National Library of Energy BETA

Sample records for torque converter lockup

  1. Helical buckling and lock-up conditions for coiled tubing in curved wells

    SciTech Connect (OSTI)

    He, X.; Kyllingstad, A.

    1995-03-01

    An improved formula for critical buckling loads has been derived. This formula, which takes the well curvature into account, has been verified in small scale laboratory tests. The theory has been applied to survey data from a real horizontal well and it predicts that the well curvature substantially affects the critical force for helical buckling, and thereby also the maximum run-in length of coiled tubing. Criteria for operational limits, such as lock-up and tubing failure, are also discussed in the paper.

  2. Fabricated torque shaft

    DOE Patents [OSTI]

    Mashey, Thomas Charles (Anderson, SC)

    2002-01-01

    A fabricated torque shaft is provided that features a bolt-together design to allow vane schedule revisions with minimal hardware cost. The bolt-together design further facilitates on-site vane schedule revisions with parts that are comparatively small. The fabricated torque shaft also accommodates stage schedules that are different one from another in non-linear inter-relationships as well as non-linear schedules for a particular stage of vanes.

  3. DSA torque test robot

    SciTech Connect (OSTI)

    McMillan, D.E.

    1990-11-01

    A rotary solenoid used in the Dual Strong-Link Assembly (DSA) has a housing diameter of 0.67 inches, and overall length of approximately 1.37 inches. The rotor and housing each have four poles. When the coil is energized and the shaft is rotated, magnetic torque is produced which completes four nominally identical cycles during each revolution of the shaft. At zero and 90 degrees of shaft rotation, the poles are aligned and the rotor is stable. The mid-point between poles is unstable; any displacement produces a torque toward one of the stable points. A torque measurement is performed on each solenoid produced. The measurement technique used previously was labor intensive and required that analog torque plots be manually interpreted to determine compliance with the torque specification. This paper describes a robotically assisted torque measurement system that was developed and placed into production. This system reduces cycle time from approximately 6 minutes per part to a little more than 1 minute per part.

  4. Beam converter

    DOE Patents [OSTI]

    Poulsen, Peter

    2003-05-06

    A converter and method for converting electron energy to irradiative energy comprising foam and/or foil. Foam and foil optionally comprise a high-Z material, such as, but not limited to, tantalum.

  5. Reconstructing the intermittent dynamics of the torque in wind turbines

    E-Print Network [OSTI]

    Lind, Pedro G; Peinke, Joachim

    2014-01-01

    We apply a framework introduced in the late nineties to analyze load measurements in off-shore wind energy converters (WEC). The framework is borrowed from statistical physics and properly adapted to the analysis of multivariate data comprising wind velocity, power production and torque measurements, taken at one single WEC. In particular, we assume that wind statistics drives the fluctuations of the torque produced in the wind turbine and show how to extract an evolution equation of the Langevin type for the torque driven by the wind velocity. It is known that the intermittent nature of the atmosphere, i.e. of the wind field, is transferred to the power production of a wind energy converter and consequently to the shaft torque. We show that the derived stochastic differential equation quantifies the dynamical coupling of the measured fluctuating properties as well as it reproduces the intermittency observed in the data. Finally, we discuss our approach in the light of turbine monitoring, a particular importa...

  6. Thermionic converter

    DOE Patents [OSTI]

    Fitzpatrick, G.O.

    1987-05-19

    A thermionic converter is set forth which includes an envelope having an electron collector structure attached adjacent to a wall. An electron emitter structure is positioned adjacent the collector structure and spaced apart from opposite wall. The emitter and collector structures are in a common chamber. The emitter structure is heated substantially only by thermal radiation. Very small interelectrode gaps can be maintained utilizing the thermionic converter whereby increased efficiency results. 10 figs.

  7. Thermomagnetic Torque in Nh3 

    E-Print Network [OSTI]

    Adair, Thomas W.; McClurg, G. R.

    1970-01-01

    raises the question of whether the Scott torque has the same sign as the molecular g~ factor in ammonia as it does in all other gases. The research reported here shows that NH3 is quite normal. Progress on a detailed theory for the transport... torque. The new ap- paratus' used in the present work gave no measur- able torque at zero magnetic field, and therefore no correction was needed. The ammonia was high-purity gas from the Mathe- son Gas Products Company with a stated purity of 99. 99...

  8. Quick torque coupling

    DOE Patents [OSTI]

    Luft, Peter A. (El Cerrito, CA)

    2009-05-12

    A coupling for mechanically connecting modular tubular struts of a positioning apparatus or space frame, comprising a pair of toothed rings (10, 12) attached to separate strut members (16), the teeth (18, 20) of the primary rings (10, 12) mechanically interlocking in both an axial and circumferential manner, and a third part comprising a sliding, toothed collar (14) the teeth (22) of which interlock the teeth (18, 20) of the primary rings (10, 12), preventing them from disengaging, and completely locking the assembly together. A secondary mechanism provides a nesting force for the collar, and/or retains it. The coupling is self-contained and requires no external tools for installation, and can be assembled with gloved hands in demanding environments. No gauging or measured torque is required for assembly. The assembly can easily be visually inspected to determine a "go" or "no-go" status. The coupling is compact and relatively light-weight. Because of it's triply interlocking teeth, the connection is rigid. The connection does not primarily rely on clamps, springs or friction based fasteners, and is therefore reliable in fail-safe applications.

  9. Proton transport and torque generation in rotary biomotors

    E-Print Network [OSTI]

    A. Yu. Smirnov; S. Savel'ev; L. G. Mourokh; Franco Nori

    2008-05-29

    We analyze the dynamics of rotary biomotors within a simple nano-electromechanical model, consisting of a stator part and a ring-shaped rotor having twelve proton-binding sites. This model is closely related to the membrane-embedded F$_0$ motor of adenosine triphosphate (ATP) synthase, which converts the energy of the transmembrane electrochemical gradient of protons into mechanical motion of the rotor. It is shown that the Coulomb coupling between the negative charge of the empty rotor site and the positive stator charge, located near the periplasmic proton-conducting channel (proton source), plays a dominant role in the torque-generating process. When approaching the source outlet, the rotor site has a proton energy level higher than the energy level of the site, located near the cytoplasmic channel (proton drain). In the first stage of this torque-generating process, the energy of the electrochemical potential is converted into potential energy of the proton-binding sites on the rotor. Afterwards, the tangential component of the Coulomb force produces a mechanical torque. We demonstrate that, at low temperatures, the loaded motor works in the shuttling regime where the energy of the electrochemical potential is consumed without producing any unidirectional rotation. The motor switches to the torque-generating regime at high temperatures, when the Brownian ratchet mechanism turns on. In the presence of a significant external torque, created by ATP hydrolysis, the system operates as a proton pump, which translocates protons against the transmembrane potential gradient. Here we focus on the F$_0$ motor, even though our analysis is applicable to the bacterial flagellar motor.

  10. Robot-assisted torque measurement

    SciTech Connect (OSTI)

    Lembke, J.R.

    1986-03-01

    An Intelledex 605T robot was used to evaluate the feasibility of automating the measurement of rotary solenoid torque, with the goal of improving productivity. The solenoid chosen for the evaluation is expected to be produced in relatively large quantities for several programs. A new measurement concept was devised, in which the robot connects the solenoid shaft to a torque sensor, rotates the solenoid housing, and correlates rotational data with digitized torque measurements. Prototype tooling was designed and fabricated, and the measurement concept was evaluated in comparison with the manual method which is presently used. The automatic robot-based measurement system was shown to yield results that are in good agreement with manual measurements. The technique automatically performs all necessary operations once the solenoids have been placed into a part loading fixture, with a cycle time significantly reduced from the manual method. Manual interpretation of chart data is not required, because the results are digitized. The system can compare the measured torque to specification limits and can provide a printed report of acceptance or rejection. 12 figs.

  11. Torque Equation (See section 4.9)

    E-Print Network [OSTI]

    McCalley, James D.

    1 Torque Equation (See section 4.9) Our goal is to combine the state-space voltage equations with the state-space torque equations. To achieve this, we need to do the following three things to the torque equation: 1. Address the difference in power bases. 2. Address the difference in speed (time) bases. 3

  12. Self-oscillation in spin torque oscillator stabilized by field-like torque

    SciTech Connect (OSTI)

    Taniguchi, Tomohiro; Tsunegi, Sumito; Kubota, Hitoshi; Imamura, Hiroshi

    2014-04-14

    The effect of the field-like torque on the self-oscillation of the magnetization in spin torque oscillator with a perpendicularly magnetized free layer was studied theoretically. A stable self-oscillation at zero field is excited for negative ? while the magnetization dynamics stops for ??=?0 or ??>?0, where ? is the ratio between the spin torque and the field-like torque. The reason why only the negative ? induces the self-oscillation was explained from the view point of the energy balance between the spin torque and the damping. The oscillation power and frequency for various ? were also studied by numerical simulation.

  13. The Casimir Torque on a Cylindrical Gear

    E-Print Network [OSTI]

    Vaidya, Varun

    2013-01-01

    We utilize Effective Field Theory(EFT) techniques to calculate the casimir torque on a cylindrical gear in the presence of a polarizable but neutral object. We present results for the energy and torque as a function of angle for a gear with multiple cogs, as well as for the case of a concentric cylindrical gear.

  14. The Casimir Torque on a Cylindrical Gear

    E-Print Network [OSTI]

    Varun Vaidya

    2013-09-02

    We utilize Effective Field Theory(EFT) techniques to calculate the casimir torque on a cylindrical gear in the presence of a polarizable but neutral object. We present results for the energy and torque as a function of angle for a gear with multiple cogs, as well as for the case of a concentric cylindrical gear.

  15. Large amplitude oscillation of magnetization in spin-torque oscillator stabilized by field-like torque

    SciTech Connect (OSTI)

    Taniguchi, Tomohiro Kubota, Hitoshi; Imamura, Hiroshi; Tsunegi, Sumito

    2015-05-07

    Oscillation frequency of spin torque oscillator with a perpendicularly magnetized free layer and an in-plane magnetized pinned layer is theoretically investigated by taking into account the field-like torque. It is shown that the field-like torque plays an important role in finding the balance between the energy supplied by the spin torque and the dissipation due to the damping, which results in a steady precession. The validity of the developed theory is confirmed by performing numerical simulations based on the Landau-Lifshitz-Gilbert equation.

  16. Power Converters for Accelerators

    E-Print Network [OSTI]

    Visintini, R

    2015-01-01

    Particle accelerators use a great variety of power converters for energizing their sub-systems; while the total number of power converters usually depends on the size of the accelerator or combination of accelerators (including the experimental setup), the characteristics of power converters depend on their loads and on the particle physics requirements: this paper aims to provide an overview of the magnet power converters in use in several facilities worldwide.

  17. Switching Power Converter A/D Converters

    E-Print Network [OSTI]

    to make intelligent decisions on load and system management prior to system faults. With the increased use of the converter [1]. Traditionally, system monitoring and control is performed by a central power management

  18. Casimir Torque in Inhomogeneous Dielectric Plates

    E-Print Network [OSTI]

    William Long; Lucas Schuermann

    2014-04-17

    In this work, we consider a torque caused by the well known quantum mechanical Casimir effect arising from quantized field fluctuations between plates with inhomogeneous, sharply discontinuous, dielectric properties. While the Casimir effect is a relatively well understood phenomenon, systems resulting in lateral or rotational forces are far less developed; to our knowledge, a theoretical study of discontinuous dielectric variants of such systems has not been attempted. We utilize a Proximity Force Approximation in conjunction with the Lifshitz dielectric formula to perform theoretical analyses of resultant torques in systems with bisected and quadrisected dielectric regions. We also develop a high precision Monte Carlo type numerical integrator to approximate our derived expressions. Our calculations of an energy density linear with the alignment angle result in a constant torque and have implications in NEMS (nano electromechanical systems) and MEMS (micro electromechanical systems), including a postulated nanoscale oscillating drive mechanism powered by quantum field interactions.

  19. Torque limit of PM motors for field-weakening region operation

    DOE Patents [OSTI]

    Royak, Semyon (Beachwood, OH); Harbaugh, Mark M. (Richfield, OH)

    2012-02-14

    The invention includes a motor controller and technique for controlling a permanent magnet motor. In accordance with one aspect of the present technique, a permanent magnet motor is controlled by receiving a torque command, determining a physical torque limit based on a stator frequency, determining a theoretical torque limit based on a maximum available voltage and motor inductance ratio, and limiting the torque command to the smaller of the physical torque limit and the theoretical torque limit. Receiving the torque command may include normalizing the torque command to obtain a normalized torque command, determining the physical torque limit may include determining a normalized physical torque limit, determining a theoretical torque limit may include determining a normalized theoretical torque limit, and limiting the torque command may include limiting the normalized torque command to the smaller of the normalized physical torque limit and the normalized theoretical torque limit.

  20. Interleaved power converter

    DOE Patents [OSTI]

    Zhu, Lizhi (Canton, MI)

    2007-11-13

    A power converter architecture interleaves full bridge converters to alleviate thermal management problems in high current applications, and may, for example, double the output power capability while reducing parts count and costs. For example, one phase of a three phase inverter is shared between two transformers, which provide power to a rectifier such as a current doubler rectifier to provide two full bridge DC/DC converters with three rather than four high voltage inverter legs.

  1. Universal thermochemical energy converter

    DOE Patents [OSTI]

    Labinov, Solomon Davidovich (Oak Ridge, TN); Sand, James R. (Oak Ridge, TN); Conklin, James C. (Knoxville, TN); VanCoevering, James (Oak Ridge, TN); Courville, George E. (Oak Ridge, TN)

    2001-01-01

    Disclosed are methods and apparatus for a thermochemical closed cycle employing a polyatomic, chemically active working fluid for converting heat energy into useful work.

  2. Spinorbit-torque engineering via oxygen manipulation

    E-Print Network [OSTI]

    Yao, Shao Q

    at room temperature, which is desirable in spintronic devices such as spin transfer torque memories. When for spintronic memory and logic devices. Magnetization switching using conventional current-induced spin transfer stability, simplicity and scalability of SOT make it attractive for next-generation spintronic devices

  3. Microminiature thermionic converters

    DOE Patents [OSTI]

    King, Donald B. (Albuquerque, NM); Sadwick, Laurence P. (Salt Lake City, UT); Wernsman, Bernard R. (Clairton, PA)

    2001-09-25

    Microminiature thermionic converts (MTCs) having high energy-conversion efficiencies and variable operating temperatures. Methods of manufacturing those converters using semiconductor integrated circuit fabrication and micromachine manufacturing techniques are also disclosed. The MTCs of the invention incorporate cathode to anode spacing of about 1 micron or less and use cathode and anode materials having work functions ranging from about 1 eV to about 3 eV. Existing prior art thermionic converter technology has energy conversion efficiencies ranging from 5-15%. The MTCs of the present invention have maximum efficiencies of just under 30%, and thousands of the devices can be fabricated at modest costs.

  4. Torque ripple in a Darrieus, vertical axis wind turbine

    SciTech Connect (OSTI)

    Reuter, R.C. Jr.

    1980-09-01

    Interaction between a steady wind and a rotating, Darrieus, vertical axis wind turbine produces time periodic aerodynamic loads which cause time dependent torque variations, referred to as torque ripple, to occur in the mechanical link between the turbine and the electrical generator. There is concern for the effect of torque ripple upon fatigue life of drive train components and upon power quality. An analytical solution characterizing the phenomenon of torque ripple has been obtained which is based upon a Fourier expansion of the time dependent features of the problem. Numerical results for torque ripple, some experimental data, determination of acceptable levels and methods of controlling it, are presented and discussed.

  5. Voltage Converter TYPICAL APPLICATION

    E-Print Network [OSTI]

    Berns, Hans-Gerd

    1 LTC660 100mA CMOS Voltage Converter TYPICAL APPLICATION U s Simple Conversion of 5V to ­5V Supply s Output Drive: 100mA s ROUT: 6.5 (0.65V Loss at 100mA) s BOOST Pin (Pin 1) for Higher Switching Frequency-capacitor voltage converter. It performs supply voltage conversion from positive to negative from an input range

  6. Swing switching of spin-torque valves

    E-Print Network [OSTI]

    Tom Dunn; Alex Kamenev

    2012-10-10

    We propose a method for inducing magnetization reversal using an AC spin current polarized perpendicular to the equilibrium magnetization of the free magnetic layer. We show that the critical AC spin current is significantly smaller than the corresponding DC one. The effect is understood as a consequence of the underdamped nature of the spin-torque oscillators. It allows to use the kinetic inertia to overcome the residual energy barrier, rather than suppressing the latter by a large spin current. The effect is similar to a swing which may be set into high amplitude motion by a weak near-resonant push. The optimal AC frequency is identified as the upper bifurcation frequency of the corresponding driven nonlinear oscillator. Together with fast switching times it makes the perpendicular AC method to be the most efficient way to realize spin-torque memory valve.

  7. Vector generator scan converter

    DOE Patents [OSTI]

    Moore, James M. (Livermore, CA); Leighton, James F. (Livermore, CA)

    1990-01-01

    High printing speeds for graphics data are achieved with a laser printer by transmitting compressed graphics data from a main processor over an I/O (input/output) channel to a vector generator scan converter which reconstructs a full graphics image for input to the laser printer through a raster data input port. The vector generator scan converter includes a microprocessor with associated microcode memory containing a microcode instruction set, a working memory for storing compressed data, vector generator hardward for drawing a full graphic image from vector parameters calculated by the microprocessor, image buffer memory for storing the reconstructed graphics image and an output scanner for reading the graphics image data and inputting the data to the printer. The vector generator scan converter eliminates the bottleneck created by the I/O channel for transmitting graphics data from the main processor to the laser printer, and increases printer speed up to thirty fold.

  8. Vector generator scan converter

    DOE Patents [OSTI]

    Moore, J.M.; Leighton, J.F.

    1988-02-05

    High printing speeds for graphics data are achieved with a laser printer by transmitting compressed graphics data from a main processor over an I/O channel to a vector generator scan converter which reconstructs a full graphics image for input to the laser printer through a raster data input port. The vector generator scan converter includes a microprocessor with associated microcode memory containing a microcode instruction set, a working memory for storing compressed data, vector generator hardware for drawing a full graphic image from vector parameters calculated by the microprocessor, image buffer memory for storing the reconstructed graphics image and an output scanner for reading the graphics image data and inputting the data to the printer. The vector generator scan converter eliminates the bottleneck created by the I/O channel for transmitting graphics data from the main processor to the laser printer, and increases printer speed up to thirty fold. 7 figs.

  9. Numerical Estimation of Frictional Torques with Rate and State Friction

    E-Print Network [OSTI]

    Arun K. Singh; T. N. Singh

    2015-01-20

    In this paper, numerical estimation of frictional torques is carried out of a rotary elastic disc on a hard and rough surface under different rotating conditions. A one dimensional spring- mass rotary system is numerically solved under the quasistatic condition with the rate and state dependent friction model. It is established that torque of frictional strength as well as torque of steady dynamic stress increases with radius and found to be maximum at the periphery of the disc. Torque corresponding to frictional strength estimated using the analytical solution matches closely with the simulation only in the case of high stiffness of the connecting spring. In steady relaxation simulation, a steadily rotating disc is suddenly stopped and relaxational angular velocity and corresponding frictional torque decreases with both steady angular velocity and stiffness of the connecting spring in the velocity strengthening regime. In velocity weakening regime, in contrast, torque of relaxation stress deceases but relaxation velocity increases. The reason for the contradiction is explained.

  10. Liquid metal thermal electric converter

    DOE Patents [OSTI]

    Abbin, Joseph P. (Albuquerque, NM); Andraka, Charles E. (Albuquerque, NM); Lukens, Laurance L. (Albuquerque, NM); Moreno, James B. (Albuquerque, NM)

    1989-01-01

    A liquid metal thermal electric converter which converts heat energy to electrical energy. The design of the liquid metal thermal electric converter incorporates a unique configuration which directs the metal fluid pressure to the outside of the tube which results in the structural loads in the tube to be compressive. A liquid metal thermal electric converter refluxing boiler with series connection of tubes and a multiple cell liquid metal thermal electric converter are also provided.

  11. Definition of Power Converters

    E-Print Network [OSTI]

    Bordry, F

    2015-01-01

    The paper is intended to introduce power conversion principles and to define common terms in the domain. The concept s of sources and switches are defined and classified. From the basic laws of source interconnections, a generic method of power converter synthesis is presented. Some examples illustrate this systematic method. Finally, the commutation cell and soft commuta tion are introduced and discussedd.

  12. NovaTorque | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIXsourceII Jump to:Information 3rd|Northfork Electric Coop, IncUSA(TXR150000)NovaTorque

  13. The Geography of European Convertible Bonds: Why Firms Issue Convertibles?

    E-Print Network [OSTI]

    Saskatchewan, University of

    1 The Geography of European Convertible Bonds: Why Firms Issue Convertibles? Franck Bancel Usha R at the geography of CB issuance. The size and development of the CB market varies widely across countries and over

  14. Increasing the High Speed Torque of Bipolar Stepper

    E-Print Network [OSTI]

    Peters, Dennis

    the windings of the motor dictates the high speed torque. This application note shows that increasing the slew rates of the winding currents in a bipolar stepper motor pushes the motor to deliver more torque at high°) bipolar currents (Figure 1) energize the windings of a bipolar stepper motor. One step occurs at each

  15. Economic analysis of robotic torque measurement system

    SciTech Connect (OSTI)

    Lembke, J.R.

    1991-07-01

    A cleanroom robot is being used to measure the torque characteristic of rotary solenoids, replacing a manual measurement procedure. The system can test two different part numbers and can distinguish between these parts without operator assistance. To make the system more cost-effective, several tests have been added to sequence. Bearing drag and coil resistance are measured, and the change in resistance due to coil heating is monitored. The insulation resistance between coil and housing is measured at 250 volts. The bar-coded serial number of each unit is read by passing the housing over a bar code wand. All information is used to generate a report for each unit tested, showing part number, serial number, measured data, and pass-fail notification. The system saves 0.114 standard hours per part compared to manual testing and generates a return on investment of over 20 percent. 2 refs., 4 figs.

  16. Cycloidal Wave Energy Converter

    SciTech Connect (OSTI)

    Stefan G. Siegel, Ph.D.

    2012-11-30

    This program allowed further advancing the development of a novel type of wave energy converter, a Cycloidal Wave Energy Converter or CycWEC. A CycWEC consists of one or more hydrofoils rotating around a central shaft, and operates fully submerged beneath the water surface. It operates under feedback control sensing the incoming waves, and converts wave power to shaft power directly without any intermediate power take off system. Previous research consisting of numerical simulations and two dimensional small 1:300 scale wave flume experiments had indicated wave cancellation efficiencies beyond 95%. The present work was centered on construction and testing of a 1:10 scale model and conducting two testing campaigns in a three dimensional wave basin. These experiments allowed for the first time for direct measurement of electrical power generated as well as the interaction of the CycWEC in a three dimensional environment. The Atargis team successfully conducted two testing campaigns at the Texas A&M Offshore Technology Research Center and was able to demonstrate electricity generation. In addition, three dimensional wave diffraction results show the ability to achieve wave focusing, thus increasing the amount of wave power that can be extracted beyond what was expected from earlier two dimensional investigations. Numerical results showed wave cancellation efficiencies for irregular waves to be on par with results for regular waves over a wide range of wave lengths. Using the results from previous simulations and experiments a full scale prototype was designed and its performance in a North Atlantic wave climate of average 30kW/m of wave crest was estimated. A full scale WEC with a blade span of 150m will deliver a design power of 5MW at an estimated levelized cost of energy (LCOE) in the range of 10-17 US cents per kWh. Based on the new results achieved in the 1:10 scale experiments these estimates appear conservative and the likely performance at full scale will exceed this initial performance estimates. In advancing the Technology Readiness Level (TRL) of this type of wave energy converter from 3 to 4, we find the CycWEC to exceed our initial estimates in terms of hydrodynamic performance. Once fully developed and optimized, it has the potential to not just outperform all other WEC technologies, but to also deliver power at a lower LCOE than competing conventional renewables like wind and solar. Given the large wave power resource both domestically and internationally, this technology has the potential to lead to a large improvement in our ability to produce clean electricity at affordable cost.

  17. Bidirectional buck boost converter

    DOE Patents [OSTI]

    Esser, A.A.M.

    1998-03-31

    A bidirectional buck boost converter and method of operating the same allows regulation of power flow between first and second voltage sources in which the voltage level at each source is subject to change and power flow is independent of relative voltage levels. In one embodiment, the converter is designed for hard switching while another embodiment implements soft switching of the switching devices. In both embodiments, first and second switching devices are serially coupled between a relatively positive terminal and a relatively negative terminal of a first voltage source with third and fourth switching devices serially coupled between a relatively positive terminal and a relatively negative terminal of a second voltage source. A free-wheeling diode is coupled, respectively, in parallel opposition with respective ones of the switching devices. An inductor is coupled between a junction of the first and second switching devices and a junction of the third and fourth switching devices. Gating pulses supplied by a gating circuit selectively enable operation of the switching devices for transferring power between the voltage sources. In the second embodiment, each switching device is shunted by a capacitor and the switching devices are operated when voltage across the device is substantially zero. 20 figs.

  18. Bidirectional buck boost converter

    DOE Patents [OSTI]

    Esser, Albert Andreas Maria (Niskayuna, NY)

    1998-03-31

    A bidirectional buck boost converter and method of operating the same allows regulation of power flow between first and second voltage sources in which the voltage level at each source is subject to change and power flow is independent of relative voltage levels. In one embodiment, the converter is designed for hard switching while another embodiment implements soft switching of the switching devices. In both embodiments, first and second switching devices are serially coupled between a relatively positive terminal and a relatively negative terminal of a first voltage source with third and fourth switching devices serially coupled between a relatively positive terminal and a relatively negative terminal of a second voltage source. A free-wheeling diode is coupled, respectively, in parallel opposition with respective ones of the switching devices. An inductor is coupled between a junction of the first and second switching devices and a junction of the third and fourth switching devices. Gating pulses supplied by a gating circuit selectively enable operation of the switching devices for transferring power between the voltage sources. In the second embodiment, each switching device is shunted by a capacitor and the switching devices are operated when voltage across the device is substantially zero.

  19. Mechanics of torque generation in the bacterial flagellar motor

    E-Print Network [OSTI]

    Mandadapu, Kranthi K; Berry, Richard M; Oster, George

    2015-01-01

    The bacterial flagellar motor (BFM) is responsible for driving bacterial locomotion and chemotaxis, fundamental processes in pathogenesis and biofilm formation. In the BFM, torque is generated at the interface between transmembrane proteins (stators) and a rotor. It is well-established that the passage of ions down a transmembrane gradient through the stator complex provides the energy needed for torque generation. However, the physics involved in this energy conversion remain poorly understood. Here we propose a mechanically specific model for torque generation in the BFM. In particular, we identify two fundamental forces involved in torque generation: electrostatic and steric. We propose that electrostatic forces serve to position the stator, while steric forces comprise the actual 'power stroke'. Specifically, we predict that ion-induced conformational changes about a proline 'hinge' residue in an $\\alpha$-helix of the stator are directly responsible for generating the power stroke. Our model predictions f...

  20. Electromagnetic Compatibility of Power Converters

    E-Print Network [OSTI]

    Charoy, A

    2015-01-01

    This paper describes the main challenges related to power converters in a scientific environment. It proposes some methods of EMC analysis, design, meas urement, and EMC troubleshooting.

  1. Self-powered microthermionic converter

    DOE Patents [OSTI]

    Marshall, Albert C.; King, Donald B.; Zavadil, Kevin R.; Kravitz, Stanley H.; Tigges, Chris P.; Vawter, Gregory A.

    2004-08-10

    A self-powered microthermionic converter having an internal thermal power source integrated into the microthermionic converter. These converters can have high energy-conversion efficiencies over a range of operating temperatures. Microengineering techniques are used to manufacture the converter. The utilization of an internal thermal power source increases potential for mobility and incorporation into small devices. High energy efficiency is obtained by utilization of micron-scale interelectrode gap spacing. Alpha-particle emitting radioisotopes can be used for the internal thermal power source, such as curium and polonium isotopes.

  2. Mechanics of torque generation in the bacterial flagellar motor

    E-Print Network [OSTI]

    Kranthi K. Mandadapu; Jasmine A. Nirody; Richard M. Berry; George Oster

    2015-01-13

    The bacterial flagellar motor (BFM) is responsible for driving bacterial locomotion and chemotaxis, fundamental processes in pathogenesis and biofilm formation. In the BFM, torque is generated at the interface between transmembrane proteins (stators) and a rotor. It is well-established that the passage of ions down a transmembrane gradient through the stator complex provides the energy needed for torque generation. However, the physics involved in this energy conversion remain poorly understood. Here we propose a mechanically specific model for torque generation in the BFM. In particular, we identify two fundamental forces involved in torque generation: electrostatic and steric. We propose that electrostatic forces serve to position the stator, while steric forces comprise the actual 'power stroke'. Specifically, we predict that ion-induced conformational changes about a proline 'hinge' residue in an $\\alpha$-helix of the stator are directly responsible for generating the power stroke. Our model predictions fit well with recent experiments on a single-stator motor. Furthermore, we propose several experiments to elucidate the torque-speed relationship in motors where the number of stators may not be constant. The proposed model provides a mechanical explanation for several fundamental features of the flagellar motor, including: torque-speed and speed-ion motive force relationships, backstepping, variation in step sizes, and the puzzle of swarming experiments.

  3. CHIC - Converting Hamburgers Into Cows

    E-Print Network [OSTI]

    Townsend, Joseph A

    components and convert them into SciXML. This is sectioned into text-rich and data-rich streams and stand-off annotation (SAF) is created for each. Embedded domain specific objects can be converted into XML (Chemical Markup Language). The different workflow...

  4. Power Converters for Cycling Machines

    E-Print Network [OSTI]

    Bouteille, J F

    2015-01-01

    Cycling accelerators require power converters that are capable of storing the energy that oscillates between lattice magnets and the converter during the acceleration process. This paper presents the basic requirements for such systems and reviews the various electrical circuits that have been used for a variety of differing applications. The designs currently used for fast-, medium- and slow-cycling accelerators are presented.

  5. Heat engine and electric motor torque distribution strategy for a hybrid electric vehicle

    DOE Patents [OSTI]

    Boberg, Evan S. (Hazel Park, MI); Gebby, Brian P. (Hazel Park, MI)

    1999-09-28

    A method is provided for controlling a power train system for a hybrid electric vehicle. The method includes a torque distribution strategy for controlling the engine and the electric motor. The engine and motor commands are determined based upon the accelerator position, the battery state of charge and the amount of engine and motor torque available. The amount of torque requested for the engine is restricted by a limited rate of rise in order to reduce the emissions from the engine. The limited engine torque is supplemented by motor torque in order to meet a torque request determined based upon the accelerator position.

  6. Current-induced torque driven ferromagnetic resonance in magnetic microstructures

    E-Print Network [OSTI]

    Fang, Dong

    2011-03-15

    of this Thesis a b Figure 1.2: An illustration of the spin-transfer torque effect in spin-valve device structures, adapted from [36]. a, A single magnetic layer with a spin- polarised electron passing through it. The magnet transmits and scatters the collinear... when an electric current passes through the pinned layer of a spin-valve, which can then act on the magnetisation in the free layer. 5 1.2 Context of this Thesis The current-induced torque in uniform ferromagnets has its origin in two quantum mechanical...

  7. Synchronization of spin torque nano-oscillators through dipolar interactions

    SciTech Connect (OSTI)

    Chen, Hao-Hsuan, E-mail: d95222014@ntu.edu.tw; Wu, Jong-Ching, E-mail: phjcwu@cc.ncue.edu.tw; Horng, Lance [Department of Physics, National Changhua University of Education, Changhua 500, Taiwan (China); Lee, Ching-Ming [Graduate School of Materials Science, National Yunlin University of Science and Technology, Douliou, 64002, Taiwan (China); Chang, Ching-Ray, E-mail: crchang@phys.ntu.edu.tw; Chang, Jui-Hang [Department of Physics and Center for Quantum Sciences and Engineering, National Taiwan University, Taipei 10617, Taiwan (China)

    2014-04-07

    In an array of spin-torque nano-oscillators (STNOs) that combine a perpendicular polarized fixed layer with strong in-plane anisotropy in the free layers, magnetic dipolar interactions can effectively phase-lock the array, thus further enhancing the power of the output microwave signals. We perform a qualitative analysis of the synchronization of an array based on the Landau-Lifshitz-Gilbert equation, with a spin-transfer torque that assumes strong in-plane anisotropy. Finally, we present the numerical results for four coupled STNOs to provide further evidence for the proposed theory.

  8. Switched-Mode Power Converter Programmable

    E-Print Network [OSTI]

    Switched-Mode Power Converter Programmable compensator Identification & design Vref DPWM vout digital controller design for switching power converters. Starting from an experimentally identified Digital Controller Design for Switching Converters Abstract--This paper presents an approach to automated

  9. Converting Biomass to High-Value Feedstocks

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Converting Biomass to High-Value Feedstocks Advanced feedstocks play an important role in economically and efficiently converting biomass into bioenergy products. Advanced...

  10. Analytical Method of Torque Calculation for Interior Permanent Magnet Synchronous Machines

    E-Print Network [OSTI]

    Tolbert, Leon M.

