization study, the general optimization approach, and the specific optimization method used for each subsystem are described. Results are then discussed of the optimization of the pond configuration, total system, and piping. Pond design and ground rule sensitivity studies are reported. (LEW)

Drost, M.K.; Brown, L.M.; Barnhart, J.S.; Cavola, R.G.; Hauser, S.G.; Johnson, B.M.

1983-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "optimal power flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Optimal RF Conditioning of Advanced Photon Source (APS) Fundamental Power Coupler  

E-Print Network (OSTI)

Experience at many laboratories regarding conditioning of RF Fundamental Power Couplers (FPC) has shown that it is a very apprehensive and laborious process. While the principle should remain unchanged, which is to gradually increase the rf power applied to the coupler while monitoring the vacuum level, the methodology is sometime different. With coupler lifetime being finite, some RF conditioning methods may be more conservative than others. The basic principle of coupler conditioning is to avoid the phenomena of metallisation, violent electrical discharges or other possible destructive phenomena. This document summarizes an optimized method which has demonstrated its effectiveness and for which the fundamental principles are: • Regulate RF power as a function of vacuum pressure around the coupler as fast as possible. • Apply a longer repetition period than the vacuum reading delay. • Follow the bare principle: low energy for low risk, by delivering pulses to the not yet conditioned coupler, initially...

Montesinos, E

2013-01-01T23:59:59.000Z

282

Method of optimizing the efficiency of a steam turbine power plant  

SciTech Connect

A method is disclosed for improving the operational efficiency of a steam turbine power plant by governing the adjustment of the throttle steam pressure of a steam turbine at a desired power plant output demand value. In the preferred embodiment, the impulse chamber pressure of a high pressure section of the steam turbine is measured as a representation of the steam flow through the steam turbine. At times during the operation of the plant at the desired output demand value, the throttle pressure is perturbed. The impulse chamber pressure is measured before and after the perturbations of the throttle pressure. Because changing thermodynamic conditions may occur possibly as a result of the perturbations and provide an erroneous representation of the steam flow through the turbine, the impulse chamber pressure measurements are compensated for determined measurable thermodynamic conditions in the steam turbine. A compensated change in impulse chamber pressure measurement in a decreasing direction as a result of the direction of perturbation of the steam throttle pressure may indicate that further adjustment in the same direction is beneficial in minimizing the steam flow through the steam turbine at the desired plant output demand value. The throttle steam pressure adjustment may be continually perturbed in the same direction until the compensated change in impulse chamber pressure before and after measurements falls below a predetermined value, whereby the steam flow is considered substantially at a minimum for the desired plant output demand value.

Silvestri, G.J.

1981-11-03T23:59:59.000Z

283

The Effect of Power-Law Body Forces on a Thermally Driven Flow between Concentric Rotating Spheres  

Science Conference Proceedings (OSTI)

A numerical study is conducted to determine the effect of power-law body forces on a thermally driven axisymmetric flow field confined between concentric co-rotating spheres. This study is motivated by Spacelab geophysical fluid-flow experiments, ...

Michele G. Macaraeg

1986-02-01T23:59:59.000Z

284

Nonlinear power flow control applications to conventional generator swing equations subject to variable generation.  

Science Conference Proceedings (OSTI)

In this paper, the swing equations for renewable generators are formulated as a natural Hamiltonian system with externally applied non-conservative forces. A two-step process referred to as Hamiltonian Surface Shaping and Power Flow Control (HSSPFC) is used to analyze and design feedback controllers for the renewable generator system. This formulation extends previous results on the analytical verification of the Potential Energy Boundary Surface (PEBS) method to nonlinear control analysis and design and justifies the decomposition of the system into conservative and non-conservative systems to enable a two-step, serial analysis and design procedure. In particular, this approach extends the work done by developing a formulation which applies to a larger set of Hamiltonian Systems that has Nearly Hamiltonian Systems as a subset. The results of this research include the determination of the required performance of a proposed Flexible AC Transmission System (FACTS)/storage device to enable the maximum power output of a wind turbine while meeting the power system constraints on frequency and phase. The FACTS/storage device is required to operate as both a generator and load (energy storage) on the power system in this design. The Second Law of Thermodynamics is applied to the power flow equations to determine the stability boundaries (limit cycles) of the renewable generator system and enable design of feedback controllers that meet stability requirements while maximizing the power generation and flow to the load. Necessary and sufficient conditions for stability of renewable generators systems are determined based on the concepts of Hamiltonian systems, power flow, exergy (the maximum work that can be extracted from an energy flow) rate, and entropy rate.

Robinett, Rush D., III; Wilson, David Gerald

2010-05-01T23:59:59.000Z

285

Power Flow Management in a High Penetration Wind-Diesel Hybrid Power System with Short-Term Energy Storage  

Science Conference Proceedings (OSTI)

This paper is intended as an introduction to some of the control challenges faced by developers of high penetration wind-diesel systems, with a focus on the management of power flows in order to achieve precise regulation of frequency and voltage in the face of rapidly varying wind power input and load conditions. The control algorithms presented herein are being implemented in the National Renewable Energy Laboratory (NREL) high penetration wind-diesel system controller that will be installed in the village of Wales, Alaska, in early 2000.

Drouilhet, S. M.

1999-07-29T23:59:59.000Z

286

Optimal control of remote hybrid power systems. Part 1: Simplified model  

SciTech Connect

In this two-part study, time-series models are used to determine optimal dispatch strategies, in conjunction with optimally-sized components, in remote hybrid power systems. The objective of the dispatch optimization is to minimize the costs associated with diesel fuel, diesel starts, and battery erosion, based on a thorough economic analysis of present worth life-cycle cost. An ideal predictive control strategy is used as a basis of comparison. In Part 1 (reported here), a simplified time-series model is used to obtain preliminary conceptual results. These results illustrate the nature of the optimal dispatch strategy and indicate that a simple SOC setpoint strategy can be practically as effective as the ideal predictive control. In Part 2 (at a later date), a more detailed model will be used to obtain more accurate, quantitative results. The authors anticipate that these results will be correlated to dimensionless economic, design, and performance parameters, rendering them useful as design guidelines over a wide variety of load profiles, climates, equipment specifications, and economic variables.

Barley, C D [Colorado State Univ., Fort Collins, CO (United States). Mechanical Engineering Dept.; [National Renewable Energy Lab., Golden, CO (United States). Wind Technology Div.; Winn, C B [Colorado State Univ., Fort Collins, CO (United States); Flowers, L; Green, H J [National Renewable Energy Lab., Golden, CO (United States). Wind Technology Div.

1995-04-01T23:59:59.000Z

287

Diploma Thesis Optimal Operation of a Hydroelectric Power System Subject to Stochastic Inflows and Load  

E-Print Network (OSTI)

Optimal scheduling of hydro-thermal power plants is crucial for economical electricity production. In this diploma thesis, a stochastic programming approach is used to find optimal scheduling policies in terms of minimal production cost. Stochasticity from water inflows and energy load is included in the model. The problems are approximated by the Sample Average Approximation (SAA) method and solved using a nested decomposition procedure. The precision of the solution is assessed in terms of confidence bounds computed with help of the SAA samples. Acknowledgments I would like to thank my supervisor Kristian Nolde and Andreas Poncet from ABB Corporate Research for the challenging discussion about the modelling problem. I owe many thanks to Jonas Nart, who gave mindful criticism and pointed out many inconsistencies during the writing of this thesis. Of course, any deficiencies are completely

Markus Uhr; Supervisor Kristian Nolde; Prof Dr; M. Morari

2006-01-01T23:59:59.000Z

288

Optimization of non-condensable gas removal system in geothermal power plant  

SciTech Connect

Optimization of non-condensable gas (hereinafter called N.C.G.) removal system in geothermal power station, in a special case that the geothermal steam contains large amount of noncondensable gas, is discussed. Four different alternative N.C.G. removal systems are studied, which are steam jet gas ejectors, centrifugal gas compressors, combined systems of steam ejectors and centrifugal compressors and back pressure turbine-without N.C.G. removal system. This report summarizes the results and gives recommendations as to the most suitable gas removal system and also as to optimum condenser pressure, in cases of large quantity N.C.G. content in geothermal steam.

Tajima, S.; Nomura, M.

1982-10-01T23:59:59.000Z

289

Flow of power-law fluids in self-affine fracture channels  

E-Print Network (OSTI)

The two-dimensional pressure driven flow of non-Newtonian power-law fluids in self-affine fracture channels at finite Reynolds number is calculated. The channels have constant mean aperture and two values $\\zeta$=0.5 and 0.8 of the Hurst exponent are considered. The calculation is based on the lattice-Boltzmann method, using a novel method to obtain a power-law variation in viscosity, and the behavior of shear-thinning, Newtonian and shear-thickening liquids is compared. Local aspects of the flow fields, such as maximum velocity and pressure fluctuations, were studied, and the non-Newtonian fluids were compared to the (previously-studied) Newtonian case. The permeability results may be collapsed into a master curve of friction factor vs. Reynolds number using a scaling similar to that employed for porous media flow, and exhibits a transition from a linear regime to a more rapid variation at Re increases.

Yiguang Yan; Joel Koplik

2007-11-29T23:59:59.000Z

290

Big Bend Power Station Neural Network-Intelligent Sootblower (NN-ISB) Optimization  

NLE Websites -- All DOE Office Websites (Extended Search)

Big Bend Power Station neural network- Big Bend Power Station neural network- intelligent SootBlower (nn-iSB) oPtimization (comPleted) Project Description The overall goal of this project was to develop a Neural Network-Intelligent Sootblowing (NN-ISB) system on the 445 MW Tampa Electric Big Bend Unit #2 to initiate sootblowing in response to real-time events or conditions within the boiler rather than relying on general rule-based protocols. Other goals were to increase unit efficiency, reduce NO X , and improve stack opacity. In a coal-fired boiler, the buildup of ash and soot on the boiler tubes can lead to a reduction in boiler efficiency. Thus, one of the most important boiler auxiliary operations is the cleaning of heat-absorbing surfaces. Ash and soot deposits are removed by a process known as sootblowing, which uses mechanical devices for on-line cleaning

291

Automation uses common data base. [Power Resource Optimization by Electronics (PROBE)  

SciTech Connect

Supervisory-control and data-acquisition (SCADA) systems are not new to electric utilities, but the extension of this technology into substation and distribution-feeder automation has been slow. General Electric Co. and Commonwealth Edison Co. have installed a substation/distribution-automation research system at the latter's LaGrange Park substation to demonstrate feasibility and gain field experience. Niagara Mohawk Power Corp has recently joined in evaluating the functional specifications, in planning and in evaluating field tests, and is sharing in the funding. The project has been named PROBE (power resource optimization by electronics), and its key concept is use of a common data base for substation and distribution information. The project will include three phases of which the initial trial evaluation at LaGrange Park is identified as PROBE-1.

1976-09-01T23:59:59.000Z

292

Optimal control system design for IGCC power plants with CO2 capture  

Science Conference Proceedings (OSTI)

Designing an optimal control system for an integrated gasification combined cycle (IGCC) power plant with CO2 capture addresses the challenge of efficiently operating and controlling a coal-fed IGCC plant with the desired extent of CO2 capture in the face of disturbances without violating operational and environmental constraints. The control system design needs to optimize a desired scalar objective function while satisfying all the operational and environmental constraints in the presence of measured and unmeasured disturbances. Various objective functions can be considered for the control system design such as maximization of profit, maximization of the power produced, or minimization of the auxiliary power. The design of such a control system makes the plant suitable to play an active role in the smart grid era as the plant will have the required agility. In addition, other penalty function(s) such as emission penalties for CO2 or other criteria pollutants can be considered in the framework as well as losses associated with any hydrogen or carbon monoxide loses. The proposed control system design is performed in two stages. In the first stage, a top-down analysis is performed to generate a list of controlled, manipulated, and disturbance variables considering a scalar operational objective and other process constraints. In the second stage, a bottom-up approach for simultaneous design of the control structure and the controllers is used. In this paper, the first stage of the two-stage approach is applied to the IGCC’s acid gas removal (AGR) process which removes both H2S and CO2 from the shifted synthesis gas. While these results are still preliminary, they demonstrate the application of the proposed approach for a commercial-scale plant and show some interesting results related to controlled variable selection. Such an approach can be followed not only to design control systems for new power plants, but also to retrofit control systems for existing plants with suitable modifications.

Jones, D.; Bhattacharyya, D.; Turton, R.; Zitney, S.

2012-01-01T23:59:59.000Z

293

Application of the Moment–SOS Approach to Global Optimization of ...  

E-Print Network (OSTI)

Nov 18, 2013 ... Finding a global solution to the optimal power flow (OPF) problem is difficult .... ?lm ? C denotes the ratio of the ideal phase-shifting transformer.

294

Power-law scaling of asymmetries in viscous flow with PT-symmetric inflow and outflow  

E-Print Network (OSTI)

In recent years, open systems with balanced loss and gain, that are invariant under the combined parity and time-reversal (PT) operations, have been studied via asymmetries of their solutions. They represent systems as diverse as coupled optical waveguides, silicon photonic circuits, and electrical or mechanical oscillators. We numerically investigate the asymmetries of incompressible viscous flow in two and three dimensions with "balanced" inflow-outflow (PT-symmetric) configurations. By introducing configuration-dependent classes of asymmetry functions in velocity, kinetic energy density, and vorticity fields, we find that the flow asymmetries exhibit power-law scaling in the laminar regime with the Reynolds number ranging over four decades. At small Reynolds numbers, the flow asymmetries in the balanced configurations are orders of magnitude smaller than those that occur in traditional configurations. Our results imply that PT-symmetric inflow-outflow configurations provide a hitherto unexplored avenue to tune flow properties.

Huidan; Yu; Xi Chen; Yousheng Xu; Yogesh N. Joglekar

2013-04-19T23:59:59.000Z

295

Power-aware multi-core simulation for early design stage hardware/software co-optimization  

Science Conference Proceedings (OSTI)

Stringent performance targets and power constraints push designers towards building specialized workload-optimized systems across a broad spectrum of the computing arena, including supercomputing applications as exemplified by the IBM BlueGene and Intel ... Keywords: design space exploration, hardware/software co-design, multi-core processor, performance modeling, power modeling

Wim Heirman; Souradip Sarkar; Trevor E. Carlson; Ibrahim Hur; Lieven Eeckhout

2012-09-01T23:59:59.000Z

296

IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 27, NO. 3, AUGUST 2012 1521 Optimal Placement of Phasor Measurement  

E-Print Network (OSTI)

their deployment on every bus, which in turn motivates their strategic placement across the power grid. As state estimation is at the core of grid monitoring, PMU deployment is optimized here based on estimation concentrators. Merits of PMUs (a.k.a. synchrophasors) over conventional power meters in- clude increased

Giannakis, Georgios

297

Design of a Power Oscillation Damper for DFIG-based Wind Energy Conversion System Using Modified Particle Swarm Optimizer  

Science Conference Proceedings (OSTI)

This paper presents a method to design a Power Oscillation Damper (POD) for Double-Fed Induction Generator (DFIG) based Wind Energy Conversion System (WECS), operating with voltage control loop. Based on eigen values information from Small Signal Stability ... Keywords: Computational Intelligence, double fed induction generator, power oscillation damper, modified particle swarm optimizer, small signal stability analysis, wind energy conversion system

Huazhang Huang; C. Y. Chung

2012-05-01T23:59:59.000Z

298

Optimization of renewable power system for small scale seawater reverse osmosis desalination unit in Mrair-Gabis village, Libya  

Science Conference Proceedings (OSTI)

Potential of renewable power system for small scale seawater reverse osmosis desalination unit in Mrair-Gabis village, Libya is evaluated. HOMER optimization model is used to evaluate the different possible configuration options for supplying the electrical ... Keywords: HOMER, Mrair-Gabis-Libya, power system, reverse osmosis seawater desalination

Kh. Abulqasem; M. A. Alghoul; M. N. Mohammed; Alshrif. Mustafa; Kh. Glaisa; Nowshad. Amin; A. Zaharim; K. Sopian

2011-07-01T23:59:59.000Z

299

Optimization Online - All Areas Submissions - September 2013  

E-Print Network (OSTI)

A Short Proof that the Extension Complexity of the Correlation Polytope Grows Exponentially Volker Kaibel ... Rounding on the standard simplex: regular grids for global optimization ... Convex Quadratic Relaxations of Power Flows Hassan  ...

300

Network flow model for multi-energy systems  

Science Conference Proceedings (OSTI)

This paper describes a novel approach to model networks with multiple energy carrier. The proposed nodal matrix establishes a link between an optimization of enclosed areas and their interconnections via networks. In the envisioned network flow model ... Keywords: energy conversion, energy hubs, grids, line losses, network flow, optimal power flow

Matthias Schulze; Goran Gašparovi?

2010-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "optimal power flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Estimation of steady-state unbalanced system conditions combining conventional power flow and fault analysis software  

Science Conference Proceedings (OSTI)

In real three-phase power systems the voltages and currents are not fully symmetrical. A method has been developed to estimate the effects of slight unbalanced network conditions for steady-state operation. A conventional power flow is followed by a linear incremental calculation using a three-phase model of the network. The unbalanced condition is handled like a multiple unbalanced fault. The process is illustrated for the case of a transformer bank with non-identical single phase units. The results show the effects of different transformer reactances and different voltage ratios, respectively.

Reichelt, D.; Ecknauer, E. [Nordostschweizerische Kraftwerke AG, Baden (Switzerland); Glavitsch, H. [Swiss Federal Inst. of Tech., Zurich (Switzerland)

1996-02-01T23:59:59.000Z

302

Distributed control of reactive power flow in a radial distribution circuit with high photovoltaic penetration  

SciTech Connect

We show how distributed control of reactive power can serve to regulate voltage and minimize resistive losses in a distribution circuit that includes a significant level of photovoltaic (PV) generation. To demonstrate the technique, we consider a radial distribution circuit with a single branch consisting of sequentially-arranged residential-scale loads that consume both real and reactive power. In parallel, some loads also have PV generation capability. We postulate that the inverters associated with each PV system are also capable of limited reactive power generation or consumption, and we seek to find the optimal dispatch of each inverter's reactive power to both maintain the voltage within an acceptable range and minimize the resistive losses over the entire circuit. We assume the complex impedance of the distribution circuit links and the instantaneous load and PV generation at each load are known. We compare the results of the optimal dispatch with a suboptimal local scheme that does not require any communication. On our model distribution circuit, we illustrate the feasibility of high levels of PV penetration and a significant (20% or higher) reduction in losses.

Chertkov, Michael [Los Alamos National Laboratory; Turitsyn, Konstantin [Los Alamos National Laboratory; Backhaus, Scott [Los Alamos National Laboratory; Sule, Petr [NEW MEXICO CONSORTIUM

2009-01-01T23:59:59.000Z

303

Distributed control of reactive power flow in a radial distribution circuit with high photovoltaic penetration  

SciTech Connect

We show how distributed control of reactive power can serve to regulate voltage and minimize resistive losses in a distribution circuit that includes a significant level of photovoltaic (PV) generation. To demonstrate the technique, we consider a radial distribution circuit with a single branch consisting of sequentially-arranged residential-scale loads that consume both real and reactive power. In parallel, some loads also have PV generation capability. We postulate that the inverters associated with each PV system are also capable of limited reactive power generation or consumption, and we seek to find the optimal dispatch of each inverter's reactive power to both maintain the voltage within an acceptable range and minimize the resistive losses over the entire circuit. We assume the complex impedance of the distribution circuit links and the instantaneous load and PV generation at each load are known. We compare the results of the optimal dispatch with a suboptimal local scheme that does not require any communication. On our model distribution circuit, we illustrate the feasibility of high levels of PV penetration and a significant (20% or higher) reduction in losses.

Chertkov, Michael [Los Alamos National Laboratory; Turitsyn, Konstantin [Los Alamos National Laboratory; Backhaus, Scott [Los Alamos National Laboratory; Sule, Petr [NEW MEXICO CONSORTIUM

2009-01-01T23:59:59.000Z

304

Integrated models of distribution transformers and their loads for three-phase power flow analyses  

Science Conference Proceedings (OSTI)

This paper introduces integrated models of distribution transformers and their loads for three-phase power flow analyses. All transformer connections can be easily included, such as single-phase, open wye, open delta and three-phase. For an existing three-phase power flow program without rigorous transformer models, only a slight modification of this program is needed to analyze distribution systems in more detail by using these proposed models. For those with rigorous transformer models, the rigorous transformer models usually make the program converge with difficulty, or even diverge. The convergence characteristics of these program can be dramatically improved if proposed integrated models are used instead of the rigorous transformer models. Moreover, these models can be easily applied by some functions of advanced distribution management systems or automatic mapping and facility management systems, such as transformer load management and feeder load management, to evaluate the individual phase loads along a feeder.

Chen, T.H.; Chang, Y.L. [National Taiwan Inst. of Tech., Taipei (Taiwan, Province of China). Dept. of Electrical Engineering

1996-01-01T23:59:59.000Z

305

Flow simulation of the Component Development Integration Facility magnetohydrodynamic power train system  

DOE Green Energy (OSTI)

This report covers application of Argonne National Laboratory`s (ANL`s) computer codes to simulation and analysis of components of the magnetohydrodynamic (MHD) power train system at the Component Development and Integration Facility (CDIF). Major components of the system include a 50-MWt coal-fired, two-stage combustor and an MHD channel. The combustor, designed and built by TRW, includes a deswirl section between the first and the second-stage combustor and a converging nozzle following the second-stage combustor, which connects to the MHD channel. ANL used computer codes to simulate and analyze flow characteristics in various components of the MHD system. The first-stage swirl combustor was deemed a mature technology and, therefore, was not included in the computer simulation. Several versions of the ICOMFLO computer code were used for the deswirl section and second-stage combustor. The MGMHD code, upgraded with a slag current leakage submodel, was used for the MHD channel. Whenever possible data from the test facilities were used to aid in calibrating parameters in the computer code, to validate the computer code, or to set base-case operating conditions for computations with the computer code. Extensive sensitivity and parametric studies were done on cold-flow mixing in the second-stage combustor, reacting flow in the second-stage combustor and converging nozzle, and particle-laden flow in the deswirl zone of the first-stage combustor, the second-stage combustor, and the converging nozzle. These simulations with subsequent analysis were able to show clearly in flow patterns and various computable measures of performance a number of sensitive and problematical areas in the design of the power train. The simulations of upstream components also provided inlet parameter profiles for simulation of the MHD power generating channel. 86 figs., 18 tabs.

Chang, S.L.; Lottes, S.A.; Bouillard, J.X.; Petrick, M.

1997-11-01T23:59:59.000Z

306

Conformal Thermal Models for Optimal Loading and Elapsed Life Estimation of Power Transformers.  

E-Print Network (OSTI)

??Power and Generator Transformers are important and expensive elements of a power system. Inadvertent failure of Power Transformers would cause long interruption in power supply… (more)

Pradhan, Manoj Kumar

2004-01-01T23:59:59.000Z

307

Power Optimization of Wireless Media Systems With Space-Time Block Codes  

E-Print Network (OSTI)

to higher power consumption of mobile devices. Added to thisdevices, the power consumption of such devices is requiredhigher consumption of power in mobile devices. Power

Yousefi'zadeh, Homayoun; Jafarkhani, Hamid; Moshfeghi, Mehran

2004-01-01T23:59:59.000Z

308

Power optimization of wireless media systems with space-time block codes  

E-Print Network (OSTI)

to higher power consumption of mobile devices. Added to thisdevices, the power consumption of such devices is requiredhigher consumption of power in mobile devices. Power

Yousefi'zadeh, H; Jafarkhani, H; Moshfeghi, M

2004-01-01T23:59:59.000Z

309

Optimizing urban traffic flow using Genetic Algorithm with Petri net analysis as fitness function  

Science Conference Proceedings (OSTI)

This paper describes a new methodology adopted for urban traffic stream optimization. By using Petri net analysis as fitness function of a Genetic Algorithm, an entire urban road network is controlled in real time. With the advent of new technologies ... Keywords: Genetic Algorithm, Optimization, Petri net, Urban traffic

Henrique Dezani, Regiane D. S. Bassi, Norian Marranghello, Luís Gomes, Furio Damiani, Ivan Nunes Da Silva

2014-01-01T23:59:59.000Z

310

Detailed analysis of an endoreversible fuel cell : Maximum power and optimal operating temperature determination  

E-Print Network (OSTI)

Producing useful electrical work in consuming chemical energy, the fuel cell have to reject heat to its surrounding. However, as it occurs for any other type of engine, this thermal energy cannot be exchanged in an isothermal way in finite time through finite areas. As it was already done for various types of systems, we study the fuel cell within the finite time thermodynamics framework and define an endoreversible fuel cell. Considering different types of heat transfer laws, we obtain an optimal value of the operating temperature, corresponding to a maximum produced power. This analysis is a first step of a thermodynamical approach of design of thermal management devices, taking into account performances of the whole system.

A. Vaudrey; P. Baucour; F. Lanzetta; R. Glises

2009-05-18T23:59:59.000Z

311

Detailed analysis of an endoreversible fuel cell : Maximum power and optimal operating temperature determination  

E-Print Network (OSTI)

Producing useful electrical work in consuming chemical energy, the fuel cell have to reject heat to its surrounding. However, as it occurs for any other type of engine, this thermal energy cannot be exchanged in an isothermal way in finite time through finite areas. As it was already done for various types of systems, we study the fuel cell within the finite time thermodynamics framework and define an endoreversible fuel cell. Considering different types of heat transfer laws, we obtain an optimal value of the operating temperature, corresponding to a maximum produced power. This analysis is a first step of a thermodynamical approach of design of thermal management devices, taking into account performances of the whole system.

Vaudrey, A; Lanzetta, F; Glises, R

2009-01-01T23:59:59.000Z

312

Real-Time Combined Heat and Power Operational Strategy Using a Hierarchical Optimization Algorithm  

Science Conference Proceedings (OSTI)

Existing attempts to optimize the operation of Combined Heat and Power (CHP) systems for building applications have two major limitations: the electrical and thermal loads are obtained from historical weather profiles; and the CHP system models ignore transient responses by using constant equipment efficiencies. This paper considers the transient response of a building combined with a hierarchical CHP optimal control algorithm to obtain a real-time integrated system that uses the most recent weather and electric load information. This is accomplished by running concurrent simulations of two transient building models. The first transient building model uses current as well as forecast input information to obtain short term predictions of the thermal and electric building loads. The predictions are then used by an optimization algorithm, i.e., a hierarchical controller, that decides the amount of fuel and of electrical energy to be allocated at the current time step. In a simulation, the actual physical building is not available and, hence, to simulate a real-time environment, a second, building model with similar but not identical input loads are used to represent the actual building. A state-variable feedback loop is completed at the beginning of each time step by copying, i.e., measuring, the state variable from the actual building and restarting the predictive model using these ?measured? values as initial conditions. The simulation environment presented in this paper features nonlinear effects such as the dependence of the heat exchanger effectiveness on their operating conditions. The results indicate that the CHP engine operation dictated by the proposed hierarchical controller with uncertain weather conditions have the potential to yield significant savings when compared to conventional systems using current values of electricity and fuel prices.

Yun, Kyung Tae; Cho, Heejin; Luck, Rogelio; Mago, Pedro J.

2011-06-01T23:59:59.000Z

313

Optimization of Electric Power Systems for Off-Grid Domestic Applications: An Argument for Wind/Photovoltaic Hybrids  

SciTech Connect

The purpose of this research was to determine the optimal configuration of home power systems relevant to different regions in the United States. The hypothesis was that, regardless of region, the optimal system would be a hybrid incorporating wind technology, versus a photovoltaic hybrid system without the use of wind technology. The method used in this research was HOMER, the Hybrid Optimization Model for Electric Renewables. HOMER is a computer program that optimizes electrical configurations under user-defined circumstances. According to HOMER, the optimal system for the four regions studied (Kansas, Massachusetts, Oregon, and Arizona) was a hybrid incorporating wind technology. The cost differences between these regions, however, were dependent upon regional renewable resources. Future studies will be necessary, as it is difficult to estimate meteorological impacts for other regions.

Jennings, W.; Green, J.

2001-01-01T23:59:59.000Z

314

Power source for an axial-flow CO/sub 2/laser tube  

SciTech Connect

A power device is described for an axial-flow-type CO/sub 2/ laser shell comprising: a high voltage DC power source directly connected to a cathode of the laser shell, in which a discharge for laser pumping takes place, for applying a constant high DC voltage to the cathode; and a high voltage pulse power source connected through a ballast resistance to an anode of the laser shell for applying a high pulse voltage to the anode, the high voltage pulse power source having a DC power circuit, a switching element having a first terminal to receive a command signal instructing switching operation, and second and third terminals connected or disconnected by the switching operation, the second terminal being connected to the DC power circuit and the third terminal being connected to the anode of the laser shell through ballast resistance, and a PWM controller having an output terminal connected to the first terminal of the switching element, for outputting a pulsed voltage with a predetermined repetition frequency and width, as the command signal.

Koseki, R.

1988-12-27T23:59:59.000Z

315

Optimal Scheduling of Industrial Combined Heat and Power Plants under Time-sensitive Electricity Prices  

E-Print Network (OSTI)

Combined heat and power (CHP) plants are widely used in industrial applications. In the aftermath of the recession, many of the associated production processes are under-utilized, which challenges the competitiveness of chemical companies. However, under-utilization can be a chance for tighter interaction with the power grid, which is in transition to the so-called smart grid, if the CHP plant can dynamically react to time-sensitive electricity prices. In this paper, we describe a generalized mode model on a component basis that addresses the operational optimization of industrial CHP plants. The mode formulation tracks the state of each plant component in a detailed manner and can account for different operating modes, e.g. fuel-switching for boilers and supplementary firing for gas turbines, and transitional behavior. Transitional behavior such as warm and cold start-ups, shutdowns and pre-computed start-up trajectories is modeled with modes as well. The feasible region of operation for each component is described based on input-output relationships that are thermodynamically sound, such as the Willans line for steam turbines. Furthermore, we emphasize the use of mathematically efficient logic constraints that allow solving the large-scale models fast. We provide an industrial case study and study the impact of different scenarios for under-utilization. 1

Sumit Mitra; Ignacioe. Grossmann

2012-01-01T23:59:59.000Z

316

Optimization and analysis of LiH thermal energy storage device configurations for space power applications  

DOE Green Energy (OSTI)

Thermal energy storage (TES) can be used to reduce the area and mass of the heat rejection system for space-based sprint power systems. During the sprint mode power cycle, reject heat is placed into storage. The heat is then rejected to the ultimate sink over the much longer non-operational portion of the orbits, through a correspondingly smaller radiator. Preliminary analysis has shown significant weight advantage for the heat storage plus radiator concept over the radiator only concept. Thermal performance analysis and optimization of five heat sink TES configurations using LiH was completed. The configurations are: (a) LiH encapsulated spheres in the packed bed, (b) standard tube and shell arrangement with LiH on the tube side, (c) tube and shell with LiH on the shell side, (d) alternating concentric rings of LiH and heat transport fluid, and (e) parallel slabs of LiH. System performance was calculated for a wide range of parameters and included effects of prespecified internal voids, enhanced conductivity and internal fins.

Siman-Tov, M.; Williams, P.; Olszewski, M.

1987-01-01T23:59:59.000Z

317

OPTIMAL OPERATION OF MULTI-TERMINAL VSC BASED MVDC SHIPBOARD POWER SYSTEM.  

E-Print Network (OSTI)

?? The Medium Voltage DC (MVDC) architecture of shipboard power system (SPS) with higher power density and enhanced power control is seen as a future… (more)

Yeleti, Sandeep

2011-01-01T23:59:59.000Z

318

Gate-turn-off thyristors provide new level of power-flow control  

SciTech Connect

The availability of high-power, gate-turn-off (GTO) thyristors has made possible the development of a new class of solid-state devices that promise an unprecedented degree of control over the flow of power in the nation`s network. The first of these, a static compensator known as Statcom, which offers dynamic control over the flow of VArs into, or out of, the network, was unveiled last month at the Tennessee Valley Authority`s (TVA) Sullivan substation in eastern Tennessee. The principal element of the Statcom is a voltage-sourced inverter that converts dc voltage at its input terminals into a 3-phase alternating output voltage. To eliminate the quasi square wave that a single inverter would generate - along with unacceptable harmonics - the Statcom uses many such inverters, appropriately phase-shifted, and combines their outputs through electromagnetic linkages to produce a nearly sinusoidal output waveform. By numerous voltage additions and subtractions, eight inverters used in the Statcom generate a 48-pulse, nearly sinusoidal output waveform. The GTO-based inverters and electronic feedback control give the Statcom a dynamic performance far exceeding that of other reactive power compensators. In fact, the device can transition from full rated capacitive to full-rated VArs in approximately one-quarter cycle. Nominal rating of each inverter is 12.5 MVA. 12 figs.

NONE

1995-12-01T23:59:59.000Z

319

Wind power application for low flow irrigation from the Edwards-Trinity aquifer of West Texas  

E-Print Network (OSTI)

Attempts were made to reduce the cost of energy for irrigation in West Texas. To do this two wind turbines of 10 kW size were installed in Garden City and Stiles, Texas to pump water. The turbines were installed on 30 m towers. The pumping water head at Garden City and Stiles were 48 m and 80 m, respectively.A double Fourier series analysis of wind speed characteristics was done to better predict wind speed for the test areas and the use of a N=3 and M=7 harmonic term was suggested for this region. A relationship of flow pumped from a wind powered pumping system was developed to better predict flow rate based on available wind speed and pumping water depth data.The economic analysis of this system showed that if the local utility sold power at rate of $0.09kWh then a wind powered pumping system can be economically feasible if the cost of a 10 kW wind turbine was less than $5000 payable over 30 years at 5% interest rate. The current cost of such a system is $30,000, making it prohibitively expensive. However, such a system may become a more economical alternative as the cost of electricity increases and the cost of the turbines decrease.

Molla, Saiful Islam

1997-01-01T23:59:59.000Z

320

Z .Journal of Power Sources 76 1998 6980 Optimal fuel cell system design considering functional performance and  

E-Print Network (OSTI)

a semi-permeable Zmembrane, generating DC electricity, some heat at about .808C , and water of Victoria to develop the next generation fuel Z .cells for transportation NGFT , in collaborationZ .Journal of Power Sources 76 1998 69­80 Optimal fuel cell system design considering functional

Xue, Deyi

Note: This page contains sample records for the topic "optimal power flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


322

Using the NOABL flow model and mathematical optimization as a micrositing tool  

DOE Green Energy (OSTI)

This report describes the use of an improved mass-consistent model that is intended for diagnosing wind fields in complex terrain. The model was developed by merging an existing mass-consistent model, the NOABL model, with an optimization procedure. The optimization allows objective calculation of important model input parameters that previously had been supplied through guesswork; in this manner, the accuracy of the calculated winds has been greatly increased. The report covers such topics as the software structure of the model, assembling an input file, processing the model's output, and certain cautions about the model's operation. The use of the model is illustrated by a test case.

Wegley, H.L.; Barnard, J.C.

1986-11-01T23:59:59.000Z

323

Effects of blade configurations on flow distribution and power output of a Zephyr vertical axis wind turbine  

Science Conference Proceedings (OSTI)

Numerical simulations with FLUENT software were conducted to investigate the fluid flow through a novel vertical axis wind turbine (VAWT). Simulation of flow through the turbine rotor was performed with the aim of predicting the performance characteristics ... Keywords: blade configuration, power output, rotor, simulation, vertical axis wind turbine

J. O. Ajedegba; G. F. Naterer; M. A. Rosen; E. Tsang

2008-02-01T23:59:59.000Z

324

Piezoelectric Artificial Kelp: Experimentally Validated Parameter Optimization of a Quasi-Static, Flow-Driven Energy Harvester  

E-Print Network (OSTI)

Piezoelectric energy harvesting is the process of taking an external mechanical input and converting it directly into electrical energy via the piezoelectric effect. To determine the power created by a piezoelectric energy harvester, a specific application with defined input and design constraints must first be chosen. The following thesis established a concept design of a hydrokinetic energy harvesting system, the piezoelectric artificial kelp (PAK), which uses piezoelectric materials to harvest coastal ocean waves while having a beneficial impact on the surrounding environment. The harvester design mimics the configuration of sea-kelp, a naturally occurring plant that anchors to the ocean floor and extends into the water column. Underwater currents caused by wave-action result in periodic oscillations in the kelp. In order to determine the average power generated by this design concept, predictive tools were devised that allowed for the determination of the optimized average power produced by the piezoelectric energy harvester. For a stiff energy harvester, the linear differential equations were analytically solved to find an equation for the average power generated as a function of design parameters. These equations were used to compare the effect on power output of the design configuration and piezoelectric material choice between a piezopolymer (PVDF) and a piezoceramic (PZT). The homogeneous bimorph was found to have the optimal design configuration and it was shown that a harvester constructed using PVDF would produce approximately 1.6 times as much power as one using PZT. For a flexible energy harvester, an iterative nonlinear solution technique using an assumed polynomial solution for the local curvature of the energy harvester was used to verify and extend the analytic solutions to large deflections. An energy harvester was built using off-the-shelf piezoelectric elements and tested in a wave tank facility to validate experimentally the voltage and average power predicted by the analytical solution. The iterative code showed the PAK harvester to produce volumetric power on the order of other energy harvesting concepts (17.8 micro [mu]W/cm³). Also, a full-scale PAK harvester approximately ten meters long in typical wave conditions was found to produce approximately one watt of power.

Pankonien, Alexander Morgan

2011-08-01T23:59:59.000Z

325

Possible connection between the optimal path and flow in percolation clusters Eduardo Lpez,1  

E-Print Network (OSTI)

path. We calculate the probability distribution P opt r,L of the optimal path length opt, and find the tracer path length tr of tracers inside percolation through their probability distribution P tr r,L . We in porous media related to second- ary oil extraction, in which an invading fluid water, steam, etc

Stanley, H. Eugene

326

Hydrogen turbines for space power systems: A simplified axial flow gas turbine model  

SciTech Connect

This paper descirbes a relatively simple axial flow gas expansion turbine mass model, which we developed for use in our space power system studies. The model uses basic engineering principles and realistic physical properties, including gas conditions, power level, and material stresses, to provide reasonable and consistent estimates of turbine mass and size. Turbine design modifications caused by boundary layer interactions, stress concentrations, stage leakage, or bending and thermal stresses are not accounted for. The program runs on an IBM PC, uses little computer time and has been incorporated into our system-level space power platform analysis computer codes. Parametric design studies of hydrogen turbines using this model are presented for both nickel superalloy and carbon/carbon composite turbines. The effects of speed, pressure ratio, and power level on hydrogen turbine mass are shown and compared to a baseline case 100-MWe, 10,000-rpm hydrogen turbine. Comparison with more detailed hydrogen turbine designs indicates that our simplified model provides mass estimates that are within 25% of the ones provided by more complex calculations. 8 figs.