    Analytical Method of Torque Calculation for Interior Permanent Magnet Synchronous Machines Seong (FEA). Also, this method can be applied to any type of synchronous machine. Index Terms-- equivalent circuit, inductance, permanent magnet machine, synchronous motors, torque. I. NOMENCLATURE BFE brushless

  11. Optimal Passive Dynamics for Torque/Force Control Kevin Kemper, Devin Koepl and Jonathan Hurst

    E-Print Network [OSTI]

    Hurst, Jonathan

    Optimal Passive Dynamics for Torque/Force Control Kevin Kemper, Devin Koepl and Jonathan Hurst software control strategy. Discussions about the passive dynamics are often imprecise, lacking's passive dynamics (stiffness, damping, motor inertia and torque limits) and the resulting performance

  12. Theory comparison and numerical benchmarking on neoclassical toroidal viscosity torque

    SciTech Connect (OSTI)

    Wang, Zhirui; Park, Jong-Kyu; Logan, Nikolas; Kim, Kimin; Menard, Jonathan E. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)] [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Liu, Yueqiang [Euratom/CCFE Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom)] [Euratom/CCFE Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom)

    2014-04-15

    Systematic comparison and numerical benchmarking have been successfully carried out among three different approaches of neoclassical toroidal viscosity (NTV) theory and the corresponding codes: IPEC-PENT is developed based on the combined NTV theory but without geometric simplifications [Park et al., Phys. Rev. Lett. 102, 065002 (2009)]; MARS-Q includes smoothly connected NTV formula [Shaing et al., Nucl. Fusion 50, 025022 (2010)] based on Shaing's analytic formulation in various collisionality regimes; MARS-K, originally computing the drift kinetic energy, is upgraded to compute the NTV torque based on the equivalence between drift kinetic energy and NTV torque [J.-K. Park, Phys. Plasma 18, 110702 (2011)]. The derivation and numerical results both indicate that the imaginary part of drift kinetic energy computed by MARS-K is equivalent to the NTV torque in IPEC-PENT. In the benchmark of precession resonance between MARS-Q and MARS-K/IPEC-PENT, the agreement and correlation between the connected NTV formula and the combined NTV theory in different collisionality regimes are shown for the first time. Additionally, both IPEC-PENT and MARS-K indicate the importance of the bounce harmonic resonance which can greatly enhance the NTV torque when E×B drift frequency reaches the bounce resonance condition.

  13. The Shaft Torque of a Tandem Axial-Piston Pump

    E-Print Network [OSTI]

    Manring, Noah D.

    The Shaft Torque of a Tandem Axial- Piston Pump Noah D. Manring Viral S. Mehta Mechanical of this study is to identify the best indexed position of two rotating groups within a tandem axial-piston pump characteristics of the pump, other vibration aspects of the machine are also expected to be reduced. In particular

  14. Passive torque regulation in an underactuated flapping wing robotic insect

    E-Print Network [OSTI]

    Wood, Robert

    , the Berkeley Micromechanical Flying Insect (MFI) is a FWMAV platform with the ability to execute a range angles of attack [1]. The associated reduction in complexity has allowed this aeromechanical platform. 1: A car differential balances output torques using an underactuated mechanism. Degree of freedom q1

  15. TORQUE AND DRAG CALCULATIONS IN THREE-DIMENSIONAL WELLBORES 

    E-Print Network [OSTI]

    Prurapark, Ruktai A.

    2010-07-14

    Torque and drag (T&D) modeling is regarded as extremely helpful in well planning because it helps to predict and prevent drilling problems that might occur during the drilling process. Although T&D software has existed since the 1990s, some...

  16. Active surge control of centrifugal compressors using drive torque

    E-Print Network [OSTI]

    Gravdahl, Jan Tommy

    Active surge control of centrifugal compressors using drive torque Jan Tommy Gravdahl , Olav control is presented. A centrifugal compressor driven by an electrical motor is studied, and the drive of centrifugal com- pressors, which occurs when the operating point of the compressor is located to the left

  17. Closed-loop torque feedback for a universal field-oriented controller

    DOE Patents [OSTI]

    De Doncker, R.W.A.A.; King, R.D.; Sanza, P.C.; Haefner, K.B.

    1992-11-24

    A torque feedback system is employed in a universal field-oriented (UFO) controller to tune a torque-producing current command and a slip frequency command in order to achieve robust torque control of an induction machine even in the event of current regulator errors and during transitions between pulse width modulated (PWM) and square wave modes of operation. 1 figure.

  18. Closed-loop torque feedback for a universal field-oriented controller

    SciTech Connect (OSTI)

    De Doncker, Rik W. A. A.; King, Robert D.; Sanza, Peter C.; Haefner, Kenneth B.

    1992-01-01

    A torque feedback system is employed in a universal field-oriented (UFO) controller to tune a torque-producing current command and a slip frequency command in order to achieve robust torque control of an induction machine even in the event of current regulator errors and during transitions between pulse width modulated (PWM) and square wave modes of operation.

  19. Charge-pump voltage converter

    DOE Patents [OSTI]

    Brainard, John P. (Albuquerque, NM); Christenson, Todd R. (Albuquerque, NM)

    2009-11-03

    A charge-pump voltage converter for converting a low voltage provided by a low-voltage source to a higher voltage. Charge is inductively generated on a transfer rotor electrode during its transit past an inductor stator electrode and subsequently transferred by the rotating rotor to a collector stator electrode for storage or use. Repetition of the charge transfer process leads to a build-up of voltage on a charge-receiving device. Connection of multiple charge-pump voltage converters in series can generate higher voltages, and connection of multiple charge-pump voltage converters in parallel can generate higher currents. Microelectromechanical (MEMS) embodiments of this invention provide a small and compact high-voltage (several hundred V) voltage source starting with a few-V initial voltage source. The microscale size of many embodiments of this invention make it ideally suited for MEMS- and other micro-applications where integration of the voltage or charge source in a small package is highly desirable.

  20. Speed And Power Control Of An Engine By Modulation Of The Load Torque

    DOE Patents [OSTI]

    Ziph, Benjamin (Ann Arbor, MI); Strodtman, Scott (Ypsilanti, MI); Rose, Thomas K (Chelsea, MI)

    1999-01-26

    A system and method of speed and power control for an engine in which speed and power of the engine is controlled by modulation of the load torque. The load torque is manipulated in order to cause engine speed, and hence power to be changed. To accomplish such control, the load torque undergoes a temporary excursion in the opposite direction of the desired speed and power change. The engine and the driven equipment will accelerate or decelerate accordingly as the load torque is decreased or increased, relative to the essentially fixed or constant engine torque. As the engine accelerates or decelerates, its power increases or decreases in proportion.

  1. Traction drive automatic transmission for gas turbine engine driveline

    DOE Patents [OSTI]

    Carriere, Donald L. (Livonia, MI)

    1984-01-01

    A transaxle driveline for a wheeled vehicle has a high speed turbine engine and a torque splitting gearset that includes a traction drive unit and a torque converter on a common axis transversely arranged with respect to the longitudinal centerline of the vehicle. The drive wheels of the vehicle are mounted on a shaft parallel to the turbine shaft and carry a final drive gearset for driving the axle shafts. A second embodiment of the final drive gearing produces an overdrive ratio between the output of the first gearset and the axle shafts. A continuously variable range of speed ratios is produced by varying the position of the drive rollers of the traction unit. After starting the vehicle from rest, the transmission is set for operation in the high speed range by engaging a first lockup clutch that joins the torque converter impeller to the turbine for operation as a hydraulic coupling.

  2. Enhancement of Spin-transfer torque switching via resonant tunneling

    SciTech Connect (OSTI)

    Chatterji, Niladri; Tulapurkar, Ashwin A.; Muralidharan, Bhaskaran

    2014-12-08

    We propose the use of resonant tunneling as a route to enhance the spin-transfer torque switching characteristics of magnetic tunnel junctions. The proposed device structure is a resonant tunneling magnetic tunnel junction based on a MgO-semiconductor heterostructure sandwiched between a fixed magnet and a free magnet. Using the non-equilibrium Green's function formalism coupled self consistently with the Landau-Lifshitz-Gilbert-Slonczewski equation, we demonstrate enhanced tunnel magneto-resistance characteristics as well as lower switching voltages in comparison with traditional trilayer devices. Two device designs based on MgO based heterostructures are presented, where the physics of resonant tunneling leads to an enhanced spin transfer torque thereby reducing the critical switching voltage by up to 44%. It is envisioned that the proof-of-concept presented here may lead to practical device designs via rigorous materials and interface studies.

  3. Angular momentum and torque described with the complex octonion

    SciTech Connect (OSTI)

    Weng, Zi-Hua, E-mail: xmuwzh@xmu.edu.cn [School of Physics and Mechanical and Electrical Engineering, Xiamen University, Xiamen 361005 (China)

    2014-08-15

    The paper aims to adopt the complex octonion to formulate the angular momentum, torque, and force etc in the electromagnetic and gravitational fields. Applying the octonionic representation enables one single definition of angular momentum (or torque, force) to combine some physics contents, which were considered to be independent of each other in the past. J. C. Maxwell used simultaneously two methods, the vector terminology and quaternion analysis, to depict the electromagnetic theory. It motivates the paper to introduce the quaternion space into the field theory, describing the physical feature of electromagnetic and gravitational fields. The spaces of electromagnetic field and of gravitational field can be chosen as the quaternion spaces, while the coordinate component of quaternion space is able to be the complex number. The quaternion space of electromagnetic field is independent of that of gravitational field. These two quaternion spaces may compose one octonion space. Contrarily, one octonion space can be separated into two subspaces, the quaternion space and S-quaternion space. In the quaternion space, it is able to infer the field potential, field strength, field source, angular momentum, torque, and force etc in the gravitational field. In the S-quaternion space, it is capable of deducing the field potential, field strength, field source, current continuity equation, and electric (or magnetic) dipolar moment etc in the electromagnetic field. The results reveal that the quaternion space is appropriate to describe the gravitational features, including the torque, force, and mass continuity equation etc. The S-quaternion space is proper to depict the electromagnetic features, including the dipolar moment and current continuity equation etc. In case the field strength is weak enough, the force and the continuity equation etc can be respectively reduced to that in the classical field theory.

  4. Angular momentum and torque described with the complex octonion

    E-Print Network [OSTI]

    Zi-Hua Weng

    2015-07-21

    The paper aims to adopt the complex octonion to formulate the angular momentum, torque, and force etc in the electromagnetic and gravitational fields. Applying the octonionic representation enables one single definition of angular momentum (or torque, force) to combine some physics contents, which were considered to be independent of each other in the past. J. C. Maxwell used simultaneously two methods, the vector terminology and quaternion analysis, to depict the electromagnetic theory. It motivates the paper to introduce the quaternion space into the field theory, describing the physical feature of electromagnetic and gravitational fields. The spaces of two fields can be chosen as the quaternion spaces, while the coordinate component of quaternion space is able to be the complex number. The quaternion space of electromagnetic field is independent of that of gravitational field. These two quaternion spaces may compose one octonion space. Contrarily, one octonion space can be separated into two subspaces, the quaternion space and S-quaternion space. In the quaternion space, it is able to infer the field potential, field strength, field source, angular momentum, torque, and force etc in the gravitational field. In the S-quaternion space, it is capable of deducing the field potential, field strength, field source, current continuity equation, and electric (or magnetic) dipolar moment etc in the electromagnetic field. The results reveal that the quaternion space is appropriate to describe the gravitational features, including the torque, force, and mass continuity equation etc. The S-quaternion space is proper to depict the electromagnetic features, including the dipolar moment and current continuity equation etc. In case the field strength is weak enough, the force and the continuity equation etc can be respectively reduced to that in the classical field theory.

  5. Torque on an exoplanet from an anisotropic evaporative wind

    E-Print Network [OSTI]

    Teyssandier, Jean; Adams, Fred C; Quillen, Alice C

    2015-01-01

    Winds from short-period Earth and Neptune mass exoplanets, driven by high energy radiation from a young star, may evaporate a significant fraction of a planet's mass. If the momentum flux from the evaporative wind is not aligned with the planet/star axis, then it can exert a torque on the planet's orbit. Using steady-state one-dimensional evaporative wind models we estimate this torque using a lag angle that depends on the product of the speed of the planet's upper atmosphere and a flow timescale for the wind to reach its sonic radius. We also estimate the momentum flux from time-dependent one-dimensional hydrodynamical simulations. We find that only in a very narrow regime in planet radius, mass and stellar radiation flux is a wind capable of exerting a significant torque on the planet's orbit. Similar to the Yarkovsky effect, the wind causes the planet to drift outward if atmospheric circulation is prograde (super-rotating) and in the opposite direction if the circulation is retrograde. A close-in super Ear...

  6. Portable convertible blast effects shield

    DOE Patents [OSTI]

    Pastrnak, John W. (Livermore, CA); Hollaway, Rocky (Modesto, CA); Henning, Carl D. (Livermore, CA); Deteresa, Steve (Livermore, CA); Grundler, Walter (Hayward, CA); Hagler, Lisle B. (Berkeley, CA); Kokko, Edwin (Dublin, CA); Switzer, Vernon A. (Livermore, CA)

    2011-03-15

    A rapidly deployable portable convertible blast effects shield/ballistic shield includes a set two or more frusto-conically-tapered telescoping rings operably connected to each other to convert between a telescopically-collapsed configuration for storage and transport, and a telescopically-extended upright configuration forming an expanded inner volume. In a first embodiment, the upright configuration provides blast effects shielding, such as against blast pressures, shrapnel, and/or fire balls. And in a second embodiment, the upright configuration provides ballistic shielding, such as against incoming weapons fire, shrapnel, etc. Each ring has a high-strength material construction, such as a composite fiber and matrix material, capable of substantially inhibiting blast effects and impinging projectiles from passing through the shield. And the set of rings are releasably securable to each other in the telescopically-extended upright configuration by the friction fit of adjacent pairs of frusto-conically-tapered rings to each other.

  7. Portable convertible blast effects shield

    DOE Patents [OSTI]

    Pastrnak, John W. (Livermore, CA); Hollaway, Rocky (Modesto, CA); Henning, Carl D. (Livermore, CA); Deteresa, Steve (Livermore, CA); Grundler, Walter (Hayward, CA); Hagler,; Lisle B. (Berkeley, CA); Kokko, Edwin (Dublin, CA); Switzer, Vernon A (Livermore, CA)

    2010-10-26

    A rapidly deployable portable convertible blast effects shield/ballistic shield includes a set two or more telescoping cylindrical rings operably connected to each other to convert between a telescopically-collapsed configuration for storage and transport, and a telescopically-extended upright configuration forming an expanded inner volume. In a first embodiment, the upright configuration provides blast effects shielding, such as against blast pressures, shrapnel, and/or fire balls. And in a second embodiment, the upright configuration provides ballistic shielding, such as against incoming weapons fire, shrapnel, etc. Each ring has a high-strength material construction, such as a composite fiber and matrix material, capable of substantially inhibiting blast effects and impinging projectiles from passing through the shield. And the set of rings are releasably securable to each other in the telescopically-extended upright configuration, such as by click locks.

  8. Portable convertible blast effects shield

    DOE Patents [OSTI]

    Pastrnak, John W. (Livermore, CA); Hollaway, Rocky (Modesto, CA); Henning, Carl D. (Livermore, CA); Deteresa, Steve (Livermore, CA); Grundler, Walter (Hayward, CA); Hagler, Lisle B. (Berkeley, CA); Kokko, Edwin (Dublin, CA); Switzer, Vernon A (Livermore, CA)

    2007-05-22

    A rapidly deployable portable convertible blast effects shield/ballistic shield includes a set two or more telescoping cylindrical rings operably connected to each other to convert between a telescopically-collapsed configuration for storage and transport, and a telescopically-extended upright configuration forming an expanded inner volume. In a first embodiment, the upright configuration provides blast effects shielding, such as against blast pressures, shrapnel, and/or fire balls. And in a second embodiment, the upright configuration provides ballistic shielding, such as against incoming weapons fire, shrapnel, etc. Each ring has a high-strength material construction, such as a composite fiber and matrix material, capable of substantially inhibiting blast effects and impinging projectiles from passing through the shield. And the set of rings are releasably securable to each other in the telescopically-extended upright configuration, such as by click locks.

  9. General Impedance Synthesis Using Simple Switching Converters

    E-Print Network [OSTI]

    Tse, Chi K. "Michael"

    -frequency storage element and a pair of switches, such as the buck, buck-boost and boost converters, as shown in FigGeneral Impedance Synthesis Using Simple Switching Converters Joe C. P. Liu, Chi K. Tse, Franki N converters is studied in this paper. We begin with showing that any impedance can be synthesized by a circuit

  10. Complex Behavior in Switching Power Converters

    E-Print Network [OSTI]

    Tse, Chi K. "Michael"

    Complex Behavior in Switching Power Converters CHI K. TSE, SENIOR MEMBER, IEEE, AND MARIO DI--Bifurcation, chaos, dc­dc converters, nonlinear dy- namics, power electronics, switching power converters. I power devices, control methods, circuit design, computer-aided analysis, passive components, packaging

  11. Auxiliary resonant DC tank converter

    DOE Patents [OSTI]

    Peng, Fang Z. (Knoxville, TN)

    2000-01-01

    An auxiliary resonant dc tank (ARDCT) converter is provided for achieving soft-switching in a power converter. An ARDCT circuit is coupled directly across a dc bus to the inverter to generate a resonant dc bus voltage, including upper and lower resonant capacitors connected in series as a resonant leg, first and second dc tank capacitors connected in series as a tank leg, and an auxiliary resonant circuit comprising a series combination of a resonant inductor and a pair of auxiliary switching devices. The ARDCT circuit further includes first clamping means for holding the resonant dc bus voltage to the dc tank voltage of the tank leg, and second clamping means for clamping the resonant dc bus voltage to zero during a resonant period. The ARDCT circuit resonantly brings the dc bus voltage to zero in order to provide a zero-voltage switching opportunity for the inverter, then quickly rebounds the dc bus voltage back to the dc tank voltage after the inverter changes state. The auxiliary switching devices are turned on and off under zero-current conditions. The ARDCT circuit only absorbs ripples of the inverter dc bus current, thus having less current stress. In addition, since the ARDCT circuit is coupled in parallel with the dc power supply and the inverter for merely assisting soft-switching of the inverter without participating in real dc power transmission and power conversion, malfunction and failure of the tank circuit will not affect the functional operation of the inverter; thus a highly reliable converter system is expected.

  12. Enterprise converting buses to biodiesel

    Broader source: Energy.gov [DOE]

    Rental car customers may be able to breathe a little easier during their next trip to the airport. Alamo Rent A Car, Enterprise Rent-A-Car, and National Car Rental, all brands operated by the subsidiaries of Enterprise Holdings, are converting their airport shuttle buses to run on biodiesel fuel. The move is a good one for the environment, and will ultimately reduce the company’s carbon emissions. “We are saving 420,000 gallons of petroleum diesel,”  says Lee Broughton, director of corporate identity and sustainability for Enterprise Holdings.    

  13. Converting Energy to Medical Progress

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit the followingConcentratingPortal ControllingConvection feedbacksConverting

  14. Torque for electron spin induced by electron permanent electric dipole moment

    SciTech Connect (OSTI)

    Senami, Masato E-mail: akitomo@scl.kyoto-u.ac.jp; Fukuda, Masahiro E-mail: akitomo@scl.kyoto-u.ac.jp; Ogiso, Yoji E-mail: akitomo@scl.kyoto-u.ac.jp; Tachibana, Akitomo E-mail: akitomo@scl.kyoto-u.ac.jp

    2014-10-06

    The spin torque of the electron is studied in relation to the electric dipole moment (EDM) of the electron. The spin dynamics is known to be given by the spin torque and the zeta force in quantum field theory. The effect of the EDM on the torque of the spin brings a new term in the equation of motion of the spin. We study this effect for a solution of the Dirac equation with electromagnetic field.

  15. SPIN-TORQUE IN SYSTEMS WITH INHOMOGENEOUS MAGETIZATION

    SciTech Connect (OSTI)

    Zangwill, Andrew

    2013-04-23

    The work performed during the grant period focused on the phenomenon of spin-transfer torque. This is a quantum mechanical effect whereby the angular momentum of conduction electrons is transferred to the magnetization of ferromagnetic structures. Our work on this subject began with phenomenological drift-diffusion and Landau-Lifshitz-Gilbert equations to demonstrate unambiguously that unpolarized current flow from a nonmagnet into a ferromagnet can produce a precession-type instability of the magnetization. We then used Boltzmann calculations appropriate to spin-valve type magnetic heterostructures composed of a non-magnetic thin film sandwiched between two thin film layers with uniform magnetization. Perhaps our most important paper dealt with quantum and semi-classical calculations of spin-transfer torque in systems with domain walls and other inhomogeneous distributions of magnetization. The latter work caused us to suggest that the Landau-Lifshitz approach to magnetic damping provided a clearer picture of the physics than the more popular (but formally equivalent) Gilbert approach to damping. Finally, we returned to our Boltzmann calculations and made a serious effort to analyze experimental data on current-induced magnetization in switching in magnetic spin-valve structures. Our work was part of a world-wide effort to study and harness the transport of the electron's spin and was one of the first sustained theoretical efforts in this direction in the United States. The payoff is just now being seen. In November of 2012, the Everspin Corporation announced the release of the first commercial spin-torque magnetoresistive random access memory.

  16. In-line rotating torque sensor with on-board amplifier

    DOE Patents [OSTI]

    Kronberg, James W. (Beech Island, SC)

    1990-01-01

    A rotating torque sensor apparatus and method for measuring small torques comprising a shaft, a platform having a circuit board and a first moment arm attached to the shaft, a rotatable wheel coaxial with the shaft and having a second moment arm spaced apart from the first moment arm with a load cell therebetween for generating an electric signal as the torque is applied to the shaft and transferred through the moment arms to the load cell. The electrical signal is conducted from the load cell to the circuit board for filtering and amplification before being extracted from the torque assembly through a slip ring.

  17. Universal adaptive torque control for PM motors for field-weakening region operation

    DOE Patents [OSTI]

    Royak, Semyon (Beachwood, OH); Harbaugh, Mark M. (Richfield, OH); Breitzmann, Robert J. (South Russel, OH); Nondahl, Thomas A. (Wauwatosa, WI); Schmidt, Peter B. (Franklin, WI); Liu, Jingbo (Milwaukee, WI)

    2011-03-29

    The invention includes a motor controller and method for controlling a permanent magnet motor. In accordance with one aspect of the present technique, a permanent magnet motor is controlled by, among other things, receiving a torque command, determining a normalized torque command by normalizing the torque command to a characteristic current of the motor, determining a normalized maximum available voltage, determining an inductance ratio of the motor, and determining a direct-axis current based upon the normalized torque command, the normalized maximum available voltage, and the inductance ratio of the motor.

  18. Sandia Energy - WEC-Sim (Wave Energy Converter SIMulator)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    WEC-Sim (Wave Energy Converter SIMulator) Home Stationary Power Energy Conversion Efficiency Water Power WEC-Sim (Wave Energy Converter SIMulator) WEC-Sim (Wave Energy Converter...

  19. Modeling Torque Versus Speed, Shot Noise, and Rotational Diffusion of the Bacterial Flagellar Motor

    E-Print Network [OSTI]

    Mora, Thierry

    Modeling Torque Versus Speed, Shot Noise, and Rotational Diffusion of the Bacterial Flagellar Motor for the flagellar motor that enables bacteria to swim. Our model explains the experimentally measured torque-speed relationship of the proton-driven E. coli motor at various pH and temperature conditions. In particular

  20. Ocean floor mounting of wave energy converters

    DOE Patents [OSTI]

    Siegel, Stefan G

    2015-01-20

    A system for mounting a set of wave energy converters in the ocean includes a pole attached to a floor of an ocean and a slider mounted on the pole in a manner that permits the slider to move vertically along the pole and rotate about the pole. The wave energy converters can then be mounted on the slider to allow adjustment of the depth and orientation of the wave energy converters.

  1. Low torque hydrodynamic lip geometry for rotary seals

    DOE Patents [OSTI]

    Dietle, Lannie L.; Schroeder, John E.

    2015-07-21

    A hydrodynamically lubricating geometry for the generally circular dynamic sealing lip of rotary seals that are employed to partition a lubricant from an environment. The dynamic sealing lip is provided for establishing compressed sealing engagement with a relatively rotatable surface, and for wedging a film of lubricating fluid into the interface between the dynamic sealing lip and the relatively rotatable surface in response to relative rotation that may occur in the clockwise or the counter-clockwise direction. A wave form incorporating an elongated dimple provides the gradual convergence, efficient impingement angle, and gradual interfacial contact pressure rise that are conducive to efficient hydrodynamic wedging. Skewed elevated contact pressure zones produced by compression edge effects provide for controlled lubricant movement within the dynamic sealing interface between the seal and the relatively rotatable surface, producing enhanced lubrication and low running torque.

  2. Magnetization reversal driven by a spin torque oscillator

    SciTech Connect (OSTI)

    Sbiaa, R.

    2014-09-01

    Magnetization reversal of a magnetic free layer under spin transfer torque (STT) effect from a magnetic hard layer with a fixed magnetization direction and an oscillating layer is investigated. By including STT from the oscillating layer with in-plane anisotropy and orthogonal polarizer, magnetization-time dependence of free layer is determined. The results show that the frequency and amplitude of oscillations can be varied by adjusting the current density and magnetic properties. For an optimal oscillation frequency (f{sub opt}), a reduction of the switching time (t{sub 0}) of the free layer is observed. Both f{sub opt} and t{sub 0} increase with the anisotropy field of the free layer.

  3. Elastic monopoles and external torques in nematic liquid crystal colloids

    E-Print Network [OSTI]

    O. M. Tovkach; S. B. Chernyshuk; B. I. Lev

    2013-11-19

    Up to now it is commonly believed that a colloidal particle suspended in a nematic liquid crystal never produces elastic monopoles because this violates the mechanical equilibrium condition. And the only way to obtain deformations of director field falling off with distance as r^{-1} is to exert an external torque \\Gamma_{ext} on the colloid \\cite{de_Gennes}. In this paper we demonstrate that this statement is not quite correct and elastic monopoles, as well as dipoles and quadrupoles, can be induced without any external influence just by the particle itself. A behavior of a spherical colloidal particle with asymmetric anchoring strength distribution is considered theoretically. It is demonstrated that such a particle when suspended in a nematic host can produce director deformations decreasing as $r^{-1}$, i.e. elastic monopoles, by itself without any external influence.

  4. Vacuum-insulated catalytic converter

    DOE Patents [OSTI]

    Benson, David K. (Golden, CO)

    2001-01-01

    A catalytic converter has an inner canister that contains catalyst-coated substrates and an outer canister that encloses an annular, variable vacuum insulation chamber surrounding the inner canister. An annular tank containing phase-change material for heat storage and release is positioned in the variable vacuum insulation chamber a distance spaced part from the inner canister. A reversible hydrogen getter in the variable vacuum insulation chamber, preferably on a surface of the heat storage tank, releases hydrogen into the variable vacuum insulation chamber to conduct heat when the phase-change material is hot and absorbs the hydrogen to limit heat transfer to radiation when the phase-change material is cool. A porous zeolite trap in the inner canister absorbs and retains hydrocarbons from the exhaust gases when the catalyst-coated substrates and zeolite trap are cold and releases the hydrocarbons for reaction on the catalyst-coated substrate when the zeolite trap and catalyst-coated substrate get hot.

  5. Controller for a wave energy converter

    DOE Patents [OSTI]

    Wilson, David G.; Bull, Diana L.; Robinett, III, Rush D.

    2015-09-22

    A wave energy converter (WEC) is described, the WEC including a power take off (PTO) that converts relative motion of bodies of the WEC into electrical energy. A controller controls operation of the PTO, causing the PTO to act as a motor to widen a wave frequency spectrum that is usable to generate electrical energy.

  6. RF digital-to-analog converter

    DOE Patents [OSTI]

    Conway, Patrick H. (Rancho Palos Verdes, CA); Yu, David U. L. (Rancho Palos Verdes, CA)

    1995-01-01

    A digital-to analogue converter for producing an RF output signal proportional to a digital input word of N bits from an RF reference input, N being an integer greater or equal to 2. The converter comprises a plurality of power splitters, power combiners and a plurality of mixers or RF switches connected in a predetermined configuration.

  7. RF digital-to-analog converter

    DOE Patents [OSTI]

    Conway, P.H.; Yu, D.U.L.

    1995-02-28

    A digital-to-analog converter is disclosed for producing an RF output signal proportional to a digital input word of N bits from an RF reference input, N being an integer greater or equal to 2. The converter comprises a plurality of power splitters, power combiners and a plurality of mixers or RF switches connected in a predetermined configuration. 18 figs.

  8. Time interleaved counter analog to digital converters 

    E-Print Network [OSTI]

    Danesh, Seyed Amir Ali

    2011-11-22

    The work explores extending time interleaving in A/D converters, by applying a high-level of parallelism to one of the slowest and simplest types of data-converters, the counter ADC. The motivation for the work is to ...

  9. Switched Mode Four-Quadrant Converters

    E-Print Network [OSTI]

    Thurel, Y

    2015-01-01

    This paper was originally presented at CAS-2004, and was slightly modified for CAS-2014. It presents a review of the key parameters that impact the design choices for a true four-quadrant power converter, in the range 1-10 kW, mainly based on switching mode converter topology. This paper will first describe the state-of-the-art for this power converter family, giving the drawbacks and advantages of different possible solutions. It will also present practical results obtained from the CERN-designed converter. It will finally give some important tips regarding critical phases like test one, when conducting a project dealing with this type of power converter.

  10. Nonadiabatic Spin Torque Investigated Using Thermally Activated Magnetic Domain Wall Dynamics

    E-Print Network [OSTI]

    Dunin-Borkowski, Rafal E.

    Nonadiabatic Spin Torque Investigated Using Thermally Activated Magnetic Domain Wall Dynamics M microscopy, we investigate the thermally activated motion of domain walls (DWs) between two positions properly analyzed, thermally activated processes at tem- peratures even well below the Curie temperature

  11. Voltage induced magnetostrictive switching of nanomagnets: Strain assisted strain transfer torque random access memory

    SciTech Connect (OSTI)

    Khan, Asif Nikonov, Dmitri E.; Manipatruni, Sasikanth; Ghani, Tahir; Young, Ian A.

    2014-06-30

    A spintronic device, called the “strain assisted spin transfer torque (STT) random access memory (RAM),” is proposed by combining the magnetostriction effect and the spin transfer torque effect which can result in a dramatic improvement in the energy dissipation relative to a conventional STT-RAM. Magnetization switching in the device which is a piezoelectric-ferromagnetic heterostructure via the combined magnetostriction and STT effect is simulated by solving the Landau-Lifshitz-Gilbert equation incorporating the influence of thermal noise. The simulations show that, in such a device, each of these two mechanisms (magnetostriction and spin transfer torque) provides in a 90° rotation of the magnetization leading a deterministic 180° switching with a critical current significantly smaller than that required for spin torque alone. Such a scheme is an attractive option for writing magnetic RAM cells.

  12. Design of a low-mass high-torque brushless motor for application in quadruped robotics

    E-Print Network [OSTI]

    Farve, Niaja Nichole

    2012-01-01

    The Biomimetic Robotics Group is attempting to build the fastest quadruped robot powered by electromagnetic means. The limitations in achieving this goal are the torque produced from motors used to power the robot, as well ...

  13. Concentric ring flywheel with hooked ring carbon fiber separator/torque coupler

    DOE Patents [OSTI]

    Kuklo, T.C.

    1999-07-20

    A concentric ring flywheel with expandable separators, which function as torque couplers, between the rings to take up the gap formed between adjacent rings due to differential expansion between different radius rings during rotation of the flywheel. The expandable separators or torque couplers include a hook-like section at an upper end which is positioned over an inner ring and a shelf-like or flange section at a lower end onto which the next adjacent outer ring is positioned. As the concentric rings are rotated the gap formed by the differential expansion there between is partially taken up by the expandable separators or torque couplers to maintain torque and centering attachment of the concentric rings. 2 figs.

  14. Investigations of the torque anomaly in an annular sector. I. Global calculations, scalar case

    E-Print Network [OSTI]

    Milton, Kimball A; Parashar, Prachi; Abalo, E K; Fulling, Stephen A; Bouas, Jeffrey D; Carter, Hamilton; Kirsten, Klaus

    2013-01-01

    In an attempt to understand a recently discovered torque anomaly in quantum field theory with boundaries, we calculate the Casimir energy and torque of a scalar field subject to Dirichlet boundary conditions on an annular sector defined by two coaxial cylinders intercut by two planes through the axis. In this model the particularly troublesome divergence at the cylinder axis does not appear, but new divergences associated with the curved boundaries are introduced. All the divergences associated with the volume, the surface area, the corners, and the curvature are regulated by point separation either in the direction of the axis of the cylinder or in the (Euclidean) time; the full divergence structure is isolated, and the remaining finite energy and torque are extracted. Formally, only the regulator based on axis splitting yields the expected balance between energy and torque. Because of the logarithmic curvature divergences, there is an ambiguity in the linear dependence of the energy on the wedge angle; if t...

  15. Converting a Motorcycle to Electric Power

    E-Print Network [OSTI]

    Simcoe, Christopher M.

    2009-12-18

    Research was conducted to determine how simple and practical it would be to convert a standard gasoline powered motorcycle to electric power. The research involved background investigation of useful concepts in electric powered motorcycles...

  16. Transformer Synthesis for VHF Converters I. INTRODUCTION

    E-Print Network [OSTI]

    Perreault, Dave

    , such as a series resonance to replace the tank and transformer in a resonant converter [8], [9]. Such integrated increased loss due to flux shielding as compared to spiral designs. !"#$%&'"()'*%')$""% +,)+%-"./%011

  17. New Perspectives on Wave Energy Converter Control 

    E-Print Network [OSTI]

    Price, Alexandra A E

    2009-01-01

    This work examines some of the fundamental problems behind the control of wave energy converters (WECs). Several new perspectives are presented to aid the understanding of the problem and the interpretation of the ...