Hudson, S.L.

1988-01-01T23:59:59.000Z

327

EV Charging Through Wireless Power Transfer: Analysis of Efficiency Optimization and Technology Trends  

Science Conference Proceedings (OSTI)

This paper is aimed at reviewing the technology trends for wireless power transfer (WPT) for electric vehicles (EV). It also analyzes the factors affecting its efficiency and describes the techniques currently used for its optimization. The review of the technology trends encompasses both stationary and moving vehicle charging systems. The study of the stationary vehicle charging technology is based on current implementations and on-going developments at WiTricity and Oak Ridge National Lab (ORNL). The moving vehicle charging technology is primarily described through the results achieved by the Korean Advanced Institute of Technology (KAIST) along with on-going efforts at Stanford University. The factors affecting the efficiency are determined through the analysis of the equivalent circuit of magnetic resonant coupling. The air gap between both transmitting and receiving coils along with the magnetic field distribution and the relative impedance mismatch between the related circuits are the primary factors affecting the WPT efficiency. Currently the industry is looking at an air gap of 25 cm or below. To control the magnetic field distribution, Kaist has recently developed the Shaped Magnetic Field In Resonance (SMFIR) technology that uses conveniently shaped ferrite material to provide low reluctance path. The efficiency can be further increased by means of impedance matching. As a result, Delphi's implementation of the WiTricity's technology exhibits a WPT efficiency above 90% for stationary charging while KAIST has demonstrated a maximum efficiency of 83% for moving vehicle with its On Line Vehicle (OLEV) project. This study is restricted to near-field applications (short and mid-range) and does not address long-range technology such as microwave power transfer that has low efficiency as it is based on radiating electromagnetic waves. This paper exemplifies Delphi's work in powertrain electrification as part of its innovation for the real world program geared toward a safer, greener and more connected driving. Moreover, it draws from and adds to Dr. Andrew Brown Jr.'s SAE books 'Active Safety and the Mobility Industry', 'Connectivity and Mobility Industry', and 'Green Technologies and the Mobility Industry'. Magnetic resonant coupling is the foundation of modern wireless power transfer. Its efficiency can be controlled through impedance matching and magnetic field shaping. Current implementations use one or both of these control methods and enable both stationary and mobile charging with typical efficiency within the 80% and 90% range for an air gap up to 25 cm.

Miller, John M [ORNL; Rakouth, Heri [Delphi Automotive Systems, USA; Suh, In-Soo [Korea Advanced Institute of Science and Technology

2012-01-01T23:59:59.000Z

328

Optimized Flow Sheet for a Reference Commercial-Scale Nuclear-Driven High-Temperature Electrolysis Hydrogen Production Plant  

DOE Green Energy (OSTI)

This report presents results from the development and optimization of a reference commercialscale high-temperature electrolysis (HTE) plant for hydrogen production. The reference plant design is driven by a high-temperature helium-cooled reactor coupled to a direct Brayton power cycle. The reference design reactor power is 600 MWt, with a primary system pressure of 7.0 MPa, and reactor inlet and outlet fluid temperatures of 540° C and 900°C, respectively. The electrolysis unit used to produce hydrogen consists of 4.176 × 10 6 cells with a per-cell active area of 225 cm2. A nominal cell area-specific resistance, ASR, value of 0.4 Ohm•cm2 with a current density of 0.25 A/cm2 was used, and isothermal boundary conditions were assumed. The optimized design for the reference hydrogen production plant operates at a system pressure of 5.0 MPa, and utilizes an air-sweep system to remove the excess oxygen that is evolved on the anode side of the electrolyzer. The inlet air for the air-sweep system is compressed to the system operating pressure of 5.0 MPa in a four-stage compressor with intercooling. The overall system thermal-to-hydrogen production efficiency (based on the low heating value of the produced hydrogen) is 49.07% at a hydrogen production rate of 2.45 kg/s with the high-temperature helium-cooled reactor concept. The information presented in this report is intended to establish an optimized design for the reference nuclear-driven HTE hydrogen production plant so that parameters can be compared with other hydrogen production methods and power cycles to evaluate relative performance characteristics and plant economics.

M. G. McKellar; J. E. O'Brien; E. A. Harvego; J. S. Herring

2007-11-01T23:59:59.000Z

329

Optimal consumption and investment with bounded downside risk for power utility functions  

E-Print Network (OSTI)

We investigate optimal consumption and investment problems for a Black-Scholes market under uniform restrictions on Value-at-Risk and Expected Shortfall. We formulate various utility maximization problems, which can be solved explicitly. We compare the optimal solutions in form of optimal value, optimal control and optimal wealth to analogous problems under additional uniform risk bounds. Our proofs are partly based on solutions to Hamilton-Jacobi-Bellman equations, and we prove a corresponding verification theorem. This work was supported by the European Science Foundation through the AMaMeF programme.

Kluppelberg, Claudia

2010-01-01T23:59:59.000Z

330

A Research on Instability of Small Flow in SCADA and an Optimizing Design for Control  

Science Conference Proceedings (OSTI)

SCADA is a set of systems with a higher automatic level of the long-distance pipeline. When the sub-transmission stations in the state of full load, the automatic control of sub-output capacity is quite stable working at certain settings. However, partly ... Keywords: PID control, SCADA system, small flow, sub-output control

Youqiang Guo; Zijun Zhang; Xuezhu Pei

2009-07-01T23:59:59.000Z

331

Unrestored Flow Optimization in Survivable Networks Based on p-Cycles  

Science Conference Proceedings (OSTI)

This paper deals with Unrestorable Flow Optimisation (UFO) problem in networks protected by p-cycles. This novel protection technique is used as the efficient tool for ensuring survivability of computer networks. In this paper there have been formulated ... Keywords: UFO problem, computer network, optimisation, p-cycles, survivability

Adam Smutnicki

2009-05-01T23:59:59.000Z

332

Optimal wind turbines placement within a distribution market environment  

Science Conference Proceedings (OSTI)

This paper proposes a hybrid optimization method for optimal allocation of wind turbines (WTs) that combines genetic algorithm (GA) and market-based optimal power flow (OPF). The method jointly maximizes net present value (NPV) related to WTs investment ... Keywords: Genetic algorithm, Net present value, Social welfare maximization, Wind turbines

Geev Mokryani, Pierluigi Siano

2013-10-01T23:59:59.000Z

333

Optimal power flow application issues in the Pool paradigm George Grossa,*, Ettore Bompardb  

E-Print Network (OSTI)

and Energy Systems Area, 339 Everitt Laboratory, 1406 W. Green Street, Urbana, IL 61801-2991, USA b disputes among the players and the central decision-making authority. Directions for future research of a generator. In light of the important economic signals emanating from the OPF results, the application

Gross, George

334

Power-Delay Optimizations in Gate Sizing 1 Sachin S. Sapatnekar  

E-Print Network (OSTI)

-circuit power. Since real-life waveforms have nonzero transition times, the short-circuit power could have-circuit power during the output falling transition. Therefore, as wn or wp increase, the short-circuit power on the short circuit power as compared to wp is larger than for the output falling transition. This is also

Sapatnekar, Sachin

335

Optimization Online - Global Optimization Submissions - 2011  

E-Print Network (OSTI)

Optimization and homotopy methods for the Gibbs free energy of magmatic mixtures ... On DC. optimization algorithms for solving minmax flow problems

336

Previous work conducted in the laboratory demonstrated optimal control of refrigerant flow and airflow for a breadboard CVSHP (Miller 1987a). This previous work was continued in the present study by investigation  

E-Print Network (OSTI)

#12;Previous work conducted in the laboratory demonstrated optimal control of refrigerant flow optimal refrigerant flow and airflow control settings. Previous studies by Tanaka and Yamanaka (1982 pump were replaced with fine metering hand valves having variable flow area for both heating

Oak Ridge National Laboratory

337

Optimal selection of on-site generation with combined heat and power applications  

E-Print Network (OSTI)

the burning of natural gas for on-site power generation andnatural gas absorption chiller GenL i , m , t , h , u Generated power by distributed generation

Siddiqui, Afzal S.; Marnay, Chris; Bailey, Owen; Hamachi LaCommare, Kristina

2004-01-01T23:59:59.000Z

338

An Integrated Framework for Gas Turbine Based Power Plant Operational Modeling and Optimization .  

E-Print Network (OSTI)

??The deregulation of the electric power market introduced a strong element of competition. Power plant operators strive to develop advanced operational strategies to maximize the… (more)

Zhao, Yongjun

2005-01-01T23:59:59.000Z

339

Modeling, Optimization and Power Efficiency Comparison of High-speed Inter-chip Electrical and Optical Interconnect Architectures in Nanometer CMOS Technologies  

E-Print Network (OSTI)

Inter-chip input-output (I/O) communication bandwidth demand, which rapidly scaled with integrated circuit scaling, has leveraged equalization techniques to operate reliably on band-limited channels at additional power and area complexity. High-bandwidth inter-chip optical interconnect architectures have the potential to address this increasing I/O bandwidth. Considering future tera-scale systems, power dissipation of the high-speed I/O link becomes a significant concern. This work presents a design flow for the power optimization and comparison of high-speed electrical and optical links at a given data rate and channel type in 90 nm and 45 nm CMOS technologies. The electrical I/O design framework combines statistical link analysis techniques, which are used to determine the link margins at a given bit-error rate (BER), with circuit power estimates based on normalized transistor parameters extracted with a constant current density methodology to predict the power-optimum equalization architecture, circuit style, and transmit swing at a given data rate and process node for three different channels. The transmitter output swing is scaled to operate the link at optimal power efficiency. Under consideration for optical links are a near-term architecture consisting of discrete vertical-cavity surface-emitting lasers (VCSEL) with p-i-n photodetectors (PD) and three long-term integrated photonic architectures that use waveguide metal-semiconductor-metal (MSM) photodetectors and either electro-absorption modulator (EAM), ring resonator modulator (RRM), or Mach-Zehnder modulator (MZM) sources. The normalized transistor parameters are applied to jointly optimize the transmitter and receiver circuitry to minimize total optical link power dissipation for a specified data rate and process technology at a given BER. Analysis results shows that low loss channel characteristics and minimal circuit complexity, together with scaling of transmitter output swing, allows electrical links to achieve excellent power efficiency at high data rates. While the high-loss channel is primarily limited by severe frequency dependent losses to 12 Gb/s, the critical timing path of the first tap of the decision feedback equalizer (DFE) limits the operation of low-loss channels above 20 Gb/s. Among the optical links, the VCSEL-based link is limited by its bandwidth and maximum power levels to a data rate of 24 Gb/s whereas EAM and RRM are both attractive integrated photonic technologies capable of scaling data rates past 30 Gb/s achieving excellent power efficiency in the 45 nm node and are primarily limited by coupling and device insertion losses. While MZM offers robust operation due to its wide optical bandwidth, significant improvements in power efficiency must be achieved to become applicable for high density applications.

Palaniappan, Arun

2010-12-01T23:59:59.000Z

340

Nonlinear power flow feedback control for improved stability and performance of airfoil sections  

DOE Patents (OSTI)

A computer-implemented method of determining the pitch stability of an airfoil system, comprising using a computer to numerically integrate a differential equation of motion that includes terms describing PID controller action. In one model, the differential equation characterizes the time-dependent response of the airfoil's pitch angle, .alpha.. The computer model calculates limit-cycles of the model, which represent the stability boundaries of the airfoil system. Once the stability boundary is known, feedback control can be implemented, by using, for example, a PID controller to control a feedback actuator. The method allows the PID controller gain constants, K.sub.I, K.sub.p, and K.sub.d, to be optimized. This permits operation closer to the stability boundaries, while preventing the physical apparatus from unintentionally crossing the stability boundaries. Operating closer to the stability boundaries permits greater power efficiencies to be extracted from the airfoil system.

Wilson, David G.; Robinett, III, Rush D.

2013-09-03T23:59:59.000Z

Note: This page contains sample records for the topic "optimal power flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

An Optimization-Based Algorithm for Scheduling Hydrothermal Power Systems with Cascaded Reservoirs and Discrete Hydro Constraints  

E-Print Network (OSTI)

An optimization-based algorithm is presented for the short-term scheduling of hydrothermal power systems using the Lagrangian relaxation technique. This paper concentrates on the solution methodology for hydro subproblems with cascaded reservoirs and discrete hydro constraints. Continuous reservoir dynamics and constraints, discontinuous operating regions, discrete operating states, and hydraulic coupling of cascaded reservoirs are considered in an integrated fashion. The key idea is to substitute out the reservoir dynamics and to relax the reservoir level constraints by using another set of multipliers, making a hydro subproblem unit-wise and stage-wise decomposable. The optimal generation level for each operating state at each hour can be obtained simply by minimizing a single variable function. Dynamic programming is then applied to optimize the operating states across the planning horizon with a small number of well-structured transitions. A modified subgradient algorithm is used...

Xiaohong Guan; Ernan Ni; Renhou Li; Peter B. Luh

1997-01-01T23:59:59.000Z

342

Topology optimization for fluid---thermal interaction problems under constant input power  

Science Conference Proceedings (OSTI)

This paper deals with density-based topology optimization considering fluid and thermal interactions, in which the Navier---Stokes and heat transport equations are coupled. We particularly focus on designing heat exchangers. In the engineering context, ... Keywords: Fluid---thermal interaction, Heat transfer, Topology optimization

Tadayoshi Matsumori; Tsuguo Kondoh; Atsushi Kawamoto; Tsuyoshi Nomura

2013-04-01T23:59:59.000Z

343

Bundle Methods in Stochastic Optimal Power Management: A Disaggregated Approach Using Preconditioners  

Science Conference Proceedings (OSTI)

A specialized variant of bundle methods suitable for large-scale problems with separable objective is presented. The method is applied to the resolution of a stochastic unit-commitment problem solved by Lagrangian relaxation. The model includes hydro- ... Keywords: Lagrangian relaxation, bundle methods, optimization, preconditioning, stochastic optimization, unit-commitment problems

Léonard Bacaud; Claude Lemaréchal; Arnaud Renaud; Claudia Sagastizábal

2001-12-01T23:59:59.000Z

344

Optimal control system design of an acid gas removal unit for an IGCC power plants with CO2 capture  

Science Conference Proceedings (OSTI)

Future IGCC plants with CO{sub 2} capture should be operated optimally in the face of disturbances without violating operational and environmental constraints. To achieve this goal, a systematic approach is taken in this work to design the control system of a selective, dual-stage Selexol-based acid gas removal (AGR) unit for a commercial-scale integrated gasification combined cycle (IGCC) power plant with pre-combustion CO{sub 2} capture. The control system design is performed in two stages with the objective of minimizing the auxiliary power while satisfying operational and environmental constraints in the presence of measured and unmeasured disturbances. In the first stage of the control system design, a top-down analysis is used to analyze degrees of freedom, define an operational objective, identify important disturbances and operational/environmental constraints, and select the control variables. With the degrees of freedom, the process is optimized with relation to the operational objective at nominal operation as well as under the disturbances identified. Operational and environmental constraints active at all operations are chosen as control variables. From the results of the optimization studies, self-optimizing control variables are identified for further examination. Several methods are explored in this work for the selection of these self-optimizing control variables. Modifications made to the existing methods will be discussed in this presentation. Due to the very large number of candidate sets available for control variables and due to the complexity of the underlying optimization problem, solution of this problem is computationally expensive. For reducing the computation time, parallel computing is performed using the Distributed Computing Server (DCS®) and the Parallel Computing® toolbox from Mathworks®. The second stage is a bottom-up design of the control layers used for the operation of the process. First, the regulatory control layer is designed followed by the supervisory control layer. Finally, an optimization layer is designed. In this paper, the proposed two-stage control system design approach is applied to the AGR unit for an IGCC power plant with CO{sub 2} capture. Aspen Plus Dynamics® is used to develop the dynamic AGR process model while MATLAB is used to perform the control system design and for implementation of model predictive control (MPC).

Jones, D.; Bhattacharyya, D.; Turton, R.; Zitney, S.

2012-01-01T23:59:59.000Z

345

Multi-index and self-approximate-optimal operation for a smart electrical power grid  

Science Conference Proceedings (OSTI)

An instrumented, intelligent electrical power grid, or smart grid, is under research and is being preliminarily constructed in many parts of the world to deal with new challenges to modern power systems brought on by pressures on environment and resources. ...

G. He; Y. Sun; Q. Lu; T. Li; H. Lv; W. Yin; J. Dong

2010-11-01T23:59:59.000Z

346

Stochastic Optimization Approach to Water Management in Cooling-Constrained Power Plants  

E-Print Network (OSTI)

constraints and weather conditions on generation capacity. In a pulverized coal power plant study we have source of freshwater withdrawals in the United States [10]. In base-load power plants (i.e., coal of evaporation. A 500 MW coal-fired power plant that employs once-through cooling can use more than 10 million

347

LQ Optimal Control of Wind Turbines in Hybrid Power Systems N.A. Cutululis1  

E-Print Network (OSTI)

Systems, Faculty of Electrical Engineering, "Dunrea de Jos" University of Galati, Abstract: Wind ­ diesel taken into account for the design of a wind ­ diesel power system is the wind power penetration, which electrical load. However, the penetration of wind power into small diesel-based grids is limited because

348

Power Optimization a Reality Check Stephen Dawson-Haggerty, Andrew Krioukov, David Culler  

E-Print Network (OSTI)

propor- tional to performance delivered, zero power is con- sumed when idle and the transition from idle vs. Sleep Idle states are power-saving modes that a device can enter quickly, without losing state" which it enters when halted. These idle states have varying exit latencies and power. However

O'Brien, James F.

349

Rigorous Kinetic Modeling, Optimization, and Operability Studies of a Modified Claus Unit for an Integrated Gasification Combined Cycle (IGCC) Power Plant with CO{sub 2} Capture  

Science Conference Proceedings (OSTI)

The modified Claus process is one of the most common technologies for sulfur recovery from acid gas streams. Important design criteria for the Claus unit, when part of an Integrated Gasification Combined Cycle (IGCC) power plant, are the ability to destroy ammonia completely and the ability to recover sulfur thoroughly from a relatively low purity acid gas stream without sacrificing flame stability. Because of these criteria, modifications to the conventional process are often required, resulting in a modified Claus process. For the studies discussed here, these modifications include the use of a 95% pure oxygen stream as the oxidant, a split flow configuration, and the preheating of the feeds with the intermediate pressure steam generated in the waste heat boiler (WHB). In the future, for IGCC plants with CO{sub 2} capture, the Claus unit must satisfy emission standards without sacrificing the plant efficiency in the face of typical disturbances of an IGCC plant, such as rapid change in the feed flow rates due to load-following and wide changes in the feed composition because of changes in the coal feed to the gasifier. The Claus unit should be adequately designed and efficiently operated to satisfy these objectives. Even though the Claus process has been commercialized for decades, most papers concerned with the modeling of the Claus process treat the key reactions as equilibrium reactions. Such models are validated by manipulating the temperature approach to equilibrium for a set of steady-state operating data, but they are of limited use for dynamic studies. One of the objectives of this study is to develop a model that can be used for dynamic studies. In a Claus process, especially in the furnace and the WHB, many reactions may take place. In this work, a set of linearly independent reactions has been identified, and kinetic models of the furnace flame and anoxic zones, WHB, and catalytic reactors have been developed. To facilitate the modeling of the Claus furnace, a four-stage method was devised so as to determine which set of linearly independent reactions would best describe the product distributions from available plant data. Various approaches are taken to derive the kinetic rate expressions, which are either missing in the open literature or found to be inconsistent. A set of plant data is used for optimal estimation of the kinetic parameters. The final model agrees well with the published plant data. Using the developed kinetics models of the Claus reaction furnace, WHB, and catalytic stages, two optimization studies are carried out. The first study shows that there exists an optimal steam pressure generated in the WHB that balances hydrogen yield, oxygen demand, and power generation. In the second study, it is shown that an optimal H{sub 2}S/SO{sub 2} ratio exists that balances single-pass conversion, hydrogen yield, oxygen demand, and power generation. In addition, an operability study has been carried out to examine the operating envelope in which both the H{sub 2}S/SO{sub 2} ratio and the adiabatic flame temperature can be controlled in the face of disturbances typical for the operation of an IGCC power plant with CO{sub 2} capture. Impact of CO{sub 2} capture on the Claus process has also been discussed.