  18. Method and apparatus for monitoring motor operated valve motor output torque and power at valve seating

    DOE Patents [OSTI]

    Casada, Donald A. (Oak Ridge, TN)

    1996-01-01

    A method and apparatus are provided for monitoring a motor operated valve during the brief period when the valve seats and the torque switch trips to deenergize the valve motor. The method uses voltage measurements on the load side of a deenergizing switch that opens to deenergize the motor to determine, among other things, final motor rotational speed and the decelerating torque at motor deenergization.

  19. Method and apparatus for monitoring motor operated valve motor output torque and power at valve seating

    DOE Patents [OSTI]

    Casada, D.A.

    1996-01-16

    A method and apparatus are provided for monitoring a motor operated valve during the brief period when the valve seats and the torque switch trips to deenergize the valve motor. The method uses voltage measurements on the load side of a deenergizing switch that opens to deenergize the motor to determine, among other things, final motor rotational speed and the decelerating torque at motor deenergization. 14 figs.

  20. Defect structures and torque on an elongated colloidal particle immersed in a liquid crystal host

    E-Print Network [OSTI]

    D. Andrienko; M. P. Allen; G. Skacej; S. Zumer

    2002-03-06

    Combining molecular dynamics and Monte Carlo simulation we study defect structures around an elongated colloidal particle embedded in a nematic liquid crystal host. By studying nematic ordering near the particle and the disclination core region we are able to examine the defect core structure and the difference between two simulation techniques. In addition, we also study the torque on a particle tilted with respect to the director, and modification of this torque when the particle is close to the cell wall.

  1. Perpendicular spin transfer torque magnetic random access memories with high spin torque efficiency and thermal stability for embedded applications (invited)

    SciTech Connect (OSTI)

    Thomas, Luc, E-mail: luc.thomas@headway.com; Jan, Guenole; Zhu, Jian; Liu, Huanlong; Lee, Yuan-Jen; Le, Son; Tong, Ru-Ying; Pi, Keyu; Wang, Yu-Jen; Shen, Dongna; He, Renren; Haq, Jesmin; Teng, Jeffrey; Lam, Vinh; Huang, Kenlin; Zhong, Tom; Torng, Terry; Wang, Po-Kang [TDK-Headway Technologies, Inc., Milpitas, California 95035 (United States)

    2014-05-07

    Magnetic random access memories based on the spin transfer torque phenomenon (STT-MRAMs) have become one of the leading candidates for next generation memory applications. Among the many attractive features of this technology are its potential for high speed and endurance, read signal margin, low power consumption, scalability, and non-volatility. In this paper, we discuss our recent results on perpendicular STT-MRAM stack designs that show STT efficiency higher than 5?k{sub B}T/?A, energy barriers higher than 100?k{sub B}T at room temperature for sub-40?nm diameter devices, and tunnel magnetoresistance higher than 150%. We use both single device data and results from 8?Mb array to demonstrate data retention sufficient for automotive applications. Moreover, we also demonstrate for the first time thermal stability up to 400?°C exceeding the requirement of Si CMOS back-end processing, thus opening the realm of non-volatile embedded memory to STT-MRAM technology.

  2. Bi-directional dc-dc Converter | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Maryland. merit08goodarzi.pdf More Documents & Publications WBG Converters and Chargers Vehicle Technologies Office Merit Review 2014: WBG Converters and Chargers Vehicle...

  3. Combined Torque and Emission Control for a Turbocharged Gasoline Engine Key words: turbocharged engine, model-based control, torque control, emission control

    E-Print Network [OSTI]

    Frenklach, Michael

    Combined Torque and Emission Control for a Turbocharged Gasoline Engine Key words: turbocharged impact of spark-ignited gasoline engines, it is critical to minimize harmful exhaust emissions of meeting strict emissions requirements [3]. Furthermore, many automotive companies are embracing the trend

  4. Isolated and soft-switched power converter

    DOE Patents [OSTI]

    Peng, Fang Zheng (Knoxville, TN); Adams, Donald Joe (Knoxville, TN)

    2002-01-01

    An isolated and soft-switched power converter is used for DC/DC and DC/DC/AC power conversion. The power converter includes two resonant tank circuits coupled back-to-back through an isolation transformer. Each resonant tank circuit includes a pair of resonant capacitors connected in series as a resonant leg, a pair of tank capacitors connected in series as a tank leg, and a pair of switching devices with anti-parallel clamping diodes coupled in series as resonant switches and clamping devices for the resonant leg. The power converter is well suited for DC/DC and DC/DC/AC power conversion applications in which high-voltage isolation, DC to DC voltage boost, bidirectional power flow, and a minimal number of conventional switching components are important design objectives. For example, the power converter is especially well suited to electric vehicle applications and load-side electric generation and storage systems, and other applications in which these objectives are important. The power converter may be used for many different applications, including electric vehicles, hybrid combustion/electric vehicles, fuel-cell powered vehicles with low-voltage starting, remote power sources utilizing low-voltage DC power sources, such as photovoltaics and others, electric power backup systems, and load-side electric storage and generation systems.

  5. Accretion-Powered Stellar Winds II: Numerical Solutions for Stellar Wind Torques

    E-Print Network [OSTI]

    Sean Matt; Ralph E. Pudritz

    2008-01-18

    [Abridged] In order to explain the slow rotation observed in a large fraction of accreting pre-main-sequence stars (CTTSs), we explore the role of stellar winds in torquing down the stars. For this mechanism to be effective, the stellar winds need to have relatively high outflow rates, and thus would likely be powered by the accretion process itself. Here, we use numerical magnetohydrodynamical simulations to compute detailed 2-dimensional (axisymmetric) stellar wind solutions, in order to determine the spin down torque on the star. We explore a range of parameters relevant for CTTSs, including variations in the stellar mass, radius, spin rate, surface magnetic field strength, the mass loss rate, and wind acceleration rate. We also consider both dipole and quadrupole magnetic field geometries. Our simulations indicate that the stellar wind torque is of sufficient magnitude to be important for spinning down a ``typical'' CTTS, for a mass loss rate of $\\sim 10^{-9} M_\\odot$ yr$^{-1}$. The winds are wide-angle, self-collimated flows, as expected of magnetic rotator winds with moderately fast rotation. The cases with quadrupolar field produce a much weaker torque than for a dipole with the same surface field strength, demonstrating that magnetic geometry plays a fundamental role in determining the torque. Cases with varying wind acceleration rate show much smaller variations in the torque suggesting that the details of the wind driving are less important. We use our computed results to fit a semi-analytic formula for the effective Alfv\\'en radius in the wind, as well as the torque. This allows for considerable predictive power, and is an improvement over existing approximations.

  6. Power system applications for PASC converter systems

    SciTech Connect (OSTI)

    Donnelly, M.K.; Johnson, R.M.

    1994-04-01

    This paper shows, using computer EMTP simulations, some preliminary results of applying pulse amplitude synthesis and control (PASC) technology to single-source level voltage converter system. The method can be applied to any single terminal pair source with appropriate modifications in power extraction interface and computer control program to match source and load impedance characteristics. The PASC realization as discussed here employs banks of transformers, one bank per phase, in which the primaries are connected in parallel through a switch matrix to the dc source. Two opposite polarity primaries per transformer are pulsed alternatively in time to produce an oscillatory sinusoidal output waveform. PASC conversion system capabilities to produce both leading and lagging power factor power output in single-phase and three-phase {Delta} or Y configurations are illustrated. EMTP simulations are used to demonstrate the converter capabilities. Also included are discussions regarding harmonics and potential control strategies to adapt the converter to an application or to minimize harmonics.

  7. Study of Stability Regions in Parallel Connected Boost Converters

    E-Print Network [OSTI]

    Tse, Chi K. "Michael"

    Study of Stability Regions in Parallel Connected Boost Converters Yuehui Huang and Chi K. Tse attractors of parallel connected boost switching converters under a master- slave current sharing scheme. We boost converters. Under the master- slave scheme, one of the converters is the master and the other

  8. SATURATED TORQUE FORMULA FOR PLANETARY MIGRATION IN VISCOUS DISKS WITH THERMAL DIFFUSION: RECIPE FOR PROTOPLANET POPULATION SYNTHESIS

    SciTech Connect (OSTI)

    Masset, F. S. [Instituto de Ciencias Fisicas, Universidad Nacional Autonoma de Mexico (UNAM), Apdo. Postal 48-3, 62251-Cuernavaca, Morelos (Mexico); Casoli, J., E-mail: masset@fis.unam.m, E-mail: jules.casoli@cea.f, E-mail: masset@fis.unam.m [Laboratoire AIM, CEA/DSM, CNRS, Universite Paris Diderot, Irfu/Service d'Astrophysique, Bat. 709, CEA/Saclay, 91191 Gif-sur-Yvette (France)

    2010-11-10

    We provide torque formulae for low-mass planets undergoing type I migration in gaseous disks. These torque formulae put special emphasis on the horseshoe drag, which is prone to saturation: the asymptotic value reached by the horseshoe drag depends on a balance between coorbital dynamics (which tends to cancel out or saturate the torque) and diffusive processes (which tend to restore the unperturbed disk profiles, thereby desaturating the torque). We entertain the question of this asymptotic value and derive torque formulae that give the total torque as a function of the disk's viscosity and thermal diffusivity. The horseshoe drag features two components: one that scales with the vortensity gradient and another that scales with the entropy gradient and constitutes the most promising candidate for halting inward type I migration. Our analysis, which is complemented by numerical simulations, recovers characteristics already noted by numericists, namely, that the viscous timescale across the horseshoe region must be shorter than the libration time in order to avoid saturation and that, provided this condition is satisfied, the entropy-related part of the horseshoe drag remains large if the thermal timescale is shorter than the libration time. Side results include a study of the Lindblad torque as a function of thermal diffusivity and a contribution to the corotation torque arising from vortensity viscously created at the contact discontinuities that appear at the horseshoe separatrices. For the convenience of the reader mostly interested in the torque formulae, Section 8 is self-contained.

  9. Coupling between switching regulation and torque generation in bacterial flagellar motor

    E-Print Network [OSTI]

    Fan Bai; Tohru Minamino; Zhanghan Wu; Keiichi Namba; Jianhua Xing

    2013-07-25

    The bacterial flagellar motor plays a crucial role in both bacterial locomotion and chemotaxis. Recent experiments reveal that the switching dynamics of the motor depends on the motor rotation speed, and thus the motor torque, non-monotonically. Here we present a unified mathematical model which models motor torque generation based on experimental torque-speed curves and torque-dependent switching based on the conformational spread model. The model successfully reproduces the observed switching rate as a function of the rotation speed, and provides a generic physical explanation independent of most details. A stator affects the switching dynamics through two mechanisms: accelerating the conformation flipping rates of individual rotor switching units, which favours slower motor speed and thus increasing torque; and affecting more switching units within unit time, which favours faster speed. Consequently, the switching rate shows a maximum at intermediate speed. Our model predicts that a motor switches more often with more stators. The load-switching relation may serve as a mechanism for sensing the physical environment, similar to the chemotaxis system for sensing the chemical environment. It may also coordinate the switch dynamics of motors within a cell.

  10. High-frequency matrix converter with square wave input

    DOE Patents [OSTI]

    Carr, Joseph Alexander; Balda, Juan Carlos

    2015-03-31

    A device for producing an alternating current output voltage from a high-frequency, square-wave input voltage comprising, high-frequency, square-wave input a matrix converter and a control system. The matrix converter comprises a plurality of electrical switches. The high-frequency input and the matrix converter are electrically connected to each other. The control system is connected to each switch of the matrix converter. The control system is electrically connected to the input of the matrix converter. The control system is configured to operate each electrical switch of the matrix converter converting a high-frequency, square-wave input voltage across the first input port of the matrix converter and the second input port of the matrix converter to an alternating current output voltage at the output of the matrix converter.

  11. Converting Centrifugal Chillers to HCFC-123 

    E-Print Network [OSTI]

    Siebert, B.

    1994-01-01

    of large water chillers in addressing the CFC issue. These owners, for a variety of reasons, chose to address the issue through the conversion of the existing equipment to an HCFC refrigerant. For each of the three owners, the option of converting...

  12. Hybrid switch for resonant power converters

    DOE Patents [OSTI]

    Lai, Jih-Sheng; Yu, Wensong

    2014-09-09

    A hybrid switch comprising two semiconductor switches connected in parallel but having different voltage drop characteristics as a function of current facilitates attainment of zero voltage switching and reduces conduction losses to complement reduction of switching losses achieved through zero voltage switching in power converters such as high-current inverters.

  13. Large voltage-induced modification of spin-orbit torques in Pt/Co/GdOx

    SciTech Connect (OSTI)

    Emori, Satoru Bauer, Uwe; Woo, Seonghoon; Beach, Geoffrey S. D.

    2014-12-01

    We report on large modifications of current-induced spin-orbit torques in a gated Pt/Co/Gd-oxide microstrip due to voltage-driven O{sup 2?} migration. The Slonczewski-like and field-like torques are quantified using a low-frequency harmonic technique based on the polar magneto-optical Kerr effect. Voltage-induced oxidation of Co enhances the Slonczewski-like torque by as much as an order of magnitude and simultaneously reduces the anisotropy energy barrier by a factor of ?5. Such magneto-ionic tuning of interfacial spin-orbit effects may significantly enhance the efficiency of magnetization switching and provide additional degrees of freedom in spintronic devices.

  14. Alignment of Dust with Magnetic Inclusions: Radiative Torques and Superparamagnetic Barnett and Nuclear Relaxation

    E-Print Network [OSTI]

    A. Lazarian; T. Hoang

    2008-01-03

    We consider grains with superparamagnetic inclusions and report two new condensed matter effects that can enhance the internal relaxation of the energy of a wobbling grain, namely, superparamagnetic Barnett relaxation, as well as, an increase of frequencies for which nuclear relaxation becomes important. This findings extends the range of grain sizes for which grains are thermally trapped, i.e. rotate thermally, in spite of the presence of uncompensated pinwheel torques. In addition, we show that the alignment of dust grains by radiative torques gets modified for superparamagnetic grains, with grains obtaining perfect alignment with respect to magnetic fields as soon as the grain gaseous randomization time gets larger than that of paramagnetic relaxation. The same conclusion is valid for the mechanical alignment of helical grains. If observations confirm that the degrees of alignment are higher than radiative torques can produce alone, this may be a proof of the presence of superparamagentic inclusions.

  15. On the Dramatic Spin-up/Spin-down Torque Reversals in Accreting Pulsars

    E-Print Network [OSTI]

    Robert W. Nelson; Lars Bildsten; Deepto Chakrabarty; Mark H. Finger; Danny T. Koh; Thomas A. Prince; Bradley C. Rubin; D. Mathew Scott; Brian A. Vaughan; Robert B. Wilson

    1997-08-21

    Dramatic torque reversals between spin up and spin down have been observed in half of the persistent X-ray pulsars monitored by the BATSE all-sky monitor on CGRO. Theoretical models developed to explain early pulsar timing data can explain spin down torques via a disk-magnetosphere interaction if the star nearly corotates with the inner accretion disk. To produce the observed BATSE torque reversals, however, these equilibrium models require the disk to alternate between two mass accretion rates, with $\\dot M_{\\pm}$ producing accretion torques of similar magnitude, but always of opposite sign. Moreover, in at least one pulsar (GX 1+4) undergoing secular spin down the neutron star spins down faster during brief ($\\sim 20$ day) hard X-ray flares -- this is opposite the correlation expected from standard theory, assuming BATSE pulsed flux increases with mass accretion rate. The $10$ day to 10 yr intervals between torque reversals in these systems are much longer than any characteristic magnetic or viscous time scale near the inner disk boundary and are more suggestive of a global disk phenomenon. We discuss possible explanations of the observed torque behavior. Despite the preferred sense of rotation defined by the binary orbit, the BATSE observations are surprisingly consistent with an earlier suggestion by Makishima \\etal (1988) for GX~1+4: the disks in these systems somehow alternate between episodes of prograde and retrograde rotation. We are unaware of any mechanism that could produce a stable retrograde disk in a binary undergoing Roche-lobe overflow, but such flip-flop behavior does occur in numerical simulations of wind-fed systems. One possibility is that the disks in some of these binaries are fed by an X-ray excited wind.

  16. Zero field high frequency oscillations in dual free layer spin torque oscillators

    SciTech Connect (OSTI)

    Braganca, P. M., E-mail: patrick.braganca@hgst.com; Pi, K.; Zakai, R.; Childress, J. R.; Gurney, B. A. [HGST, 3404 Yerba Buena Rd., San Jose, California 95135 (United States)] [HGST, 3404 Yerba Buena Rd., San Jose, California 95135 (United States)

    2013-12-02

    We observe microwave oscillations in relatively simple spin valve spin torque oscillators consisting of two in-plane free layers without spin polarizing layers. These devices exhibit two distinct modes which can reach frequencies >25?GHz in the absence of an applied magnetic field. Macrospin simulations identify these two modes as optical and acoustic modes excited by the coupling of the two layers through dipole field and spin torque effects. These results demonstrate the potential of this system as a large output power, ultrahigh frequency signal generator that can operate without magnetic field.

  17. Modeling torque versus speed, shot noise, and rotational diffusion of the bacterial flagellar motor

    E-Print Network [OSTI]

    Thierry Mora; Howard Yu; Ned S. Wingreen

    2009-10-05

    We present a minimal physical model for the flagellar motor that enables bacteria to swim. Our model explains the experimentally measured torque-speed relationship of the proton-driven E. coli motor at various pH and temperature conditions. In particular, the dramatic drop of torque at high rotation speeds (the "knee") is shown to arise from saturation of the proton flux. Moreover, we show that shot noise in the proton current dominates the diffusion of motor rotation at low loads. This suggests a new way to probe the discreteness of the energy source, analogous to measurements of charge quantization in superconducting tunnel junctions.

  18. Local spin torque induced by electron electric dipole moment in the YbF molecule

    SciTech Connect (OSTI)

    Fukuda, Masahiro; Senami, Masato; Ogiso, Yoji; Tachibana, Akitomo

    2014-10-06

    In this study, we show the modification of the equation of motion of the electronic spin, which is derived by the quantum electron spin vorticity principle, by the effect of the electron electric dipole moment (EDM). To investigate the new contribution to spin torque by EDM, using first principle calculations, we visualize distributions of the local spin angular momentum density and local spin torque density of the YbF molecule on which the static electric field and magnetic field are applied at t = 0.

  19. MULTILEVEL CONVERTERS - A NEW BREED OF POWER CONVERTERS Jih-Sheng...

    Office of Scientific and Technical Information (OSTI)

    has been a well-known method and has been implemented in 18- and 48-pulse converters for battery energy storage and static condenser (STATCON) applications, respectively 15,161....

  20. On the force and torque on systems of rigid bodies: A remark on an integral formula due to Howe

    E-Print Network [OSTI]

    Tabak, Esteban G.

    On the force and torque on systems of rigid bodies: A remark on an integral formula due to Howe 2007 M. S. Howe J. Fluid Mech. 206, 131 1989 presented integral formulas for the force and torque induced by free vorticity, and viscous skin friction. Here a simple extension of Howe's formulas is done

  1. VERIFICATION OF A FINITE ELEMENT MODEL OF AN UNMANNED AERIAL VEHICLE WING TORQUE BOX VIA EXPERIMENTAL MODAL TESTING

    E-Print Network [OSTI]

    Yaman, Yavuz

    VERIFICATION OF A FINITE ELEMENT MODEL OF AN UNMANNED AERIAL VEHICLE WING TORQUE BOX VIA Aeronautical Association, Faculty of Aeronautics and Astronautics, TURKEY KEYWORDS Unmanned Aerial Vehicle Wing (FEM) of an unmanned aerial vehicle wing torque box was verified by the experimental modal testing

  2. Optical analog-to-digital converter

    DOE Patents [OSTI]

    Vawter, G. Allen (Corrales, NM); Raring, James (Goleta, CA); Skogen, Erik J. (Albuquerque, NM)

    2009-07-21

    An optical analog-to-digital converter (ADC) is disclosed which converts an input optical analog signal to an output optical digital signal at a sampling rate defined by a sampling optical signal. Each bit of the digital representation is separately determined using an optical waveguide interferometer and an optical thresholding element. The interferometer uses the optical analog signal and the sampling optical signal to generate a sinusoidally-varying output signal using cross-phase-modulation (XPM) or a photocurrent generated from the optical analog signal. The sinusoidally-varying output signal is then digitized by the thresholding element, which includes a saturable absorber or at least one semiconductor optical amplifier, to form the optical digital signal which can be output either in parallel or serially.

  3. Converting DYNAMO simulations to Powersim Studio simulations

    SciTech Connect (OSTI)

    Walker, La Tonya Nicole; Malczynski, Leonard A.

    2014-02-01

    DYNAMO is a computer program for building and running 'continuous' simulation models. It was developed by the Industrial Dynamics Group at the Massachusetts Institute of Technology for simulating dynamic feedback models of business, economic, and social systems. The history of the system dynamics method since 1957 includes many classic models built in DYANMO. It was not until the late 1980s that software was built to take advantage of the rise of personal computers and graphical user interfaces that DYNAMO was supplanted. There is much learning and insight to be gained from examining the DYANMO models and their accompanying research papers. We believe that it is a worthwhile exercise to convert DYNAMO models to more recent software packages. We have made an attempt to make it easier to turn these models into a more current system dynamics software language, Powersim © Studio produced by Powersim AS2 of Bergen, Norway. This guide shows how to convert DYNAMO syntax into Studio syntax.

  4. Component technology for Stirling power converters

    SciTech Connect (OSTI)

    Thieme, L.G.

    1994-09-01

    NASA Lewis Research Center has organized a component technology program as part of the efforts to develop Stirling converter technology for space power applications. The Stirling space power program is part of the NASA High Capacity Power Project of the Civil Space Technology Initiative (CSTI). NASA Lewis is also providing technical management for a DOE/Sandia program to develop Stirling converters for solar terrestrial power producing electricity for the utility grid. The primary contractors for the space power and solar terrestrial programs develop component technologies directly related to their program goals. This Lewis component technology effort, while coordinated with the main programs, aims at longer term issues, advanced technologies, and independent assessments. This paper will present an overview of work on linear alternators, engine/alternator/load interactions and controls, heat exchangers, materials, life and reliability, and bearings.

  5. Direct Torque Control for Interior Permanent Magnet Synchronous Motors with Respect to Optimal Efficiency

    E-Print Network [OSTI]

    Noé, Reinhold

    applications. Highly utilized machines are often designed as interior permanent magnet synchronous motorsDirect Torque Control for Interior Permanent Magnet Synchronous Motors with Respect to Optimal@lea.upb.de, boecker@lea.upb.de URL: http://wwwlea.upb.de Keywords «Interior permanent magnet synchronous motor

  6. Optimal Design of Motor and Gear for Drives with High Acceleration and Load Torque

    E-Print Network [OSTI]

    Noé, Reinhold

    Optimal Design of Motor and Gear for Drives with High Acceleration and Load Torque H. Grotstollen-acceleration product are transmitted unchanged by an ideal gear. At a first step those motors can be selected which offer sufficient rated power and power rate. When designing gears for each of these motors two ranges

  7. Control of Electro-Rheological Fluid Based Torque Generation Components For Use in Active Rehabilitation Devices

    E-Print Network [OSTI]

    Mavroidis, Constantinos

    a gear system is connected. The key features of AKROD include: a compact, lightweight design with highly we present the design and control algorithms for novel electro-rheological fluid based torque-rheological fluid (ERF) element that connects to the output of the gear system. Using the electrically controlled

  8. Achieving Consistent Maximum Brake Torque with Varied Injection Timing in a DI Diesel Engine 

    E-Print Network [OSTI]

    Kroeger, Timothy H

    2013-09-19

    The brake torque of a direct-injection diesel engine is known to plateau over a range of injection timings. Injection timing affects the engine’s ignition delay and the fractions of fuel which burn in premixed and diffusion modes. Therefore...

  9. Adaptive Torque Control of Electro-Rheological Fluid Brakes Used in Active Knee Rehabilitation Devices

    E-Print Network [OSTI]

    Mavroidis, Constantinos

    1 Adaptive Torque Control of Electro-Rheological Fluid Brakes Used in Active Knee Rehabilitation-rheological fluid (ERF) based variable resistance brakes that are used in compact and portable rehabilitation Control, Actuators for Rehabilitation Robotics I. INTRODUCTION Electro-rheological fluids (ERFs

  10. Technical Section Evaluating the influence of induced passive torques in the

    E-Print Network [OSTI]

    Rodríguez, Inmaculada

    , Gran via de les corts catalans, 585, 08007 Barcelona, Spain b Virtual Reality Lab, EPFL, Switzerland produce a passive torque at the limits of the joint range of motion. We present a fatigue model in which in an unconscious way. In particular, some postural adjustments arise due to muscle fatigue. In several fields

  11. Passive torque wrench and angular position detection using a single-beam optical trap

    E-Print Network [OSTI]

    Wang, Michelle

    Passive torque wrench and angular position detection using a single-beam optical trap James Inman,1 August 26, 2010 The recent advent of angular optical trapping techniques has allowed for rotational torsional measurements across a wide range of biological systems. © 2010 Optical Society of America OCIS

  12. Torque-generating malaria-infected red blood cells in an optical trap

    E-Print Network [OSTI]

    Sharma, Shobhona

    Torque-generating malaria-infected red blood cells in an optical trap J.A. Dharmadhikari, S. Roy, A 005, India # atmol1@tifr.res.in Abstract: We have used optical tweezers to trap normal and Plasmodium emerge from our experiments. Firstly, while the optical field modifies both types of RBCs in the same

  13. Torque Enhancement, Spin Equilibrium, and Jet Power from Disk-Induced Opening of Pulsar Magnetic Fields

    E-Print Network [OSTI]

    Parfrey, Kyle; Beloborodov, Andrei M

    2015-01-01

    The interaction of a rotating star's magnetic field with a surrounding plasma disk lies at the heart of many questions posed by neutron stars in X-ray binaries. We consider the opening of stellar magnetic flux due to differential rotation along field lines coupling the star and disk, using a simple model for the disk-opened flux, the torques exerted on the star by the magnetosphere, and the power extracted by the electromagnetic wind. We examine the conditions under which the system enters an equilibrium spin state, in which the accretion torque is instantaneously balanced by the pulsar wind torque alone. For magnetic moments, spin frequencies, and accretion rates relevant to accreting millisecond pulsars, the spin-down torque from this enhanced pulsar wind can be substantially larger than that predicted by existing models of the disk-magnetosphere interaction, and is in principle capable of maintaining spin equilibrium at frequencies less than 1 kHz. We speculate that this mechanism may account for the non-d...

  14. A biped static balance control and torque pattern learning under unknown periodic external forces

    E-Print Network [OSTI]

    Ito, Satoshi

    A biped static balance control and torque pattern learning under unknown periodic external forces balancing task in which an unknown external force is exerted, using so-called `ankle strategy' model. When an external force is pe- riodic, a human adaptively maintains the balance, next learns how much force should

  15. Direct torque control of permanent magnet synchronous motors with non-sinusoidal back-EMF 

    E-Print Network [OSTI]

    Ozturk, Salih Baris

    2009-05-15

    This work presents the direct torque control (DTC) techniques, implemented in four- and six-switch inverter, for brushless dc (BLDC) motors with non-sinusoidal back- EMF using two and three-phase conduction modes. First of all, the classical direct...

  16. Heat Pump Water Heater using Solid-State Energy Converters |...

    Energy Savers [EERE]

    Heat Pump Water Heater using Solid-State Energy Converters Heat Pump Water Heater using Solid-State Energy Converters Sheetak will work on developing a full scale prototype of its...

  17. An economical single to three phase converter for induction motors 

    E-Print Network [OSTI]

    Di Zerega, Philp Van Uytandaele

    1994-01-01

    There are several different types of single to three phase converters for induction motors available today. However, many of the presently available phase converters suffer from disadvantages such as high cost or low performance. An economical...

  18. DOE Announces Webinars on the Wave Energy Converter Prize, the...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    the Wave Energy Converter Prize, the Best of the Clean Cities Tools and Resources, and More DOE Announces Webinars on the Wave Energy Converter Prize, the Best of the Clean Cities...

  19. Digital radix converters for high accuracy data conversion 

    E-Print Network [OSTI]

    Ghanta, Venkataratnam Chowdary

    1993-01-01

    A sub-binary radix Digital to Analog converter(DAC) which achieves high effective resolution is demonstrated. The converter does not have any built-in-self calibration mechanisms, but achieves high resolution and accuracy through the sub...

  20. Calibration of the optical torque wrench Francesco Pedaci,1,2 Zhuangxiong Huang,1,2 Maarten van Oene,1 and

    E-Print Network [OSTI]

    Dekker, Nynke

    Calibration of the optical torque wrench Francesco Pedaci,1,2 Zhuangxiong Huang,1,2 Maarten van-first authors *n.h.dekker@tudelft.nl Abstract: The optical torque wrench is a laser trapping technique that expands the capability of standard optical tweezers to torque manipulation and measurement, using

  1. Aalborg Universitet Single stage grid converters for battery energy storage

    E-Print Network [OSTI]

    Munk-Nielsen, Stig

    Aalborg Universitet Single stage grid converters for battery energy storage Trintis, Ionut; Munk). Single stage grid converters for battery energy storage. In 5th IET International Conference on Power from vbn.aau.dk on: juli 04, 2015 #12;SINGLE STAGE GRID CONVERTERS FOR BATTERY ENERGY STORAGE I

  2. Optimizing Ballast Design of Wave Energy Converters Using Evolutionary Algorithms

    E-Print Network [OSTI]

    Tumer, Kagan

    Optimizing Ballast Design of Wave Energy Converters Using Evolutionary Algorithms Mitch Colby, 97331 kagan.tumer@oregonstate.edu ABSTRACT Wave energy converters promise to be a viable alternative% improvement in power output over a ballast-free wave energy converter. General Terms Algorithms; Applications

  3. General Impedance Synthesizer Using Minimal Configuration of Switching Converters

    E-Print Network [OSTI]

    Tse, Chi K. "Michael"

    converter may contain a storage element and a pair of switches, such as the buck, buck-boost and boostGeneral Impedance Synthesizer Using Minimal Configuration of Switching Converters Joe C.P. Liu Chi a minimum number of switching converters is stud- ied in this paper. We begin with showing that any

  4. Design Methodology for a Very High Frequency Resonant Boost Converter

    E-Print Network [OSTI]

    Perreault, Dave

    Design Methodology for a Very High Frequency Resonant Boost Converter Justin M. Burkhart , Roman@ti.com Abstract--This document introduces a design methodology for a resonant boost converter topology demonstrated for boost conversion at frequencies up to 110MHz using a resonant boost converter topology in [5

  5. Coupled Dual Interleaved Flyback Converter for High Input Voltage Application

    E-Print Network [OSTI]

    Lehman, Brad

    proposed integrated boost converters [7] that are beginning to see applications in automotive power buck-boost (Flyback) power converter [9,10] that utilizes one magnetic core to integrate two FlybackCoupled Dual Interleaved Flyback Converter for High Input Voltage Application Ting Qian, Brad

  6. Modelling and geometry optimisation of wave energy converters

    E-Print Network [OSTI]

    Nørvåg, Kjetil

    Modelling and geometry optimisation of wave energy converters Adi Kurniawan Supervisors: Prof;Research questions Modelling How to develop more realistic wave energy converter (WEC) models while wave energy converter (WEC) models while at the same time reduce their simulation time? Optimisation

  7. Resource convertibility and ordered commutative monoids

    E-Print Network [OSTI]

    Tobias Fritz

    2015-07-02

    Resources and their use and consumption form a central part of our life. Many branches of science and engineering are concerned with the question of which given resource objects can be converted into which target resource objects. For example, information theory studies the conversion of a noisy communication channel instance into an exchange of information. Inspired by work in quantum information theory, we develop a general mathematical toolbox for this type of question. The convertibility of resources into other ones and the possibility of combining resources is accurately captured by the mathematics of ordered commutative monoids. As an intuitive example, we consider chemistry, where chemical reaction equations such as \\[ \\mathrm{2H_2 + O_2} \\to \\mathrm{2H_2O} \\] are concerned both with a convertibility relation "$\\to$" and a combination operation "$+$". We study ordered commutative monoids from an algebraic and functional-analytic perspective and derive a wealth of results which should have applications to concrete resource theories, such as a formula for rates of conversion. As a running example showing that ordered commutative monoids are also of purely mathematical interest, we exemplify our results with the ordered commutative monoid of graphs. While closely related to both Girard's linear logic and to Deutsch's constructor theory, our framework also produces results very reminiscent of the utility theorem of von Neumann and Morgenstern in decision theory and of a theorem of Lieb and Yngvason on thermodynamics. Concerning pure algebra, our observation is that some pieces of algebra can be developed in a context in which equality is not necessarily symmetric, i.e. in which the equality relation is replaced by an ordering relation. For example, notions like cancellativity or torsion-freeness are still sensible and very natural concepts in our ordered setting.

  8. Voltage balanced multilevel voltage source converter system

    DOE Patents [OSTI]

    Peng, F.Z.; Lai, J.S.

    1997-07-01

    Disclosed is a voltage balanced multilevel converter for high power AC applications such as adjustable speed motor drives and back-to-back DC intertie of adjacent power systems. This converter provides a multilevel rectifier, a multilevel inverter, and a DC link between the rectifier and the inverter allowing voltage balancing between each of the voltage levels within the multilevel converter. The rectifier is equipped with at least one phase leg and a source input node for each of the phases. The rectifier is further equipped with a plurality of rectifier DC output nodes. The inverter is equipped with at least one phase leg and a load output node for each of the phases. The inverter is further equipped with a plurality of inverter DC input nodes. The DC link is equipped with a plurality of rectifier charging means and a plurality of inverter discharging means. The plurality of rectifier charging means are connected in series with one of the rectifier charging means disposed between and connected in an operable relationship with each adjacent pair of rectifier DC output nodes. The plurality of inverter discharging means are connected in series with one of the inverter discharging means disposed between and connected in an operable relationship with each adjacent pair of inverter DC input nodes. Each of said rectifier DC output nodes are individually electrically connected to the respective inverter DC input nodes. By this means, each of the rectifier DC output nodes and each of the inverter DC input nodes are voltage balanced by the respective charging and discharging of the rectifier charging means and the inverter discharging means. 15 figs.

  9. Converting urban tree maintenance residue to energy

    SciTech Connect (OSTI)

    Murphey, W.K.; Massey, J.G.; Sumrall, A.

    1980-01-01

    Three methods of utilizing urban wood waste collected by a tree maintenance firm in Houston, Texas (handling 30,000 ton waste/year) are examined: (a) hauling to a remote landfill; (b) chipping and hauling to a (local) power plant and converting to electricity; and (c) chipping and selling to an outside firm for use as boiler fuel. Breakdown of costs are given for each method in monetary and energy terms. Method (b) was the cheapest, producing a net energy gain (870 million Btu/day), but the firm chose method (c), since it realized a direct monetary return.

  10. Solid state transport-based thermoelectric converter

    DOE Patents [OSTI]

    Hu, Zhiyu

    2010-04-13

    A solid state thermoelectric converter includes a thermally insulating separator layer, a semiconducting collector and an electron emitter. The electron emitter comprises a metal nanoparticle layer or plurality of metal nanocatalyst particles disposed on one side of said separator layer. A first electrically conductive lead is electrically coupled to the electron emitter. The collector layer is disposed on the other side of the separator layer, wherein the thickness of the separator layer is less than 1 .mu.m. A second conductive lead is electrically coupled to the collector layer.

  11. CCLIBS: The CERN Power Converter Control Libraries

    E-Print Network [OSTI]

    King, Quentin; Magrans De Abril, Marc; Martino, Michele; Murillo Garcia, Raul; Nicoletti, Achille

    2015-01-01

    Accurate control of power converters is a vital activity in large physics projects. Several different control scenarios may coexist, including regulation of a circuit’s voltage, current, or field strength within a magnet. Depending on the type of facility, a circuit’s reference value may be changed asynchronously or synchronously with other circuits. Synchronous changes may be on demand or under the control of a cyclic timing system. In other cases, the reference may be calculated in real-time by an outer regulation loop of some other quantity, such as the tune of the beam in a synchrotron. The power stage may be unipolar or bipolar in voltage and current. If it is unipolar in current, it may be used with a polarity switch. Depending on the design, the power stage may be controlled by a firing angle or PWM duty-cycle reference, or a voltage or current reference. All these cases are supported by the CERN Converter Control Libraries (CCLIBS). These open-source C libraries include advanced reference generati...

  12. Power Maximization in Wave-Energy Converters Using Sampled -Data Extremum Seeking /

    E-Print Network [OSTI]

    Chen, Tianjia

    2013-01-01

    Power Maximization in Wave-Energy Converters Using Sampled-design optimization of wave energy converters con- sistingN. Sahinkaya. A review of wave energy converter technology.

  13. Non-contact gears: II. Casimir torque between concentric corrugated cylinders for the scalar case

    E-Print Network [OSTI]

    Ines Cavero-Pelaez; Kimball A. Milton; Prachi Parashar; K. V. Shajesh

    2008-07-03

    The Casimir interaction between two concentric corrugated cylinders provides the mechanism for non-contact gears. To this end, we calculate the Casimir torque between two such cylinders, described by $\\delta$-potentials, which interact through a scalar field. We derive analytic expressions for the Casimir torque for the case when the corrugation amplitudes are small in comparison to the corrugation wavelengths. We derive explicit results for the Dirichlet case, and exact results for the weak coupling limit, in the leading order. The results for the corrugated cylinders approach the corresponding expressions for the case of corrugated parallel plates in the limit of large radii of cylinders (relative to the difference in their radii) while keeping the corrugation wavelength fixed.

  14. Non-linear evolution of the angular momentum of protostructures from tidal torques

    E-Print Network [OSTI]

    Paolo Catelan; Tom Theuns

    1996-04-15

    We discuss the non-linear evolution of the angular momentum L acquired by protostructures, like protogalaxies and protoclusters, due to tidal interactions with the surrounding matter inhomogeneities. The primordial density distribution is assumed to be Gaussian and the non-linear dynamics of the collisionless mass fluid is followed using Lagrangian perturbation theory. For a Cold Dark Matter spectrum, the inclusion of the leading-order Lagrangian correction terms results in a value of the rms ensemble average ^{1/2} which is only a factor of 1.3 higher than the corresponding linear estimate, irrespective of the scale. Consequently, the predictions of linear theory are rather accurate in quantifying the evolution of the angular momentum of protostructures before collapse sets in. In the Einstein-de Sitter universe, the initial torque is a good estimate for the tidal torque over the whole period during which the object is spun up.

  15. Method and system for determining the torque required to launch a vehicle having a hybrid drive-train

    DOE Patents [OSTI]

    Hughes, Douglas A.

    2006-04-04

    A method and system are provided for determining the torque required to launch a vehicle having a hybrid drive-train that includes at least two independently operable prime movers. The method includes the steps of determining the value of at least one control parameter indicative of a vehicle operating condition, determining the torque required to launch the vehicle from the at least one determined control parameter, comparing the torque available from the prime movers to the torque required to launch the vehicle, and controlling operation of the prime movers to launch the vehicle in response to the comparing step. The system of the present invention includes a control unit configured to perform the steps of the method outlined above.

  16. Optical forces and optical torques on various materials arising from optical lattices in the Lorentz-Mie regime

    E-Print Network [OSTI]

    Jia, Lin

    By combining the Maxwell stress tensor with the finite-difference time-domain (FDTD) method, we calculate the optical force and optical torque on particles from optical lattices. We compare our method to the two-component ...

  17. Strategies for using electromyographic signals to control ankle torque in an active joint brace for alleviating drop-foot gait

    E-Print Network [OSTI]

    Lin, Elizabeth C

    2006-01-01

    This thesis describes the efforts to develop control strategies that use EMG signals from the anterior tibialis muscle to control ankle torque in an active ankle-foot orthosis. This would ultimately help rehabilitate persons ...

  18. Calculation of rotordynamic unbalance response including torque and cross-coupled stiffness and damping effects 

    E-Print Network [OSTI]

    Kleespies, Henry Sattoli

    1986-01-01

    code was developed using the transfer matrix method to investigate the effects of cross-coupled sti ffness, cross-coupled damping, and torque on synchronous response of rotating machinery. Several models showing the effects of cross.... Phase plot of rotor with ZX damping. Figure 3 1. Response plot for rotor with forward driving cross-coupled stiffness. Figure 32. Response plot with cross-coupled 53 55 57 sti ffness negating lateral damping. Figure 33. Response plot with cross...

  19. Current dependence of spin torque switching rate based on Fokker-Planck approach

    SciTech Connect (OSTI)

    Taniguchi, Tomohiro Imamura, Hiroshi

    2014-05-07

    The spin torque switching rate of an in-plane magnetized system in the presence of an applied field is derived by solving the Fokker-Planck equation. It is found that three scaling currents are necessary to describe the current dependence of the switching rate in the low-current limit. The dependences of these scaling currents on the applied field strength are also studied.

  20. Converting energy from fusion into useful forms

    E-Print Network [OSTI]

    Kovari, M; Jenkins, I; Kiely, C

    2014-01-01

    If fusion power reactors are to be feasible, it will still be necessary to convert the energy of the nuclear reaction into usable form. The heat produced will be removed from the reactor core by a primary coolant, which might be water, helium, molten lithium-lead, molten lithium-containing salt, or CO2. The heat could then be transferred to a conventional Rankine cycle or Brayton (gas turbine) cycle. Alternatively it could be used for thermochemical processes such as producing hydrogen or other transport fuels. Fusion presents new problems because of the high energy neutrons released. These affect the selection of materials and the operating temperature, ultimately determining the choice of coolant and working cycle. The limited temperature ranges allowed by present day irradiated structural materials, combined with the large internal power demand of the plant, will limit the overall thermal efficiency. The operating conditions of the fusion power source, the materials, coolant, and energy conversion system w...

  1. Mechanical vibration to electrical energy converter

    DOE Patents [OSTI]

    Kellogg, Rick Allen (Tijeras, NM); Brotz, Jay Kristoffer (Albuquerque, NM)

    2009-03-03

    Electromechanical devices that generate an electrical signal in response to an external source of mechanical vibrations can operate as a sensor of vibrations and as an energy harvester for converting mechanical vibration to electrical energy. The devices incorporate a magnet that is movable through a gap in a ferromagnetic circuit, wherein a coil is wound around a portion of the ferromagnetic circuit. A flexible coupling is used to attach the magnet to a frame for providing alignment of the magnet as it moves or oscillates through the gap in the ferromagnetic circuit. The motion of the magnet can be constrained to occur within a substantially linear range of magnetostatic force that develops due to the motion of the magnet. The devices can have ferromagnetic circuits with multiple arms, an array of magnets having alternating polarity and, encompass micro-electromechanical (MEM) devices.

  2. Modular Power Converters for PV Applications

    SciTech Connect (OSTI)

    Ozpineci, Burak; Tolbert, Leon M

    2012-05-01

    This report describes technical opportunities to serve as parts of a technological roadmap for Shoals Technologies Group in power electronics for PV applications. There are many different power converter circuits that can be used for solar inverter applications. The present applications do not take advantage of the potential for using common modules. We envision that the development of a power electronics module could enable higher reliability by being durable and flexible. Modules would have fault current limiting features and detection circuits such that they can limit the current through the module from external faults and can identify and isolate internal faults such that the remaining modules can continue to operate with only minimal disturbance to the utility or customer. Development of a reliable, efficient, low-cost, power electronics module will be a key enabling technology for harnessing more power from solar panels and enable plug and play operation. Power electronics for computer power supplies, communication equipment, and transportation have all targeted reliability and modularity as key requirements and have begun concerted efforts to replace monolithic components with collections of common smart modules. This is happening on several levels including (1) device level with intelligent control, (2) functional module level, and (3) system module. This same effort is needed in power electronics for solar applications. Development of modular units will result in standard power electronic converters that will have a lower installed and operating cost for the overall system. These units will lead to increased adaptability and flexibility of solar inverters. Incorporating autonomous fault current limiting and reconfiguration capabilities into the modules and having redundant modules will lead to a durable converter that can withstand the rigors of solar power generation for more than 30 years. Our vision for the technology roadmap is that there is no need for detailed design of new power converters for each new application or installation. One set of modules and controllers can be pre-developed and the only design question would be how many modules need to be in series or parallel for the specific power requirement. Then, a designer can put the modules together and add the intelligent reconfigurable controller. The controller determines how many modules are connected, but it might also ask for user input for the specific application during setup. The modules include protection against faults and can reset it, if necessary. In case of a power device failure, the controller reconfigures itself to continue limited operation until repair which might be as simple as taking the faulty module out and inserting a new module. The result is cost savings in design, maintenance, repair, and a grid that is more reliable and available. This concept would be a perfect fit for the recently announced funding opportunity announcement (DE-FOA-0000653) on Plug and Play Photovoltaics.

  3. Force and torque acting on particles in a transitionally rough open channel flow

    E-Print Network [OSTI]

    Chan-Braun, Clemens; Uhlmann, Markus

    2011-01-01

    Direct numerical simulation of open channel flow over a geometrically rough wall has been performed at a bulk Reynolds number of approximately 2900. The wall consisted of a layer of spheres in a square arrangement. Two cases have been considered. In the first case the spheres are small (with diameter equivalent to 10.7 wall units) and the limit of the hydraulically smooth flow regime is approached. In the second case the spheres are more than three times larger (49.3 wall units) and the flow is in the transitionally rough flow regime. Special emphasis is given on the characterisation of the force and torque acting on a particle due to the turbulent flow. It is found that in both cases the mean drag, lift and spanwise torque are to a large extent produced at the top region of the particle surface. The intensity of the particle force fluctuations is significantly larger in the large-sphere case, while the trend differs for the fluctuations of the individual components of the torque. A simplified model is used t...

  4. Integrated Solar Power Converters: Wafer-Level Sub-Module Integrated DC/DC Converter

    SciTech Connect (OSTI)

    2012-02-09

    Solar ADEPT Project: CU-Boulder is developing advanced power conversion components that can be integrated into individual solar panels to improve energy yields. The solar energy that is absorbed and collected by a solar panel is converted into useable energy for the grid through an electronic component called an inverter. Many large, conventional solar energy systems use one, central inverter to convert energy. CU-Boulder is integrating smaller, microinverters into individual solar panels to improve the efficiency of energy collection. The University’s microinverters rely on electrical components that direct energy at high speeds and ensure that minimal energy is lost during the conversion process—improving the overall efficiency of the power conversion process. CU-Boulder is designing its power conversion devices for use on any type of solar panel.

  5. SEP Success Story: State Energy Program Helping Arkansans Convert...

    Broader source: Energy.gov (indexed) [DOE]

    to purchase andor convert their Arkansas-licensed vehicles to compressed natural gas (CNG). | All Rights Reserved. The Arkansas Energy Office recently launched a Compressed...

  6. Sandia Energy - Advanced Controls of Wave Energy Converters May...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Advanced Controls of Wave Energy Converters May Increase Power Capture Up to 330% Home Renewable Energy Energy Water Power Partnership News News & Events Computational Modeling &...

  7. NREL Refines Method to Convert Lignin to Nylon Precursor - News...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    to Convert Lignin to Nylon Precursor Recent Findings Published in Energy & Environmental Science February 26, 2015 A new study from the Energy Department's National Renewable...

  8. Secretary Chu Announces Six Projects to Convert Captured CO2...

    Energy Savers [EERE]

    that Americans can use. "These innovative projects convert carbon pollution from a climate threat to an economic resource," said Secretary Chu. "This is part of our broad...

  9. Wave Energy Converter Effects on Nearshore Wave Propagation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Energy Converter Effects on Nearshore Wave Propagation Jesse Roberts 1 , Grace Chang *2 , Craig Jones *3 Sandia National Laboratories 1515 Eubank SE, Albuquerque, NM 87123 USA 1...

  10. Sandia Energy - Sandia, NREL Release Wave Energy Converter Modeling...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Release Wave Energy Converter Modeling and Simulation Code: WEC-Sim Home Renewable Energy Energy Water Power Partnership News News & Events Computational Modeling & Simulation...

  11. Improved Low-Temperature Performance of Catalytic Converters...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    National Laboratory. Toxic vehicle emissions, such as carbon monoxide and unburned hydrocarbons, are chemically converted to benign compounds, like carbon dioxide (CO2) and water,...

  12. Method and apparatus for effecting light-off of a catalytic converter in a hybrid powertrain system

    DOE Patents [OSTI]

    Roos, Bryan Nathaniel; Spohn, Brian L

    2013-07-02

    A powertrain system includes a hybrid transmission and an internal combustion engine coupled to an exhaust aftertreatment device. A method for operating the powertrain system includes operating the hybrid transmission to generate tractive torque responsive to an operator torque request with the internal combustion engine in an engine-off state so long as the tractive torque is less than a threshold. The internal combustion engine is operated in an engine-on state at preferred operating conditions to effect light-off of the exhaust aftertreatment device and the hybrid transmission is coincidentally operated to generate tractive torque responsive to the operator torque request when the operator torque request exceeds the threshold. The internal combustion engine is then operated in the engine-on state to generate tractive torque responsive to the operator torque request.

  13. Switching power converter Figure 1(a): Switching DC-DC converter with analog voltage-mode control

    E-Print Network [OSTI]

    + ­ RC L Vg 1 2 i + v _ Vref + _ Gc(s) VM = 1 PWM u c Switching power converter H v dTs H = 1 design of digital compensators. I. INTRODUCTION Discrete-time modeling of dc-dc switching converters has IEEE. #12;+ ­ R C L Vg 1 2 i + v _ Vref + _ Gc(z) VM = 1 DPWM u c Switching power converter H v dTs H

  14. Harmonic Elimination for Multilevel Converter with Programmed PWM Method

    E-Print Network [OSTI]

    Tolbert, Leon M.

    Harmonic Elimination for Multilevel Converter with Programmed PWM Method Zhong Du, Leon M. Tolbert presents a programmed PWM method to eliminate specific higher order harmonics of multilevel converters. First, resultant theory is applied to transcendental equations to eliminate low order harmonics

  15. IEEE INFOCOM 2002 1 Design of Wavelength Converting Switches for

    E-Print Network [OSTI]

    Turner, Jonathan S.

    IEEE INFOCOM 2002 1 Design of Wavelength Converting Switches for Optical Burst Switching Jeyashankher Ramamirtham, Jonathan Turner Abstract-- Optical Burst Switching (OBS) is an experi- mental network- tronic control. In this paper, we study two designs for wave- length converting switches

  16. Design of Wavelength Converting Switches for Optical Burst Switching

    E-Print Network [OSTI]

    Design of Wavelength Converting Switches for Optical Burst Switching Jeyashankher Ramamirtham, Jonathan Turner Abstract-- Optical Burst Switching (OBS) is an experi- mental network technology. In this paper, we study two designs for wavelength converting switches that are suitable for use in optical

  17. Semiconductors 8-bit multiplying D/A converter

    E-Print Network [OSTI]

    Gustafsson, Torgny

    Philips Semiconductors MC1408-8 8-bit multiplying D/A converter Product data Supersedes data of 1994 Aug 31 File under Integrated Circuits, IC11 Handbook 2001 Aug 03 INTEGRATED CIRCUITS #12;Philips Semiconductors Product data MC1408-88-bit multiplying D/A converter 22001 Aug 03 853-0935 26835 DESCRIPTION

  18. Minimum Phase Response in Digitally Controlled Boost and Flyback Converters

    E-Print Network [OSTI]

    -frequency switching power converters has been related to point-of-load synchronous buck converters, while fewer, Mariko Shirazi and Dragan Maksimovic Colorado Power Electronics Center ECE Department, University-phase responses, thus simplifying compensator design in wide bandwidth closed-loop voltage regulators based

  19. Practical On-Line Identification of Power Converter Dynamic Responses

    E-Print Network [OSTI]

    parameters to maintain stability at the .. 1 4Switched-Mode Power Converter 1-b I 1 PIIdenfgcation& design-frequency switching power converters has been shown to provide many possible benefits, including improved immunity power convertcrs. These findings provide the first step towards automating the control loop design

  20. Design Considerations for Very High Frequency dc-dc Converters

    E-Print Network [OSTI]

    Perreault, Dave

    the gating power while ensuring fast on- off transitions of the semiconductor switch. The rectifier of switching power converters operating at greatly increased switching frequencies. Greatly increasedDesign Considerations for Very High Frequency dc-dc Converters Juan M. Rivas, David Jackson, Olivia

  1. MATHEMATICAL ANALYSIS OF A WAVE ENERGY CONVERTER ARNAUD ROUGIREL

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    MATHEMATICAL ANALYSIS OF A WAVE ENERGY CONVERTER MODEL ARNAUD ROUGIREL Abstract. In a context where for buoy-type ocean wave energy converter. The simplest model for this scheme is a non autonomous piecewise and periodic solutions, and compare the energy performance of this novel WEC with respect to the one of wave

  2. Multiple Input Converters for Fuel Cells Burak Ozpineci1

    E-Print Network [OSTI]

    Tolbert, Leon M.

    Multiple Input Converters for Fuel Cells Burak Ozpineci1 burak@ieee.org Leon M. Tolbert1,2 tolbert-2100 Abstract-- Multilevel converters have been used previously to integrate several fuel cell modules for higher power applications. Some previous publications have also shown improvements in fuel cell

  3. The New Modular Control System for Power Converters at CERN

    E-Print Network [OSTI]

    Di Cosmo, Matteo

    2015-01-01

    The CERN accelerator complex consists of several generations of particle accelerators, with around 5000 power converters supplying regulated current and voltage to normal and superconducting magnet circuits. Today around 12 generations of converter control platforms can be found in the accelerator complex, ranging in age and technology. The diversity of these platforms has a significant impact on operability, maintenance and support of power converters. Over the past few years a new generation of modular controls called RegFGC3 has been developed by CERN’s power conversion group, with a goal to provide a standardised control platform, supporting a wide variety of converter topologies. The aim of this project is to reduce maintenance costs by decreasing the variety and diversity of control systems whilst simultaneously improving the operability and reliability of power converters and their controls. This paper describes the state of the on-going design and realization of the RegFGC3 platform, focusing on fun...

  4. Synchronization of an array of spin torque nano oscillators in periodic applied external magnetic field

    E-Print Network [OSTI]

    B. Subash; V. K. Chandrasekar; M. Lakshmanan

    2013-04-03

    Considering an array of spin torque transfer nano oscillators (STNOs), we have investigated the synchronization property of the system under the action of a common periodically driven applied external magnetic field by numerically analyzing the underlying system of Landau-Lifshitz-Gilbert-Slonczewski (LLGS) equations for the macro-spin variables. We find the novel result that the applied external magnetic field can act as a medium to induce synchronization of periodic oscillations, both in-phase and anti-phase, even without coupling through spin current, thereby leading to the exciting possibility of enhancement of microwave power in a straightforward way.

  5. Optimization of spin-torque switching using AC and DC pulses

    SciTech Connect (OSTI)

    Dunn, Tom [Department of Physics, University of Minnesota, Minneapolis, Minnesota 55455 (United States); Kamenev, Alex [Department of Physics, University of Minnesota, Minneapolis, Minnesota 55455 (United States); Fine Theoretical Physics Institute, University of Minnesota, Minneapolis, Minnesota 55455 (United States)

    2014-06-21

    We explore spin-torque induced magnetic reversal in magnetic tunnel junctions using combined AC and DC spin-current pulses. We calculate the optimal pulse times and current strengths for both AC and DC pulses as well as the optimal AC signal frequency, needed to minimize the Joule heat lost during the switching process. The results of this optimization are compared against numeric simulations. Finally, we show how this optimization leads to different dynamic regimes, where switching is optimized by either a purely AC or DC spin-current, or a combination AC/DC spin-current, depending on the anisotropy energies and the spin-current polarization.

  6. Magnet Technology for Power Converters: Nanocomposite Magnet Technology for High Frequency MW-Scale Power Converters

    SciTech Connect (OSTI)

    2012-02-27

    Solar ADEPT Project: CMU is developing a new nanoscale magnetic material that will reduce the size, weight, and cost of utility-scale PV solar power conversion systems that connect directly to the grid. Power converters are required to turn the energy that solar power systems create into useable energy for the grid. The power conversion systems made with CMU’s nanoscale magnetic material have the potential to be 150 times lighter and significantly smaller than conventional power conversion systems that produce similar amounts of power.

  7. Spatial and temporal scales of force and torque acting on wall-mounted spherical particles in open channel flow

    E-Print Network [OSTI]

    Chan-Braun, Clemens; Uhlmann, Markus

    2013-01-01

    Data from direct numerical simulation of open channel flow over a geometrically rough wall at a bulk Reynolds number of 2900, generated by Chan-Braun et al. ["Force and torque acting on particles in a transitionally rough open-channel flow", J. Fluid Mech. 684, 441--474 (2011), 10.1017/jfm.2011.311] are further analysed with respect to the time and length scales of force and torque acting on the wall-mounted spheres. For the two sizes of spheres in a square arrangement (11 and 49 wall units in diameter, yielding hydraulically smooth and transitionally rough flow, respectively), the spatial structure of drag, lift and spanwise torque is investigated. The auto-correlation and spectra in time as well as the space-time correlation and convection velocities are presented and discussed. It is found that the statistics of spanwise particle torque are similar to those of shear stress at a smooth wall. Particle drag and lift are shown to differ from spanwise particle torque, exhibiting considerably smaller time and le...

  8. Wind turbines convert the kinetic energy in moving air into rotational energy, which in turn is converted

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Wind turbines convert the kinetic energy in moving air into rotational energy, which in turn is converted to electricity. Since wind speeds vary from month to month and second to second, the amount of electricity wind can make varies constantly. Sometimes a wind turbine will make no power at all

  9. DYNAMIC ANALYSIS OF THE BULK TRITIUM SHIPPING PACKAGE SUBJECTED TO CLOSURE TORQUES AND SEQUENTIAL IMPACTS

    SciTech Connect (OSTI)

    Wu, T; Paul Blanton, P; Kurt Eberl, K

    2007-07-09

    This paper presents a finite-element technique to simulate the structural responses and to evaluate the cumulative damage of a radioactive material packaging requiring bolt closure-tightening torque and subjected to the scenarios of the Hypothetical Accident Conditions (HAC) defined in the Code of Federal Regulations Title 10 part 71 (10CFR71). Existing finite-element methods for modeling closure stresses from bolt pre-load are not readily adaptable to dynamic analyses. The HAC events are required to occur sequentially per 10CFR71 and thus the evaluation of the cumulative damage is desirable. Generally, each HAC event is analyzed separately and the cumulative damage is partially addressed by superposition. This results in relying on additional physical testing to comply with 10CFR71 requirements for assessment of cumulative damage. The proposed technique utilizes the combination of kinematic constraints, rigid-body motions and structural deformations to overcome some of the difficulties encountered in modeling the effect of cumulative damage. This methodology provides improved numerical solutions in compliance with the 10CFR71 requirements for sequential HAC tests. Analyses were performed for the Bulk Tritium Shipping Package (BTSP) designed by Savannah River National Laboratory to demonstrate the applications of the technique. The methodology proposed simulates the closure bolt torque preload followed by the sequential HAC events, the 30-foot drop and the 30-foot dynamic crush. The analytical results will be compared to the package test data.

  10. Tidal torques dynamical friction and the structure of clusters of galaxies

    E-Print Network [OSTI]

    A. Del Popolo; M. Gambera

    2001-05-22

    We study the joint effect of tidal torques and dynamical friction on the collapse of density peaks solving numerically the equations of motion of a shell of barionic matter falling into the central regions of a cluster of galaxies. We calculate the evolution of the expansion parameter, a(t), of the perturbation using a coefficient of dynamical friction eta_{cl} obtained from a clustered system and taking into account the gravitational interaction of the quadrupole moment of the system with the tidal field of the matter of the neighboring proto-galaxies. We show that within high-density environments, such as rich clusters of galaxies, tidal torques and dynamical friction slow down the collapse of low-nu peaks producing an observable variation of the parameter of expansion of the shell. As a consequence a bias of dynamical nature arises because high-density peaks preferentially collapse to form halos within which visible objects eventually will condense. For a standard Cold Dark Matter model this dynamical bias can account for a substantial part of the total bias required by observations on cluster scales.

  11. On the Correlation of Torque and Luminosity in GX 1+4

    E-Print Network [OSTI]

    Deepto Chakrabarty; Lars Bildsten; Mark H. Finger; John M. Grunsfeld; Danny T. Koh; Robert W. Nelson; Thomas A. Prince; Brian A. Vaughan; Robert B. Wilson

    1997-03-07

    Over five years of daily hard X-ray (>20 keV) monitoring of the 2-min accretion-powered pulsar GX 1+4 with the Compton Gamma Ray Observatory/BATSE large-area detectors has found nearly continuous rapid spin-down, interrupted by a bright 200-d spin-up episode. During spin-down, the torque becomes more negative as the luminosity increases (assuming that the 20-60 keV pulsed flux traces bolometric luminosity), the opposite of what is predicted by standard accretion torque theory. No changes in the shape of the 20-100 keV pulsed energy spectrum were detected, so that a very drastic change in the spectrum below 20 keV or the pulsed fraction would be required to make the 20-60 keV pulsed flux a poor luminosity tracer. These are the first observations which flatly contradict standard magnetic disk accretion theory, and they may have important implications for understanding the spin evolution of X-ray binaries, cataclysmic variables, and protostars. We briefly discuss the possibility that GX 1+4 may be accreting from a retrograde disk during spin-down, as previously suggested.

  12. Generating Isolated Outputs in a Multilevel Modular Capacitor Clamped DC-DC Converter

    E-Print Network [OSTI]

    Tolbert, Leon M.

    -dc converters based on inductive energy transfer method (IETM) such as buck, boost, and buck-boost converter967 Generating Isolated Outputs in a Multilevel Modular Capacitor Clamped DC-DC Converter (MMCCC clamped dc-dc converter. The multilevel modular capacitor clamped converter (MMCCC) has several key

  13. Bifurcation in a System of Coupled Buck Converters Herbert H. C. Iu

    E-Print Network [OSTI]

    Tse, Chi K. "Michael"

    electronic regulators (e.g. buck converter, boost converter and buck-boost converter) have been thoroughlyBifurcation in a System of Coupled Buck Converters Herbert H. C. Iu , Chi K. Tse and Octavian the bifurcation behaviour of a system of coupled buck converters under current-mode control. The effects due

  14. Modeling and Analysis of Hybrid Converters Michael Evzelman Shmuel (Sam) Ben-Yaakov

    E-Print Network [OSTI]

    by simulation and experimentally. The experimental converter included a Boost converter followed by x3 switched. This can be conveniently done by hybrid converters with multiple Figure 1. Hybrid Boost SCCx3 converterModeling and Analysis of Hybrid Converters Michael Evzelman Shmuel (Sam) Ben-Yaakov Power

  15. Bifurcation in Parallel-Connected Buck Converters under Current-Mode Control

    E-Print Network [OSTI]

    Tse, Chi K. "Michael"

    converter, boost converter and buck-boost converter) have been thoroughly studied in the past decade [1], [2Bifurcation in Parallel-Connected Buck Converters under Current-Mode Control H. H. C. Iu School a system of parallel-connected dc/dc buck converters under current-mode control. The effects of variations

  16. Protocols for the Equitable Assessment of Marine Energy Converters 

    E-Print Network [OSTI]

    Ingram, David; Smith, George; Bittencourt-Ferreira, Claudio; Smith, Helen

    This book contains the suite of protocols for the equitable evaluation of marine energy converters (based on either tidal or wave energy) produced by the EquiMar consortium led by the University of Edinburgh. These protocols ...

  17. Oversampled pipline A/D converters with mismatch shaping

    E-Print Network [OSTI]

    Shabra, Ayman U. (Ayman Umar)

    2001-01-01

    This thesis introduces a technique to improve the linearity of pipeline analog to digital converters (ADC). Through a combination of oversampling and mismatch shaping, the distortion introduced by component mismatch is ...

  18. Design Methodology for a Very High Frequency Resonant Boost Converter

    E-Print Network [OSTI]

    Burkhart, Justin M.

    This paper introduces a design methodology for a resonant boost converter topology that is suitable for operation at very high frequencies. The topology we examine features a low parts count and fast transient response, ...

  19. Design methodology for a very high frequency resonant boost converter

    E-Print Network [OSTI]

    Burkhart, Justin M.

    This document introduces a design methodology for a resonant boost converter topology that is suitable for operation at very high frequencies. The topology we examine features a low parts count and fast transient response ...

  20. Development, evaluation, and design applications of an AMTEC converter model 

    E-Print Network [OSTI]

    Spence, Cliff Alan

    2002-01-01

    An AMTEC converter model was developed and its effectiveness as a design tool was evaluated. To develop the model, requirements of the model were defined, modeling equations were selected, and a methodology for model development was established...

  1. Soft switched high frequency ac-link converter 

    E-Print Network [OSTI]

    Balakrishnan, Anand Kumar

    2009-05-15

    Variable frequency drives typically have employed dc voltage or current links for power distribution between the input and output converters and as a means to temporarily store energy. The dc link based power conversion systems have several inherent...

  2. Method for converting uranium oxides to uranium metal

    DOE Patents [OSTI]

    Duerksen, Walter K. (Norris, TN)

    1988-01-01

    A process is described for converting scrap and waste uranium oxide to uranium metal. The uranium oxide is sequentially reduced with a suitable reducing agent to a mixture of uranium metal and oxide products. The uranium metal is then converted to uranium hydride and the uranium hydride-containing mixture is then cooled to a temperature less than -100.degree. C. in an inert liquid which renders the uranium hydride ferromagnetic. The uranium hydride is then magnetically separated from the cooled mixture. The separated uranium hydride is readily converted to uranium metal by heating in an inert atmosphere. This process is environmentally acceptable and eliminates the use of hydrogen fluoride as well as the explosive conditions encountered in the previously employed bomb-reduction processes utilized for converting uranium oxides to uranium metal.

  3. Converting normal insulators into topological insulators via tuning orbital levels

    E-Print Network [OSTI]

    Shi, Wu-Jun

    Tuning the spin-orbit coupling strength via foreign element doping and modifying bonding strength via strain engineering are the major routes to convert normal insulators to topological insulators. We here propose an ...

  4. Non-synchronous control of self-oscillating resonant converters

    DOE Patents [OSTI]

    Glaser, John Stanley (Niskayuna, NY); Zane, Regan Andrew (Scotia, NY)

    2002-01-01

    A self-oscillating switching power converter has a controllable reactance including an active device connected to a reactive element, wherein the effective reactance of the reactance and the active device is controlled such that the control waveform for the active device is binary digital and is not synchronized with the switching converter output frequency. The active device is turned completely on and off at a frequency that is substantially greater than the maximum frequency imposed on the output terminals of the active device. The effect is to vary the average resistance across the active device output terminals, and thus the effective output reactance, thereby providing converter output control, while maintaining the response speed of the converter.

  5. A Dual Supply Buck Converter with Improved Light Load Efficiency 

    E-Print Network [OSTI]

    Chen, Hui

    2013-05-02

    Power consumption is the primary concern in battery-operated portable applications. Buck converters have gained popularity in powering portable devices due to their compact size, good current delivery capability and high efficiency. However...

  6. Vehicle Technologies Office Merit Review 2014: WBG Converters and Chargers

    Broader source: Energy.gov [DOE]

    Presentation given by Oak Ridge National Laboratory at 2014 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about WBG converters...

  7. Bi-directional power control system for voltage converter

    DOE Patents [OSTI]

    Garrigan, N.R.; King, R.D.; Schwartz, J.E.