Jones, Dustin; Bhattacharyya, Debangsu; Turton, Richard; Zitney, Stephen E

2011-12-15T23:59:59.000Z

350

Rigorous Kinetic Modeling and Optimization Study of a Modified Claus Unit for an Integrated Gasification Combined Cycle (IGCC) Power Plant with CO{sub 2} Capture  

SciTech Connect

The modified Claus process is one of the most common technologies for sulfur recovery from acid gas streams. Important design criteria for the Claus unit, when part of an Integrated Gasification Combined Cycle (IGCC) power plant, are the ability to destroy ammonia completely and the ability to recover sulfur thoroughly from a relatively low purity acid gas stream without sacrificing flame stability. Because of these criteria, modifications to the conventional process are often required, resulting in a modified Claus process. For the studies discussed here, these modifications include the use of a 95% pure oxygen stream as the oxidant, a split flow configuration, and the preheating of the feeds with the intermediate pressure steam generated in the waste heat boiler (WHB). In the future, for IGCC plants with CO{sub 2} capture, the Claus unit must satisfy emission standards without sacrificing the plant efficiency in the face of typical disturbances of an IGCC plant, such as rapid change in the feed flow rates due to load-following and wide changes in the feed composition because of changes in the coal feed to the gasifier. The Claus unit should be adequately designed and efficiently operated to satisfy these objectives. Even though the Claus process has been commercialized for decades, most papers concerned with the modeling of the Claus process treat the key reactions as equilibrium reactions. Such models are validated by manipulating the temperature approach to equilibrium for a set of steady-state operating data, but they are of limited use for dynamic studies. One of the objectives of this study is to develop a model that can be used for dynamic studies. In a Claus process, especially in the furnace and the WHB, many reactions may take place. In this work, a set of linearly independent reactions has been identified, and kinetic models of the furnace flame and anoxic zones, WHB, and catalytic reactors have been developed. To facilitate the modeling of the Claus furnace, a four-stage method was devised so as to determine which set of linearly independent reactions would best describe the product distributions from available plant data. Various approaches are taken to derive the kinetic rate expressions, which are either missing in the open literature or found to be inconsistent. A set of plant data is used for optimal estimation of the kinetic parameters. The final model agrees well with the published plant data. Using the developed kinetics models of the Claus reaction furnace, WHB, and catalytic stages, two optimization studies are carried out. The first study shows that there exists an optimal steam pressure generated in the WHB that balances hydrogen yield, oxygen demand, and power generation. In the second study, it is shown that an optimal H{sub 2}S/SO{sub 2} ratio exists that balances single-pass conversion, hydrogen yield, oxygen demand, and power generation. In addition, an operability study has been carried out to examine the operating envelope in which both the H{sub 2}S/SO{sub 2} ratio and the adiabatic flame temperature can be controlled in the face of disturbances typical for the operation of an IGCC power plant with CO{sub 2} capture. Impact of CO{sub 2} capture on the Claus process has also been discussed.

Jones, Dustin; Bhattacharyya, Debangsu; Turton, Richard; Zitney, Stephen E.

2012-02-08T23:59:59.000Z

351

Optimizing Patterns of Land Use to Reduce Peak Runoff Flow and Nonpoint Source Pollution with an Integrated Hydrological and Land-Use Model  

Science Conference Proceedings (OSTI)

The goal of this study is to develop and apply a methodology for delineating optimal land-use patterns that minimize peak runoff flow at watershed outlets by coupling a hydrological model and a land-use model. Under the assumption supported in ...

In-Young Yeo; Steven I. Gordon; Jean-Michel Guldmann

2004-05-01T23:59:59.000Z

352

Optimization Online - Stochastic Optimization Approach to Water ...  

E-Print Network (OSTI)

Mar 18, 2012 ... Optimization Online. Stochastic Optimization Approach to Water Management in Cooling-Constrained Power Plants. Juan M. Salazar(juan ...

353

Event-Triggered Optimal Power Dispatch M.D. Lemmon, University of Notre Dame  

E-Print Network (OSTI)

done using renewable generation sources such as photovoltaic cells or wind turbines. Power generation can also be accomplished through small microturbines and gas/diesel generators. Storage devices

Lemmon, Michael

354

Optimal Dispatch of Photovoltaic Inverters in Residential Distribution Systems  

E-Print Network (OSTI)

- fined limit. The premise for these active power curtailment (APC) strategies is that the resistance method for determining the active- and reactive-power set points for PV inverters in resi- dential. Index Terms--Distribution networks, inverter control, photo- voltaic systems, optimal power flow

Giannakis, Georgios

355

Optimal partitioned fault-tolerant bus layout for reducing power in nanometer designs  

Science Conference Proceedings (OSTI)

As technology scales down to nanometer dimensions, coupling capacitances between adjacent bus wires grow rapidly, and have a significant impact on power consumption and signal integrity of an integrated circuit. As buses are major components of a design, ... Keywords: coupling capacitance, fault-tolerant, low power, reliability

Shanq-Jang Ruan; Edwin Naroska; Chun-Chih Chen

2006-04-01T23:59:59.000Z

356

Stochastic Modeling and Optimization for Robust Power Management in a Partially Observable System  

E-Print Network (OSTI)

or hard disk. The power management hardware/software monitors the state transition in the system and issues state-transition commands to the SP. Similar to [2] and [3], we assume that the power managed generate service request at different rates. The state transition probability can be obtained by software

Qiu, Qinru

357

Adjoint sensitivity analysis for numerical weather prediction: applications to power grid optimization  

Science Conference Proceedings (OSTI)

We present an approach to estimate adjoint sensitivities of economic metrics of relevance in the power grid with respect to physical weather variables using numerical weather prediction models. We demonstrate that this capability can significantly enhance ... Keywords: adjoint sensitivity analysis, numerical weather prediction, power grid planning, sensor siting

Alexandru Cioaca; Victor Zavala; Emil Constantinescu

2011-11-01T23:59:59.000Z

358

Optimal Allocation of Reactive Power Source in Wind Farms Using Sensitivity Analysis and Tabu Algorithm  

Science Conference Proceedings (OSTI)

Considering wind farms real operation characteristics, a novel method using sensitivity analysis and Tabu algorithm for reactive power compensation allocations is proposed. In this paper, the sensitivity coefficient is defined as partial derivative of ... Keywords: Wind farm, Sensitivity analysis, Reactive power compensation, SVC, Tabu algorithm

Ping Zhang; XiangJun Zeng; Ling Li

2008-10-01T23:59:59.000Z

359

Improved taguchi method based contracted capacity optimization for power consumer with self-owned generating units  

Science Conference Proceedings (OSTI)

The paper proposes an improved Taguchi method to determine the best capacity contracts and dispatch the power output of the self-owned generating units from almost infinite combinations. To be achieved are savings of total power expenses of the consumers ... Keywords: capacity contracts, improved Taguchi method, self-owned generating units

Hong-Tzer Yang; Pai-Chun Peng; Chung-His Huang

2007-05-01T23:59:59.000Z

360

Leakage Power Optimization Techniques for Ultra Deep Sub-Micron Multi-Level Caches  

Science Conference Proceedings (OSTI)

On-chip L1 and L2 caches represent a sizeable fraction of the totalpower consumption of microprocessors. In deep sub-micron technology,the subthreshold leakage power is becoming the dominantfraction of the total power consumption of those caches. In ...

Nam Sung Kim; David Blaauw; Trevor Mudge

2003-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "optimal power flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Optimal Planning of Reactive Power Compensators for Oil Field Distribution Networks  

Science Conference Proceedings (OSTI)

The characteristic behavior of the loads of oil pumps is analyzed. An approach for low-voltage side reactive power compensators of oil field distribution networks is put forward. Based on the supplied loads of transformers, the index of maximum reduction ... Keywords: Genetic Algorithm, distribution network, oil field, reactive power compensation

Wu Xiaomeng; Yan Suli

2009-05-01T23:59:59.000Z

362

Bit and Power Allocation for Goodput Optimization in Coded Parallel Subchannels With ARQ  

Science Conference Proceedings (OSTI)

This paper addresses the problem of adaptively allocating the bits and the power among a set of parallel subchannels. A frame-oriented transmission with convolutional coding, hard Viterbi decoding, and automatic repeat request (ARQ) retransmission protocol ... Keywords: Bit allocation, MIMO, OFDM, bit allocation, goodput, multiple-input multiple-output (MIMO), orthogonal frequency-division multiplexing (OFDM), power allocation

B. Devillers; J. Louveaux; L. Vandendorpe

2008-08-01T23:59:59.000Z

363

Suction-recirculation device for stabilizing particle flows within a solar powered solid particle receiver  

SciTech Connect

A suction-recirculation device for stabilizing the flow of a curtain of blackened heat absorption particles falling inside of a solar receiver with an open aperture. The curtain of particles absorbs the concentrated heat from a solar mirror array reflected up to the receiver on a solar power tower. External winds entering the receiver at an oblique angle can destabilize the particle curtain and eject particles. A fan and ductwork is located behind the back wall of the receiver and sucks air out through an array of small holes in the back wall. Any entrained particles are separated out by a conventional cyclone device. Then, the air is recirculated back to the top of the receiver by injecting the recycled air through an array of small holes in the receiver's ceiling and upper aperture front wall. Since internal air is recirculated, heat losses are minimized and high receiver efficiency is maintained. Suction-recirculation velocities in the range of 1-5 m/s are sufficient to stabilize the particle curtain against external wind speeds in excess of 10 m/s.

Kolb, Gregory J. (Albuquerque, NM)

2012-02-07T23:59:59.000Z

364

Suction-recirculation device for stabilizing particle flows within a solar powered solid particle receiver  

DOE Patents (OSTI)

A suction-recirculation device for stabilizing the flow of a curtain of blackened heat absorption particles falling inside of a solar receiver with an open aperture. The curtain of particles absorbs the concentrated heat from a solar mirror array reflected up to the receiver on a solar power tower. External winds entering the receiver at an oblique angle can destabilize the particle curtain and eject particles. A fan and ductwork is located behind the back wall of the receiver and sucks air out through an array of small holes in the back wall. Any entrained particles are separated out by a conventional cyclone device. Then, the air is recirculated back to the top of the receiver by injecting the recycled air through an array of small holes in the receiver's ceiling and upper aperture front wall. Since internal air is recirculated, heat losses are minimized and high receiver efficiency is maintained. Suction-recirculation velocities in the range of 1-5 m/s are sufficient to stabilize the particle curtain against external wind speeds in excess of 10 m/s.

Kolb, Gregory J. (Albuquerque, NM)

2012-02-07T23:59:59.000Z

365

Original article: Power flow Petri Net modelling for building integrated multi-source power system with smart grid interaction  

Science Conference Proceedings (OSTI)

This paper presents an energy management modelling of a multi-source power system composed of photovoltaic (PV) array, storage and power grid connection, and taking into account messages from smart grid. The designed system can supply a tertiary building ... Keywords: Energy management, Petri Net modelling, Photovoltaic, Smart grid, Stateflow

B. C. Wang, M. Sechilariu, F. Locment

2013-05-01T23:59:59.000Z

366

Power plant degradation : a modular secondary plant and integral flow accelerated corrosion model  

E-Print Network (OSTI)

Flow Accelerated Corrosion (FAC) is the most prevalent material degradation mechanism for low carbon steel in steam-water flow systems. The band of uncertainty in predictions of wear rate due to FAC spans one to two orders ...

Van der Helm, Mark Johan, 1972-

2001-01-01T23:59:59.000Z

367

Influence of electrode stress on proton exchange membrane fuel cell performance : experimental characterization and power optimization  

E-Print Network (OSTI)

Compressive stress applied to the electrode area of a Proton Exchange Membrane (PEM) fuel cell is known to significantly affect power output. In practice, electrode stress arises during operation due to the clamping force ...

Gallant, Betar M. (Betar Maurkah)

2008-01-01T23:59:59.000Z

368

Power-Optimal Scheduling for a Green Base Station with Delay Constraints  

E-Print Network (OSTI)

renewable energy such as solar or wind energy as well as conventional sources like diesel generators by renewable energy sources, e.g. solar/wind energy and may also be connected to the power grid or diesel

Sharma, Vinod

369

Development of optimized core design and analysis methods for high power density BWRs  

E-Print Network (OSTI)

Increasing the economic competitiveness of nuclear energy is vital to its future. Improving the economics of BWRs is the main goal of this work, focusing on designing cores with higher power density, to reduce the BWR ...

Shirvan, Koroush

2013-01-01T23:59:59.000Z

370

Energy, Power Quality, and Customer Load Efficiency Optimization and Total Energy  

Science Conference Proceedings (OSTI)

Using this report's worksheets and procedures, utilities can evaluate a wide range of common end-user productivity and power quality concerns that lead to new customer services and sales initiatives.

2002-02-14T23:59:59.000Z

371

Design, analysis and optimization of the power conversion system for the Modular Pebble Bed Reactor System  

E-Print Network (OSTI)

The Modular Pebble Bed Reactor system (MPBR) requires a gas turbine cycle (Brayton cycle) as the power conversion system for it to achieve economic competitiveness as a GenIV nuclear system. The availability of controllable ...

Wang, Chunyun, 1968-

2003-01-01T23:59:59.000Z

372

Thermal desalination : structural optimization and integration in clean power and water  

E-Print Network (OSTI)

A large number of resources are dedicated to seawater desalination and will only grow as world-wide water scarcity increases. In arid areas with high temperature and salinity seawater, thermal desalination and power plants ...

Zak, Gina Marie

2012-01-01T23:59:59.000Z

373

Formal derivation of optimal active shielding for low-power on-chip buses  

Science Conference Proceedings (OSTI)

Passive shielding has been used to reduce capacitive coupling effects of adjacent bus lines by inserting passive ground or power lines (shields) between the bus lines. Active shielding is another shielding technique, in which the shield is allowed to ...

M. Ghonemia; Y. Ismail

2004-11-01T23:59:59.000Z

374

www.eprg.group.cam.ac.uk Optimal Wind Power Deployment in Europe – a Portfolio  

E-Print Network (OSTI)

Keywords Geographic diversification of wind farms can smooth out the fluctuations in wind power generation and reduce the associated system balancing and reliability costs. The paper uses historical wind production data from

Fabien Roques; Céline Hiroux; Marcelo Saguan; Fabien Roques; Céline Hiroux; Marcelo Saguan

2008-01-01T23:59:59.000Z

375

Optimization Online Digest -- February 2013  

E-Print Network (OSTI)

Extension of Completely Positive Cone Relaxation to Polynomial Optimization ... Optimal Power Grid Protection through A Defender-Attacker-Defender Model

376

Optimization Online Digest -- February 2011  

E-Print Network (OSTI)

... Optimization for Power System Configuration with Renewable Energy in Remote Areas ... Robust Energy Cost Optimization of Water Distribution System with ...

377

Modeling and optimization of a modified claus process as part of an integrted gasification combined cycle (IGCC) power plant with CO2 capture  

DOE Green Energy (OSTI)

The modified Claus process is one of the most common technologies for sulfur recovery from acid gas streams. Important design criteria for the Claus unit, when part of an Integrated Gasification Combined Cycle (IGCC) power plant, are the ability to destroy ammonia completely and recover sulfur thoroughly from a relatively low purity acid gas stream without sacrificing flame stability. Due to these criteria, modifications are often required to the conventional process, resulting in a modified Claus process. For the studies discussed here, these modifications include the use of a 95% pure oxygen stream as the oxidant, a split flow configuration, and the preheating of the feeds with the intermediate pressure steam generated in the waste heat boiler (WHB). In the future, for IGCC plants with CO2 capture, the Claus unit must satisfy emission standards without sacrificing the plant efficiency in the face of typical disturbances of an IGCC plant such as rapid change in the feed flowrates due to load-following and wide changes in the feed composition because of changes in the coal feed to the gasifier. The Claus unit should be adequately designed and efficiently operated to satisfy these objectives. Even though the Claus process has been commercialized for decades, most papers concerned with the modeling of the Claus process treat the key reactions as equilibrium reactions. Such models are validated by manipulating the temperature approach to equilibrium for a set of steady-state operating data, but are of limited use for dynamic studies. One of the objectives of this study is to develop a model that can be used for dynamic studies. In a Claus process, especially in the furnace and the WHB, many reactions may take place. In this work, a set of linearly independent reactions has been identified and kinetic models of the furnace flame and anoxic zones, WHB, and catalytic reactors have been developed. To facilitate the modeling of the Claus furnace, a four-stage method was devised so as to determine which set of linearly independent reactions would best describe the product distributions from available plant data. Various approaches are taken to derive the kinetic rate expressions which are either missing in the open literature or found to be inconsistent. A set of plant data is used for optimal estimation of the kinetic parameters. The final model agrees well with the published plant data. Using the developed kinetics models of the Claus reaction furnace, WHB, and catalytic stages, two optimization studies are carried out. The first study shows that there exists an optimal steam pressure generated in the WHB that balances hydrogen yield, oxygen demand, and power generation. In the second study, it is shown that an optimal H2S/SO2 ratio exists that balances single-pass conversion, hydrogen yield, oxygen demand, and power generation. In addition, an operability study has been carried out to examine the operating envelope in which both H2S/SO2 ratio and adiabatic flame temperature can be controlled in the face of disturbances typical for the operation of an IGCC power plant with CO2 capture. Impact of CO2 capture on the Claus process has also been discussed.

Jones, D.; Bhattacharyya, D.; Turton, R.; Zitney, S.

2011-01-01T23:59:59.000Z

378

Coordinated Control and Optimization of Virtual Power Plants for Energy and Frequency Regulation Services in Electricity Markets  

E-Print Network (OSTI)

With increasing penetration of intermittent resources such as wind and solar, power system operations are facing much more challenges in cost effective provision of energy balancing and frequency regulation services. Enabled by advances in sensing, control and communication, the concept of Virtual Power Plant (VPP) is proposed as one possible solution which aggregates and firms up spatially distributed resources? net power injection to the system. This thesis proposes a coordinated control and bidding strategy for VPPs to provide energy balancing and grid frequency regulation services in electricity market environment. In this thesis, the VPP consists of two energy conversion assets: a Doubly Fed Induction Generator (DFIG)-based wind farm and a co-located Flywheel Energy Storage System (FESS). The coordination of the VPP is implemented through power electronics?based controllers. A five-bus system test case demonstrates the technical feasibility of VPPs to respond to grid frequency deviation as well as to follow energy dispatch signals. To enable the participation of VPPs in electricity market, this thesis also proposes an optimization based bidding strategy for VPPs in both energy balancing and frequency regulation service markets. The potential economic benefits of this bidding strategy are demonstrated under Denmark wholesale electricity market structure. Four case studies show the economic benefit of coordinating VPPs.