    1999-05-11

    A control system for a voltage converter includes: a power comparator for comparing a power signal on input terminals of the converter with a commanded power signal and producing a power comparison signal; a power regulator for transforming the power comparison signal to a commanded current signal; a current comparator for comparing the commanded current signal with a measured current signal on output terminals of the converter and producing a current comparison signal; a current regulator for transforming the current comparison signal to a pulse width modulator (PWM) duty cycle command signal; and a PWM for using the PWM duty cycle command signal to control electrical switches of the converter. The control system may further include: a command multiplier for converting a voltage signal across the output terminals of the converter to a gain signal having a value between zero (0) and unity (1), and a power multiplier for multiplying the commanded power signal by the gain signal to provide a limited commanded power signal, wherein power comparator compares the limited commanded power signal with the power signal on the input terminals. 10 figs.

  8. Bi-directional power control system for voltage converter

    DOE Patents [OSTI]

    Garrigan, Neil Richard (Niskayuna, NY); King, Robert Dean (Schenectady, NY); Schwartz, James Edward (Slingerlands, NY)

    1999-01-01

    A control system for a voltage converter includes: a power comparator for comparing a power signal on input terminals of the converter with a commanded power signal and producing a power comparison signal; a power regulator for transforming the power comparison signal to a commanded current signal; a current comparator for comparing the commanded current signal with a measured current signal on output terminals of the converter and producing a current comparison signal; a current regulator for transforming the current comparison signal to a pulse width modulator (PWM) duty cycle command signal; and a PWM for using the PWM duty cycle command signal to control electrical switches of the converter. The control system may further include: a command multiplier for converting a voltage signal across the output terminals of the converter to a gain signal having a value between zero (0) and unity (1), and a power multiplier for multiplying the commanded power signal by the gain signal to provide a limited commanded power signal, wherein power comparator compares the limited commanded power signal with the power signal on the input terminals.

  9. An evaluation of a parallel-resonant current-source converter for an electrothermal thruster 

    E-Print Network [OSTI]

    Tchamdjou, Aristide-Marie

    1996-01-01

    The Parallel-Resonant Current-Source Converter promises highly efficient DCDC power conversion. It uses zero-voltage switching to reduce the losses and improve the converter efficiency. The Parallel-Resonant Current-Source Converter has been...

  10. Mass-modulation schemes for a class of wave energy converters: Experiments, models, and efficacy

    E-Print Network [OSTI]

    Diamond, CA; Judge, CQ; Orazov, B; Sava?, Ö; O'Reilly, OM

    2015-01-01

    dynamics of a novel ocean wave energy converter. Journal of5565. Dick, W. , 2005. Wave energy converter. U.S. Patentof the IPS buoy wave energy converter including the effect

  11. A New Methodology for Frequency Domain Analysis of Wave Energy Converters with Periodically Varying Physical Parameters

    E-Print Network [OSTI]

    Victoria, University of

    A New Methodology for Frequency Domain Analysis of Wave Energy Converters with Periodically Varying Methodology for Frequency Domain Analysis of Wave Energy Converters with Periodically Varying Physical of Mechanical Engineering) ABSTRACT Within a wave energy converter's operational bandwidth, device operation

  12. Power-Factor and Torque Calculation with Consideration of Cross Saturation of the Interior Permanent Magnet Synchronous Motor with

    E-Print Network [OSTI]

    Tolbert, Leon M.

    OF IPMSM Below is the well-known electromagnetic torque equation for all synchronous machines: dqqd iip Permanent Magnet Synchronous Motor with Brushless Field Excitation Seong Taek Lee1,2 , Timothy A. Burress1 permanent magnet synchronous motor (IPMSM). The conventional two-axis IPMSM model is modified to include

  13. Error-field induced electromagnetic torques in a large aspect-ratio, low-, weakly shaped tokamak plasma

    E-Print Network [OSTI]

    Fitzpatrick, Richard

    Error-field induced electromagnetic torques in a large aspect-ratio, low- , weakly shaped tokamak-ratio tokamaks Phys. Plasmas 17, 122504 (2010); 10.1063/1.3526611 A nonideal error-field response model for strongly shaped tokamak plasmas Phys. Plasmas 17, 112502 (2010); 10.1063/1.3504227 Modeling the effect

  14. Our basic understanding of Rotating Magnetic Field (RMF) current drive of flux confined FRCs involves a balance between RMF torque

    E-Print Network [OSTI]

    Washington at Seattle, University of

    separatrix pressure with open field plasma · RMF FRC has very low separatrix pressure with no open field. The FRC will expand or contract radially until these torques are in balance, with the RMF radial FRC formation when STX worked very well, STX lacked such a source of particles. Rather, the inventory

  15. Torque-Actuated Valves for Microfluidics Douglas B. Weibel, Maarten Kruithof, Scott Potenta, Samuel K. Sia, Andrew Lee, and

    E-Print Network [OSTI]

    Sia, Samuel K.

    Torque-Actuated Valves for Microfluidics Douglas B. Weibel, Maarten Kruithof, Scott Potenta, Samuel for controlling the flow of fluids in microfluidic channels. The valves consist of small machine screws (g500 µm) embedded in a layer of polyurethane cast above microfluidic channels fabricated in poly

  16. Viscoelastic Dynamics of Actin Filaments Coupled to Rotary F-ATPase: Angular Torque Profile of the Enzyme

    E-Print Network [OSTI]

    Junge, Wolfgang

    engine that drives ATP synthesis in its peripheral portion, F1, at the expense of proton (sodium) flow) operates as two rotary motor/generators coupled by a common shaft. Both portions, F1 and FO, are rotary the angular profile of the output torque at FO during ATP hydrolysis by F1 (see theoretical companion article

  17. Spin torque and heating effects in current-induced domain wall motion probed by transmission electron microscopy

    E-Print Network [OSTI]

    Dunin-Borkowski, Rafal E.

    Spin torque and heating effects in current-induced domain wall motion probed by transmission are reported. Heating on membranes leads to thermally activated random behavior at low current densities and by backcoating the SiN membranes with Al, heating effects are significantly reduced. A set of indicators

  18. Tangential force, Frictional Torque and Heating Rate of a Small Neutral Rotating Particle Moving through the Equilibrium Background Radiation

    E-Print Network [OSTI]

    G. V. Dedkov; A. A. Kyasov

    2013-02-04

    For the first time, based on the fluctuation-electromagnetic theory, we have calculated the drug force, the radiation heat flux and the frictional torque on a small rotating particle moving at a relativistic velocity through the equilibrium background radiation (photon gas). The particle and background radiation are characterized by different temperatures corresponding to the local thermodynamic equilibrium in their own reference frames.

  19. Complementary spin-Hall and inverse spin-galvanic effect torques in a ferromagnet/semiconductor bilayer

    E-Print Network [OSTI]

    Skinner, T. D.; Olejnik, K.; Cunningham, L. K.; Kurebayashi, H.; Campion, R. P.; Gallagher, B. L.; Jungwirth, T.; Ferguson, A. J.

    2015-03-31

    spin Hall effect3 (SHE) is absorbed in the ferromagnet and induces the spin transfer torque4 (STT). In the other pic- ture, a non-equilibrium spin-density is generated via the relativistic inverse spin galvanic effect5 (ISGE) and induces the spin...

  20. Measurements of Drag Torque and Lift Off Speed and Identification of Stiffness and Damping in a Metal Mesh Foil Bearing 

    E-Print Network [OSTI]

    Chirathadam, Thomas A.

    2010-07-14

    performance. Application of a sacrificial layer of solid lubricant on the top foil surface aids to reduce the rotor break-away torque. The measurements give confidence on this simple bearing technology for ready application into oil-free turbomachinery. Impact...

  1. The Torque of Rotary F-ATPase Can Unfold Subunit Gamma If Rotor and Stator Are Cross-Linked

    E-Print Network [OSTI]

    Junge, Wolfgang

    cross-linked (via an engineered disulfide bridge) with the bearing, the rotary function of F1 persists an artificial disulfide bridge did not impair the rotary ATPase activity. We newly engineered three mutantsThe Torque of Rotary F-ATPase Can Unfold Subunit Gamma If Rotor and Stator Are Cross-Linked Florian

  2. Mode-hopping mechanism generating colored noise in a magnetic tunnel junction based spin torque oscillator

    SciTech Connect (OSTI)

    Sharma, Raghav; Dürrenfeld, P.; Iacocca, E.; Heinonen, O. G.; Åkerman, J.; Muduli, P. K.

    2014-09-29

    The frequency noise spectrum of a magnetic tunnel junction based spin torque oscillator is examined where multiple modes and mode-hopping events are observed. The frequency noise spectrum is found to consist of both white noise and 1/f frequency noise. We find a systematic and similar dependence of both white noise and 1/f frequency noise on bias current and the relative angle between the reference and free layers, which changes the effective damping and hence the mode-hopping behavior in this system. The frequency at which the 1/f frequency noise changes to white noise increases as the free layer is aligned away from the anti-parallel orientation w.r.t the reference layer. These results indicate that the origin of 1/f frequency noise is related to mode-hopping, which produces both white noise as well as 1/f frequency noise similar to the case of ring lasers.

  3. Low torque hydrodynamic lip geometry for bi-directional rotation seals

    DOE Patents [OSTI]

    Dietle, Lannie L. (Houston, TX); Schroeder, John E. (Richmond, TX)

    2011-11-15

    A hydrodynamically lubricating geometry for the generally circular dynamic sealing lip of rotary seals that are employed to partition a lubricant from an environment. The dynamic sealing lip is provided for establishing compressed sealing engagement with a relatively rotatable surface, and for wedging a film of lubricating fluid into the interface between the dynamic sealing lip and the relatively rotatable surface in response to relative rotation that may occur in the clockwise or the counter-clockwise direction. A wave form incorporating an elongated dimple provides the gradual convergence, efficient impingement angle, and gradual interfacial contact pressure rise that are conducive to efficient hydrodynamic wedging. Skewed elevated contact pressure zones produced by compression edge effects provide for controlled lubricant movement within the dynamic sealing interface between the seal and the relatively rotatable surface, producing enhanced lubrication and low running torque.

  4. Low torque hydrodynamic lip geometry for bi-directional rotation seals

    DOE Patents [OSTI]

    Dietle, Lannie L. (Houston, TX); Schroeder, John E. (Richmond, TX)

    2009-07-21

    A hydrodynamically lubricating geometry for the generally circular dynamic sealing lip of rotary seals that are employed to partition a lubricant from an environment. The dynamic sealing lip is provided for establishing compressed sealing engagement with a relatively rotatable surface, and for wedging a film of lubricating fluid into the interface between the dynamic sealing lip and the relatively rotatable surface in response to relative rotation that may occur in the clockwise or the counter-clockwise direction. A wave form incorporating an elongated dimple provides the gradual convergence, efficient impingement angle, and gradual interfacial contact pressure rise that are conducive to efficient hydrodynamic wedging. Skewed elevated contact pressure zones produced by compression edge effects provide for controlled lubricant movement within the dynamic sealing interface between the seal and the relatively rotatable surface, producing enhanced lubrication and low running torque.

  5. Fast deterministic switching in orthogonal spin torque devices via the control of the relative spin polarizations

    SciTech Connect (OSTI)

    Park, Junbo; Buhrman, R. A.; Ralph, D. C.; Kavli Institute at Cornell, Ithaca, New York 14853

    2013-12-16

    We model 100 ps pulse switching dynamics of orthogonal spin transfer (OST) devices that employ an out-of-plane polarizer and an in-plane polarizer. Simulation results indicate that increasing the spin polarization ratio, C{sub P}?=?P{sub IPP}/P{sub OPP}, results in deterministic switching of the free layer without over-rotation (360° rotation). By using spin torque asymmetry to realize an enhanced effective P{sub IPP}, we experimentally demonstrate this behavior in OST devices in parallel to anti-parallel switching. Modeling predicts that decreasing the effective demagnetization field can substantially reduce the minimum C{sub P} required to attain deterministic switching, while retaining low critical switching current, I{sub p}???500??A.

  6. DOE-TSPP-8-2013, Converting DOE Technical Standards to Voluntary...

    Office of Environmental Management (EM)

    8-2013, Converting DOE Technical Standards to Voluntary Consensus Standards DOE-TSPP-8-2013, Converting DOE Technical Standards to Voluntary Consensus Standards Technical Standards...

  7. Power Maximization in Wave-Energy Converters Using Sampled -Data Extremum Seeking /

    E-Print Network [OSTI]

    Chen, Tianjia

    2013-01-01

    A review of wave energy converter technology. Proceedings ofdecades. With the technology of wave-energy convert- ers(Wave energy utilization: A review of the technologies. Re-

  8. Probing CP Violation in $h\\rightarrow\\gamma\\gamma$ with Converted...

    Office of Scientific and Technical Information (OSTI)

    CP Violation in hrightarrowgammagamma with Converted Photons Citation Details In-Document Search Title: Probing CP Violation in hrightarrowgammagamma with Converted...

  9. Sub-picosecond Resolution Time-to-Digital Converter

    SciTech Connect (OSTI)

    Ph D, Vladimir Bratov; Ph D, Vladimir Katzman; MS EE, Jeb Binkley

    2006-03-30

    Time-to-digital converters with sub-picosecond resolutions are needed to satisfy the requirements of time-on-flight measurements of the next generation of high energy and nuclear physics experiments. The converters must be highly integrated, power effective, low cost, and feature plug-and-play capabilities to handle the increasing number of channels (up to hundreds of millions) in future Department of Energy experiments. Current state-off-the-art time-to-digital converter integrated circuits do not have the sufficient degree of integration and flexibility to fulfill all the described requirements. During Phase I, the Advanced Science and Novel Technology Company in cooperation with the nuclear physics division of the Oak Ridge National Laboratory has developed the architecture of a novel time-to-digital converter with multiple channels connected to an external processor through a special interfacing block and synchronized by clock signals generated by an internal phase-locked loop. The critical blocks of the system including signal delay lines and delay-locked loops with proprietary differential delay cells, as well as the required digital code converter and the clock period counter have been designed and simulated using the advanced SiGe120 BiCMOS technological process. The results of investigations demonstrate a possibility to achieve the digitization accuracy within 1ps. ADSANTEC has demonstrated the feasibility of the proposed concept in computer simulations. The proposed system will be a critical component for the next generation of NEP experiments.

  10. Methods for degrading or converting plant cell wall polysaccharides

    DOE Patents [OSTI]

    Berka, Randy (Davis, CA); Cherry, Joel (Davis, CA)

    2008-08-19

    The present invention relates to methods for converting plant cell wall polysaccharides into one or more products, comprising: treating the plant cell wall polysaccharides with an effective amount of a spent whole fermentation broth of a recombinant microorganism, wherein the recombinant microorganism expresses one or more heterologous genes encoding enzymes which degrade or convert the plant cell wall polysaccharides into the one or more products. The present invention also relates to methods for producing an organic substance, comprising: (a) saccharifying plant cell wall polysaccharides with an effective amount of a spent whole fermentation broth of a recombinant microorganism, wherein the recombinant microorganism expresses one or more heterologous genes encoding enzymes which degrade or convert the plant cell wall polysaccharides into saccharified material; (b) fermenting the saccharified material of step (a) with one or more fermenting microoganisms; and (c) recovering the organic substance from the fermentation.

  11. Power line carrier interference from HVDC converter terminals

    SciTech Connect (OSTI)

    Tatro, P.J.; Adamson, K.A. (New England Power Service Co., Westborough, MA (United States)); Eitzmann, M.A.; Smead, M. (GE Industrial and Power Systems, Schenectady, NY (United States). Power Systems Engineering Dept.)

    1993-07-01

    Power line carrier (PLC) equipment typically operates in the frequency range from 25 kHz to 300 kHz. Interference studies for HVDC converters usually concentrate on interference from noise sources within this frequency range. However, operating experience at the Sandy Pond converter terminal has indicated that PLC equipment is also susceptible to interference from sources of power system harmonics below the PLC frequency range. Extensive field testing and analytical studies have shown that each PLC circuit has a resonant frequency below the operating frequency. If excited at this resonant frequency, high voltages may exist within the PLC circuit. The resulting saturation of PLC components leads to local generation of radio frequency (RF) noise that interferes with proper operation of PLC circuits. Sources of power system harmonics in the 3-10 kHz range, such as line commutated dc converters, are potential sources of this type of interference.

  12. Auxiliary quasi-resonant dc tank electrical power converter

    DOE Patents [OSTI]

    Peng, Fang Z.

    2006-10-24

    An auxiliary quasi-resonant dc tank (AQRDCT) power converter with fast current charging, voltage balancing (or charging), and voltage clamping circuits is provided for achieving soft-switched power conversion. The present invention is an improvement of the invention taught in U.S. Pat. No. 6,111,770, herein incorporated by reference. The present invention provides faster current charging to the resonant inductor, thus minimizing delay time of the pulse width modulation (PWM) due to the soft-switching process. The new AQRDCT converter includes three tank capacitors or power supplies to achieve the faster current charging and minimize the soft-switching time delay. The new AQRDCT converter further includes a voltage balancing circuit to charge and discharge the three tank capacitors so that additional isolated power supplies from the utility line are not needed. A voltage clamping circuit is also included for clamping voltage surge due to the reverse recovery of diodes.

  13. Process for converting cellulosic materials into fuels and chemicals

    DOE Patents [OSTI]

    Scott, Charles D. (Oak Ridge, TN); Faison, Brendlyn D. (Knoxville, TN); Davison, Brian H. (Knoxville, TN); Woodward, Jonathan (Oak Ridge, TN)

    1994-01-01

    A process for converting cellulosic materials, such as waste paper, into fuels and chemicals utilizing enzymatic hydrolysis of the major constituent of paper, cellulose. A waste paper slurry is contacted by cellulase in an agitated hydrolyzer. The cellulase is produced from a continuous, columnar, fluidized-bed bioreactor utilizing immobilized microorganisms. An attritor and a cellobiase reactor are coupled to the agitated hydrolyzer to improve reaction efficiency. The cellulase is recycled by an adsorption process. The resulting crude sugars are converted to dilute product in a fluidized-bed bioreactor utilizing microorganisms. The dilute product is concentrated and purified by utilizing distillation and/or a biparticle fluidized-bed bioreactor system.

  14. Method for converting sucrose to .beta.-D-glucose

    DOE Patents [OSTI]

    Simmons, Blake A. (San Francisco, CA); Volponi, Joanne V. (Livermore, CA); Ingersoll, David (Albuquerque, NM); Walker, Andrew (Woodinville, WA)

    2009-07-07

    Disclosed is an apparatus and method for continuously converting sucrose to .beta.-D-glucose. The method comprises a three-stage enzymatic reactor in which an aqueous solution of sucrose is first converted into a solution of fructose and .alpha.-D-glucose by passing it through a porous, packed column containing an inert media on which invertase is immobilized. This solution is then sent through a second packed column containing glucose isomerase and finally a third packed column containing mutarotase. Solution temperature and pH are adjusted to maximize glucose output.

  15. Current-induced switching of magnetic tunnel junctions: Effects of field-like spin-transfer torque, pinned-layer magnetization orientation, and temperature

    SciTech Connect (OSTI)

    Tiwari, R. K.; Jhon, M. H.; Ng, N.; Gan, C. K., E-mail: ganck@ihpc.a-star.edu.sg [Institute of High Performance Computing, Agency for Science, Technology and Research, 1 Fusionopolis Way, 16-16 Connexis, Singapore 138632 (Singapore); Srolovitz, D. J. [Department of Materials Science, Engineering, Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States)

    2014-01-13

    We study current-induced switching in magnetic tunnel junctions in the presence of a field-like spin-transfer torque and titled pinned-layer magnetization in the high current limit at finite temperature. We consider both the Slonczewski and field-like torques with coefficients a{sub J} and b{sub J}, respectively. At finite temperatures, ?=b{sub J}/a{sub J}=±1 leads to a smaller mean switching time compared that with ?=0. The reduction of switching time in the presence of the field-like term is due to the alignment effect (for ?>0) and the initial torque effect.

  16. Northwest Energy Innovations (TRL 5 6 System)- WETNZ MtiMode Wave Energy Converter Advancement Project

    Broader source: Energy.gov [DOE]

    Northwest Energy Innovations (TRL 5 6 System) - WETNZ MtiMode Wave Energy Converter Advancement Project

  17. Analysis and Optimization of Switched-Capacitor DC-DC Converters

    E-Print Network [OSTI]

    Sanders, Seth

    on conduction loss) of a ladder-type converter is found to be superior to that of a conventional boost converterAnalysis and Optimization of Switched-Capacitor DC-DC Converters Michael D. Seeman, Seth R. Sanders­ Analysis methods are developed that fully determine a switched-capacitor (SC) dc-dc converter's steady

  18. IEEE TRANSACTIONS ON POWER ELECTRONICS 1 Singular Perturbation Theory for DCDC Converters

    E-Print Network [OSTI]

    Kimball, Jonathan W.

    model. Similar results hold for boost, buck, and buck­boost converters. Experimental boost convertersIEEE TRANSACTIONS ON POWER ELECTRONICS 1 Singular Perturbation Theory for DC­DC Converters and Application to PFC Converters Jonathan W. Kimball, Senior Member, IEEE, and Philip T. Krein, Fellow, IEEE

  19. 17.March.2005 C. A. Martins, CERN AB/PO 1 Power converter

    E-Print Network [OSTI]

    McDonald, Kirk

    , 1000Vdc Converter topology 18 kV cell Power transformers (in an oil tank) 2x4 Rectifier bridges Passive Passive filter self Passive filter capacitors self capacitors DC output #12;17.March.2005 C. A. Martins Converters location: · At building 193 (AD) like ALICE/LHCb converter 2nd choice target Power converter (193

  20. Sigma-Delta Modulation of Multi-Phase High Frequency Converters

    E-Print Network [OSTI]

    Kimball, Jonathan W.

    Sigma-Delta Modulation of Multi-Phase High Frequency Converters Jonathan W. Kimball, Senior Member control architecture is proposed that merges advanced digital modulation techniques, high frequency resonant converters, and multi-phase converters. If a converter's switching frequency is high enough

  1. Comparison of architectures for two-step flash analog-to-digital converters 

    E-Print Network [OSTI]

    Reese, Robert Bryan

    1982-01-01

    A/D converters have been designed and fabricated in the last three to five ?om a survey of the literature it was discovered that the majority of these converters were of the successive approximation (SAP) type (Table I, page 4). This is because... the SAP converter offers a fast conversion time, a low complexity level and a small area requirement. Only one comparator, the design critical subcircuit of most converters, is needed in a SAP converter. Area requirements increase only moderately...

  2. Converting chemical energy of hydrogenated fuels into electricity

    E-Print Network [OSTI]

    - 1 - Fuel Cells Converting chemical energy of hydrogenated fuels into electricity Project Description Invented in 1839, fuels cells powered the Gemini and Apollo space missions, as well as the space shuttle. Although fuel cells have been successfully used in such applications, they have proven difficult

  3. Pre-converted nitric oxide gas in catalytic reduction system

    DOE Patents [OSTI]

    Hsiao, M.C.; Merritt, B.T.; Penetrante, B.M.; Vogtlin, G.E.

    1999-04-06

    A two-stage catalyst comprises an oxidative first stage and a reductive second stage. The first stage is intended to convert NO to NO{sub 2} in the presence of O{sub 2}. The second stage serves to convert NO{sub 2} to environmentally benign gases that include N{sub 2}, CO{sub 2}, and H{sub 2}O. By preconverting NO to NO{sub 2} in the first stage, the efficiency of the second stage for NO{sub x} reduction is enhanced. For example, an internal combustion engine exhaust is connected by a pipe to a first chamber. An oxidizing first catalyst converts NO to NO{sub 2} in the presence of O{sub 2} and includes platinum/alumina, e.g., Pt/Al{sub 2}O{sub 3} catalyst. A flow of hydrocarbons (C{sub x}H{sub y}) is input from a pipe into a second chamber. For example, propene can be used as a source of hydrocarbons. The NO{sub 2} from the first catalyst mixes with the hydrocarbons in the second chamber. The mixture proceeds to a second reduction catalyst that converts NO{sub 2} to N{sub 2}, CO{sub 2}, and H{sub 2}O, and includes a {gamma}-Al{sub 2}O{sub 3}. The hydrocarbons and NO{sub x} are simultaneously reduced while passing through the second catalyst. 9 figs.

  4. Pre-converted nitric oxide gas in catalytic reduction system

    DOE Patents [OSTI]

    Hsiao, Mark C. (Livermore, CA); Merritt, Bernard T. (Livermore, CA); Penetrante, Bernardino M. (San Ramon, CA); Vogtlin, George E. (Fremont, CA)

    1999-01-01

    A two-stage catalyst comprises an oxidative first stage and a reductive second stage. The first stage is intended to convert NO to NO.sub.2 in the presence of O.sub.2. The second stage serves to convert NO.sub.2 to environmentally benign gases that include N2, CO2, and H.sub.2 O. By preconverting NO to NO.sub.2 in the first stage, the efficiency of the second stage for NO.sub.x reduction is enhanced. For example, an internal combustion engine exhaust is connected by a pipe to a first chamber. An oxidizing first catalyst converts NO to NO.sub.2 in the presence of O.sub.2 and includes platinum/alumina, e.g., Pt/Al.sub.2 O.sub.3 catalyst. A flow of hydrocarbons (C.sub.x H.sub.y) is input from a pipe into a second chamber. For example, propene can be used as a source of hydrocarbons. The NO.sub.2 from the first catalyst mixes with the hydrocarbons in the second chamber. The mixture proceeds to a second reduction catalyst that converts NO.sub.2 to N2, CO2, and H.sub.2 O, and includes a gamma-alumina .gamma.-Al.sub.2 O.sub.3. The hydrocarbons and NO.sub.x are simultaneously reduced while passing through the second catalyst.

  5. Multi-level converters for three-phase photovoltaic applications

    E-Print Network [OSTI]

    Lehman, Brad

    Multi-level converters for three-phase photovoltaic applications Renato M. Nakagomi, Ye Zhao, Brad a switching matrix device and photovoltaic (PV) panels. The approach is based on the dynamic reconfiguration photovoltaic PV panels. The number of PV panels that are connected to the load can be altered using dynamic

  6. Apparatus for converting biomass to a pumpable slurry

    DOE Patents [OSTI]

    Ergun, Sabri (Hillsborough, CA); Schaleger, Larry L. (Oakland, CA); Wrathall, James A. (Berkeley, CA); Yaghoubzadeh, Nasser (El Cerrito, CA)

    1986-01-01

    An apparatus used in the pretreatment of wood chips in a process for converting biomass to a liquid hydrocarbonaceous fuel. The apparatus functions to break down the wood chips to a size distribution that can be readily handled in a slurry form. Low maintenance operation is obtained by hydrolyzing the chips in a pressure vessel having no moving parts.

  7. Ability of Catalytic Converters to Reduce Air Pollution

    E-Print Network [OSTI]

    Nizkorodov, Sergey

    NOx - 1 Ability of Catalytic Converters to Reduce Air Pollution MEASUREMENT OF SELECTED AIR Air Pollution MEASUREMENT OF SELECTED AIR POLLUTANTS IN CAR EXHAUST INTRODUCTION Automobile engines of gasoline (hydrocarbons, CxHy) in air: CxHy + O2 CO2 + H2O + heat (1) When there is the correct balance

  8. Energy Savings Assessment for Digital-to-Analog Converter Boxes

    SciTech Connect (OSTI)

    Cheung, Hoi Ying Iris; Meier, Alan; Brown, Richard

    2011-01-18

    The Digital Television (DTV) Converter Box Coupon Program was administered by the U.S. government to subsidize purchases of digital-to-analog converter boxes, with up to two $40 coupons for each eligible household. In order to qualify as Coupon Eligible Converter Boxes (CECBs), these devices had to meet a number of minimum performance specifications, including energy efficiency standards. The Energy Star Program also established voluntary energy efficiency specifications that are more stringent than the CECB requirements. In this study, we measured the power and energy consumptions for a sample of 12 CECBs (including 6 Energy Star labeled models) in-use in homes and estimated aggregate energy savings produced by the energy efficiency policies. Based on the 35 million coupons redeemed through the end of the program, our analysis indicates that between 2500 and 3700 GWh per year are saved as a result of the energy efficiency policies implemented on digital-to-analog converter boxes. The energy savings generated are equivalent to the annual electricity use of 280,000 average US homes.

  9. Everything Digital: Converting the world in 2 Exabytes

    SciTech Connect (OSTI)

    Lesk, Michael

    2003-11-05

    Nearly everything created today is in digital format: music is on digital CDs, documents come from word processing, still photography is switching to digital cameras and even movies are now edited digitally. What about the past? We have projects like the Million Book Project scanning one million books, and we know technically how to convert everything: the problems are legal, economic and organizational.

  10. REGULAR ARTICLE A comparison of methods for converting rhizotron root

    E-Print Network [OSTI]

    provide valuable information about plant root production, but measurements are usually made in units of root length per unit surface area of observation window surface. These measure- ment units developed to convert rhizotron measurement units into root mass production per unit ground area

  11. Multiport Converter Topologies for Distributed Energy System Applications 

    E-Print Network [OSTI]

    Hawke, Joshua

    2014-07-28

    . Next, three system designs are discussed: single-zone, dual-zone, and multi-zone. Each implements PSC technology and high-frequency isolated full-bridge converters to interface multiple fuel cell sources to a medium voltage grid via a single multilevel...

  12. Cycling firing method for bypass operation of bridge converters

    DOE Patents [OSTI]

    Zabar, Zivan (99-72 66th Rd., Apt. 9N, Forest Hills, NY 11375)

    1982-01-01

    The bridge converter comprises a number of switching elements and an electronic logic system which regulated the electric power levels by controlling the firing, i.e., the initiation of the conduction period of the switching elements. Cyclic firing of said elements allows the direct current to bypass the alternating current system with high power factor and negligible losses.

  13. Performance Assessment of the Wave Dragon Wave Energy Converter

    E-Print Network [OSTI]

    Hansen, René Rydhof

    Performance Assessment of the Wave Dragon Wave Energy Converter Based on the EquiMar Methodology S of the wave energy sector, device developers are called to provide reliable estimates on power performanceMar, Nissum Bredning, Hanstholm, North Sea, Ekofisk, Wave-to-wire, Wave energy. I. INTRODUCTION The wave

  14. Micromagnetic simulation of high-power spin-torque oscillator in half-metallic Heusler alloy spin valve nanopillar

    E-Print Network [OSTI]

    Chen, Long-Qing

    valve nanopillar H. B. Huang, X. Q. Ma, Z. H. Liu, C. P. Zhao, and L. Q. Chen Citation: AIP Advances 3 in half-metallic Heusler alloy spin valve nanopillar H. B. Huang,1,2 X. Q. Ma,1,a Z. H. Liu,1 C. P. Zhao,1 investigated the spin-torque oscillator in a half-metallic Heusler alloy Co2MnSi (CMS) spin-valve nanopillar

  15. A uniformly moving and rotating polarizable particle in thermal radiation field: frictional force and torque, radiation and heating

    E-Print Network [OSTI]

    G. V. Dedkov; A. A. Kyasov

    2015-04-07

    We study the fluctuation-electromagnetic interaction and dynamics of a small polarizable particle with own rotation and relativistic velocity moving in a vacuum background of arbitrary temperature. A full set of equations describing decelerating tangential force, frictional torque (at arbitrary direction of angular velocity) and intensity of nonthermal and thermal radiation is obtained, along with equations describing the particle dynamics and kinetics of heating. An interplay between different parameters is discussed. Numerical calculations are given in the case of graphite particles.

  16. Dependence of the colored frequency noise in spin torque oscillators on current and magnetic field

    SciTech Connect (OSTI)

    Eklund, Anders Sani, Sohrab R.; Chung, Sunjae; Amir Hossein Banuazizi, S.; Östling, Mikael; Gunnar Malm, B.; Bonetti, Stefano; Majid Mohseni, S.; Persson, Johan; Iacocca, Ezio; Åkerman, Johan

    2014-03-03

    The nano-scale spin torque oscillator (STO) is a compelling device for on-chip, highly tunable microwave frequency signal generation. Currently, one of the most important challenges for the STO is to increase its longer-time frequency stability by decreasing the 1/f frequency noise, but its high level makes even its measurement impossible using the phase noise mode of spectrum analyzers. Here, we present a custom made time-domain measurement system with 150?MHz measurement bandwidth making possible the investigation of the variation of the 1/f as well as the white frequency noise in a STO over a large set of operating points covering 18–25?GHz. The 1/f level is found to be highly dependent on the oscillation amplitude-frequency non-linearity and the vicinity of unexcited oscillation modes. These findings elucidate the need for a quantitative theoretical treatment of the low-frequency, colored frequency noise in STOs. Based on the results, we suggest that the 1/f frequency noise possibly can be decreased by improving the microstructural quality of the metallic thin films.

  17. Observations of thermally excited ferromagnetic resonance on spin torque oscillators having a perpendicularly magnetized free layer

    SciTech Connect (OSTI)

    Tamaru, S. Kubota, H.; Yakushiji, K.; Konoto, M.; Nozaki, T.; Fukushima, A.; Imamura, H.; Taniguchi, T.; Arai, H.; Tsunegi, S.; Yuasa, S.; Suzuki, Y.

    2014-05-07

    Measurements of thermally excited ferromagnetic resonance were performed on spin torque oscillators having a perpendicularly magnetized free layer and in-plane magnetized reference layer (abbreviated as PMF-STO in the following) for the purpose of obtaining magnetic properties in the PMF-STO structure. The measured spectra clearly showed a large main peak and multiple smaller peaks on the high frequency side. A Lorentzian fit on the main peak yielded Gilbert damping factor of 0.0041. The observed peaks moved in proportion to the out-of-plane bias field. From the slope of the main peak frequency as a function of the bias field, Lande g factor was estimated to be about 2.13. The mode intervals showed a clear dependence on the diameter of the PMF-STOs, i.e., intervals are larger for a smaller diameter. These results suggest that the observed peaks should correspond to eigenmodes of lateral spin wave resonance in the perpendicularly magnetized free layer.