Zhang, Fan

2011-12-01T23:59:59.000Z

379

Optimization of disk generator performance for base-load power plant systems applications  

SciTech Connect

Disk generators for use in base-load MHD power plants are examined for both open-cycle and closed-cycle operating modes. The OCD cases are compared with PSPEC results for a linear channel; enthalpy extractions up to 23% with 71% isentropic efficiency are achievable with generator inlet conditions similar to those used in PSPEC, thus confirming that the disk configuration is a viable alternative for base-load power generation. The evaluation of closed-cycle disks includes use of a simplified cycle model. High system efficiencies over a wide range of power levels are obtained for effective Hall coefficients in the range 2.3 to 4.9. Cases with higher turbulence (implying ..beta../sub eff/ less than or equal to 2.4) yield high system efficiencies at power levels of 100 to 500 MW/sub e/. All these CCD cases compare favorably with linear channels reported in the GE ECAS study, yielding higher isentropic efficiences for a given enthalpy extraction. Power densities in the range 70 to 170 MW/m/sup 3/ appear feasible, leading to very compact generator configurations.

Teare, J.D.; Loubsky, W.J.; Lytle, J.K.; Louis, J.F.

1980-01-01T23:59:59.000Z

380

Optimal site selection and sizing of distributed utility-scale wind power plants  

DOE Green Energy (OSTI)

As electric market product unbundling occurs, sellers in the wholesale market for electricity will find it to their advantage to be able to specify the quantity of electricity available and the time of availability. Since wind power plants are driven by the stochastic nature of the wind itself, this can present difficulties. To the extent that an accurate wind forecast is available, contract deviations, and therefore penalties, can be significantly reduced. Even though one might have the ability to accurately forecast the availability of wind power, it might not be available during enough of the peak period to provide sufficient value. However, if the wind power plant is developed over geographically disperse locations, the timing and availability of wind power from these multiple sources could provide a better match with the utility`s peak load than a single site. There are several wind plants in various stages of planning or development in the US. Although some of these are small-scale demonstration projects, significant wind capacity has been developed in Minnesota, with additional developments planned in Wyoming and Iowa. As these and other projects are planned and developed, there is a need to perform analysis of the value of geographically diverse sites on the efficiency of the overall wind plant. In this paper, the authors use hourly wind-speed data from six geographically diverse sites to provide some insight into the potential benefits of disperse wind plant development. They provide hourly wind power from each of these sites to an electric reliability simulation model. This model uses generating plant characteristics of the generators within the state of Minnesota to calculate various reliability indices. Since they lack data on wholesale power transactions, they do not include them in the analysis, and they reduce the hourly load data accordingly. The authors present and compare results of their methods and suggest some areas of future research.

Milligan, M.R. [National Renewable Energy Lab., Golden, CO (United States)] [National Renewable Energy Lab., Golden, CO (United States); Artig, R. [Minnesota Dept. of Public Service, St. Paul, MN (United States)] [Minnesota Dept. of Public Service, St. Paul, MN (United States)

1998-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "optimal power flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

A computational framework for uncertainty quantification and stochastic optimization in unit commitment with wind power generation.  

Science Conference Proceedings (OSTI)

We present a computational framework for integrating a state-of-the-art numerical weather prediction (NWP) model in stochastic unit commitment/economic dispatch formulations that account for wind power uncertainty. We first enhance the NWP model with an ensemble-based uncertainty quantification strategy implemented in a distributed-memory parallel computing architecture. We discuss computational issues arising in the implementation of the framework and validate the model using real wind-speed data obtained from a set of meteorological stations. We build a simulated power system to demonstrate the developments.

Constantinescu, E. M; Zavala, V. M.; Rocklin, M.; Lee, S.; Anitescu, M. (Mathematics and Computer Science); (Univ. of Chicago); (New York Univ.)

2011-02-01T23:59:59.000Z

382

A composite P&O MPPT control with intelligent orthogonal particle swarm optimization for steepest gradient river current power generation system  

Science Conference Proceedings (OSTI)

This paper proposes a demonstration system of steepest gradient river current (SGRC) power generation with energy storage system. A direct-drive permanent magnet synchronous generator with multiple poles is used to transfer the steepest gradient river ... Keywords: full-bridge DC/DC converter controller, maximum power point tracking (MPPT), orthogonal particle swarm optimization (OPSO), perturbation and observation (P&O) method, steepest gradient river current (SGRC) power generation

Jian-Long Kuo; Chun-Jae Chang

2010-08-01T23:59:59.000Z

383

Stochastic Modeling of a Power-Managed System: Construction and Optimization  

E-Print Network (OSTI)

a state to itself. The SP can transfer from the busy state to idle state with the transition rate equal GSYS(a) gives the state transition rates under action a. A cost function Cost(x, a) gives the system to a power-down state or another idle state whose corresponding busy state has a slower service rate

Qiu, Qinru

384

Method of optimizing performance of Rankine cycle power plants. [US DOE Patent  

DOE Patents (OSTI)

A method is described for efficiently operating a Rankine cycle power plant to maximize fuel utilization efficiency or energy conversion efficiency or minimize costs by selecting a turbine fluid inlet state which is substantially on the area adjacent and including the transposed critical temperature line.

Pope, W.L.; Pines, H.S.; Doyle, P.A.; Silvester, L.F.

1980-06-23T23:59:59.000Z

385

Intelligent predictive control of a power plant with evolutionary programming optimizer and neuro-fuzzy identifier  

Science Conference Proceedings (OSTI)

An intelligent predictive controller is implemented to control a fossil fuel power unit. This controller is a non-model based system that uses a self-organized neuro-fuzzy identifier to predict the response of the plant in a future time interval. The ...

H. Ghezelayagh; K. Y. Lee

2002-05-01T23:59:59.000Z

386

Automatic system for optimization of operation of a gas cogeneration power plant  

Science Conference Proceedings (OSTI)

The system is made with main distributed components: - first level: Industrial Computers placed in Control Room (monitors thermal and electrical processes based on the data provided by the second level); - second level: PLCs which collects data from ... Keywords: automation system, cogenerative power plant, control, monitoring, real time

Ion Miciu

2008-07-01T23:59:59.000Z

387

Design, Analysis and Optimization of the Power Conversion System for the Modular Pebble Bed Reactor System  

E-Print Network (OSTI)

technology and complies with all current codes and standards. Using the initial reference design, limiting. A dynamic model, MPBRSim, has been developed. The model integrates the reactor core and the power conversion reactor design requirements...........................................39 2.5 Overall development path

388

Optimization and Comparison of Direct and Indirect Supercritical Carbon Dioxide Power Plant Cycles for Nuclear Applications  

Science Conference Proceedings (OSTI)

There have been a number of studies involving the use of gases operating in the supercritical mode for power production and process heat applications. Supercritical carbon dioxide (CO2) is particularly attractive because it is capable of achieving relatively high power conversion cycle efficiencies in the temperature range between 550 C and 750 C. Therefore, it has the potential for use with any type of high-temperature nuclear reactor concept, assuming reactor core outlet temperatures of at least 550 C. The particular power cycle investigated in this paper is a supercritical CO2 Recompression Brayton Cycle. The CO2 Recompression Brayton Cycle can be used as either a direct or indirect power conversion cycle, depending on the reactor type and reactor outlet temperature. The advantage of this cycle when compared to the helium Brayton cycle is the lower required operating temperature; 550 C versus 850 C. However, the supercritical CO2 Recompression Brayton Cycle requires an operating pressure in the range of 20 MPa, which is considerably higher than the required helium Brayton cycle operating pressure of 8 MPa. This paper presents results of analyses performed using the UniSim process analyses software to evaluate the performance of both a direct and indirect supercritical CO2 Brayton Recompression cycle for different reactor outlet temperatures. The direct supercritical CO2 cycle transferred heat directly from a 600 MWt reactor to the supercritical CO2 working fluid supplied to the turbine generator at approximately 20 MPa. The indirect supercritical CO2 cycle assumed a helium-cooled Very High Temperature Reactor (VHTR), operating at a primary system pressure of approximately 7.0 MPa, delivered heat through an intermediate heat exchanger to the secondary indirect supercritical CO2 Brayton Recompression cycle, again operating at a pressure of about 20 MPa. For both the direct and indirect cycles, sensitivity calculations were performed for reactor outlet temperature between 550 C and 850 C. The UniSim models used realistic component parameters and operating conditions to model the complete reactor and power conversion systems. CO2 properties were evaluated, and the operating ranges of the cycles were adjusted to take advantage of the rapidly changing properties of CO2 near the critical point. The results of the analyses showed that, for the direct supercritical CO2 power cycle, thermal efficiencies in the range of 40 to 50% can be achieved. For the indirect supercritical CO2 power cycle, thermal efficiencies were approximately 10% lower than those obtained for the direct cycle over the same reactor outlet temperature range.

Edwin A. Harvego; Michael G. McKellar

2011-11-01T23:59:59.000Z

389

Optimal sizing study of hybrid wind/PV/diesel power generation unit  

Science Conference Proceedings (OSTI)

In this paper, a methodology of sizing optimization of a stand-alone hybrid wind/PV/diesel energy system is presented. This approach makes use of a deterministic algorithm to suggest, among a list of commercially available system devices, the optimal number and type of units ensuring that the total cost of the system is minimized while guaranteeing the availability of the energy. The collection of 6 months of data of wind speed, solar radiation and ambient temperature recorded for every hour of the day were used. The mathematical modeling of the main elements of the hybrid wind/PV/diesel system is exposed showing the more relevant sizing variables. A deterministic algorithm is used to minimize the total cost of the system while guaranteeing the satisfaction of the load demand. A comparison between the total cost of the hybrid wind/PV/diesel energy system with batteries and the hybrid wind/PV/diesel energy system without batteries is presented. The reached results demonstrate the practical utility of the used sizing methodology and show the influence of the battery storage on the total cost of the hybrid system. (author)

Belfkira, Rachid; Zhang, Lu; Barakat, Georges [Groupe de Recherche en Electrotechnique et Automatique du Havre, University of Le Havre, 25 rue Philippe Lebon, BP 1123, 76063 Le Havre (France)

2011-01-15T23:59:59.000Z

390

2010 - Optimization Online  

E-Print Network (OSTI)

Minimum wight Topology optimization subject to unsteady heat equation and space-time pointwise ... Optimal adaptive control of cascading power grid failures

391

O{sub 2}({sup 1}{delta}) production in flowing He/O{sub 2} plasmas. I. Axial transport and pulsed power formats  

Science Conference Proceedings (OSTI)

Chemical oxygen-iodine lasers (COILs) have promising applications due to their high efficiency and ease of scaling to multikilowatt powers. Recent research has focused on pumping the iodine with O{sub 2}({sup 1}{delta}) produced by electric discharges. In a previous work, a global model was used to develop reaction mechanisms and determine the specific energy deposition (eV/O{sub 2}) required to obtain high O{sub 2}({sup 1}{delta}) yields for electric discharge COILs. Experiments have recently achieved positive laser gain and oscillation with these energy depositions and have highlighted the importance of axial expansion of the plasma in optimizing excitation of the O{sub 2}({sup 1}{delta}). In this work, the consequences of axial transport on O{sub 2}({sup 1}{delta}) yields have been computationally investigated in flowing He/O{sub 2} plasmas at a few Torrs using a one-dimensional plasma hydrodynamics and kinetics model. We show that the experimentally observed extension of the plasma glow upstream and downstream of the electrodes is due to electron diffusion and capacitive coupling of the radio-frequency power source. We also show that {approx_equal}50% higher O{sub 2}({sup 1}{delta}) yields can be achieved with a pulsed discharge combined with continuous-wave discharge.

Stafford, D. Shane; Kushner, Mark J. [Department of Theoretical and Applied Mechanics, University of Illinois, Urbana, Illinois 61801 (United States); Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011 (United States)

2005-10-01T23:59:59.000Z

392

Steady-state simulation and optimization of an integrated gasification combined cycle power plant with CO2 capture  

SciTech Connect

Integrated gasification combined cycle (IGCC) plants are a promising technology option for power generation with carbon dioxide (CO2) capture in view of their efficiency and environmental advantages over conventional coal utilization technologies. This paper presents a three-phase, top-down, optimization-based approach for designing an IGCC plant with precombustion CO2 capture in a process simulator environment. In the first design phase, important global design decisions are made on the basis of plant-wide optimization studies with the aim of increasing IGCC thermal efficiency and thereby making better use of coal resources and reducing CO2 emissions. For the design of an IGCC plant with 90% CO2 capture, the optimal combination of the extent of carbon monoxide (CO) conversion in the water-gas shift (WGS) reactors and the extent of CO2 capture in the SELEXOL process, using dimethylether of polyethylene glycol as the solvent, is determined in the first phase. In the second design phase, the impact of local design decisions is explored considering the optimum values of the decision variables from the first phase as additional constraints. Two decisions are made focusing on the SELEXOL and Claus unit. In the third design phase, the operating conditions are optimized considering the optimum values of the decision variables from the first and second phases as additional constraints. The operational flexibility of the plant must be taken into account before taking final design decisions. Two studies on the operational flexibility of the WGS reactors and one study focusing on the operational flexibility of the sour water stripper (SWS) are presented. At the end of the first iteration, after executing all the phases once, the net plant efficiency (HHV basis) increases to 34.1% compared to 32.5% in a previously published study (DOE/NETL-2007/1281; National Energy Technology Laboratory, 2007). The study shows that the three-phase, top-down design approach presented is very useful and effective in a process simulator environment for improving efficiency and flexibility of IGCC power plants with CO2 capture. In addition, the study identifies a number of key design variables that has strong impact on the efficiency of an IGCC plant with CO2 capture.

Bhattacharyya, D.; Turton, R.; Zitney, S.

2011-01-01T23:59:59.000Z

393

Microsoft PowerPoint - Optimized 2010_UTSR_Citeno_Rev2.ppt  

NLE Websites -- All DOE Office Websites (Extended Search)

R&D Needs for Gas Turbine Power Generation R&D Needs for Gas Turbine Power Generation in a Carbon Constrained World Joe Citeno Manager Combustion & Emissions Technology 2 Copyright 2010 General Electric Company October 2010, UTSR 29% 31% 33% 35% 37% 39% 0% 20% 40% 60% 80% 100% CO2 Capture % HHV Efficiency, % GE EPRI Sources: GE Internal Study, 2007 and EPRI IGCC Design Considerations for CO2 Capture: Engineering and Economic Assessment of IGCC Coal Power Plants for near-term Deployment, 2008 500 550 600 650 0% 20% 40% 60% 80% 100% CO2 Capture % Output, MW GE EPRI 0 500 1000 1500 2000 2500 GTSC (FA) New Coal IGCC or PC Existing Coal U.S. Average CO 2 Emission Rate (lbs/MW-hr) Coal Natural Gas Thermal Efficiency Indicated (xx%) CC = Carbon Capture % eff = 40% eff = 45% IGCC with CCS CC% 90% GTCC (FA) 65% 50% References: DOE NETL; EIA; IEA and GE Energy Internal Data

394

Thermal Efficiency Optimization for Industrial Power Plants Under Load Fluctuations Using Fuzzy Logic  

E-Print Network (OSTI)

The automation of the control to a power plant is indeed a challenge mainly because of the occurrences of random and unpredictable variations in output demands as well as because of highly non-linear behavior of the system itself. It is sometimes argued that the 'best' control for a power plant is the operators themselves. Experienced operators are capable of making decisions on the basis of incomplete and imprecise information. The extent to which these decisions are correct is a matter of speculation. Erroneous conclusions, established post facto, are chalked up to the learning process and in fact, contribute to the forming of a good, experienced control team. The need to automate the control process for a plant is even more acutely felt when considering the complexity of the plants themselves and the volume of data that would have to be processed before a control decision can be taken. Factored into this decision would also be several governing parameters such as costs, reliability, other constraints and their interdependency, as well as planned and unscheduled outages for maintenance and so on. In this paper, however, only one facet of a power plant operation is considered. It is intended to demonstrate that thermal efficiency may be improved by better techniques for automated control of throttle valves in the steam turbine of the plant. One of these options, fuzzy logic, is selected, and defended, as being the more effective than current approaches. A comparative analysis is conducted of control methods for plant operations followed by a brief overview of fuzzy control and its application to control of non-linear systems. A method of applying this 'new' computer-based technique to control of non-linear, somewhat erratic plants is presented and discussed.

Steffenhagan, W.; de Sam Lazaro, A.

1995-04-01T23:59:59.000Z

395

Subtask 1.24 - Optimization of Cooling Water Resources for Power Generation  

SciTech Connect

The Energy & Environmental Research Center (EERC) has developed an interactive, Web-based decision support system (DSS{copyright} 2007 EERC Foundation) to provide power generation utilities with an assessment tool to address water supply issues when planning new or modifying existing generation facilities. The Web-based DSS integrates water and wastewater treatment technology and water law information with a geographic information system-based interactive map that links to state and federal water quality and quantity databases for North Dakota, South Dakota, Minnesota, Wyoming, Montana, Nebraska, Wisconsin, and Iowa.

Daniel Stepan; Richard Shockey; Bethany Kurz; Wesley Peck

2009-03-31T23:59:59.000Z

396

Feasibility Study of a Multi-Purpose Computer Program for Optimizing Heat Rates in Power Cycles  

E-Print Network (OSTI)

A study of currently available commercial codes which evaluate the thermal performance of turbine cycles in power plants is presented. The analytical basis, capabilities, and possible applications of these codes are described. A survey of some user utilities has revealed their strengths and limitations. This paper examines some actual cases where the use of existing codes is either inconvenient or not satisfactory, and might produce somewhat inaccurate or incomplete results. A brief outline of a computer program that can overcome some of these weaknesses is given.

Menuchin, Y.; Singh, K. P.; Hirota, N.

1981-01-01T23:59:59.000Z

397

Power system simulation and optimization models for planning nuclear refueling cycles  

SciTech Connect

From Operation Research Society of America; San Diego, California, USA (12 Nov 1973). The mid-range system being modeled may include a mix of fossil, nuclear, hydro, pumped-storage, and peaking units. For any predetermined nuclear refueling schedule, the program (ORSIM) determines an approximately optical plan of operation for the system. This includes the determination of a maintenance schedule for the non-nuclear units and a schedule of energy delivery for each plant in the system. The criterion of optimality is the minimization of the total discounted operating cost of the system over the specified study period. Over this period, the model computes the expected station load factors, the loss of load probability and unserved energy for the system, and the production costs of operating so as to meet the forecasted loads on the system. The code takes account of variations and growth in demand over the planning horizon, occurrence of unit forced outages, planned shutdowns for nuclear refuelings, maintenance scheduling, allocations of fixed hydro and nuclear energies, and interactions between nuclear unit reloadings and fuel costs. 13 references. (auth)

Turnage, J.C.; Bennett, L.L.; Joy, D.S.; Prince, B.E.

1973-10-01T23:59:59.000Z

398

A Power-Law Formulation of Laminar Flow in Short Pipes Max Sherman  

E-Print Network (OSTI)

by the same approaches that Jeppson 1 uses for turbulent ones. Other similarities are suggested, but have;10 REFERENCES 1. J.W. Jeppson, "Analysis of Flow in Pipe Networks," Ann Arbor Science, pp. 53-69, (1977). 2. H

399

Optimizing Technology to Reduce Mercury and Acid Gas Emissions from Electric Power Plants  

Science Conference Proceedings (OSTI)

Revised maps and associated data show potential mercury, sulfur, and chlorine emissions for U.S. coal by county of origin. Existing coal mining and coal washing practices result in a 25% reduction of mercury in U.S. coal before it is delivered to the power plant. Selection of low-mercury coal is a good mercury control option for plants having hot-side ESP, cold-side ESP, or hot-side ESP/FGD emission controls. Chlorine content is more important for plants having cold-side ESP/FGD or SDA/FF controls; optimum net mercury capture is indicated where chlorine is between 500 and 1000 ppm. Selection of low-sulfur coal should improve mercury capture where carbon in fly ash is used to reduce mercury emissions.

Jeffrey C. Quick; David E. Tabet; Sharon Wakefield; Roger L. Bon

2005-01-31T23:59:59.000Z

400

Distributed multi-phase distribution power flow: modeling, solution algorithm, and simulation results.  

E-Print Network (OSTI)

??With the increasing presence of distributed intelligence throughout power distribution systems, the possibilities for distributed control and operation schemes are becoming progressively more attractive and… (more)

Kleinberg, Michael R.

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "optimal power flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Optimizing Techology to Reduce Mercury and Acid Gas Emissions from Electric Power Plants  

SciTech Connect

More than 56,000 coal quality data records from five public data sets have been selected for use in this project. These data will be used to create maps showing where coals with low mercury and acid-gas emissions might be found for power plants classified by air-pollution controls. Average coal quality values, calculated for 51,156 commercial coals by U.S. county-of-origin, are listed in the appendix. Coal moisture values are calculated for commercially shipped coal from 163 U.S. counties, where the raw assay data (including mercury and chlorine values) are reported on a dry basis. The calculated moisture values are verified by comparison with observed moisture values in commercial coal. Moisture in commercial U.S. coal shows provincial variation. For example, high volatile C bituminous rank coal from the Interior province has 3% to 4% more moisture than equivalent Rocky Mountain province coal. Mott-Spooner difference values are calculated for 4,957 data records for coals collected from coal mines and exploration drill holes. About 90% of the records have Mott-Spooner difference values within {+-}250 Btu/lb.

Jeffrey C. Quick; David E. Tabet; Sharon Wakefield; Roger L. Bon

2004-01-31T23:59:59.000Z

402

Comparative cost analyses: total flow vs other power conversion systems for the Salton Sea Geothermal Resource  

SciTech Connect

Cost studies were done for Total Flow, double flash, and multistage flash binary systems for electric Energy production from the Salton Sea Geothermal Resource. The purpose was to provide the Department of energy's Division of Geothermal Energy with information by which to judge whether to continue development of the Total Flow system. Results indicate that the Total Flow and double flash systems have capital costs of $1,135 and $1,026 /kW with energy costs of 40.9 and 39.7 mills/kW h respectively. The Total Flow and double flash systems are not distinguishable on a cost basis alone; the multistage flash binary system, with capital cost of $1,343 /kW and energy cost of 46.9 mills/kW h, is significantly more expensive. If oil savings are considered in the total analysis, the Total Flow system could save 30% more oil than the double flash system, $3.5 billion at 1978 oil prices.

Wright, G.W.

1978-09-18T23:59:59.000Z

403

Comparative cost analyses: total flow vs other power conversion systems for the Salton Sea Geothermal Resource  

DOE Green Energy (OSTI)

Cost studies were done for Total Flow, double flash, and multistage flash binary systems for electric Energy production from the Salton Sea Geothermal Resource. The purpose was to provide the Department of energy's Division of Geothermal Energy with information by which to judge whether to continue development of the Total Flow system. Results indicate that the Total Flow and double flash systems have capital costs of $1,135 and $1,026 /kW with energy costs of 40.9 and 39.7 mills/kW h respectively. The Total Flow and double flash systems are not distinguishable on a cost basis alone; the multistage flash binary system, with capital cost of $1,343 /kW and energy cost of 46.9 mills/kW h, is significantly more expensive. If oil savings are considered in the total analysis, the Total Flow system could save 30% more oil than the double flash system, $3.5 billion at 1978 oil prices.

Wright, G.W.

1978-09-18T23:59:59.000Z

404

Combined cycle electric power plant and a heat recovery steam generator having improved boiler feed pump flow control  

SciTech Connect

A combined cycle electric power plant is described that includes gas and steam turbines and a steam generator for recovering the heat in the exhaust gases exited from the gas turbine and for using the recovered heat to produce and supply steam to the steam turbine. The steam generator includes an economizer tube and a high pressure evaporator tube and a boiler feed pump for directing the heat exchange fluid serially through the aforementioned tubes. A condenser is associated with the steam turbine for converting the spent steam into condensate water to be supplied to a deaerator for removing undesired air and for preliminarily heating the water condensate before being pumped to the economizer tube. Condensate flow through the economizer tube is maintained substantially constant by maintaining the boiler feed pump at a predetermined, substantially constant rate. A bypass conduit is provided to feed back a portion of the flow heated in the economizer tube to the deaerator; the portion being equal to the difference between the constant flow through the economizer tube and the flow to be directed through the high pressure evaporator tube as required by the steam turbine for its present load.

Martz, L.F.; Plotnick, R.J.

1976-06-29T23:59:59.000Z

405

Fast computation of multiphase flow in porous media by implicit discontinuous Galerkin schemes with optimal ordering of elements  

Science Conference Proceedings (OSTI)

We present a family of implicit discontinuous Galerkin schemes for purely advective multiphase flow in porous media in the absence of gravity and capillary forces. To advance the solution one time step, one must solve a discrete system of nonlinear equations. ... Keywords: Implicit upwind scheme, Porous media flow, Topological sorting

Jostein R. Natvig; Knut-Andreas Lie

2008-12-01T23:59:59.000Z

406

Simulating Field-Scale Moisture Flow Using a Combined Power-Averaging and Tensorial Connectivity-Tortuosity Approach  

SciTech Connect

Various stochastic methods have been developed over the past two decades to estimate effective unsaturated hydraulic properties. We develop in this paper an alternative practical approach to estimate three-dimensional effective unsaturated hydraulic conductivity via a combined power-averaging and tensorial connectivity-tortuosity (PA-TCT) model. An application of the new approach to data collected at a field injection site suggests that the PA-TCT model provides 1) a reasonable framework for upscaling core-scale measurements and 2) an accurate simulation of moisture flow in a heterogeneous vadose zone. The heterogeneous media at the injection site is composed of multiple geologic units, each of which is represented by an anisotropic equivalent homogeneous medium (EHM). The directional effective hydraulic conductivity for each anisotropic EHM was determined by upscaling the laboratory-measured hydraulic properties with the combined PA-TCT approach. A larger difference between the power values in the horizontal and vertical directions indicates a larger macroscopic anisotropy in unsaturated hydraulic conductivity. A moment analysis was used to quantify the center of mass and the spread of the moisture content difference. Numerical simulations showed that, if the flow domain were treated as being isotropic, the vertical migration was significantly overestimated while the lateral movement was underestimated when compared to observations. To the contrary, if the media was treated as perfectly stratified, the lateral moisture movement was considerably overestimated while the vertical movement was underestimated. However, when the flow domain was modeled as being mildly anisotropic with the PA-TCT based parameters, the model can successfully predict the moisture flow and the simulated plume matched the observed moisture plume the best.

Zhang, Z. F.; Khaleel, Raziuddin

2010-09-02T23:59:59.000Z

407

OPTIMIZING TECHNOLOGY TO REDUCE MERCURY AND ACID GAS EMISSIONS FROM ELECTRIC POWER PLANTS  

DOE Green Energy (OSTI)

Maps showing potential mercury, sulfur, chlorine, and moisture emissions for U.S. coal by county of origin were made from publicly available data (plates 1, 2, 3, and 4). Published equations that predict mercury capture by emission control technologies used at U.S. coal-fired utilities were applied to average coal quality values for 169 U.S. counties. The results were used to create five maps that show the influence of coal origin on mercury emissions from utility units with: (1) hot-side electrostatic precipitator (hESP), (2) cold-side electrostatic precipitator (cESP), (3) hot-side electrostatic precipitator with wet flue gas desulfurization (hESP/FGD), (4) cold-side electrostatic precipitator with wet flue gas desulfurization (cESP/FGD), and (5) spray-dry adsorption with fabric filter (SDA/FF) emission controls (plates 5, 6, 7, 8, and 9). Net (lower) coal heating values were calculated from measured coal Btu values, and estimated coal moisture and hydrogen values; the net heating values were used to derive mercury emission rates on an electric output basis (plate 10). Results indicate that selection of low-mercury coal is a good mercury control option for plants having hESP, cESP, or hESP/FGD emission controls. Chlorine content is more important for plants having cESP/FGD or SDA/FF controls; optimum mercury capture is indicated where chlorine is between 500 and 1000 ppm. Selection of low-sulfur coal should improve mercury capture where carbon in fly ash is used to reduce mercury emissions. Comparison of in-ground coal quality with the quality of commercially mined coal indicates that existing coal mining and coal washing practice results in a 25% reduction of mercury in U.S. coal before it is delivered to the power plant. Further pre-combustion mercury reductions may be possible, especially for coal from Texas, Ohio, parts of Pennsylvania and much of the western U.S.

Jeffrey C. Quick; David E. Tabet; Sharon Wakefield; Roger L. Bon

2005-10-01T23:59:59.000Z

408

Distributed Multi-Phase Distribution Power Flow: Modeling, Solution Algorithm and Simulation Results  

Science Conference Proceedings (OSTI)

With the increasing installation of power electronics and automated devices, the possibilities for distributed control and operation schemes are becoming progressively more attractive and feasible. This paper presents a new method for calculating distribution ...

Michael Kleinberg; Karen Miu; Chika Nwankpa

2008-08-01T23:59:59.000Z

409

JOURNAL OF COMMUNICATIONS AND NETWORKS, VOL. 14, NO. 2, APRIL 2012 151 Sum-Rate Optimal Power Policies for Energy Harvesting  

E-Print Network (OSTI)

Policies for Energy Harvesting Transmitters in an Interference Channel Kaya Tutuncuoglu and Aylin Yener by harvesting from ambient sources. Optimal power policies for energy harvesting nodes have attracted recent (Invited Paper) Abstract: This paper considers a two-user Gaussian interference channel with energy

Yener, Aylin

410

Fast-wave Power Flow Along SOL Field Lines In NSTX nd The Associated Power Deposition Profile Across The SOL In Front Of The Antenna  

SciTech Connect

Fast-wave heating and current drive efficiencies can be reduced by a number of processes in the vicinity of the antenna and in the scrape off layer (SOL). On NSTX from around 25% to more than 60% of the high-harmonic fast-wave power can be lost to the SOL regions, and a large part of this lost power flows along SOL magnetic field lines and is deposited in bright spirals on the divertor floor and ceiling. We show that field-line mapping matches the location of heat deposition on the lower divertor, albeit with a portion of the heat outside of the predictions. The field-line mapping can then be used to partially reconstruct the profile of lost fast-wave power at the midplane in front of the antenna, and the losses peak close to the last closed flux surface (LCFS) as well as the antenna. This profile suggests a radial standing-wave pattern formed by fast-wave propagation in the SOL, and this hypothesis will be tested on NSTX-U. Advanced RF codes must reproduce these results so that such codes can be used to understand this edge loss and to minimize RF heat deposition and erosion in the divertor region on ITER.

Perkins, Roy

2013-06-21T23:59:59.000Z

411

Development of a Laboratory Verified Single-Duct VAV System Model with Fan Powered Terminal Units Optimized Using Computational Fluid Dynamics  

E-Print Network (OSTI)

Single Duct Variable Air Volume (SDVAV) systems use series and parallel Fan Powered Terminal Units to control the air flow in conditioned spaces. This research developed a laboratory verified model of SDVAV systems that used series and parallel fan terminal units where the fan speeds were controlled by either Silicon Controlled Rectifiers (SCR) or Electronically Commutated Motors (ECM) motors. As part of the research, the model was used to compare the performance of the systems and to predict the harmonics generated by ECM systems. All research objectives were achieved. The CFD model, which was verified with laboratory measurements, showed the potential to identify opportunities for improvement in the design of the FPTU and accurately predicted the static pressure drop as air passed through the unit over the full operating range of the FPTU. Computational fluid dynamics (CFD) models of typical a FPTU were developed and used to investigate opportunities for optimizing the design of FPTUs. The CFD model identified key parameters required to conduct numerical simulations of FPTU and some of the internal components used to manufacture the units. One key internal component was a porous baffle used to enhance mixing when primary air and induced air entered the mixing chamber. The CFD analysis showed that a pressure-drop based on face velocity model could be used to accurately predict the performance of the FPTU. The SDVAV simulation results showed that parallel FPTUs used less energy overall than series systems that used SCR motors as long as primary air leakage was not considered. Simulation results also showed that series ECM FPTUs used about the same amount of energy, within 3 percent, of parallel FPTU even when leakage was not considered. A leakage rate of 10 percent was enough to reduce the performance of the parallel FPTU to the level of the series SCR system and the series ECM FPTUs outperformed the parallel FPTUs at all weather locations used in the study.

Davis, Michael A.

2010-08-01T23:59:59.000Z

412

Dimensioning and operating wind-hydrogen plants in power markets  

Science Conference Proceedings (OSTI)

This paper presents a two-step method for dimensioning and time-sequential operation of Wind-hydrogen (H2) plants operating in power markets. Step 1 involves identification of grid constraints and marginal power losses through load flow simulations. ... Keywords: distributed generation, hydrogen, quadratic optimization, renewable energy, weak grids, wind power

Christopher J. Greiner; Magnus Korpås; Terje Gjengedal

2008-07-01T23:59:59.000Z

413

Optimizing performance of ceramic pot filters in Northern Ghana and modeling flow through paraboloid-shaped filters/  

E-Print Network (OSTI)

This work aimed to inform the design of ceramic pot filters to be manufactured by the organization Pure Home Water (PHW) in Northern Ghana, and to model the flow through an innovative paraboloid-shaped ceramic pot filter. ...

Miller, Travis Reed

2010-01-01T23:59:59.000Z

414

Profitability Comparison Between Gas Turbines and Gas Engine in Biomass-Based Power Plants Using Binary Particle Swarm Optimization  

Science Conference Proceedings (OSTI)

This paper employs a binary discrete version of the classical Particle Swarm Optimization to compare the maximum net present value achieved by a gas turbines biomass plant and a gas engine biomass plant. The proposed algorithm determines the optimal ...

P. Reche López; M. Gómez González; N. Ruiz Reyes; F. Jurado

2007-06-01T23:59:59.000Z

415

Optimization Online - All Areas Submissions - February 2011  

E-Print Network (OSTI)

... Optimization for Power System Configuration with Renewable Energy in Remote Areas ... Robust Energy Cost Optimization of Water Distribution System with ...

416

Optimization Online - Robust Optimization Submissions - 2012  

E-Print Network (OSTI)

An Exact Algorithm for Power Grid Interdiction Problem with Line Switching Long Zhao, Bo Zeng. An Exact Algorithm for Two-stage Robust Optimization with ...

417

Optimization of the Regional Spatial Distribution of Wind Power Plants to Minimize the Variability of Wind Energy Input into Power Supply Systems  

Science Conference Proceedings (OSTI)

In contrast to conventional power generation, wind energy is not a controllable resource because of its stochastic nature, and the cumulative energy input of several wind power plants into the electric grid may cause undesired fluctuations in the ...

Federico Cassola; Massimiliano Burlando; Marta Antonelli; Corrado F. Ratto

2008-12-01T23:59:59.000Z

418

FACT: A Framework for the Application of Throughput and Power Optimizing Transformations to Control-flow Intensive Behavioral Descriptions  

E-Print Network (OSTI)

Inthispaper,wepresentanalgorithmfortheapplicationofa generalclassoftransformationstocontrol-flowintensivebehavioraldescriptions. Ouralgorithmisbasedontheobservationthat incorporationofschedulinginformationcanhelpguidetheselectionandapplicationofcandidatetransformations, andsignificantly enhancethequalityofthesynthesizedsolution.Theefficacyofthe selectedthroughputandpoweroptimizingtransformationsisenhancedbytheabilityofouralgorithmtotranscendbasicblocksin thebehavioraldescription.Thisabilityisimpartedtoouralgorithm byageneraltechniquewehavedevised.Oursystemcurrentlysupportsassociativity, commutativity,distributivity,constantpropagation, codemotion,andloopunrolling.Itisintegratedwithaschedulerwhichperformsimplicitloopunrollingandfunctionalpipelin - ing,andhastheabilitytoparallelizetheexecutionofindependent iterativeconstructswhosebodiescanshareresources.Othertransformationscaneasilybeincorporatedwithintheframework. We demonstratetheefficacyofouralgorithmbyapplyingittoseveral commonlyavai...

Ganesh Lakshminarayana; Niraj K. Jha; Ganeshlakshminarayana Andnirajk Jha

1998-01-01T23:59:59.000Z

419

A Test of the Flow Velocity Enhancement System (FVES) for Deflecting Aquatic Vegetation from the Intake of Genoa Power Station #3, Wisconsin  

Science Conference Proceedings (OSTI)

This report reviews the results of an evaluation of the Flow Velocity Enhancement System (FVES), a new technology for generating motive water in the water column to deflect downstream drifting aquatic weeds from cooling water intakes. The research was conducted at Dairyland Power’s Genoa Generating Station on the upper Mississippi River in Wisconsin.BackgroundBlockage of cooling water intake structures (CWIS) by waterborne debris occurs frequently at ...

2013-06-10T23:59:59.000Z

420

Dynamic Voltage Scaling with Links for Power Optimization of Interconnection Li Shang Li-Shiuan Peh Niraj K. Jha  

E-Print Network (OSTI)

of varying frequency transition rates. to both a decrease and increase of traffic workload. More power volt- age and frequency transition rates on overall network power- performance and found that a faster of their links to incorpo- rate the fast, dynamic transitions of DVS links. As power becomes increasingly as

Gupta, Rajiv

Note: This page contains sample records for the topic "optimal power flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Stocks and Flows of U and Pu in a World with 3.6 TWe of Nuclear Power  

Science Conference Proceedings (OSTI)

Integrated energy, environment, and economics models project that worldwide electrical energy use will increase to ?12 TWe in 2100 and nuclear power may be required to provide 3.6 TWe at this time. If pulverized coal without carbon sequestration were employed instead, the resulting incremental long-term global temperature rise would be about 2/3 deg C. Calculations are presented of the stocks and flows of uranium and plutonium associated with the scenario where this energy is provided by nuclear power. If only light-water reactors (LWRs) are used, the scenario consumes about 33.4 Mt of mined uranium. Continuing to operate the reactors in place in 2100 through the end of their assumed 60 year lifetime raises this to 59 Mt, 4.7x the NEA/ IAEA Redbook estimate for total discovered + undiscovered uranium. The waste corresponds to about 86x the legally defined capacity of Yucca Mtn. A case is also considered where a transition is begun to fast-spectrum reactors in 2040, both for a “balanced” system of LWRs and transuranic (TRU) burners with conversion ration (CR) = 0.5, and for a system of breeders. In the latter case we find that CR = 1.21 is adequate to replace all LWRs with breeders by 2100, using solely TRU from LWRs to start up the reactors – assuming reprocessed fuel is available for use two years after its removal from the reactor. The stock of plutonium circulating in the fast reactor system in 2100 is comparable to that which would have been buried in the LWR-only case. One year of fueling corresponds to 2,000 – 6,000t of Pu. Fusion energy, if first brought on line in mid-century, could in principle replace fast reactors in this scenario.