  18. Evolution of the angular momentum of protogalaxies from tidal torques: Zel'dovich approximation

    E-Print Network [OSTI]

    Paolo Catelan; Tom Theuns

    1996-04-15

    The growth of the angular momentum L of protogalaxies induced by tidal torques is reconsidered within the Zel'dovich approximation. We obtain a general expression for the ensemble expectation value of the square of L in terms of the first and second invariant of the inertia tensor of the Lagrangian volume enclosing the protoobject's collapsing mass. We then specialize the formalism to the particular case in which this volume is centered on a peak of the smoothed Gaussian density field and approximated by an isodensity ellipsoid. The result is the appropriate analytical estimate for the rms angular momentum of peaks to be compared against simulations that make use of the Hoffman-Ribak algorithm to set up a constrained density field that contains a peak with given shape. Extending the work of Heavens & Peacock, we calculate the joint probability distribution function for several spin parameters and peak mass M using the distribution of peak shapes, for different initial power spectra. The values of observed specific angular momentum versus mass are well fitted by our theoretical isoprobability contours. In contrast, the observed lower values for the specific angular momentum for ellipticals of the same mass cannot be accounted for within our linear regime investigation, highlighting the importance of strongly non-linear phenomena to explain the spin of such objects.

  19. Magnetization switching in a CoFeB/MgO magnetic tunnel junction by combining spin-transfer torque and electric field-effect

    SciTech Connect (OSTI)

    Kanai, S.; Nakatani, Y.; Yamanouchi, M.; Ikeda, S.; Sato, H.; Matsukura, F.; Ohno, H.

    2014-05-26

    We propose and demonstrate a scheme for magnetization switching in magnetic tunnel junctions, in which two successive voltage pulses are applied to utilize both spin-transfer torque and electric field effect. Under this switching scheme, a CoFeB/MgO magnetic tunnel junction with perpendicular magnetic easy axis is shown to switch faster than by spin-transfer torque alone and more reliably than that by electric fields alone.

  20. Discharging a DC bus capacitor of an electrical converter system

    DOE Patents [OSTI]

    Kajouke, Lateef A; Perisic, Milun; Ransom, Ray M

    2014-10-14

    A system and method of discharging a bus capacitor of a bidirectional matrix converter of a vehicle are presented here. The method begins by electrically shorting the AC interface of the converter after an AC energy source is disconnected from the AC interface. The method continues by arranging a plurality of switching elements of a second energy conversion module into a discharge configuration to establish an electrical current path from a first terminal of an isolation module, through an inductive element, and to a second terminal of the isolation module. The method also modulates a plurality of switching elements of a first energy conversion module, while maintaining the discharge configuration of the second energy conversion module, to at least partially discharge a DC bus capacitor.

  1. Process for converting cellulosic materials into fuels and chemicals

    DOE Patents [OSTI]

    Scott, C.D.; Faison, B.D.; Davison, B.H.; Woodward, J.

    1994-09-20

    A process is described for converting cellulosic materials, such as waste paper, into fuels and chemicals utilizing enzymatic hydrolysis of the major constituent of paper, cellulose. A waste paper slurry is contacted by cellulase in an agitated hydrolyzer. The cellulase is produced from a continuous, columnar, fluidized-bed bioreactor utilizing immobilized microorganisms. An attrition mill and a cellobiase reactor are coupled to the agitated hydrolyzer to improve reaction efficiency. The cellulase is recycled by an adsorption process. The resulting crude sugars are converted to dilute product in a fluidized-bed bioreactor utilizing microorganisms. The dilute product is concentrated and purified by utilizing distillation and/or a biparticle fluidized-bed bioreactor system. 1 fig.

  2. Low work function material development for the microminiature thermionic converter.

    SciTech Connect (OSTI)

    Zavadil, Kevin Robert; Battaile, Corbett Chandler; Marshall, Albert Christian; King, Donald Bryan; Jennison, Dwight Richard

    2004-03-01

    Thermionic energy conversion in a miniature format shows potential as a viable, high efficiency, micro to macro-scale power source. A microminiature thermionic converter (MTC) with inter-electrode spacings on the order of microns has been prototyped and evaluated at Sandia. The remaining enabling technology is the development of low work function materials and processes that can be integrated into these converters to increase power production at modest temperatures (800 - 1300 K). The electrode materials are not well understood and the electrode thermionic properties are highly sensitive to manufacturing processes. Advanced theoretical, modeling, and fabrication capabilities are required to achieve optimum performance for MTC diodes. This report describes the modeling and fabrication efforts performed to develop micro dispenser cathodes for use in the MTC.

  3. An aid to convert spreadsheets to higher quality presentations 

    E-Print Network [OSTI]

    Olajide, Wasiu Olaniyi

    2005-08-29

    with CALC. CALC is available on all common operating systems and has a well documented and easily accessible Java Application Programming Interface. 6 CHAPTER III QUALITY PRESENTATIONS A. Spreadsheets as Information Conveyors Tables are a good way to show...Office using the Java Application Programming Interface. The contents of the spreadsheet are extracted passed on to the Data Storage module. 2. Canonical Data Storage The converted data is stored in XML [16] format using the Document Object Model [17]. XML...

  4. Low current plasmatron fuel converter having enlarged volume discharges

    DOE Patents [OSTI]

    Rabinovich, Alexander (Swampscott, MA); Alexeev, Nikolai (Moscow, RU); Bromberg, Leslie (Sharon, MA); Cohn, Daniel R. (Chestnut Hill, MA); Samokhin, Andrei (Moscow, RU)

    2009-10-06

    A novel apparatus and method is disclosed for a plasmatron fuel converter ("plasmatron") that efficiently uses electrical energy to produce hydrogen rich gas. The volume and shape of the plasma discharge is controlled by a fluid flow established in a plasma discharge volume. A plasmatron according to this invention produces a substantially large effective plasma discharge volume allowing for substantially greater volumetric efficiency in the initiation of chemical reactions within a volume of bulk fluid reactant flowing through the plasmatron.

  5. Catalyst for converting synthesis gas to liquid motor fuels

    DOE Patents [OSTI]

    Coughlin, Peter K. (Yorktown Heights, NY)

    1986-01-01

    The addition of an inert metal component, such as gold, silver or copper, to a Fischer-Tropsch catalyst comprising cobalt enables said catalyst to convert synthesis gas to liquid motor fuels at about 240.degree.-370.degree. C. with advantageously reduced selectivity of said cobalt for methane in said conversion. The catalyst composition can advantageously include a support component, such as a molecular sieve, co-catalyst/support component or a combination of such support components.

  6. Intensive neutrino source on the base of lithium converter

    E-Print Network [OSTI]

    V. I. Lyashuk; Yu. S Lutostansky

    2015-04-13

    An intensive antineutrino source with a hard spectrum (with energy up to 13 MeV, average energy 6.5 MeV) can be realized on the base of beta-decay of short living isotope 8Li (0.84 s). The 8Li isotope (generated in activation of 7Li isotope) is a prime perspective antineutrino source owing to the hard antineutrino spectrum and square dependence of cross section on the energy. Up today nuclear reactors are the most intensive neutrino sources. Antineutrino reactor spectra have large uncertainties in the summary antineutrino spectrum at energy E>6 MeV. Use of 8Li isotope allows to decrease sharply the uncertainties or to exclude it completely. An intensive neutron fluxes are requested for rapid generation of 8Li isotope. The installations on the base of nuclear reactors can be an alternative for nuclear reactors as traditional neutron sources. It is possible creation of neutrino sources another in principle: on the base of tandem of accelerators, neutron generating targets and lithium converter. An intensive neutron flux (i.e., powerful neutron source) is requested for realization of considered neutrino sources (neutrino factories). Different realizations of lithium antineutrino sources (lithium converter on the base of high purified 7Li isotope) are discussed: static regime (i.e., without transport of 8Li isotope to the neutrino detector); dynamic regime (transport of 8Li isotope to the remote detector in a closed cycle); an operation of lithium converter in tandem of accelerator with a neutron-producing target on the base of tungsten, lead or bismuth. Different chemical compounds of lithium (as the substance of the converter) are considered. Heavy water solution of LiOD is proposed as a serious alternative to high-pure 7Li in a metallic state.

  7. Low current plasmatron fuel converter having enlarged volume discharges

    DOE Patents [OSTI]

    Rabinovich, Alexander; Alexeev, Nikolai; Bromberg, Leslie; Cohn, Daniel R.; Samokhin, Andrei

    2005-04-19

    A novel apparatus and method is disclosed for a plasmatron fuel converter (""plasmatron"") that efficiently uses electrical energy to produce hydrogen rich gas. The volume and shape of the plasma discharge is controlled by a fluid flow established in a plasma discharge volume. A plasmatron according to this invention produces a substantially large effective plasma discharge volume allowing for substantially greater volumetric efficiency in the initiation of chemical reactions within a volume of bulk fluid reactant flowing through the plasmatron.

  8. Design and characterization of a radio-frequency dc/dc power converter

    E-Print Network [OSTI]

    Jackson, David A. (David Alexander)

    2005-01-01

    The use of radio-frequency (RF) amplifier topologies in dc/dc power converters allows the operating frequency to be increased by more than two orders of magnitude over the frequency of conventional converters. This enables ...

  9. GUIDELINES FOR CONVERTING FTN4 PROGRAMS TO FTN5 AND THE NEW FORTRAN-77 STANDARD

    E-Print Network [OSTI]

    Friedman, R.

    2012-01-01

    1st Edition GUIDELINES FOR CONVERTING FTN4 PROGRAMS TO FTN5Edition (August 79) Guidelines for Converting FTN4 Programsprogram F45 are described in each instance. lst Edition (

  10. Design techniques for low noise and high speed A/D converters 

    E-Print Network [OSTI]

    Gupta, Amit Kumar

    2009-05-15

    subscriber line (ADSL) modems, cellular systems, high accuracy instrumentation, and medical imaging systems. This thesis suggests some design techniques for such high resolution and high sampling rate A/D converters. As the A/D converter performance keeps...

  11. Wide input range DC-DC converter with digital control scheme 

    E-Print Network [OSTI]

    Harfman Todorovic, Maja

    2006-04-12

    :1 voltage variation as well as a slow transient response. The proposed approach consists of two stages: a primary three-level boost converter stage cascaded with a high frequency, isolated boost converter topology, which provides a higher voltage gain...

  12. High-Frequency Resonant SEPIC Converter With Wide Input and Output Voltage Ranges

    E-Print Network [OSTI]

    Hu, Jingying

    This paper presents a resonant single-ended-primary-inductor-converter (SEPIC) converter and control method suitable for high frequency (HF) and very high frequency (VHF) dc-dc power conversion. The proposed design provides ...

  13. Power Maximization in Wave-Energy Converters Using Sampled -Data Extremum Seeking /

    E-Print Network [OSTI]

    Chen, Tianjia

    2013-01-01

    A review of wave energy converter technology. Proceedings ofWave energy utilization: A review of the technologies. Re-decades. With the technology of wave-energy convert- ers(

  14. The impulsive effects of momentum transfer on the dynamics of a novel ocean wave energy converter

    E-Print Network [OSTI]

    Diamond, CA; O'Reilly, OM; Sava?, O

    2013-01-01

    7] J. Falnes, A review of wave-energy extraction, MarineOrazov, O. M. O’Reilly, O. wave energy converter, Journal ofsimple model for a novel wave energy converter: non-resonant

  15. Computer-aided optimization of DC/DC converters for automotive applications

    E-Print Network [OSTI]

    Neugebauer, Timothy C.

    This paper investigates computer-aided optimization of DC/DC converters, with a focus on converters for dual-voltage automotive electrical systems. A new CAD optimization approach based on Monte Carlo search methods is ...

  16. Power Maximization in Wave-Energy Converters Using Sampled -Data Extremum Seeking /

    E-Print Network [OSTI]

    Chen, Tianjia

    2013-01-01

    design optimization of wave energy converters con- sistingN. Sahinkaya. A review of wave energy converter technology.2009. [6] A.F.O. Falc˜ao. Wave energy utilization: A review

  17. Outphasing Control of Gallium Nitride based Very High Frequency Resonant Converters

    E-Print Network [OSTI]

    Madsen, Mickey P.

    In this paper an outphasing modulation control method suitable for line regulation of very high frequency resonant converters is described.

  18. A Predictive power control of Doubly Fed Induction Generator for Wave Energy Converter

    E-Print Network [OSTI]

    Brest, Université de

    Switchgear Wave converter control Gear hal-01023509,version1-13Jul2014 Author manuscript, published in "IEEE

  19. Angular momentum exchange by gravitational torques and infall in the circumbinary disk of the protostellar system L1551 NE

    SciTech Connect (OSTI)

    Takakuwa, Shigehisa; Ho, Paul T. P. [Academia Sinica Institute of Astronomy and Astrophysics, P.O. Box 23-141, Taipei 10617, Taiwan (China); Saito, Masao [Joint ALMA Observatory, Ave. Alonso de Cordova 3107, Vitacura, Santiago (Chile); Saigo, Kazuya [ALMA Project Office, National Astronomical Observatory of Japan, Osawa 2-21-1, Mitaka, Tokyo 181-8588 (Japan); Matsumoto, Tomoaki [Faculty of Humanity and Environment, Hosei University, Chiyoda-ku, Tokyo 102-8160 (Japan); Lim, Jeremy [Department of Physics, University of Hong Kong, Pokfulam Road (Hong Kong); Hanawa, Tomoyuki, E-mail: takakuwa@asiaa.sinica.edu.tw [Center for Frontier Science, Chiba University, Inage-ku, Chiba 263-8522 (Japan)

    2014-11-20

    We report an ALMA observation of the Class I binary protostellar system L1551 NE in the 0.9 mm continuum, C{sup 18}O (3-2), and {sup 13}CO (3-2) lines at a ?1.6 times higher resolution and a ?6 times higher sensitivity than those of our previous SubMillimeter Array (SMA) observations, which revealed a r ? 300 AU scale circumbinary disk in Keplerian rotation. The 0.9 mm continuum shows two opposing U-shaped brightenings in the circumbinary disk and exhibits a depression between the circumbinary disk and the circumstellar disk of the primary protostar. The molecular lines trace non-axisymmetric deviations from Keplerian rotation in the circumbinary disk at higher velocities relative to the systemic velocity, where our previous SMA observations could not detect the lines. In addition, we detect inward motion along the minor axis of the circumbinary disk. To explain the newly observed features, we performed a numerical simulation of gas orbits in a Roche potential tailored to the inferred properties of L1551 NE. The observed U-shaped dust features coincide with locations where gravitational torques from the central binary system are predicted to impart angular momentum to the circumbinary disk, producing shocks and hence density enhancements seen as a pair of spiral arms. The observed inward gas motion coincides with locations where angular momentum is predicted to be lowered by the gravitational torques. The good agreement between our observation and model indicates that gravitational torques from the binary stars constitute the primary driver for exchanging angular momentum so as to permit infall through the circumbinary disk of L1551 NE.

  20. Aalborg Universitet Two phase interleaved buck converter for driving high power LEDs

    E-Print Network [OSTI]

    Munk-Nielsen, Stig

    Aalborg Universitet Two phase interleaved buck converter for driving high power LEDs Beczkowski. (2011). Two phase interleaved buck converter for driving high power LEDs. In Proceedings of the 14th #12;Two phase interleaved buck converter for driving high power LEDs Szymon Bczkowski, Stig Munk

  1. 111-f:l.~A PfC, qs: Hoo control of boost converters

    E-Print Network [OSTI]

    ,I-.; ... 111- f:l.~A PfC, qs: f'EEEin !f Hoo control of boost converters Rami NAIM, George WEISS at low frequencies). In a case study, for a typical low power boost converter, we obtain significantly\\vitching frequency. Boost and buck-boost converters (in continuous conduction mode) have a zero in the right half

  2. Very High Frequency Resonant Boost Converters Robert C. N. Pilawa-Podgurski

    E-Print Network [OSTI]

    Perreault, Dave

    Very High Frequency Resonant Boost Converters Robert C. N. Pilawa-Podgurski , Anthony D. Sagneri introduces a resonant boost converter topology and control method suitable for designs at very high frequency of the new resonant boost dc- dc converter topology. The design is optimized for low device stress and very

  3. PWM CONVERTERS WITH RESISTIVE INPUT Sam Ben-Yaakov and llya Zeltser

    E-Print Network [OSTI]

    and small signal responses of a Boost converter applied in APFC application. To make the input resistive be described by a simple intuitive reasoning in relation to the Boost converter (Fig. la). It is assumedthat (b) Fig. I. The Boost converter (a) and its behavioral average model (b) (after [7,8]). #12;ill

  4. MODELING OF HIGH-POWER-FACTOR RECTIFIERS BASED ON SWITCHING CONVERTERS

    E-Print Network [OSTI]

    boost [l]and up/down (flyback, kuk, Sepic, etc.) converters [a]. The purpose of this paper is to present. Specific results are discussed in detail for boost and up/down converters, which are most frequently usedMODELING OF HIGH-POWER-FACTOR RECTIFIERS BASED ON SWITCHING CONVERTERS WITH NONLINEAR

  5. FPGA based digital controller for switch-mode converter P-2013-025 Student: Yaron Huber

    E-Print Network [OSTI]

    control scheme for DC-DC converters such as: boost or buck-boost. The control scheme is designed of minimal deviation control scheme on Boost converter using PSIM #12;2. Realization: Minimaldeviationcontroller-FPGA DC Buck - Boost converter Vin Inductor Load CapacitorSwitch Vout IL PCM main computational

  6. Design of a Boost Power Factor Correction Converter Using Optimization Techniques Sergio Busquets-Monge1

    E-Print Network [OSTI]

    Lindner, Douglas K.

    Design of a Boost Power Factor Correction Converter Using Optimization Techniques Sergio Busquets Foundation under Award Number EEC-9731677. #12;Design of a Boost Power Factor Correction Converter Using of a boost power factor correction front-end converter with an input electromagnetic interference filter

  7. I-A Modulated Digitally Controlled Non-Inverting Buck-Boost Converter for

    E-Print Network [OSTI]

    I-A Modulated Digitally Controlled Non-Inverting Buck-Boost Converter for WCDMA RF Power Amplifiers.edu Abstract- This paper focuses on the non-inverting buck- boost converter supplying an adjustable DC voltage the WCDMA RFPA settling time requirements. 1. INTRODUCTION Non-inverting buck-boost DC-DC power converter

  8. Designing an Accurate and Robust LC-Compliant Asynchronous Boost DCDC Converter

    E-Print Network [OSTI]

    Rincon-Mora, Gabriel A.

    Designing an Accurate and Robust LC-Compliant Asynchronous Boost DC­DC Converter Neeraj Keskar in buck converters, little has been done in boosting applications. This paper presents an asynchronous boost converter and describes how LC variations affect stability, steady-state error, and switching

  9. Synthesis of Impedance Using Switching Converters Joe C.P. Liu

    E-Print Network [OSTI]

    Tse, Chi K. "Michael"

    and a pair of switches, such as the buck, buck-boost and boost converters. The switches are switched Synthesis of Impedance Using Switching Converters Joe C.P. Liu Chi K. Tse Franki N.K. Poon M converters is stud- ied in this paper. We begin with showing that any impedance can be synthesized

  10. A CHAOS MODEL OF SUBHARMONIC OSCILLATIONS IN CURRENT MODE PWM BOOST CONVERTERS

    E-Print Network [OSTI]

    A CHAOS MODEL OF SUBHARMONIC OSCILLATIONS IN CURRENT MODE PWM BOOST CONVERTERS Isaac Zafrany in a current mode PWM Boost converter under open and closed outer- loop conditions. A simple expression and explain by a Chaos model the behavior of a CM Boost converter under open and closed outer loop situations

  11. Controlling Chaos in DC/DC Converters Using Optimal Resonant Parametric Perturbation

    E-Print Network [OSTI]

    Tse, Chi K. "Michael"

    perturba- tion method for controlling chaos in a current-mode con- trolled buck-boost converter of control. Specifically we make a chaotic buck-boost converter operate in an unstable period-1 orbit by a more complicated feedback chaos control method. II. CURRENT-MODE CONTROLLED BUCK-BOOST CONVERTER A

  12. BIFURCATION ANALYSIS OF A POWER-FACTOR-CORRECTION BOOST CONVERTER: UNCOVERING FAST-SCALE INSTABILITY

    E-Print Network [OSTI]

    Tse, Chi K. "Michael"

    BIFURCATION ANALYSIS OF A POWER-FACTOR-CORRECTION BOOST CONVERTER: UNCOVERING FAST to a power-factor-correc- tion (PFC) boost converter to examine the fast-scale insta- bility problem to a current-programmed boost converter. In this paper, we study the onset of period-doubling (fast-scale) in

  13. Generalized Steady-state Analysis of Multiphase Interleaved Boost Converter with Coupled Inductors

    E-Print Network [OSTI]

    Lipo, Thomas

    2005-38 Generalized Steady-state Analysis of Multiphase Interleaved Boost Converter with Coupled interleaved boost converter with coupled inductors H.-B. Shin, J.-G. Park, S.-K. Chung, H.-W. Lee and T.A. Lipo Abstract: The generalised steady-state analysis of the multi-phase interleaved boost converter

  14. General Control for Boost PFC Converter from a Sliding Mode Viewpoint

    E-Print Network [OSTI]

    Tse, Chi K. "Michael"

    4452 General Control for Boost PFC Converter from a Sliding Mode Viewpoint Grace Chu, Siew control methodology for the boost PFC converter based on sliding mode control theory. The resulting rule is derived for the boost PFC converter. The aim is to provide input current tracking under all

  15. Design Optimization of Power Electronics Circuits using Genetic Algorithms A Boost PFC Converter Example

    E-Print Network [OSTI]

    Lindner, Douglas K.

    Design Optimization of Power Electronics Circuits using Genetic Algorithms ­ A Boost PFC Converter with a developed software tool for designing a low-cost boost power factor correction (PFC) front-end converter presents an approach to discrete design optimization of a complete power electronics converter

  16. Development of a 55 kW 3X DC-DC Converter for HEV Systems

    E-Print Network [OSTI]

    Tolbert, Leon M.

    efficiency provide the great potential for the very high temperature operation. The circuit parameter design converter and a traction motor to drive the vehicle. In most commercial HEV systems, the power converter, 37996 Abstract--The design of a 55 kW 3X dc-dc converter is presented for hybrid electric vehicle (HEV

  17. CHARACTERIZING DANGEROUS WAVES FOR OCEAN WAVE ENERGY CONVERTER SURVIVABILITY Justin Hovland

    E-Print Network [OSTI]

    Haller, Merrick

    gradient technologies. This paper is focused on Ocean Wave Energy Converters (OWECs) and the needCHARACTERIZING DANGEROUS WAVES FOR OCEAN WAVE ENERGY CONVERTER SURVIVABILITY Justin Hovland ABSTRACT Ocean Wave Energy Converters (OWECs) operating on the water surface are subject to storms

  18. Analysis and design of matrix converters for adjustable speed drives and distributed power sources 

    E-Print Network [OSTI]

    Cha, Han Ju

    2004-11-15

    -link. The new converter provides flexible voltage transfer ratio and galvanic isolation between input and output ac sources. Finally, the matrix converter concept is extended to dc/ac conversion from ac/ac conversion. The new dc/ac direct converter consists...

  19. Aalborg Universitet SiC heat pump converters with support for voltage unbalance in distribution grids

    E-Print Network [OSTI]

    Munk-Nielsen, Stig

    Aalborg Universitet SiC heat pump converters with support for voltage unbalance in distribution (APA): Trintis, I., Douglass, P., Maheshwari, R., & Munk-Nielsen, S. (2015). SiC heat pump converters.aau.dk on: november 29, 2015 #12;SiC heat pump converters with support for voltage unbalance in distribution

  20. Method for designing modulo {2n Binary-to-RNS converters

    E-Print Network [OSTI]

    Sousa, Leonel

    Method for designing modulo {2n ± k} Binary-to-RNS converters Hector Pettenghi1, Ricardo Chaves1-based modulo {2n ± k} Binary-to-RNS converters is pro- posed. Efficient modulo {2n ± k} converters can be used to support well balanced RNS moduli sets with large dynamic ranges. Moreover, a novel selection method

  1. Real-Time Model-Based Fault Diagnosis for Switching Power Converters

    E-Print Network [OSTI]

    Sanders, Seth

    demonstration for a 1.2 kW rack-level uninterruptable power supply (UPS) dc-dc converter for data center for a 1.2 kW rack- level uninterruptable power supply (UPS) dc-dc converter for data center applicationsReal-Time Model-Based Fault Diagnosis for Switching Power Converters Jason Poon, Ioannis C

  2. An Improved MPPT Interleaved Boost Converter for Solar Electric Vehicle Application

    E-Print Network [OSTI]

    Boyer, Edmond

    . The converter is connected between the photovoltaic power generation and dc bus in a multisource energy storage dc-dc converter; Solar electric vehicle; MPPT; Energy storage system. I. INTRODUCTION Photovoltaic energy storage system of a SEV Furthermore, for high-power applications, interleaved converters have been

  3. An Automated System for Converting App Inventor Apps to Java Interface For Creating and Managing Projects

    E-Print Network [OSTI]

    Gray, Jeffrey G.

    An Automated System for Converting App Inventor Apps to Java Interface For Creating and Managing of Computer Science Graphical Environment For Creating Layouts MIT App Inventor An Automated System for Converting App Inventor Apps to JavaAn Automated System for Converting App Inventor Apps to JavaAn Automated

  4. Enhanced synchronization in an array of spin torque nano oscillators in the presence of oscillating external magnetic field

    E-Print Network [OSTI]

    B. Subash; V. K. Chandrasekar; M. Lakshmanan

    2014-12-23

    We demonstrate that the synchronization of an array of electrically coupled spin torque nano-oscillators (STNO) modelled by Landau-Lifshitz-Gilbert-Slonczewski (LLGS) equation can be enhanced appreciably in the presence of a common external microwave magnetic field. The applied microwave magnetic field stabilizes and enhances the regions of synchronization in the parameter space of our analysis, where the oscillators are exhibiting synchronized oscillations thereby emitting improved microwave power. To characterize the synchronized oscillations we have calculated the locking range in the domain of external source frequency.

  5. Light-weight DC to very high voltage DC converter

    DOE Patents [OSTI]

    Druce, R.L.; Kirbie, H.C.; Newton, M.A.

    1998-06-30

    A DC-DC converter capable of generating outputs of 100 KV without a transformer comprises a silicon opening switch (SOS) diode connected to allow a charging current from a capacitor to flow into an inductor. When a specified amount of charge has flowed through the SOS diode, it opens up abruptly; and the consequential collapsing field of the inductor causes a voltage and current reversal that is steered into a load capacitor by an output diode. A switch across the series combination of the capacitor, inductor, and SOS diode closes to periodically reset the SOS diode by inducing a forward-biased current. 1 fig.

  6. Processes for converting lignocellulosics to reduced acid pyrolysis oil

    DOE Patents [OSTI]

    Kocal, Joseph Anthony; Brandvold, Timothy A

    2015-01-06

    Processes for producing reduced acid lignocellulosic-derived pyrolysis oil are provided. In a process, lignocellulosic material is fed to a heating zone. A basic solid catalyst is delivered to the heating zone. The lignocellulosic material is pyrolyzed in the presence of the basic solid catalyst in the heating zone to create pyrolysis gases. The oxygen in the pyrolysis gases is catalytically converted to separable species in the heating zone. The pyrolysis gases are removed from the heating zone and are liquefied to form the reduced acid lignocellulosic-derived pyrolysis oil.

  7. Bi-Directional DC-DC Converter for PHEV Applications

    SciTech Connect (OSTI)

    Abas Goodarzi

    2011-01-31

    Plug-In Hybrid Electric Vehicles (PHEV) require high power density energy storage system (ESS) for hybrid operation and high energy density ESS for Electric Vehicle (EV) mode range. However, ESS technologies to maximize power density and energy density simultaneously are not commercially feasible. The use of bi-directional DC-DC converter allows use of multiple energy storage, and the flexible DC-link voltages can enhance the system efficiency and reduce component sizing. This will improve fuel consumption, increase the EV mode range, reduce the total weight, reduce battery initial and life cycle cost, and provide flexibility in system design.

  8. A single-inductor switching DC-DC converter with five outputs and ordered power-distributive control

    E-Print Network [OSTI]

    Le, Hanh-Phuc; Chae, Chang-Seok; Lee, Kwang-Chan; Wang, Se-Won; Cho, Gyu-Ha; Cho, Gyu-Hyeong

    2007-01-01

    integrated current mode boost converter in standard 3.3=5-Vef?ciency CMOS DC-DC boost converter with current sensingdeveloping reset ICs, boost converters for PM OLED, and SIMO

  9. EMISSIONS REDUCTIONS USING HYDROGEN FROM PLASMATRON FUEL CONVERTERS

    SciTech Connect (OSTI)

    Bromberg, L

    2000-08-20

    Substantial progress in engine emission control is needed in order to meet present and proposed regulations for both spark ignition and diesel engines. Tightening regulations throughout the world reflect the ongoing concern with vehicle emissions. Recently developed compact plasmatron fuel converters have features that are suitable for onboard production of hydrogen for both fuel pretreatment and for exhaust aftertreatment applications. Systems that make use of these devices in conjunction with aftertreatment catalysts have the potential to improve significantly prospects for reduction of diesel engine emissions. Plasmatron fuel converters can provide a rapid response compact means to transform efficiently a wide range of hydrocarbon fuels into hydrogen rich gas. They have been used to reform natural gas [Bromberg1], gasoline [Green], diesel [Bromberg2] and hard-to-reform biofuels [Cohn1] into hydrogen rich gas (H2 + CO). The development of these devices has been pursued for the purpose of reducing engine exhaust pollutants by providing hydrogen rich gas for combustion in spark ignition and possibly diesel engines, as shown in Figure 1 [Cohn2]. Recent developments in compact plasmatron reformer design at MIT have resulted in substantial decreases in electrical power requirements. These new developments also increase the lifetime of the electrodes.

  10. Converting Maturing Nuclear Sites to Integrated Power Production Islands

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Solbrig, Charles W.

    2011-01-01

    Nuclear islands, which are integrated power production sites, could effectively sequester and safeguard the US stockpile of plutonium. A nuclear island, an evolution of the integral fast reactor, utilizes all the Transuranics (Pu plus minor actinides) produced in power production, and it eliminates all spent fuel shipments to and from the site. This latter attribute requires that fuel reprocessing occur on each site and that fast reactors be built on-site to utilize the TRU. All commercial spent fuel shipments could be eliminated by converting all LWR nuclear power sites to nuclear islands. Existing LWR sites have the added advantage ofmore »already possessing a license to produce nuclear power. Each could contribute to an increase in the nuclear power production by adding one or more fast reactors. Both the TRU and the depleted uranium obtained in reprocessing would be used on-site for fast fuel manufacture. Only fission products would be shipped to a repository for storage. The nuclear island concept could be used to alleviate the strain of LWR plant sites currently approaching or exceeding their spent fuel pool storage capacity. Fast reactor breeding ratio could be designed to convert existing sites to all fast reactors, or keep the majority thermal.« less

  11. Triple voltage dc-to-dc converter and method

    DOE Patents [OSTI]

    Su, Gui-Jia (Knoxville, TN)

    2008-08-05

    A circuit and method of providing three dc voltage buses and transforming power between a low voltage dc converter and a high voltage dc converter, by coupling a primary dc power circuit and a secondary dc power circuit through an isolation transformer; providing the gating signals to power semiconductor switches in the primary and secondary circuits to control power flow between the primary and secondary circuits and by controlling a phase shift between the primary voltage and the secondary voltage. The primary dc power circuit and the secondary dc power circuit each further comprising at least two tank capacitances arranged in series as a tank leg, at least two resonant switching devices arranged in series with each other and arranged in parallel with the tank leg, and at least one voltage source arranged in parallel with the tank leg and the resonant switching devices, said resonant switching devices including power semiconductor switches that are operated by gating signals. Additional embodiments having a center-tapped battery on the low voltage side and a plurality of modules on both the low voltage side and the high voltage side are also disclosed for the purpose of reducing ripple current and for reducing the size of the components.

  12. Macrospin modeling of sub-ns pulse switching of perpendicularly magnetized free layer via spin-orbit torques for cryogenic memory applications

    SciTech Connect (OSTI)

    Park, Junbo; Rowlands, G. E.; Lee, O. J.; Buhrman, R. A.; Ralph, D. C.

    2014-09-08

    We model, using the macrospin approximation, the magnetic reversal of a perpendicularly magnetized nanostructured free layer formed on a normal, heavy-metal nanostrip, subjected to spin-orbit torques (SOTs) generated by short (?0.5?ns) current pulses applied to the nanostrip, to examine the potential for SOT-based fast, efficient cryogenic memory. Due to thermal fluctuations, if solely an anti-damping torque is applied, then, for a device with sufficiently low anisotropy (H{sub anis}{sup 0}???1 kOe) suitable for application in cryogenic memory, a high magnetic damping parameter (??0.1?0.2) is required for reliable switching over a significant variation of pulse current. The additional presence of a substantial field-like torque improves switching reliability even for low damping (??0.03).

  13. Combined Effects of Gravity, Bending Moment, Bearing Clearance, and Input Torque on Wind Turbine Planetary Gear Load Sharing: Preprint

    SciTech Connect (OSTI)

    Guo, Y.; Keller, J.; LaCava, W.