Robert J. Goldston

2012-08-10T23:59:59.000Z

422

Design of a Real-Time Adaptive Power Optimal Sensor System Ari Y. Benbasat and Joseph A. Paradiso  

E-Print Network (OSTI)

sensors, their sampling rate and accuracy, and algorithms to describe both the state transitions and any state because one cycle is necessary to confirm the transition. Table 1: Summary of states and power usage (µC: MSP430F147, Gyro: ADXRS300, Accel: ADXL202) State % of Time Sensors Rate Sensor Power

423

Solar multiple optimization for a solar-only thermal power plant, using oil as heat transfer fluid in the parabolic trough collectors  

SciTech Connect

Usual size of parabolic trough solar thermal plants being built at present is approximately 50 MW{sub e}. Most of these plants do not have a thermal storage system for maintaining the power block performance at nominal conditions during long non-insolation periods. Because of that, a proper solar field size, with respect to the electric nominal power, is a fundamental choice. A too large field will be partially useless under high solar irradiance values whereas a small field will mainly make the power block to work at part-load conditions. This paper presents an economic optimization of the solar multiple for a solar-only parabolic trough plant, using neither hybridization nor thermal storage. Five parabolic trough plants have been considered, with the same parameters in the power block but different solar field sizes. Thermal performance for each solar power plant has been featured, both at nominal and part-load conditions. This characterization has been applied to perform a simulation in order to calculate the annual electricity produced by each of these plants. Once annual electric energy generation is known, levelized cost of energy (LCOE) for each plant is calculated, yielding a minimum LCOE value for a certain solar multiple value within the range considered. (author)

Montes, M.J. [E.T.S.I.Industriales - U.N.E.D., C/Juan del Rosal, 12, 28040 Madrid (Spain); Abanades, A.; Martinez-Val, J.M.; Valdes, M. [E.T.S.I.Industriales - U.P.M., C/Jose Gutierrez Abascal, 2, 28006 Madrid (Spain)

2009-12-15T23:59:59.000Z

424

The characterization of flow regimes with power spectral density distributions of pressure fluctuations during condensation in smooth and micro-fin tubes  

Science Conference Proceedings (OSTI)

This paper presents an objective predictor of the prevailing flow regime during refrigerant condensation inside smooth-, micro-fin and herringbone tubes. The power spectral density (PSD) distribution of the fluctuating condensing pressure signal was used to predict the prevailing flow regime, as opposed to the traditional (and subjective) use of visual-only methods, and/or smooth-tube flow regime maps. The prevailing flow regime was observed by using digital cameras and was validated with the use of the conventional smooth-tube flow regime transition criteria, Froude rate criteria, as well as a new flow regime map that was developed for micro-fin tube condensation. Experimental work was conducted for condensing R-22, R-407C, and R-134a at an average saturation temperature of 40{sup o}C with mass fluxes ranging from 300 to 800kg/m{sup 2}s, and with vapour qualities ranging from 0.85-0.95 at condenser inlet to 0.05-0.15 at condenser outlet. Tests were conducted with one smooth-tube condenser and three micro-fin tube condensers (with helix angles of 10{sup o}, 18{sup o}, and 37{sup o}, respectively). It is shown that the micro-fin tubes cause a delay in the transition from annular to intermittent flow by at least 19% (compared to the smooth tube), thus significantly contributing to the enhancement of heat transfer. (author)

Liebenberg, Leon; Meyer, Josua P. [Department of Mechanical and Aeronautical Engineering, University of Pretoria, Pretoria 0002 (South Africa)

2006-11-15T23:59:59.000Z

425

Optimizing the performance of streaming numerical kernels on the IBM Blue Gene/P PowerPC 450 processor  

Science Conference Proceedings (OSTI)

Several emerging petascale architectures use energy-efficient processors with vectorized computational units and in-order thread processing. On these architectures the sustained performance of streaming numerical kernels, ubiquitous in the solution of ... Keywords: Blue Gene/P, SIMD, code generation, high-performance computing, performance optimization

Tareq Malas, Aron J. Ahmadia, Jed Brown, John A. Gunnels, David E. Keyes

2013-05-01T23:59:59.000Z

426

Analysis and optimization of the Graz cycle : a coal fired power generation scheme with near-zero carbon dioxide emissions  

E-Print Network (OSTI)

Humans are releasing record amounts of carbon dioxide into the atmosphere through the combustion of fossil fuels in power generation plants. With mounting evidence that this carbon dioxide is a leading cause of global ...

Alexander, Brentan R

2007-01-01T23:59:59.000Z

427

Sleep and Wakeup Strategies in Solar-Powered Wireless Sensor/Mesh Networks: Performance Analysis and Optimization  

Science Conference Proceedings (OSTI)

A queuing analytical model is presented to investigate the performances of different sleep and wakeup strategies in a solar-powered wireless sensor/mesh network where a solar cell is used to charge the battery in a sensor/mesh node. While the solar radiation ... Keywords: Solar-powered wireless sensor/mesh networks, sleep and wakeup strategies, queuing analysis, system utility, game theory.

Dusit Niyato; Ekram Hossain; Afshin Fallahi

2007-02-01T23:59:59.000Z

428

High power gas transport laser  

SciTech Connect

Continuous wave output power from a gas transport laser is substantially increased by disposing a plurality of parallel cylindrically tubular cathodes in the main stream transversely of the direction of gas flow and spaced above a coextensive segmented anode in the opposite wall of the channel. Ballast resistors are connected between the cathodes, respectively, and the power supply to optimize the uniform arcless distribution of current passing between each cathode and the anode. Continuous output power greater than 3 kW is achieved with this electrode configuration.

Fahlen, T.S.; Kirk, R.F.

1978-02-28T23:59:59.000Z

429

Optimal design and control strategies for novel combined heat and power (CHP) fuel cell systems. Part I of II, datum design conditions and approach.  

SciTech Connect

Energy network optimization (ENO) models identify new strategies for designing, installing, and controlling stationary combined heat and power (CHP) fuel cell systems (FCSs) with the goals of (1) minimizing electricity and heating costs for building owners and (2) reducing emissions of the primary greenhouse gas (GHG) - carbon dioxide (CO{sub 2}). A goal of this work is to employ relatively inexpensive simulation studies to discover more financially and environmentally effective approaches for installing CHP FCSs. ENO models quantify the impact of different choices made by power generation operators, FCS manufacturers, building owners, and governments with respect to two primary goals - energy cost savings for building owners and CO{sub 2} emission reductions. These types of models are crucial for identifying cost and CO{sub 2} optima for particular installations. Optimal strategies change with varying economic and environmental conditions, FCS performance, the characteristics of building demand for electricity and heat, and many other factors. ENO models evaluate both 'business-as-usual' and novel FCS operating strategies. For the scenarios examined here, relative to a base case of no FCSs installed, model results indicate that novel strategies could reduce building energy costs by 25% and CO{sub 2} emissions by 80%. Part I of II articles discusses model assumptions and methodology. Part II of II articles illustrates model results for a university campus town and generalizes these results for diverse communities.

Colella, Whitney G.

2010-06-01T23:59:59.000Z

430

Marine Hydrokinetic Turbine Power-Take-Off Design for Optimal Performance and Low Impact on Cost-of-Energy: Preprint  

SciTech Connect

Marine hydrokinetic devices are becoming a popular method for generating marine renewable energy worldwide. These devices generate electricity by converting the kinetic energy of moving water, wave motion or currents, into electrical energy through the use of a power-take-off (PTO) system. Most PTO systems incorporate a mechanical or hydraulic drivetrain, power generator, and electric control/conditioning system to deliver the generated electric power to the grid at the required state. Like wind turbine applications, the PTO system must be designed for high reliability, good efficiency, and long service life with reasonable maintenance requirements, low cost, and an appropriate mechanical design for anticipated applied steady and unsteady loads. The ultimate goal of a PTO design is high efficiency and low maintenance and cost, with a low impact on the device cost-of-energy (CoE).

Beam, M.; Kline, B.; Elbing, B.; Straka, W.; Fontaine, A.; Lawson, M.; Li, Y.; Thresher, R.; Previsic, M.

2013-02-01T23:59:59.000Z

431

Marine Hydrokinetic Turbine Power-Take-Off Design for Optimal Performance and Low Impact on Cost-of-Energy: Preprint  

DOE Green Energy (OSTI)

Marine hydrokinetic devices are becoming a popular method for generating marine renewable energy worldwide. These devices generate electricity by converting the kinetic energy of moving water, wave motion or currents, into electrical energy through the use of a Power-Take-Off (PTO) system. Most PTO systems incorporate a mechanical or hydraulic drive train, power generator and electric control/conditioning system to deliver the generated electric power to the grid at the required state. Like wind turbine applications, the PTO system must be designed for high reliability, good efficiency, and long service life with reasonable maintenance requirements, low cost and an appropriate mechanical design for anticipated applied steady and unsteady loads. The ultimate goal of a PTO design is high efficiency, low maintenance and cost with a low impact on the device Cost-of-Energy (CoE).

Beam, M.; Kline, B.; Elbing, B.; Straka, W.; Fontaine, A.; Lawson, M.; Li, Y.; Thresher, R.; Previsic, M.

2012-04-01T23:59:59.000Z

432

TWO-PHASE FLOW STUDIES IN NUCLEAR POWER PLANT PRIMARY CIRCUITS USING THE THREE-DIMENSIONAL THERMAL-HYDRAULIC CODE BAGIRA.  

SciTech Connect

In this paper we present recent results of the application of the thermal-hydraulic code BAGIRA to the analysis of complex two-phase flows in nuclear power plants primary loops. In particular, we performed benchmark numerical simulation of an integral LOCA experiment performed on a test facility modeling the primary circuit of VVER-1000. In addition, we have also analyzed the flow patterns in the VVER-1000 steam generator vessel for stationary and transient operation regimes. For both of these experiments we have compared the numerical results with measured data. Finally, we demonstrate the capabilities of BAGIRA by modeling a hypothetical severe accident for a VVER-1000 type nuclear reactor. The numerical analysis, which modeled all stages of the hypothetical severe accident up to the complete ablation of the reactor cavity bottom, shows the importance of multi-dimensional flow effects.

KOHURT, P. (BNL), KALINICHENKO, S.D.; KROSHILIN, A.E.; KROSHILIN, V.E.; SMIRNOV, A.V.

2006-06-04T23:59:59.000Z

433

Two-Phase Flow Studies in Nuclear Power Plant Primary Circuits Using the Three-Dimensional Thermal-Hydraulic Code BAGIRA  

Science Conference Proceedings (OSTI)

in this paper we present recent results of the application of the thermal-hydraulic code BAGIRA to the analysis of complex two-phase flows in nuclear power plants primary loops. In particular, we performed benchmark numerical simulation of an integral LOCA experiment performed on a test facility modeling the primary circuit of VVER-1000. In addition, we have also analyzed the flow patterns in the VVER-1000 steam generator vessel for stationary and transient operation regimes. For both of these experiments we have compared the numerical results with measured data. Finally, we demonstrate the capabilities of BAGIRA by modeling a hypothetical severe accident for a VVER-1000 type nuclear reactor. The numerical analysis, which modeled all stages of the hypothetical severe accident up to the complete ablation of the reactor cavity bottom, shows the importance of multi-dimensional flow effects. (authors)

Kalinichenko, S.D.; Kroshilin, A.E.; Kroshilin, V.E.; Smirnov, A.V. [All-Russian Research Institute for Nuclear Power Plant Operations (VNIIAES) 25 Ferganskaya St., 109507 Moscow (Russian Federation); Kohut, P. [Brookhaven National Laboratory, Bldg. 475 Upton, NY 11973, (United States)

2006-07-01T23:59:59.000Z

434

Program on Technology Innovation: An Optimization Approach for Life-Cycle Management Applied to Large Power Transformers  

Science Conference Proceedings (OSTI)

This report presents results and insights from a study of the life-cycle management (LCM) of main transformers at Constellation Energy Nuclear Group's (CENG's) five nuclear power plants. The study used two asset management (AM) tools developed by Electricit de France (EDF).

2011-07-04T23:59:59.000Z

435

IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. XX, NO. XX, FEBRUARY 2013 1 The Optimized String Dynamic Photovoltaic Array  

E-Print Network (OSTI)

Dynamic Photovoltaic Array Jonathan Storey, Peter R. Wilson, Senior Member, IEEE, and Darren Bagnall Abstract--This paper presents a novel system for producing the optimum power output from photovoltaic arrays using dynamic cell reconfiguration. The proposed approach is the first in the literature

436

Design optimization methodology for power converters based on global energy requirement criteria. Application to a DC-DC flyback structure  

E-Print Network (OSTI)

produce direct current, and most existing electric loads could be powered with direct currents [4», « Life Cycle Analysis (LCA)», «Device modeling». Abstract This paper discusses a design methodology consumption profile. Introduction Nowadays, converters are currently designed to present the best cost and

Paris-Sud XI, Université de

437

Stochastic Modeling of a Power-Managed System: Construction and Optimization Qinru Qiu, Qing Wu and Massoud Pedram  

E-Print Network (OSTI)

Ai : the power management policy i,j: transition rate from state i to state j )( , ta ji i : transition rate from state i to state j at time t when action ai(t) is taken )( , t ji i i A p : transition rate from state when it makes a transition from state i to state j ri: earning rate of the system during the time

Qiu, Qinru

438

Deriving a Near-optimal Power Management Policy Using Model-Free Reinforcement Learning and Bayesian Classification  

E-Print Network (OSTI)

generating rate. The state transition matrix is given by: 0.02 0.01 0.01 0.005 0.01 0.005 0.005 0.005 0 states for the RL algorithm. In this DPM framework, power and latency tradeoffs can be precisely for the given controllable MDP can be found only if we have knowledge (and model) of the state transition

Pedram, Massoud

439

ACCEPTED TO IEEE TRANS. POWER SYSTEMS, APRIL 2011. 1 Abstract In this paper, an optimization model and techniques  

E-Print Network (OSTI)

of end-use PV, 0.4 GW of utility-scale PV, and 0.6 GW of solar-thermal electric capacity under ColemanNon-Hydro,Non-MSW RenewableEnergy(GWh) PV - End Use PV - Electric Power Sector Solar Therm al Electric Geotherm al Biom ass W Portfolio Standard: Little Incremental Solar Generation By 2025, EIA estimates just 5.5 GW of end-use PV, 0

Cañizares, Claudio A.

440

TESTS ON HALF-SCALE FLOW MODEL OF 40-MW(E) PROTOTYPE HTGR (PEACH BOTTOM ATOMIC POWER STATION)  

SciTech Connect

A half-scale clear plastic nonnuclear flow model of the 40-Mw(e) Peach Bottom High-temperature Gas-cooled Reactor (HTGR) vessel and internals was operated during the period from January 1981, through October 1981. The model was operated as an induced system using ambient air as the working fluid. The maximum Reynolds number achieved in the model was approximately one-half of the Reynolds number corresponding to the full-load design conditions in the prototype. The prototype reactor pressure-drop values extrapolated from the flow-model data indicated a pressure drop of 2.0 psi for a helium flow rate of 468,000 lb/hr and pressure of 350 psia, and a constant inlet and Outlet temperature of 650 deg F. The corresponding conservatively calculated pressure-drop value was approximately 2.9 psi. No areas of serious flow starvation were observed within the model during tests with flow through only one nozzle or through both nozzles. The inlet flow divided almost equally into the upward and downward directions. Regions where low velocities were indicated appeared to be turbulent and free from stagnation. Completely closing the four off-center openings in the top head reduced the flow of air from the outer flow jacket to the inner flow jackets by only about 20%. This result supported the design approach of providing only one nozzle in the center of the top head for flow from the outer to the inner flow jackets. The heat-transfer coefficients measured at the inner surface of the pressure vessel varied over a range from 50 to 200 Btu/(hr)(ft2)( deg F), at the design flow rate, and in general were about twice the caiculated values for corresponding points. The tilting reflector was found to be a workable concept. No vibration or movement could be induced in the core by manual manipulation of various reflector blocks. There was no detectable vibration of the core during any mode of flowmodel operation. (auth)

Ross, S.; Dav, E.A.; Skeehan, R.A.

1962-06-20T23:59:59.000Z

Note: This page contains sample records for the topic "optimal power flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

GENERAL REACTOR SIZING TECHNIQUES. VOLUME I. AEROTHERMODYNAMIC OPTIMIZATION  

SciTech Connect

A method is presented for the aerothermodynamic optimization of the net power and/or propulsive thrust per unit reactor free flow area of a nuclear power plant operating on the Brayton cycle. A system so optimized will translate into the minimum size, therefore the minimum weight, nuclear system for any selection of reactor materials, lifetime, and fuel loading. The theory and development of the thermodynamic optimization process, the importance and effect of various parameters, and specific methods to be employed in the optimization of the various forms of the Brayton cycle are discussed. A sample calculation for the case of the ramjet application is included. The results of the application of these techniques to any Brayton cycle system may be used in conjunction with nuclear sizing methods, for beryllia-moderated reactors, to determine the required reactor size as a function of fuel loading and reactivity requirements. (auth)

Prickett, W.Z.

1961-06-01T23:59:59.000Z

442

Effects of blade configuration on flow distribution and power output of a zephyr vertical axis wind turbine.  

E-Print Network (OSTI)

??Worldwide interest in renewable energy systems has increased dramatically, due to environmental concerns like climate change and other factors. Wind power is a major source… (more)

Ajedegba, John Oviemuno

2008-01-01T23:59:59.000Z

443

Constrained Graph Optimization: Interdiction and Preservation Problems  

SciTech Connect

The maximum flow, shortest path, and maximum matching problems are a set of basic graph problems that are critical in theoretical computer science and applications. Constrained graph optimization, a variation of these basic graph problems involving modification of the underlying graph, is equally important but sometimes significantly harder. In particular, one can explore these optimization problems with additional cost constraints. In the preservation case, the optimizer has a budget to preserve vertices or edges of a graph, preventing them from being deleted. The optimizer wants to find the best set of preserved edges/vertices in which the cost constraints are satisfied and the basic graph problems are optimized. For example, in shortest path preservation, the optimizer wants to find a set of edges/vertices within which the shortest path between two predetermined points is smallest. In interdiction problems, one deletes vertices or edges from the graph with a particular cost in order to impede the basic graph problems as much as possible (for example, delete edges/vertices to maximize the shortest path between two predetermined vertices). Applications of preservation problems include optimal road maintenance, power grid maintenance, and job scheduling, while interdiction problems are related to drug trafficking prevention, network stability assessment, and counterterrorism. Computational hardness results are presented, along with heuristic methods for approximating solutions to the matching interdiction problem. Also, efficient algorithms are presented for special cases of graphs, including on planar graphs. The graphs in many of the listed applications are planar, so these algorithms have important practical implications.

Schild, Aaron V [Los Alamos National Laboratory

2012-07-30T23:59:59.000Z

444

Optimization Online  

E-Print Network (OSTI)

NEOS Optimization Server · NEOS Optimization Guide · Linear Programming FAQ · Nonlinear Programming FAQ · Mathematical Programming Glossary ...

445

A Design Tool for the Optimization of Stand-alone Electric Power Systems with Combined Hydrogen-Battery Energy Storage  

E-Print Network (OSTI)

A simulation design tool was developed to investigate the design and performance of stand-alone distributed renewable electric power systems. The temporal mismatch between energy production and use results in the inclusion of energy storage devices that can become an important and expensive component of these systems. To properly size all system components, a time response model with one hour resolution was developed. Specifically, the model developed here simulates one year of grid operation with the constraint that it be "stand-alone" - that is, that there be no net change in stored energy. With two storage components, hydrogen and batteries, the system size was calculated as a function of the battery storage size, and the total system was costed with battery size as the parameter. Calculations were performed for the specific case of residential use in Yuma, Arizona. In addition to determining the size and cost of this grid, it was found that the system costs using a combination of h...

Steven Vosen Combustion; S. R. Vosen; Microfiche Copy Ao; Steven R. Vosen

1997-01-01T23:59:59.000Z

446

Optimal design and control strategies for novel combined heat and power (CHP) fuel cell systems. Part II of II, case study results.  

SciTech Connect

Innovative energy system optimization models are deployed to evaluate novel fuel cell system (FCS) operating strategies, not typically pursued by commercial industry. Most FCS today are installed according to a 'business-as-usual' approach: (1) stand-alone (unconnected to district heating networks and low-voltage electricity distribution lines), (2) not load following (not producing output equivalent to the instantaneous electrical or thermal demand of surrounding buildings), (3) employing a fairly fixed heat-to-power ratio (producing heat and electricity in a relatively constant ratio to each other), and (4) producing only electricity and no recoverable heat. By contrast, models discussed here consider novel approaches as well. Novel approaches include (1) networking (connecting FCSs to electrical and/or thermal networks), (2) load following (having FCSs produce only the instantaneous electricity or heat demanded by surrounding buildings), (3) employing a variable heat-to-power ratio (such that FCS can vary the ratio of heat and electricity they produce), (4) co-generation (combining the production of electricity and recoverable heat), (5) permutations of these together, and (6) permutations of these combined with more 'business-as-usual' approaches. The detailed assumptions and methods behind these models are described in Part I of this article pair.

Colella, Whitney G.

2010-06-01T23:59:59.000Z

447

Improved Fluid Flow Measurements: Feedwater Flow  

Science Conference Proceedings (OSTI)

This report describes the combined results of a utility survey and site visits concerning feedwater flow measurement in fossil-fueled power plants. In addition, a summary is provided of the technologies available to measure the volumetric feedwater flow rate in plants. This volumetric flow rate can be converted to a mass flow rate by knowing the pressure and temperature of the flow media. Velocity meters, differential pressure meters, and other closed-conduit flowmeters are discussed along with ...

2012-11-28T23:59:59.000Z

448

FOR ELECTRIC POWER TRANSMISSION  

E-Print Network (OSTI)

A contract network extends the concept of a contract path to address the problem of loop flow and congestion in electric power transmission systems. A contract network option provides a well defined, internally consistent framework for assigning long-term capacity rights to a complicated electric transmission network. The contract network respects the special conditions induced by Kirchoff's Laws; accommodates thermal, voltage and contingency constraints on transmission capacity; and can be adopted without disturbing existing methods for achieving an economic power dispatch subject to these constraints. By design, a contract network would maintain short-run efficiency through optimal spot price determination of transmission prices. Through payment of congestion rentals, the contract network makes a long-term capacityright holder indifferent between delivery of the power or receipt of payments in a settlement system. And the contract network framework can support allocation of transmission capacity rights through a competitive bidding process. CONTRACT NETWORKS

William W. Hogan; William W. Hogan

1990-01-01T23:59:59.000Z

449

Ionization-Based Multi-directional Flow Sensor  

NLE Websites -- All DOE Office Websites (Extended Search)

Ionization-Based Multi-directional Flow Sensor Ionization-Based Multi-directional Flow Sensor Opportunity The Department of Energy's National Energy Technology Laboratory (NETL) is seeking licensing partners interested in implementing United States Patent Number 7,523,673 entitled "Ionization Based Multi-directional Flow Sensor." Disclosed in this patent is NETL's sensor system and process for multi- directional, real-time monitoring of the flow direction and velocity of a gas stream, with minimal pressure drop, such as air flow in a hybrid power generation system. The sensor comprises an ion source accom- panied by a multidirectional ion collection device near the ion source. Possible applications include power generation and weather monitoring. Overview To optimize the performance of certain industrial processes or apparatus,

450

Process Flow Chart for Immobilizing of Radioactive High Concentration Sodium Hydroxide Product from the Sodium Processing Facility at the BN-350 Nuclear power plant in Aktau, Kazakhstan  

Science Conference Proceedings (OSTI)

This paper describes the results of a joint research investigations carried out by the group of Kazakhstan, British and American specialists in development of a new material for immobilization of radioactive 35% sodium hydroxide solutions from the sodium coolant processing facility of the BN-350 nuclear power plant. The resulting solid matrix product, termed geo-cement stone, is capable of isolating long lived radionuclides from the environment. The physico-mechanical properties of geo-cement stone have been investigated and the flow chart for its production verified in a full scale experiments. (author)

Burkitbayev, M.; Omarova, K.; Tolebayev, T. [Ai-Farabi Kazakh National University, Chemical Faculty, Republic of Kazakhstan (Kazakhstan); Galkin, A. [KATEP Ltd., Republic of Kazakhstan (Kazakhstan); Bachilova, N. [NIISTROMPROEKT Ltd., Republic of Kazakhstan (Kazakhstan); Blynskiy, A. [Nuclear Technology Safety Centre, Republic of Kazakhstan (Kazakhstan); Maev, V. [MAEK-Kazatomprom Ltd., Republic of Kazakhstan (Kazakhstan); Wells, D. [NUKEM Limited- a member of the Freyssinet Group, Winfrith Technology Centre, Dorchester, Dorset (United Kingdom); Herrick, A. [NUKEM Limited- a member of the Freyssinet Group, Caithness (United Kingdom); Michelbacher, J. [Idaho National Laboratory, Idaho Falls (United States)

2008-07-01T23:59:59.000Z

451

Electric power 2007  

SciTech Connect

Subjects covered include: power industry trends - near term fuel strategies - price/quality/delivery/opportunity; generating fleet optimization and plant optimization; power plant safety and security; coal power plants - upgrades and new capacity; IGCC, advanced combustion and CO{sub 2} capture technologies; gas turbine and combined cycle power plants; nuclear power; renewable power; plant operations and maintenance; power plant components - design and operation; environmental; regulatory issues, strategies and technologies; and advanced energy strategies and technologies. The presentations are in pdf format.

NONE

2007-07-01T23:59:59.000Z

452

The Coordinated Control of a Central Air Conditioning System Based on Variable Chilled Water Temperature and Variable Chilled Water Flow  

E-Print Network (OSTI)

At present, regulation of water flow by means of pump frequency conversion is one of the major methods for power-saving in central air conditioning systems. In this article, optimization regulation for central air conditioning system on the basis of coordinative optimization control for variable chilled water temperature and variable chilled water flow to obtain better power savings is put forward. According to typical meteorological year data, hourly air conditioning load of whole year for every typical room has been calculated with the transmission function method. In order to guarantee each typical room, the highest cooling load rate is used as an input parameter for optimization calculation. Based on the surface cooler check model, the smallest energy consumption of chiller and chiller water pump was taken as the objective function of the optimization model. The performance characteristics of a chiller, water pump, regulation valve and pipeline are taken into account, and the optimization chilled water temperature and chilled water flow were carried out. The case study for a commercial building in Guangzhou showed that the annual power consumption of the chillers and pumps of the air conditioning system is lower by 17% only with employment of variable water flow regulation by pump frequency conversion. In the case of optimization control with coordinative control of variable chilled water temperature and variable chilled water flow, the annual power consumption of the chillers and pumps of the air conditioning system is reduced by 22% in presence of remarkable power saving effects. Increasing the chilled water temperature will reduce the dehumidified capability of the air cooler, and the indoor relative humidity will increase. The simulation showed that the adjustment optimized process meets the comfort of each typical room. The lower the cooling load rate is, the more obvious the effect of power-saving is. The highest power-saving rate appears in December, which is 36.7%. Meanwhile, the least rate appears in July, which is only 14.5%.

Liu, J.; Mai, Y.; Liu, X.

2006-01-01T23:59:59.000Z

453

Analysis of hybrid power system incorporating squirrel cage induction generators  

Science Conference Proceedings (OSTI)

This paper presents generic model of hybrid power system consisting in a combined solution one wind turbine with asynchronous generator and on hydro generator with synchronous machine. This technology was developed by to reduce the cost of supplying ... Keywords: asynchronous generator, homer, optimal design, renewable energy, variable speed generation, voltage and frequency controller, water flow

Sorin Ioan Deaconu; Marcel Topor; Gabriel Nicolae Popa; Diana Bistrian

2009-07-01T23:59:59.000Z

454

Gas permeation carbon capture --- Process modeling and optimization  

SciTech Connect

A multi-staged gas permeation carbon capture process model was developed in Aspen Custom Modeler{reg_sign} (ACM) and optimized in the context of the retrofit of a 550 MW subcritical pulverized coal (PC) power plant. The gas permeation stages in the process are described by a custom multi-component, hollowfiber membrane model. Gas transport across the asymmetric membrane was modeled according to the solution-diffusion model for the selective skin layer and the assumption of negligible flux resistance by the porous support. Counter-current, one-dimensional plug flow was assumed with permeate pressure drop in the fiber lumen side due to capillary constrained flow. A modular optimization framework was used to minimize the levelized cost of electricity (LCOE) by optimizing a set of key process variables. The framework allows the external control of multiple simulation modules from different software packages from a common interface.

Morinelly, Juan; Miller, David

2011-01-01T23:59:59.000Z

455

PowerPoint Presentation  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Investigation of Advanced Stochastic Investigation of Advanced Stochastic Unit Commitment Solution for Optimal Management of Uncertainty C. Lindsay Anderson CERTS Review, Cornell University August 6, 2013 Overview * Objective * Proposed directions - Probabilistic constraints - Algorithms * Challenges * Conclusions What is "Advanced"? * SCUC is a multi-stage and bi-level optimization problem - Level 1: Binary unit on/off decisions - Level 2: OPF/ED submodel for security * Many variations on this structure to balance details and computational tractability * Stochastic formulations have mainly been scenario-based with dc power flow Objective * Investigation of a formulations for SCUC that will be Flexible: able to include supply and demand side resources in a realistic way, integrate with other

456

Optimization Online - All Areas Submissions - February 2013  

E-Print Network (OSTI)

A NOTE ON THE EXTENSION COMPLEXITY OF THE KNAPSACK POLYTOPE Sebastian Pokutta, Mathieu Van Vyve. Other Topics Optimal Power Grid ...

457

Power network analysis and optimization  

E-Print Network (OSTI)

V dd : minimal voltage requirement. Voltage is V min :V min : minimal voltage requirement; Voltage is considered

Zhang, Wanping

2009-01-01T23:59:59.000Z

458

Optimization in Mung Chiang  

E-Print Network (OSTI)

Optimization in Networking Mung Chiang Princeton University 10th MOPTA August 18, 2010 #12;Routing variables {xl, s} #12;Power Control P. Hande,S. Rangan, M. Chiang, X. Wu, "Distributed uplink power control. Chen, S. Liu, S. Sengputa, M. Chiang, J. Li, and P. A. Chou, "P2P streaming capacity", IEEE

Chiang, Mung

459

Optimal control of photovoltaic arrays  

Science Conference Proceedings (OSTI)

A high value of the energy conversion efficiency is not the only feature a photovoltaic power processing system must have. An optimal control of the photovoltaic generator must be also designed in order to maximize the electrical power it produces, even ... Keywords: Maximum power point tracking, Photovoltaic systems, Power electronics

N. Femia, G. Petrone, G. Spagnuolo, M. Vitelli

2013-05-01T23:59:59.000Z

460

Optimal operational strategies for a day-ahead electricity market in the presence of market power using multi-objective evolutionary algorithm.  

E-Print Network (OSTI)

??This dissertation introduces a novel approach for optimally operating a day-ahead electricity market not only by economically dispatching the generation resources but also by minimizing… (more)

Rodrigo, Deepal

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "optimal power flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Peak power identification on power bumps during test application  

Science Conference Proceedings (OSTI)

Peak power during test can seriously impact circuit performance as well as the power safety for both CUT and tester. In this paper, we propose a method of layout-aware weighted switching activity identification flow that evaluates peak current/power ... Keywords: CMOS device, peak power identification, power bumps, test application, layout-aware weighted switching activity identification flow, dynamic power model, parasitic capacitance, resistance network, power bus, power delivery path, IR-drop, commercial power sign-off analysis tool

Wei Zhao; M. Tehranipoor

2011-07-01T23:59:59.000Z

462

The power tool  

Science Conference Proceedings (OSTI)

POWER Tool--Planning, Optimization, Waste Estimating and Resourcing tool, a hand-held field estimating unit and relational database software tool for optimizing disassembly and final waste form of contaminated systems and equipment.

HAYFIELD, J.P.

1999-02-01T23:59:59.000Z

463

Fact Sheet: Vanadium Redox Flow Batteries (October 2012) | Department of  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Vanadium Redox Flow Batteries (October 2012) Vanadium Redox Flow Batteries (October 2012) Fact Sheet: Vanadium Redox Flow Batteries (October 2012) DOE's Energy Storage Program is funding research to develop next-generation vanadium redox flow batteries (VRBs) that reduce costs by improving energy and power densities, widening the operating temperature window, and simplifying and optimizing stack/system designs. These efforts build on Pacific Northwest National Laboratory research that has developed new redox electrolytes that enable increased VRB operating temperatures and energy storage capabilities. Fact Sheet: Vanadium Redox Flow Batteries (October 2012) More Documents & Publications Energy Storage Systems 2012 Peer Review Presentations - Day 3, Session 2 Energy Storage Systems 2012 Peer Review Presentations - Poster Session 2

464

Portfolio Optimization: Concepts and Challenges  

Science Conference Proceedings (OSTI)

The term "portfolio optimization" -- the process of finding and exploiting opportunities to add value by changing the composition of a business portfolio -- has been occurring with increasing frequency in the electric power industry. For example, portfolio optimization has appeared as a topic on agendas for numerous industry conferences. Vendors of commercial software for trading and risk management also are starting to promote portfolio optimization's capabilities. Though portfolio optimization is a hot...

2002-12-18T23:59:59.000Z

465

Gasification CFD Modeling for Advanced Power Plant Simulations  

Science Conference Proceedings (OSTI)

In this paper we have described recent progress on developing CFD models for two commercial-scale gasifiers, including a two-stage, coal slurry-fed, oxygen-blown, pressurized, entrained-flow gasifier and a scaled-up design of the PSDF transport gasifier. Also highlighted was NETL’s Advanced Process Engineering Co-Simulator for coupling high-fidelity equipment models with process simulation for the design, analysis, and optimization of advanced power plants. Using APECS, we have coupled the entrained-flow gasifier CFD model into a coal-fired, gasification-based FutureGen power and hydrogen production plant. The results for the FutureGen co-simulation illustrate how the APECS technology can help engineers better understand and optimize gasifier fluid dynamics and related phenomena that impact overall power plant performance.

Zitney, S.E.; Guenther, C.P.

2005-09-01T23:59:59.000Z

466

Bull Run Fossil Plant Online Coal Flow Adjustable Riffler Test  

Science Conference Proceedings (OSTI)

Boiler optimization at fossil-fired power plants would be enhanced if the flow of coal and air in individual pulverizer fuel delivery lines could be balanced. The static splitter devices currently in service do not adequately maintain coal balance, especially when plant conditions change. This report summarizes the results of a test program to demonstrate the feasibility of using a novel riffler to make online adjustments to a stream of pneumatically conveyed pulverized coal at a working plant. The demon...

2008-03-13T23:59:59.000Z

467

PowerPoint Presentation  

NLE Websites -- All DOE Office Websites (Extended Search)

* Grain-oriented electrical steels for high efficiency power and distribution transformers. * Alloys for renewable energy systems. * Alloy design for optimization of...

468

Building Energy Software Tools Directory: CHP Capacity Optimizer  

NLE Websites -- All DOE Office Websites (Extended Search)

Related Links CHP Capacity Optimizer CHP Capacity Optimizer logo Selecting the proper installed capacity for cooling, heating, and power (CHP) equipment is critical to the...

469

Improvements in sparse matrix/vector technique applications for on-line load flow calculation  

Science Conference Proceedings (OSTI)

Sparsity technique is applied to a wide range of problems in power systems analysis. In this paper the authors propose several analytical and computational improvements in sparsity applications. The new partial matrix refactorization method and ordering algorithm are presented. The proposed method is very efficient when applied to various kinds of programs, such as: on-line load flow, optimal power flow and steady-state security analysis. The proposed methodology is applied in a fast decoupled load flow program which include the treatment of tap violations on under-load tap changing (ULTC) transformers and reactive power generation on PV buses. Effects of proposed improvements are well tested and documented on the three networks: 118 bus IEEE test network and two utility networks with 209 and 519 buses, respectively. Keywords: sparsity technique, load flow analysis, security analysis.

Ristanovic, P.; Bjelogrlic, M.; Babic, B.S.

1989-02-01T23:59:59.000Z

470

Modeling and optimization of permanent magnetic motors  

E-Print Network (OSTI)

This thesis develops analytic models for the prediction and optimization of radial-flux permanent magnet motor torque and efficiency. It also facilitates the design optimization of electromagnetically-powered rotorcraft ...

Pinkham, Andrew P

2008-01-01T23:59:59.000Z

471

Optimal Planning of a Load Transfer Substation Pair between Two Normally Closed-Loop Feeders Considering Minimization of System Power Losses Using a Genetic Algorithm  

Science Conference Proceedings (OSTI)

This paper proposes an effective approach for planning a load transfer substation pair(LTSP) between two normally closed-loop feeders considering minimization of system power losses. Firstly, the annual equivalent load of each load point is calculated. ... Keywords: distribution feeder, normally closed-loop feeder, distribution substation, genetic algorithm, power losses

Wei-Tzer Huang; Kai-chao Yao; Shiuan-Tai Chen; Hsiau-Hsian Nien; Deng-Chung Lin; Po-Tung Huang

2010-12-01T23:59:59.000Z

472

Designing Axial Flow Fan for Flow and Noise  

E-Print Network (OSTI)

A comprehensive finite element methodology is developed to predict the compressible flow performance of a non-symmetric 7-blade axial flow fan, and to quantify the source strength and sound pressure levels at any location in the system. The acoustic and flow performances of the fan are predicted simultaneously using a computational aero-acoustic technique combining transient flow analysis and noise propagation. The calculated sound power levels compare favorably with the measured sound power data per AMCA 300-96 code.

Subrata Roy; Phillip Cho; Fred Périé; International Off-highway

1999-01-01T23:59:59.000Z