    2012-09-01

    This computational work investigates planetary gear load sharing of three-mount suspension wind turbine gearboxes. A three dimensional multibody dynamic model is established, including gravity, bending moments, fluctuating mesh stiffness, nonlinear tooth contact, and bearing clearance. A flexible main shaft, planetary carrier, housing, and gear shafts are modeled using reduced degrees-of-freedom through modal compensation. This drivetrain model is validated against the experimental data of Gearbox Reliability Collaborative for gearbox internal loads. Planet load sharing is a combined effect of gravity, bending moment, bearing clearance, and input torque. Influences of each of these parameters and their combined effects on the resulting planet load sharing are investigated. Bending moments and gravity induce fundamental excitations in the rotating carrier frame, which can increase gearbox internal loads and disturb load sharing. Clearance in carrier bearings reduces the bearing load carrying capacity and thus the bending moment from the rotor can be transmitted into gear meshes. With bearing clearance, the bending moment can cause tooth micropitting and can induce planet bearing fatigue, leading to reduced gearbox life. Planet bearings are susceptible to skidding at low input torque.

  14. Enhanced thermal and gas flow performance in a three-way catalytic converter through use of insulation within the ceramic monolith

    Broader source: Energy.gov [DOE]

    Emissions performance comparison of conventional catalytic converter with multi-channel catalytic converter (ceramic fiber insulation layers introduced into ceramic monolith of three-way catalytic converter)

  15. The Effects of Stator Compliance, Backs Steps, Temperature, and Clockwise Rotation on the Torque-Speed Curve of Bacterial Flagellar Motor

    E-Print Network [OSTI]

    Giovanni Meacci; Ganhui Lan; Yuhai Tu

    2010-08-13

    Rotation of a single bacterial flagellar motor is powered by multiple stators tethered to the cell wall. In a "power-stroke" model the observed independence of the speed at low load on the number of stators is explained by a torque-dependent stepping mechanism independent of the strength of the stator tethering spring. On the other hand, in models that depend solely on the stator spring to explain the observed behavior, exceedingly small stator spring constants are required. To study the dynamics of the motor driven by external forces (such as those exerted by an optical tweezer), back-stepping is introduced when stators are driven far out of equilibrium. Our model with back-stepping reproduces the observed absence of a barrier to backward rotation, as well the behaviors in the high-speed negative-torque regime. Recently measured temperature dependence of the motor speed near zero load (Yuan & Berg 2010 Biophys J) is explained quantitatively by the thermally activated stepping rates in our model. Finally, we suggest that the general mechanical properties of all molecular motors (linear and rotary), characterized by their force(torque)-speed curve, can be determined by their power-stroke potentials and the dependence of the stepping rates on the mechanical state of the motor (force or speed). The torque-speed curve for the clockwise rotating flagellar motor has been observed for the first time recently (Yuan et al. 2010 PNAS). Its quasi-linear behavior is quantitatively reproduced by our model. In particular, we show that concave and convex shapes of the torque-speed curve can be achieved by changing the interaction potential from linear to quadratic form. We also show that reversing the stepping rate dependence on force (torque) can lead to non-monotonicity in the speed-load dependency.

  16. Apparatuses and method for converting electromagnetic radiation to direct current

    DOE Patents [OSTI]

    Kotter, Dale K; Novack, Steven D

    2014-09-30

    An energy conversion device may include a first antenna and a second antenna configured to generate an AC current responsive to incident radiation, at least one stripline, and a rectifier coupled with the at least one stripline along a length of the at least one stripline. An energy conversion device may also include an array of nanoantennas configured to generate an AC current in response to receiving incident radiation. Each nanoantenna of the array includes a pair of resonant elements, and a shared rectifier operably coupled to the pair of resonant elements, the shared rectifier configured to convert the AC current to a DC current. The energy conversion device may further include a bus structure operably coupled with the array of nanoantennas and configured to receive the DC current from the array of nanoantennas and transmit the DC current away from the array of nanoantennas.

  17. Low Head, Vortex Induced Vibrations River Energy Converter

    SciTech Connect (OSTI)

    Bernitsas, Michael B.; Dritz, Tad

    2006-06-30

    Vortex Induced Vibrations Aquatic Clean Energy (VIVACE) is a novel, demonstrated approach to extracting energy from water currents. This invention is based on a phenomenon called Vortex Induced Vibrations (VIV), which was first observed by Leonardo da Vinci in 1504AD. He called it ‘Aeolian Tones.’ For decades, engineers have attempted to prevent this type of vibration from damaging structures, such as offshore platforms, nuclear fuel rods, cables, buildings, and bridges. The underlying concept of the VIVACE Converter is the following: Strengthen rather than spoil vortex shedding; enhance rather than suppress VIV; harness rather than mitigate VIV energy. By maximizing and utilizing this unique phenomenon, VIVACE takes this “problem” and successfully transforms it into a valuable resource for mankind.

  18. A Study of Radiative Bottomonium Transitions using Converted Photons

    SciTech Connect (OSTI)

    Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Martinelli, M.; /INFN, Bari /Bari U.; Milanes, D.A.; /INFN, Bari; Palano, A.; Pappagallo, M.; /INFN, Bari /Bari U.; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Brown, D.N.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; /UC, Berkeley; Koch, H.; Schroeder, T.; /Ruhr U., Bochum; Asgeirsson, D.J.; Hearty, C.; /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /Indian Inst. Tech., Guwahati /Harvard U. /Harvey Mudd Coll. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Paris U., VI-VII /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /INFN, Naples /Naples U. /NIKHEF, Amsterdam /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Southern Methodist U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas Nuclear Corp., Austin /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U. /Victoria U. /Warwick U. /Wisconsin U., Madison

    2011-08-15

    The authors use (111 {+-} 1) million {Upsilon}(3S) and (89 {+-} 1) million {Upsilon}(2S) events recorded by the BABAR detector at the PEP-II B-factory at SLAC to perform a study of radiative transitions betwen bottomonium states using photons that have been converted to e{sup +}e{sup -} pairs by the detector material. They observe {Upsilon}(3S) {yields} {gamma}{chi}{sub b0,2}(1P) decay, make precise measurements of the branching fractions for {chi}{sub b1,2}(1P, 2P) {yields} {gamma}{Upsilon}(1S) and {chi}{sub b1,2}(2P) {yields} {gamma}{Upsilon}(2S) decays, and search for radiative decay to the {eta}{sub b}(1S) and {eta}{sub b}(2S) states.

  19. Utilizing zero-sequence switchings for reversible converters

    DOE Patents [OSTI]

    Hsu, John S.; Su, Gui-Jia; Adams, Donald J.; Nagashima, James M.; Stancu, Constantin; Carlson, Douglas S.; Smith, Gregory S.

    2004-12-14

    A method for providing additional dc inputs or outputs (49, 59) from a dc-to-ac inverter (10) for controlling motor loads (60) comprises deriving zero-sequence components (V.sub.ao, V.sub.bo, and V.sub.co) from the inverter (10) through additional circuit branches with power switching devices (23, 44, 46), transforming the voltage between a high voltage and a low voltage using a transformer or motor (42, 50), converting the low voltage between ac and dc using a rectifier (41, 51) or an H-bridge (61), and providing at least one low voltage dc input or output (49, 59). The transformation of the ac voltage may be either single phase or three phase. Where less than a 100% duty cycle is acceptable, a two-phase modulation of the switching signals controlling the inverter (10) reduces switching losses in the inverter (10). A plurality of circuits for carrying out the invention are also disclosed.

  20. The Force of a Tsunami on a Wave Energy Converter

    E-Print Network [OSTI]

    O'Brien, Laura; Renzi, Emiliano; Dutykh, Denys; Dias, Frédéric

    2012-01-01

    With an increasing emphasis on renewable energy resources, wave power technology is fast becoming a realistic solution. However, the recent tsunami in Japan was a harsh reminder of the ferocity of the ocean. It is known that tsunamis are nearly undetectable in the open ocean but as the wave approaches the shore its energy is compressed creating large destructive waves. The question posed here is whether a nearshore wave energy converter (WEC) could withstand the force of an incoming tsunami. The analytical 3D model of Renzi & Dias (2012) developed within the framework of a linear theory and applied to an array of fixed plates is used. The time derivative of the velocity potential allows the hydrodynamic force to be calculated.

  1. Performance of Mismatched PV Systems With Submodule Integrated Converters

    SciTech Connect (OSTI)

    Olalla, C; Deline, C; Maksimovic, D

    2014-01-01

    Mismatch power losses in photovoltaic (PV) systems can be reduced by the use of distributed power electronics at the module or submodule level. This paper presents an experimentally validated numerical model that can be used to predict power production with distributed maximum power point tracking (DMPPT) down to the cell level. The model allows the investigations of different DMPPT architectures, as well as the impact of conversion efficiencies and power constraints. Results are presented for annual simulations of three representative partial shading scenarios and two scenarios where mismatches are due to aging over a period of 25 years. It is shown that DMPPT solutions that are based on submodule integrated converters offer 6.9-11.1% improvements in annual energy yield relative to a baseline centralized MPPT scenario.

  2. NREL Research on Converting Biomass to Liquid Fuels

    ScienceCinema (OSTI)

    None

    2013-05-29

    Unlike other renewable energy sources, biomass can be converted directly into liquid fuels, called "biofuels," to help meet transportation fuel needs. The two most common types of biofuels are ethanol and biodiesel. Today, ethanol is made from starches and sugars, but at the National Renewable Energy Laboratory (NREL) scientists are developing technology to allow it to be made from cellulose and hemicellulose, the fibrous material that makes up the bulk of most plant matter. Biodiesel is made by combining alcohol (usually methanol) with vegetable oil, animal fat, or recycled cooking grease. It can be used as an additive (typically 20%) to reduce vehicle emissions or in its pure form as a renewable alternative fuel for diesel engines. For a text version of this video visit http://www.nrel.gov/learning/re_biofuels.html

  3. Reference Model 6 (RM6): Oscillating Wave Energy Converter.

    SciTech Connect (OSTI)

    Bull, Diana L; Smith, Chris; Jenne, Dale Scott; Jacob, Paul; Copping, Andrea; Willits, Steve; Fontaine, Arnold; Brefort, Dorian; Gordon, Margaret Ellen; Copeland, Robert; Jepsen, Richard A.

    2014-10-01

    This report is an addendum to SAND2013-9040: Methodology for Design and Economic Analysis of Marine Energy Conversion (MEC) Technologies. This report describes an Oscillating Water Column Wave Energy Converter reference model design in a complementary manner to Reference Models 1-4 contained in the above report. In this report, a conceptual design for an Oscillating Water Column Wave Energy Converter (WEC) device appropriate for the modeled reference resource site was identified, and a detailed backward bent duct buoy (BBDB) device design was developed using a combination of numerical modeling tools and scaled physical models. Our team used the methodology in SAND2013-9040 for the economic analysis that included costs for designing, manufacturing, deploying, and operating commercial-scale MEC arrays, up to 100 devices. The methodology was applied to identify key cost drivers and to estimate levelized cost of energy (LCOE) for this RM6 Oscillating Water Column device in dollars per kilowatt-hour (%24/kWh). Although many costs were difficult to estimate at this time due to the lack of operational experience, the main contribution of this work was to disseminate a detailed set of methodologies and models that allow for an initial cost analysis of this emerging technology. This project is sponsored by the U.S. Department of Energy's (DOE) Wind and Water Power Technologies Program Office (WWPTO), within the Office of Energy Efficiency & Renewable Energy (EERE). Sandia National Laboratories, the lead in this effort, collaborated with partners from National Laboratories, industry, and universities to design and test this reference model.

  4. Reference Model 5 (RM5): Oscillating Surge Wave Energy Converter

    SciTech Connect (OSTI)

    Yu, Y. H.; Jenne, D. S.; Thresher, R.; Copping, A.; Geerlofs, S.; Hanna, L. A.

    2015-01-01

    This report is an addendum to SAND2013-9040: Methodology for Design and Economic Analysis of Marine Energy Conversion (MEC) Technologies. This report describes an Oscillating Water Column Wave Energy Converter (OSWEC) reference model design in a complementary manner to Reference Models 1-4 contained in the above report. A conceptual design for a taut moored oscillating surge wave energy converter was developed. The design had an annual electrical power of 108 kilowatts (kW), rated power of 360 kW, and intended deployment at water depths between 50 m and 100 m. The study includes structural analysis, power output estimation, a hydraulic power conversion chain system, and mooring designs. The results were used to estimate device capital cost and annual operation and maintenance costs. The device performance and costs were used for the economic analysis, following the methodology presented in SAND2013-9040 that included costs for designing, manufacturing, deploying, and operating commercial-scale MEC arrays up to 100 devices. The levelized cost of energy estimated for the Reference Model 5 OSWEC, presented in this report, was for a single device and arrays of 10, 50, and 100 units, and it enabled the economic analysis to account for cost reductions associated with economies of scale. The baseline commercial levelized cost of energy estimate for the Reference Model 5 device in an array comprised of 10 units is $1.44/kilowatt-hour (kWh), and the value drops to approximately $0.69/kWh for an array of 100 units.

  5. 1654 IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 24, NO. 6, JUNE 2009 Very-High-Frequency Resonant Boost Converters

    E-Print Network [OSTI]

    Perreault, Dave

    Boost Converters Robert C. N. Pilawa-Podgurski, Student Member, IEEE, Anthony D. Sagneri, Student Member amplifier, class- inverter, harmonic peaking, resonant boost converter, resonant dc­ dc converter, resonant.2016098 Fig. 1. Schematic of the proposed resonant boost converter topology. [6]­[8], and [10], it is often

  6. A Virtual DSP System for Design Instruction of Power Converters AA.. KKeeyyhhaannii aanndd MM.. NN.. MMaarrwwaallii GGeerraalldd BBaauummggaarrttnneerr

    E-Print Network [OSTI]

    Baumgartner, Gerald

    1 A Virtual DSP System for Design Instruction of Power Converters AA.. KKeeyyhhaannii aanndd MM the development of an object oriented DSP based for design and control of power converters. The testbed `hard' switching power converters, a resonant converter utilizes a controlled series or parallel LC

  7. Avoidance of Tearing Mode Locking and Disruption with Electro-Magnetic Torque Introduced by Feedback-based Mode Rotation Control in DIII-D and RFX-mod

    SciTech Connect (OSTI)

    Okabayashi, M. [PPPL; Zanca, P. [Euratom-ENEA; Strait, E. J. [General Atomics

    2014-09-01

    Disruptions caused by tearing modes (TMs) are considered to be one of the most critical roadblocks to achieving reliable, steady-state operation of tokamak fusion reactors. Here we have demonstrated a very promising scheme to avoid such disruptions by utilizing the electro-magnetic (EM) torque produced with 3D coils that are available in many tokamaks. In this scheme, the EM torque to the modes is created by a toroidal phase shift between the externally-applied field and the excited TM fields, compensating for the mode momentum loss due to the interaction with the resistive wall and uncorrected error fields. Fine control of torque balance is provided by a feedback scheme. We have explored this approach in two vastly different devices and plasma conditions: DIII-D and RFX-mod operated in tokamak mode. In DIII-D, the plasma target was high ?N plasmas in a non-circular divertor tokamak. In RFX-mod, the plasma was ohmically-heated plasma with ultralow safety factor in a circular limiter discharge of active feedback coils outside the thick resistive shell. The DIII-D and RFX-mod experiments showed remarkable consistency with theoretical predictions of torque balance. The application to ignition-oriented devices such as International Thermonuclear Experimental Reactor (ITER) would expand the horizon of its operational regime. The internal 3D coil set currently under consideration for edge localized mode suppression in ITER would be well suited to this purpose.

  8. Torque magnetometry study of metamagnetic transitions in single-crystal HoNi(2)B(2)C at T approximate to 1.9 K 

    E-Print Network [OSTI]

    Rathnayaka, K. D. D.; Belevtsev, B. I.; Naugle, Donald G.

    2007-01-01

    Metamagnetic transitions in single-crystal rare-earth nickel borocarbide HoNi(2)B(2)C have been studied at T approximate to 1.9 K with a Quantum Design torque magnetometer. This compound is highly anisotropic with a variety of metamagnetic states...

  9. Efficient, High-Torque Electric Vehicle Motor: Advanced Electric Vehicle Motors with Low or No Rare Earth Content

    SciTech Connect (OSTI)

    2012-01-01

    REACT Project: QM Power will develop a new type of electric motor with the potential to efficiently power future generations of EVs without the use of rare-earth-based magnets. Many of today’s EV motors use rare earth magnets to efficiently provide torque to the wheels. QM Power’s motors would contain magnets that use no rare earth minerals, are light and compact, and can deliver more power with greater efficiency and at reduced cost. Key innovations in this project include a new motor design with iron-based magnetic materials, a new motor control technique, and advanced manufacturing techniques that substantially reduce the cost of the motor. The ultimate goal of this project is to create a cost-effective EV motor that offers the rough peak equivalent of 270 horsepower.

  10. High power all-metal spin torque oscillator using full Heusler Co{sub 2}(Fe,Mn)Si

    SciTech Connect (OSTI)

    Seki, Takeshi Sakuraba, Yuya; Ueda, Masaki; Okura, Ryo; Takanashi, Koki; Arai, Hiroko; Imamura, Hiroshi

    2014-09-01

    We showed the high rf power (P{sub out}) emission from an all-metal spin torque oscillator (STO) with a Co{sub 2}Fe{sub 0.4}Mn{sub 0.6}Si (CFMS)/Ag/CFMS giant magnetoresistance (GMR) stack, which was attributable to the large GMR effect thanks to the highly spin-polarized CFMS. The oscillation spectra were measured by varying the magnetic field direction, and the perpendicular magnetic field was effective to increase P{sub out} and the Q factor. We simultaneously achieved a high output efficiency of 0.013%, a high Q of 1124, and large frequency tunability. CFMS-based all-metal STO is promising for overcoming the difficulties that conventional STOs are confronted with.

  11. Interfacial spin-filter assisted spin transfer torque effect in Co/BeO/Co magnetic tunnel junction

    SciTech Connect (OSTI)

    Tang, Y.-H. Chu, F.-C.

    2015-03-07

    The first-principles calculation is employed to demonstrate the spin-selective transport properties and the non-collinear spin-transfer torque (STT) effect in the newly proposed Co/BeO/Co magnetic tunnel junction. The subtle spin-polarized charge transfer solely at O/Co interface gives rise to the interfacial spin-filter (ISF) effect, which can be simulated within the tight binding model to verify the general expression of STT. This allows us to predict the asymmetric bias behavior of non-collinear STT directly via the interplay between the first-principles calculated spin current densities in collinear magnetic configurations. We believe that the ISF effect, introduced by the combination between wurtzite-BeO barrier and the fcc-Co electrode, may open a new and promising route in semiconductor-based spintronics applications.

  12. High efficiency of the spin-orbit torques induced domain wall motion in asymmetric interfacial multilayered Tb/Co wires

    SciTech Connect (OSTI)

    Bang, Do; Awano, Hiroyuki

    2015-05-07

    We investigated current-induced DW motion in asymmetric interfacial multilayered Tb/Co wires for various thicknesses of magnetic and Pt-capping layers. It is found that the driving mechanism for the DW motion changes from interfacial to bulk effects at much thick magnetic layer (up to 19.8?nm). In thin wires, linearly depinning field dependence of critical current density and in-plane field dependence of DW velocity suggest that the extrinsic pinning governs field-induced DW motion and injecting current can be regarded as an effective field. It is expected that the high efficiency of spin-orbit torques in thick magnetic multilayers would have important implication for future spintronic devices based on in-plane current induced-DW motion or switching.

  13. Steady-state domain wall motion driven by adiabatic spin-transfer torque with assistance of microwave field

    SciTech Connect (OSTI)

    Wang, Xi-guang; Guo, Guang-hua Nie, Yao-zhuang; Xia, Qing-lin; Tang, Wei; Wang, D.; Zeng, Zhong-ming

    2013-12-23

    We have studied the current-induced displacement of a 180° Bloch wall by means of micromagnetic simulation and analytical approach. It is found that the adiabatic spin-transfer torque can sustain a steady-state domain wall (DW) motion in the direction opposite to that of the electron flow without Walker Breakdown when a transverse microwave field is applied. This kind of motion is very sensitive to the microwave frequency and can be resonantly enhanced by exciting the domain wall thickness oscillation mode. A one-dimensional analytical model was established to account for the microwave-assisted wall motion. These findings may be helpful for reducing the critical spin-polarized current density and designing DW-based spintronic devices.

  14. An Integrated Onboard Charger and Accessary Power Converter for Plug-in Electric Vehicles

    SciTech Connect (OSTI)

    Su, Gui-Jia; Tang, Lixin

    2013-01-01

    Abstract: In this paper, an integrated onboard battery charger and accessary dc-dc converter for plug-in electric vehicles (PEVs) is presented. The idea is to utilize the already available traction drive inverters and motors of a PEV as the frond converter of the charger circuit and the transformer of the 14 V accessary dc-dc converter to provide galvanic isolation. The topology was verified by modeling and experimental results on a 5 kW charger prototype

  15. Characterization of U.S. Wave Energy Converter Test Sites: A...

    Broader source: Energy.gov (indexed) [DOE]

    data and wave energy characteristics at three U.S. wave energy converter (WEC) test and potential deployment sites. Its purpose is to enable the comparison of wave...

  16. Intensive neutrino source on the base of lithium converter

    E-Print Network [OSTI]

    Lyashuk, V I

    2015-01-01

    An intensive antineutrino source with a hard spectrum (with energy up to 13 MeV, average energy 6.5 MeV) can be realized on the base of beta-decay of short living isotope 8Li (0.84 s). The 8Li isotope (generated in activation of 7Li isotope) is a prime perspective antineutrino source owing to the hard antineutrino spectrum and square dependence of cross section on the energy. Up today nuclear reactors are the most intensive neutrino sources. Antineutrino reactor spectra have large uncertainties in the summary antineutrino spectrum at energy E>6 MeV. Use of 8Li isotope allows to decrease sharply the uncertainties or to exclude it completely. An intensive neutron fluxes are requested for rapid generation of 8Li isotope. The installations on the base of nuclear reactors can be an alternative for nuclear reactors as traditional neutron sources. It is possible creation of neutrino sources another in principle: on the base of tandem of accelerators, neutron generating targets and lithium converter. An intensive neu...

  17. How to convert gradually to oil-refinery hydrocracking

    SciTech Connect (OSTI)

    Basta, N.

    1986-01-06

    Over the past ten years, demand for refined petroleum products has been relatively constant, primarily because of worldwide conservation efforts. In fact, the demand for residual fuels has actually declined, while the market for gasoline has risen just slightly. Only middle distillates, which have seen a moderate increase since 1975, will continue to rise slowly over the next several years, says UOP Inc., a Des Plaines, Illinois, division of Allied-Signal Inc. This rise, coupled with the decline in resid demand, dictates the need for conversion capacity that will be capable of selectively producing distillate products. Traditionally, this need has been filled by hydrocracking gas oils to distillates. However, full conversion to hydrocracking requires high capital investment, which may not be possible in today's competitive refining industry. As a solution to this problem, UOP has developed a staged approach to distillate production, which allows the refiner both to phase in capital costs and to increase production over a number of years, says Mark Reno, manager of hydrocracking process development. The staged approach involves (1) constructing a mild-hydrocracking (MHC) unit that would produce less distillate, but at a lower cost; (2) upgrading to full conversion at a later date. The aldready-installed MHC equipment would be used with only minor modifications. UOP offers its own mild/full hydrocracking technology, called unibon; the firm says it can also convert a customer's existing hydrotreating equipment.

  18. Converting acoustic energy into useful other energy forms

    DOE Patents [OSTI]

    Putterman, Seth J. (Sherman Oaks, CA); Barber, Bradley Paul (Northridge, CA); Hiller, Robert Anthony (Los Angeles, CA); Lofstedt, Ritva Maire Johanna (Los Angeles, CA)

    1997-01-01

    Sonoluminescence is an off-equilibrium phenomenon in which the energy of a resonant sound wave in a liquid is highly concentrated so as to generate flashes of light. The conversion of sound to light represents an energy amplification of eleven orders of magnitude. The flashes which occur once per cycle of the audible or ultrasonic sound fields can be comprised of over one million photons and last for less 100 picoseconds. The emission displays a clocklike synchronicity; the jitter in time between consecutive flashes is less than fifty picoseconds. The emission is blue to the eye and has a broadband spectrum increasing from 700 nanometers to 200 nanometers. The peak power is about 100 milliWatts. The initial stage of the energy focusing is effected by the nonlinear oscillations of a gas bubble trapped in the liquid. For sufficiently high drive pressures an imploding shock wave is launched into the gas by the collapsing bubble. The reflection of the shock from its focal point results in high temperatures and pressures. The sonoluminescence light emission can be sustained by sensing a characteristic of the emission and feeding back changes into the driving mechanism. The liquid is in a sealed container and the seeding of the gas bubble is effected by locally heating the liquid after sealing the container. Different energy forms than light can be obtained from the converted acoustic energy. When the gas contains deuterium and tritium there is the feasibility of the other energy form being fusion, namely including the generation of neutrons.

  19. Aalborg Universitet Review on Multi-Level Voltage Source Converter Based HVDC Technologies for Grid

    E-Print Network [OSTI]

    Bak, Claus Leth

    Connection of Large Offshore Wind Farms Glasdam, Jakob ; Hjerrild, Jesper; Kocewiak, Lukasz Hubert; Bak-Level Voltage Source Converter Based HVDC Technologies for Grid Connection of Large Offshore Wind Farms. I IEEE of large offshore wind farms (OWFs) employing current state-of- the-art voltage source converter based high

  20. A hybrid switched-capacitor/inductor converter for small conversion ratios

    E-Print Network [OSTI]

    Nakibuuka, Norah Elena

    2013-01-01

    A hybrid three-switch DC-DC step-up power converter for on chip applications is proposed. It is shown that the hybrid-three switch step-up converter can offer advantages such as reduced size of magnetic components, reduced ...

  1. Design of high speed low voltage data converters for UWB communication systems 

    E-Print Network [OSTI]

    Lee, Choong Hoon

    2006-08-16

    For A/D converters in ultra-wideband (UWB) communication systems, the flash A/D type is commonly used because of its fast speed and simple architecture. However, the number of comparators in a flash A/D converter exponentially ...

  2. Aalborg Universitet An assessment of converter modelling needs for offshore wind power plants

    E-Print Network [OSTI]

    Bak, Claus Leth

    Aalborg Universitet An assessment of converter modelling needs for offshore wind power plants). An assessment of converter modelling needs for offshore wind power plants connected via VSC-HVDC networks Power into Power Systems as well as on Transmission Networks for Offshore Wind Plants. Energynautics

  3. Aalborg Universitet Harmonic Analysis of Offshore Wind Farms with Full Converter Wind Turbines

    E-Print Network [OSTI]

    Bak, Claus Leth

    Aalborg Universitet Harmonic Analysis of Offshore Wind Farms with Full Converter Wind Turbines Analysis of Offshore Wind Farms with Full Converter Wind Turbines. In Proceeding of the 8th International.aau.dk on: juli 06, 2015 #12; Abstract--This paper presents the harmonic analysis of offshore wind farm (OWF

  4. Solar Power To Help Convert Carbon Dioxide Into Fuel : Renewable Energy News

    E-Print Network [OSTI]

    Lovley, Derek

    Solar Power To Help Convert Carbon Dioxide Into Fuel : Renewable Energy News TUESDAY 25 MAY, 2010 | | Solar Power To Help Convert Carbon Dioxide Into Fuel by Energy Matters Microbiologist Derek Lovley of energy, the solar panels, can also harvest energy 100 times more effectively than plants. Other

  5. Regulation and Compensation of Source Harmonics for the Boost ConverterBased Power Factor

    E-Print Network [OSTI]

    Perreault, Dave

    Regulation and Compensation of Source Harmonics for the Boost Converter­Based Power Factor of a diode bridge and associated boost converter. This circuit is the most widely employed of the fam- ily for the boost­ based power factor precompensator which guarantees fast regulation of the output voltage towards

  6. Single Comparator Based A/D Converter for Output Voltage Sensing in

    E-Print Network [OSTI]

    Single Comparator Based A/D Converter for Output Voltage Sensing in Power Factor Correction frequency (2fline) without the use of a traditional analog to digital converter (A/D). The proposed method/D or a traditional A/D in a digitally controlled 300W boost PFC. I. INTRODUCTION Many implementations of digital

  7. Digital Control Strategy for Multi-Phase Interleaved Boundary Mode and DCM Boost PFC Converters

    E-Print Network [OSTI]

    Noé, Reinhold

    Digital Control Strategy for Multi-Phase Interleaved Boundary Mode and DCM Boost PFC Converters T switching frequency, DCM boost PFC converter can be operated with constant as well as with variable.schafmeister@delta-es.com Abstract-- A digital control strategy which provides optimal interleaving of multi-phase boost power factor

  8. Time domain design of digital compensators for PWM DC-DC converters

    E-Print Network [OSTI]

    transformation and discretization. Digital PID controllers for a Buck and Boost type converters were implemented (via the various transformation algorithms), a digital compensator operates, in reality, in the sampledTime domain design of digital compensators for PWM DC-DC converters Mor Mordechai Peretz and Sam

  9. Sensorless Current Sharing in Digitally Controlled Two-Phase Buck DC-DC Converters

    E-Print Network [OSTI]

    is discussed. Experimental results are shown for a two-phase synchronous buck converter with 6V input voltage synchronous buck converter shown in Fig.1 has been built to test the proposed sensorless current sharing the digital command d. A sensorless current sharing block generates two command duty cycles d1 and d2 in order

  10. A New Approach to Solving the Harmonic Elimination Equations for a Multilevel Converter

    E-Print Network [OSTI]

    Tolbert, Leon M.

    is required. A multilevel inverter is ideal for connecting such distributed dc energy sources (solar cellsA New Approach to Solving the Harmonic Elimination Equations for a Multilevel Converter John N that the transcendental equations characterizing the har- monic content can be converted to polynomial equations which

  11. Bi-directional Current-fed Medium Frequency Transformer Isolated AC-DC Converter 

    E-Print Network [OSTI]

    Essakiappan, Somasundaram

    2011-08-08

    demand for power converters with bi-directional capabilities. The objective of this thesis is to develop a high power quality, bi-directional AC-DC power converter that is a solution to the aforementioned problems. This thesis studies an existing topology...

  12. Fault-tolerant Partial-resonant High-frequency AC-link Converters and Their Applications 

    E-Print Network [OSTI]

    Keyhani, Hamidreza

    2014-01-08

    in the converter shutdown, and thus system availability is improved. The high-frequency ac link of the introduced converters is composed of an ac inductor and small ac capacitor. The link inductor is responsible for transferring power, while the link capacitor...

  13. ROM-less RNS-to-binary converter moduli Pedro Miguens Matutino

    E-Print Network [OSTI]

    Sousa, Leonel

    ROM-less RNS-to-binary converter moduli {22 - 1, 22 + 1, 2 - 3, 2 + 3} Pedro Miguens Matutino ISEL--In this paper, a novel ROM-less RNS-to-binary converter is proposed, using a new balanced moduli set {22 - 1, 22 metric can be achieved for the full RNS architecture using the proposed moduli set. Keywords

  14. ASIC and FPGA Implementations of Modern 4-Moduli RNS Reverse Converters

    E-Print Network [OSTI]

    Sousa, Leonel

    ASIC and FPGA Implementations of Modern 4-Moduli RNS Reverse Converters Using Distinct complex and essential part of residue number system (RNS), and has a significant role in the general performance of RNS. Recently, it is showed that the reverse converter performance could be significantly

  15. Memoryless RNS-to-Binary Converters for the {2n+1 -1} Moduli Set

    E-Print Network [OSTI]

    Cotofana, Sorin

    Memoryless RNS-to-Binary Converters for the {2n+1 - 1, 2n , 2n - 1} Moduli Set Kazeem Alagbe, Memoryless Converter. I.. Introduction The Residue Number System (RNS) is a non-weighted number system that utilizes remainders to represent num- bers. RNS has received considerable attention in arithmetic

  16. Accelerated lifetime testing of energy storage capacitors used in particle accelerators power converters

    E-Print Network [OSTI]

    Boattini, Fulvio

    2015-01-01

    Energy storage capacitors are used in large quantities in high power converters for particle accelerators. In this application capacitors see neither a DC nor an AC voltage but a combination of the two. The paper presents a new power converter explicitly designed to perform accelerated testing on these capacitors and the results of the tests.

  17. Application of wave generator theory to the development of a Wave Energy Converter

    E-Print Network [OSTI]

    Wood, Stephen L.

    Application of wave generator theory to the development of a Wave Energy Converter by Maila Sepri approve the attached thesis Application of wave generator theory to the development of a Wave Energy Application of wave generator theory to the development of a Wave Energy Converter by Maila Sepri Principal

  18. Development of SNL-SWAN, a Validated Wave Energy Converter Array Modeling Tool

    E-Print Network [OSTI]

    Siefert, Chris

    Development of SNL-SWAN, a Validated Wave Energy Converter Array Modeling Tool Kelley Ruehl#1 energy will lead to the necessary deployment of Wave Energy Converters (WECs) in arrays, or wave farms state dependent wave energy conversion of WECs. Keywords-- wave energy, wave farm, WEC array, SWAN

  19. Influence of control strategy on the global efficiency of a Direct Wave Energy Converter with

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Influence of control strategy on the global efficiency of a Direct Wave Energy Converter, France Abstract--The choice of control strategy for Direct Wave Energy Converters (DWEC) is often a simple loss model in order to design a better control strategy. Keywords--Wave energy conversion; Point

  20. Control influence on the electromagnetic generator pre-design for a wave energy converter

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    461 1 Control influence on the electromagnetic generator pre-design for a wave energy converter M of an electromagnetic generator for wave energy recovery. We will start by describing the wave energy converter (WEC of the study problem. Keywords: optimization, control, design methodology, direct drive generator, wave energy

  1. Study of Power Converter Topologies with Energy Recovery and grid power flow control Part B: boost converter with energy storage

    E-Print Network [OSTI]

    Rogelio, Garcia Retegui; Gustavo, Uicich; Mario, Benedetti; Gilles, Le Godec; Konstantinos, Papastergiou

    2015-01-01

    In the framework of a Transfer line (TT2) Consolidation Programme, a number of studies on Energy cycling have been commissioned. Part of this work involves the study of dierent power electronic system topologies for magnet energy recovery. In this report, the use of a boost front-end converter supplying DC link of a 4-quadrant magnet supply is analysed. The key objective of the study is to find control strategies that result in the control of the peak power required from the power network as well as to recover the magnet energy into capacitor banks with controlled voltage fluctuation. The study comprises the modelling of the system by means of the method of state averaging and the development of regulation strategies to energy management. The proposed control strategies can be divided in two groups: in the first group, the magnet current is used to define the reference for the control system, while in the second group this current is unknown and some strategies are devised to limit the power drawn from the el...

  2. Switching coordination of distributed dc-dc converters for highly efficient photovoltaic power plants

    DOE Patents [OSTI]

    Agamy, Mohammed; Elasser, Ahmed; Sabate, Juan Antonio; Galbraith, Anthony William; Harfman Todorovic, Maja

    2014-09-09

    A distributed photovoltaic (PV) power plant includes a plurality of distributed dc-dc converters. The dc-dc converters are configured to switch in coordination with one another such that at least one dc-dc converter transfers power to a common dc-bus based upon the total system power available from one or more corresponding strings of PV modules. Due to the coordinated switching of the dc-dc converters, each dc-dc converter transferring power to the common dc-bus continues to operate within its optimal efficiency range as well as to optimize the maximum power point tracking in order to increase the energy yield of the PV power plant.

  3. Utility-Scale Power Router: Dynamic Control of Grid Assets Using Direct AC Converter Cells

    SciTech Connect (OSTI)

    2010-09-01

    ADEPT Project: Georgia Tech is developing a cost-effective, utility-scale power router that uses an enhanced transformer to more efficiently direct power on the grid. Existing power routing technologies are too expensive for widespread use, but the ability to route grid power to match real-time demand and power outages would significantly reduce energy costs for utilities, municipalities, and consumers. Georgia Tech is adding a power converter to an existing grid transformer to better control power flows at about 1/10th the cost of existing power routing solutions. Transformers convert the high-voltage electricity that is transmitted through the grid into the low-voltage electricity that is used by homes and businesses. The added converter uses fewer steps to convert some types of power and eliminates unnecessary power storage, among other improvements. The enhanced transformer is more efficient, and it would still work even if the converter fails, ensuring grid reliability.

  4. A Generalized Class of Stationary Frame-Current Controllers for Grid-Connected AC–DC Converters

    E-Print Network [OSTI]

    Hwang, J. George

    Within power systems, high-power pulsewidth-modulated ac-dc converters are used in flexible ac transmission systems controllers and for interfacing renewable energy sources to the grid. These converters traditionally ...

  5. A High Efficiency DC-DC Converter Topology Suitable for Distributed Large Commercial and Utility Scale PV Systems

    SciTech Connect (OSTI)

    Mohammed S. Agamy; Maja Harfman-Todorovic; Ahmed Elasser; Robert L. Steigerwald; Juan A. Sabate; Song Chi; Adam J. McCann; Li Zhang; Frank Mueller

    2012-09-01

    In this paper a DC-DC power converter for distributed photovoltaic plant architectures is presented. The proposed converter has the advantages of simplicity, high efficiency, and low cost. High efficiency is achieved by having a portion of the input PV power directly fed forward to the output without being processed by the converter. The operation of this converter also allows for a simplified maximum power point tracker design using fewer measurements

  6. Interaction of Fast-Scale and Slow-Scale Bifurcations in Current-Mode Controlled DC/DC Converters

    E-Print Network [OSTI]

    Tse, Chi K. "Michael"

    of fast-scale and slow-scale bifurcations in the boost converter under current- mode control operating, and it manifests as period-doubling in the time scale, as reported in Iu et al. [7] for parallel boost converters, Wong et al. [8] for noise-coupled boost converters, and Wu et al. [9] for power

  7. Abstract Many control schemes for dc-dc converters begin with the assertion that inductor currents are "fast" states and

    E-Print Network [OSTI]

    Kimball, Jonathan W.

    work, singular perturbation theory is applied to boost converters to provide rigorous justification derives from an analysis of an approximate model. Similar results hold for buck and buck-boost converters. An experimental boost converter and a simulated PFC boost support the derived requirement. Keywords

  8. Experimental Evaluation of a Cascade Sliding Mode-PI Controller for a Coupled-Inductor Boost Converter

    E-Print Network [OSTI]

    Batlle, Carles

    the experimental results ob- tained for a cascade sliding mode PI control in a coupled-inductor Boost converter) operations. A piece- wise complementarity model of the coupled-inductor boost converter was proposed in [6 control for a coupled-inductor boost converter was proposed. The control strategy was developed using

  9. Fig.1: Digital Controller with modified buck-boost converter LOAD-INTERACTIVE STEERED-INDUCTOR DC-DC

    E-Print Network [OSTI]

    Prodiæ, Aleksandar

    Fig.1: Digital Controller with modified buck-boost converter LOAD-INTERACTIVE STEERED-INDUCTOR DC-inverting buck- boost. Transient response results show that, compared to standard converters with near-inverting buck-boost converter, i.e. steered-inductor buck-boost, a digital controller, and a communication block

  10. Phase-Shifted Full Bridge DC-DC Converter with Energy Recovery Clamp and Reduced Circulating Current

    E-Print Network [OSTI]

    Phase-Shifted Full Bridge DC-DC Converter with Energy Recovery Clamp and Reduced Circulating@aei.com Abstract - This paper introduces a full bridge converter with reduced circulating current and a reduction bridge converter operating at 32 kHz switching frequency. Losses and efficiency of the experimental

  11. A Fully Integrated Switched-Capacitor DC-DC Converter with Dual Output for Low Power Application

    E-Print Network [OSTI]

    Ayers, Joseph

    . The entire converter system uses two 2-to-1 converter blocks. The upper output voltage (3.2V) is generated from the 2-to-1_up converter by means of averaging the 5V input and the generated lower output voltage is designed using high-voltage 0.35m BCDMOS technology. Both output voltages are regulated by means of pulse

  12. Computer-Aided Optimization of dc/dc Converters for Automotive Applications Timothy C. Neugebauer David J. Perreault

    E-Print Network [OSTI]

    Perreault, Dave

    Computer-Aided Optimization of dc/dc Converters for Automotive Applications Timothy C. Neugebauer/dc converters, with a focus on converters for dual-voltage automotive electrical systems. A new CAD optimization is the next evolutionary step for automotive electrical systems. High-power loads will be moved to a new high

  13. Power-Factor and Torque Calculation under Consideration of Cross Saturation of the Interior Permanent Magnet Synchronous Motor with Brushless Field Excitation

    SciTech Connect (OSTI)

    Lee, Seong T [ORNL; Burress, Timothy A [ORNL; Tolbert, Leon M [ORNL

    2009-01-01

    This paper introduces a new method for calculating the power factor and output torque by considering the cross saturation between direct-axis (d-axis) and quadrature-axis (q-axis) of an interior permanent magnet synchronous motor (IPMSM). The conventional two-axis IPMSM model is modified to include the cross saturation effect by adding the cross-coupled inductance terms. This paper also contains the new method of calculating the cross-coupled inductance values as well as self-inductance values in d- and q-axes. The analyzed motor is a high-speed brushless field excitation machine that offers high torque per ampere per core length at low speed and weakened flux at high speed, which was developed for the traction motor of a hybrid electric vehicle. The conventional two-axis IPMSM model was modified to include the cross-saturation effect by adding the cross-coupled inductance terms Ldq and Lqd. By the advantage of the excited structure of the experimental IPMSM, the analyzing works were performed under two conditions, the highest and lowest excited conditions. Therefore, it is possible to investigate the cross-saturation effect when a machine has higher magnetic flux from its rotor. The following is a summary of conclusions that may be drawn from this work: (1) Considering cross saturation of an IPMSM offers more accurate expected values of motor parameters in output torque calculation, especially when negative d-axis current is high; (2) A less saturated synchronous machine could be more affected by the cross-coupled saturation effect; (3) Both cross-coupled inductances, L{sub qd} and L{sub dq}, are mainly governed by d-axis current rather than q-axis current; (4) The modified torque equation, can be used for the dynamic model of an IPMSM for developing a better control model or control strategy; and (5) It is possible that the brushless field excitation structure has a common magnetic flux path on both d- and q-axis, and as a result, the reluctance torque of the machine could be reduced.

  14. Methodology for determining feasibility and cost for converting dredged material to topsoil 

    E-Print Network [OSTI]

    Graalum, Sara Jo Ann

    1997-01-01

    ). The purpose of this thesis is to discuss the applicability of converting dredged material to topsoil as a beneficial use of dredged material. The site selection in terms of location, material, and marketing are paramount in determining the most economically...

  15. Design of ultra low power analog-to-digital converter for ambulatory EEG recording

    E-Print Network [OSTI]

    El-Damak, Dina Reda

    2012-01-01

    Portable acquisition of biopotential signals requires the design of compact, energy efficient circuits and systems. Such systems typically include analog-to-digital converter for digitizing signals from AFE and feeding it ...

  16. Wavelength tunable polarization mode converter utilizing static strain effects in lithium niobate 

    E-Print Network [OSTI]

    Kwon, Ojin

    1999-01-01

    Electro-optically tunable polarization mode converters have been produced in LiNbO? substrate using all static strain optic effects. Maximum conversion efficiency of 98.3% was achieved at 66414m wavelength in TE to TM ...

  17. A 3-phase AC to AC matrix converter using the Venturini method 

    E-Print Network [OSTI]

    Dabbousi, Rami M. Osama

    2002-01-01

    flow, as well as sinusoidal currents and voltages in both input and output, with a reduction in the harmonics usually associated with converters. Therefore, this report discusses and analyzes all of the above characteristics, as well...

  18. Quantification of the influence of directional sea state parameters over the performances of wave energy converters 

    E-Print Network [OSTI]

    Pascal, Remy Claude Rene

    2012-11-29

    Accurate predictions of the annual energy yield from wave energy converters are essential to the development of the wave industry. The current method based on power matrices uses only a small part of the data available ...

  19. t is 2030, and a fleet of ten Gulfstream business jets have been converted to a

    E-Print Network [OSTI]

    Chen, Yiling

    I t is 2030, and a fleet of ten Gulfstream business jets have been converted to a new purpose concept of cooling the world by deflecting sunlight.UnlikejournalistEliKintisch's2010 book Hack the Planet

  20. Reliability Assessment of Fault-Tolerant Dc-Dc Converters for Photovoltaic Applications

    E-Print Network [OSTI]

    Liberzon, Daniel

    Reliability Assessment of Fault-Tolerant Dc-Dc Converters for Photovoltaic Applications Sairaj V in photovoltaic energy processing applications is presented. The proposed approach acknowledges the influence through several case studies. Index Terms-- Markov reliability modeling, photovoltaic systems, power

  1. Design of Wavelength Converting Switches for Optical Burst Jeyashankher Ramamirtham and Jonathan Turner

    E-Print Network [OSTI]

    Design of Wavelength Converting Switches for Optical Burst Switching Jeyashankher Ramamirtham Switches for Optical Burst Switching£ Jeyashankher Ramamirtham, Jonathan TurnerÝ Abstract Optical Burst Switching (OBS) is an experimental network technology that enables the construction of very high capacity

  2. Request for Information Regarding a Proposed Funding Opportunity for Administration of the Wave Energy Converter Prize

    Broader source: Energy.gov [DOE]

    This announcement is intended to serve as a Notice of Intent of the upcoming Funding Opportunity Announcement (FOA) regarding Administration of the Wave Energy Converter (WEC) Prize and Request for Information to solicit information regarding pote

  3. Request for Information Regarding a Proposed Funding Opportunity for Administration of the Wave Energy Converter Prize

    Broader source: Energy.gov [DOE]

    This announcement is intended to serve as a Notice of Intent of the upcoming Funding Opportunity Announcement (FOA) regarding Administration of the Wave Energy Converter (WEC) Prize and Request for Information.

  4. Design of a very high frequency resonant boost DC-DC converter

    E-Print Network [OSTI]

    Burkhart, Justin (Justin Michael)

    2010-01-01

    THIS thesis explores the development of a very high frequency DC-DC resonant boost converter. The topology examined features low parts count and fast transient response but suffers from higher device stresses compared to ...

  5. Improving the control strategy for a four-switch buck-boost converter

    E-Print Network [OSTI]

    Whitaker, Michael Peter

    2007-01-01

    The four-switch buck-boost converter, such as implemented with the Linear Technology LTC3440 integrated circuit, is useful in many applications. While this topology can be highly efficient, new strategies for controlling ...

  6. Design of a Very High Frequency dc-dc boost converter

    E-Print Network [OSTI]

    Sagneri, Anthony (Anthony David)

    2007-01-01

    Passive component volume is a perennial concern in power conversion. With new circuit architectures operating at extreme high frequencies it becomes possible to miniaturize the passive components needed for a power converter, ...

  7. Design and evaluation of a very high frequency dc/dc converter

    E-Print Network [OSTI]

    Pilawa-Podgurski, Robert C. N

    2007-01-01

    This thesis presents a resonant boost topology suitable for very high frequency (VHF, 30-300 MHz) dc-dc power conversion. The proposed design is a fixed frequency, fixed duty ratio resonant converter featuring low device ...

  8. Power Maximization in Wave-Energy Converters Using Sampled -Data Extremum Seeking /

    E-Print Network [OSTI]

    Chen, Tianjia

    2013-01-01

    with controlled motion. Power from sea waves, pages 381–399,SAN DIEGO Power Maximization in Wave-Energy Converters Usingfor wave energy con- verters with limited power takeoff

  9. Effect of a nonlinear power take off on a wave energy converter 

    E-Print Network [OSTI]

    Bailey, Helen Louise

    2011-11-22

    This thesis is titled The influence of a nonlinear Power Take Off on a Wave Energy Converter. It looks at the effect that having a nonlinear Power Take Off (PTO) has on an inertial referenced, slack moored, point absorber, ...

  10. Energy harvesting in silicon wavelength converters Kevin K. Tsia, Sasan Fathpour, and Bahram Jalali

    E-Print Network [OSTI]

    Jalali. Bahram

    ://www.ee.ucla.edu/~oecs/ Abstract: Nonlinear loss is the central problem in silicon devices that operate using nonlinear optical report the first demonstration of nonlinear photovoltaic effect in silicon wavelength converters

  11. Process for Converting Waste Glass Fiber into Value-Added Products

    Broader source: Energy.gov [DOE]

    Solid wastes are generated at glass fiber manufacturing facilities. With the help of a grant from DOE’s Inventions and Innovation Program, Albacem, LLC, developed a new process that converts these...

  12. The Utilization and Recovery of Energy from Blast Furnaces and Converters 

    E-Print Network [OSTI]

    Hegemann, K. R.; Niess, T.; Baare, R. D.

    1979-01-01

    comprising a gas cleaning unit for dust removal and a turbine for converting the recoverable thermal energy into mechanical and electrical energy. The adjustable annular gap scrubber for separating fine dust also serves as an element for regulating the gas...

  13. Converting Hybrid Wire-frames to B-rep Models Jie-Hui Gong

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Converting Hybrid Wire-frames to B-rep Models Jie-Hui Gong Dept. of Comp. Sci. and Technol of curved surfaces [Liu et al. 2001; Gong et al. 2006b]. The CSG oriented approach, however, is generally

  14. Design and Control of a Floating Wave-Energy Converter Utilizing a Permanent Magnet Linear Generator

    E-Print Network [OSTI]

    Tom, Nathan Michael

    2013-01-01

    electrical generator technology for wave energy converters,”seen, clean technologies, such as ocean wave energy, presentwave energy point absorber,” Proceedings of the IFAC Conference on Control Methodologies and Technology

  15. Radio frequency dc-dc converters : device characterization, topology evaluation, and design

    E-Print Network [OSTI]

    Leitermann, Olivia

    2008-01-01

    High frequency power conversion is attractive for the opportunities it affords for improved performance. Dc-dc converters operating at high frequencies use smaller-valued energy storage elements, which tend to be physically ...

  16. Impedance Control Network Resonant dc-dc Converter for Wide-Range High-Efficiency Operation

    E-Print Network [OSTI]

    Lu, Jie

    This paper introduces a new resonant converter architecture that utilizes multiple inverters and a lossless impedance control network (ICN) to maintain zero voltage switching (ZVS) and near zero current switching (ZCS) ...

  17. Development of an isolated flyback converter employing boundary-mode operation and magnetic flux sensing feedback

    E-Print Network [OSTI]

    Kenia, Mayur V. (Mayur Vasant), 1981-

    2004-01-01

    This thesis focuses on the marriage of magnetic-flux-sensing feedback and boundary-mode operation in a flyback converter to create a simple, small, low-cost, isolated, and tightly regulated power supply. Although each ...

  18. Soft-Switching High-Frequency AC-Link Universal Power Converters with Galvanic Isolation 

    E-Print Network [OSTI]

    Amirabadi, Mahshid

    2013-08-07

    be used in a variety of applications, including photovoltaic power generation, wind power generation, and electric vehicles. In these converters the link current and voltage are both alternating and their frequency can be high, which leads...

  19. A Dual-Supply Buck Converter with Improved Light-Load Efficiency 

    E-Print Network [OSTI]

    Zhang, Chao

    2012-07-16

    Power consumption and device size have been placed at the primary concerns for battery-operated portable applications. Switching converters gain popularity in powering portable devices due to their high efficiency, compact sizes and high current...

  20. Design and analysis of multiphase DC-DC converters with coupled inductors 

    E-Print Network [OSTI]

    Shi, Meng

    2007-09-17

    , directly coupled inductors have the benefit of low sensitivity to input variation at high frequencies. In addition, the proposed new structure for multiphase DC-DC converters has excellent current sharing performance and reduced current ripple. Computer...

  1. High Gain Transformerless DC-DC Converters for Renewable Energy Sources 

    E-Print Network [OSTI]

    Denniston, Nicholas Aaron

    2011-08-08

    Renewable energy sources including photovoltaic cells, fuel cells, and wind turbines require converters with high voltage gain in order to interface with power transmission and distribution networks. These conversions are conventionally made using...

  2. Nyquist-Rate Switched-Capacitor Analog-to-Digital Converters 

    E-Print Network [OSTI]

    Larsson, Andreas 1978-

    2012-11-28

    The miniaturization and digitization of modern microelectronic systems have made Analog-to-Digital converters (ADC) key building components in many applications. Internet and entertainment technologies demand higher and ...

  3. Frequency-based current-sharing techniques for paralleled power converters

    E-Print Network [OSTI]

    Perreault, David J.

    A new current-sharing technique for paralleled power converters, which is based on frequency encoding of the current-sharing information, is introduced. The approach has significant advantages over existing methods, including ...

  4. Predictive Power Control of Doubly-Fed Induction Generator for Wave Energy Converters

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Energy Converter Control Main Circuit Breaker Medium Voltage Switchgear Line Coupling Transformer Gear Medium Voltage Switchgear Line Coupling Transformer Fig. 1. An illustrative example of DFIG-based WEC

  5. Frequency selective analog to digital converter design : optimality, fundamental limitations, and performance bounds

    E-Print Network [OSTI]

    Osqui, Mitra M., 1980-

    2013-01-01

    In this thesis, the problem of analysis and design of Analog to Digital Converters (ADCs) is studied within an optimal feedback control framework. A general ADC is modeled as a causal, discrete-time dynamical system with ...

  6. Behavioral modeling and digital calibration of pipeline analog to digital converters 

    E-Print Network [OSTI]

    Bilhan, Erkan

    2001-01-01

    This research focuses on digital calibration of pipeline analog to digital converters (ADCs) and also modeling of error sources and design parameters of pipeline ADCs. Modern applications such as communications systems require high resolution ADCs...

  7. Zero-Crossing-Based Ultra-Low-Power A/D Converters

    E-Print Network [OSTI]

    Lee, Hae-Seung

    Since the first demonstration of a comparator-based switched-capacitor circuit, analog-to-digital (A/D) converters based on virtual ground detection have made steady and significant progress. Comparators have been replaced ...

  8. A New Integrated Onboard Charger and Accessory Power Converter for Plug-in Electric Vehicles

    SciTech Connect (OSTI)

    Su, Gui-Jia [ORNL; Tang, Lixin [ORNL

    2014-01-01

    In this paper, a new approach is presented for integrating the function of onboard battery charging into the traction drive system and accessory dc-dc converter of a plug-in electric vehicle (PEV). The idea is to utilize the segmented traction drive system of a PEV as the frond converter of the charging circuit and the transformer and high voltage converter of the 14 V accessory dc-dc converter to form a galvanically isolated onboard charger. Moreover, a control method is presented for suppressing the battery current ripple component of twice the grid frequency with the reduced dc bus capacitor in the segmented inverter. The resultant integrated charger has lower cost, weight, and volume than a standalone charger due to a substantially reduced component count. The proposed integrated charger topology was verified by modeling and experimental results on a 5.8 kW charger prototype.

  9. Two U.S. University Research Reactors to be Converted From Highly...

    Broader source: Energy.gov (indexed) [DOE]

    of Energy (DOE) has begun to convert research reactors from using highly-enriched uranium (HEU) to low-enriched uranium fuel (LEU) at the University of Florida and Texas A&M...

  10. Design and Control of a Floating Wave-Energy Converter Utilizing a Permanent Magnet Linear Generator

    E-Print Network [OSTI]

    Tom, Nathan Michael

    2013-01-01

    electrical generator technology for wave energy converters,”wave energy point absorber,” Proceedings of the IFAC Conference on Control Methodologies and Technologyseen, clean technologies, such as ocean wave energy, present

  11. Area Efficient D/A Converters For Accurate DC Operation Brandon Royce Greenley

    E-Print Network [OSTI]

    Moon, Un-Ku

    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 6.2 Mismatch Modeling For Area Optimization . . . . . . . . . . . . . . . . . . . . . . . 51 6Area Efficient D/A Converters For Accurate DC Operation by Brandon Royce Greenley A THESIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 5.1 Measurement Setup

  12. Compact self-contained electrical-to-optical converter/transmitter

    DOE Patents [OSTI]

    Seligmann, D.A.; Moss, W.C.; Valk, T.C.; Conder, A.D.

    1995-11-21

    A first optical receiver and a second optical receiver are provided for receiving a calibrate command and a power switching signal, respectively, from a remote processor. A third receiver is provided for receiving an analog electrical signal from a transducer. A calibrator generates a reference signal in response to the calibrate command. A combiner mixes the electrical signal with the reference signal to form a calibrated signal. A converter converts the calibrated signal to an optical signal. A transmitter transmits the optical signal to the remote processor. A primary battery supplies power to the calibrator, the combiner, the converter, and the transmitter. An optically-activated switch supplies power to the calibrator, the combiner, the converter, and the transmitter in response to the power switching signal. An auxiliary battery supplies power continuously to the switch. 13 figs.

  13. Compact self-contained electrical-to-optical converter/transmitter

    DOE Patents [OSTI]

    Seligmann, Daniel A. (Manteca, CA); Moss, William C. (San Mateo, CA); Valk, Theodore C. (Livermore, CA); Conder, Alan D. (Tracy, CA)

    1995-01-01

    A first optical receiver and a second optical receiver are provided for receiving a calibrate command and a power switching signal, respectively, from a remote processor. A third receiver is provided for receiving an analog electrical signal from a transducer. A calibrator generates a reference signal in response to the calibrate command. A combiner mixes the electrical signal with the reference signal to form a calibrated signal. A converter converts the calibrated signal to an optical signal. A transmitter transmits the optical signal to the remote processor. A primary battery supplies power to the calibrator, the combiner, the converter, and the transmitter. An optically-activated switch supplies power to the calibrator, the combiner, the converter, and the transmitter in response to the power switching signal. An auxiliary battery supplies power continuously to the switch.

  14. An 8-bit current mode ripple folding analog to digital converter 

    E-Print Network [OSTI]

    Dinc, Huseyin

    2002-01-01

    Design of an 8-bit current mode, ripple-folding analog to digital (A/D) converter is discussed. The ripple folding technique and the possible implementations in different process technologies are summarized. To have an A/D ...

  15. Design of high speed folding and interpolating analog-to-digital converter 

    E-Print Network [OSTI]

    Li, Yunchu

    2004-09-30

    High-speed and low resolution analog-to-digital converters (ADC) are key elements in the read channel of optical and magnetic data storage systems. The required resolution is about 6-7 bits while the sampling rate and ...

  16. A zero-crossing based pipelined analog-to-digital converter with supply voltage scalibility

    E-Print Network [OSTI]

    Lee, Sunghyuk

    2010-01-01

    A zero-crossing based pipelined analog-to-digital converter (ADC) has been designed and is fabricated in a 65nm CMOS process. The highly digital implementation characteristic of the zero-crossing detection technique enables ...

  17. The capacitively coupled converter (C³) for high power DC-DC conversion 

    E-Print Network [OSTI]

    Khan, Shahriar

    1992-01-01

    THE CAPACITIVELY COUPLED CONVERTER (C3) FOR HIGH POWER DC-DC CONVERSION A Thesis by SHAHRIAR KHAN Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER... OF SCIENCE May 1992 Major Subject: Electrical Engineering THE CAPACITIVELY COUPLED CONVERTER (Cs) FOR HIGH POWER DC-DC CONVERSION A Thesis by SHAHRIAR KHAN Approved as to style and content by: Mehrdad Ehsani (Chair of Committee) Prasad Enjeti...

  18. 100kW Energy Transfer Multiplexer Power Converter Prototype Development Project

    SciTech Connect (OSTI)

    S. Merrill Skeist; Richard H. (Dick) Baker; Anthony G.P. Marini; DOE Project Officer - Keith Bennett

    2006-03-21

    Project Final Report for "100kW Energy Transfer Multiplexer Power Converter Prototype Development Project" prepared under DOE grant number DE-FG36-03GO13138. This project relates to the further development and prototype construction/evaluation for the Energy Transfer Multiplexer (ETM) power converter topology concept. The ETM uses a series resonant link to transfer energy from any phase of a multiphase input to any phase of a multiphase output, converting any input voltage and frequency to any output voltage and frequency. The basic form of the ETM converter consists of an eight (8)-switch matrix (six phase power switches and two ground power switches) and a series L-C resonant circuit. Electronic control of the switches allows energy to be transferred in the proper amount from any phase to any other phase. Depending upon the final circuit application, the switches may be either SCRs or IGBTs. The inherent characteristics of the ETM converter include the following: Power processing in either direction (bidirectional); Large voltage gain without the need of low frequency magnetics; High efficiency independent of output load and frequency; Wide bandwidth with fast transient response and; Operation as a current source. The ETM is able to synthesize true sinusoidal waveforms with low harmonic distortions. For a low power PM wind generation system, the ETM has the following characteristics and advantages: It provides voltage gain without the need of low frequency magnetics (DC inductors) and; It has constant high efficiency independent of the load. The ETM converter can be implemented into a PM wind power system with smaller size, reduced weight and lower cost. As a result of our analyses, the ETM offers wind power generation technology for the reduction of the cost and size as well as the increase in performance of low power, low wind speed power generation. This project is the further theoretical/analytical exploration of the ETM converter concept in relationship to PM wind power generator applications in the 100kW and under power range. The theoretical/analytical and bench scale work focuses on simplifying the basic ETM converter topology (in terms of parts count and complexity) for the specific application of the low power PM system. The project goals and objectives were for Spellman HV will develop a 100kW prototype ETM power converter based on paralleled lower ratings converters. The proposed configuration of this prototype is a 100kW rated converter comprised of four (4) 34kW rated modules connected in parallel (the fourth converter is included to demonstrate N+1 fault tolerance). This approach is more viable as there is lower technological risk involved in developing a 34kW-rated converter than a single 100kW unit. The modular system approach should have a lower deployment and service cost over a single unit system, because of the economics of scale (smaller units at a higher volume means lower manufacturing cost) and because of improved serviceability (a non-redundant power system with one failed module will still operate at a lower power level). There is also the added benefit that greater commercial application and acceptance should be achieved by having a modular system available in which fault tolerance (N+1 or 2N) is a feature. This modular approach would allow the output power to be increased by adding more paralleled converters. Thus, the maximum output power of the overall power system is a function of the interconnection medium (the hot swap connection subsystem), rather than the ratings of a single module. The project was implemented with Spellman HV acting as the program management and production assembly and test facility; The Baker Company acting as a technical consultant and resource when required; and dtm Associates acting as the design/development resource for the hardware development of the 100kW ETM converter prototype.

  19. Compact, Low-Profile Power Converters: Highly-Laminated, High-Saturation-Flux-Density, Magnetic Cores for On-Chip Inductors in Power Converter Applications

    SciTech Connect (OSTI)

    None

    2010-09-01

    ADEPT Project: Georgia Tech is creating compact, low-profile power adapters and power bricks using materials and tools adapted from other industries and from grid-scale power applications. Adapters and bricks convert electrical energy into useable power for many types of electronic devices, including laptop computers and mobile phones. These converters are often called wall warts because they are big, bulky, and sometimes cover up an adjacent wall socket that could be used to power another electronic device. The magnetic components traditionally used to make adapters and bricks have reached their limits; they can't be made any smaller without sacrificing performance. Georgia Tech is taking a cue from grid-scale power converters that use iron alloys as magnetic cores. These low-cost alloys can handle more power than other materials, but the iron must be stacked in insulated plates to maximize energy efficiency. In order to create compact, low-profile power adapters and bricks, these stacked iron plates must be extremely thin-only hundreds of nanometers in thickness, in fact. To make plates this thin, Georgia Tech is using manufacturing tools used in microelectromechanics and other small-scale industries.

  20. SUBCONTRACT REPORT: DC-DC Converter for Fuel Cell and Hybrid Vehicles

    SciTech Connect (OSTI)

    Marlino, Laura D; Zhu, Lizhi

    2007-07-01

    The goal of this project is to develop and fabricate a 5kW dc-dc converter with a baseline 14V output capability for fuel cell and hybrid vehicles. The major objectives for this dc-dc converter technology are to meet: Higher efficiency (92%); High coolant temperature,e capability (105 C); High reliability (15 Years/150,000miles); Smaller volume (5L); Lower weight (6kg); and Lower cost ($75/kW). The key technical challenge for these converters is the 105 C coolant temperatures. The power switches and magnetics must be designed to sustain these operating temperatures reliably, without a large cost/mass/volume penalty.

  1. DC to DC power converters and methods of controlling the same

    SciTech Connect (OSTI)

    Steigerwald, Robert Louis; Elasser, Ahmed; Sabate, Juan Antonio; Todorovic, Maja Harfman; Agamy, Mohammed

    2012-12-11

    A power generation system configured to provide direct current (DC) power to a DC link is described. The system includes a first power generation unit configured to output DC power. The system also includes a first DC to DC converter comprising an input section and an output section. The output section of the first DC to DC converter is coupled in series with the first power generation unit. The first DC to DC converter is configured to process a first portion of the DC power output by the first power generation unit and to provide an unprocessed second portion of the DC power output of the first power generation unit to the output section.

  2. Chemical reactor and method for chemically converting a first material into a second material

    DOE Patents [OSTI]

    Kong, Peter C. (Idaho Falls, ID)

    2008-04-08

    A chemical reactor and method for converting a first material into a second material is disclosed and wherein the chemical reactor is provided with a feed stream of a first material which is to be converted into a second material; and wherein the first material is combusted in the chemical reactor to produce a combustion flame, and a resulting gas; and an electrical arc is provided which is passed through or superimposed upon the combustion flame and the resulting gas to facilitate the production of the second material.

  3. Chemical reactor for converting a first material into a second material

    DOE Patents [OSTI]

    Kong, Peter C

    2012-10-16

    A chemical reactor and method for converting a first material into a second material is disclosed and wherein the chemical reactor is provided with a feed stream of a first material which is to be converted into a second material; and wherein the first material is combusted in the chemical reactor to produce a combustion flame, and a resulting gas; and an electrical arc is provided which is passed through or superimposed upon the combustion flame and the resulting gas to facilitate the production of the second material.

  4. Dual Current-Mode Control for Single-Switch Two-Output Switching Power Converters S. C. Wong, C. K. Tse and K. C. Tang

    E-Print Network [OSTI]

    Tse, Chi K. "Michael"

    a single-switch two-output boost converter, in which a continuous-mode converter and a discontinuous boost converters, one operating in contin- uous conduction mode (CCM) and the other in discontinuous. We shall make reference to a single-switch two-output boost converter later in the paper. Suppose

  5. Abstract-This paper addresses boost converter circuits that are built for very low input voltages, i.e. less than 1 V. Such circuits

    E-Print Network [OSTI]

    Kimball, Jonathan W.

    Abstract- This paper addresses boost converter circuits that are built for very low input voltages-VOLTAGE BOOST CONVERTER EFFICIENCY Efficiency of the basic power converter circuits such as buck, boost, etc input voltages. I. INTRODUCTION Power converters driven from low input voltage (

  6. Electro-mechanical energy conversion system having a permanent magnet machine with stator, resonant transfer link and energy converter controls

    DOE Patents [OSTI]

    Skeist, S. Merrill; Baker, Richard H.

    2006-01-10

    An electro-mechanical energy conversion system coupled between an energy source and an energy load comprising an energy converter device including a permanent magnet induction machine coupled between the energy source and the energy load to convert the energy from the energy source and to transfer the converted energy to the energy load and an energy transfer multiplexer to control the flow of power or energy through the permanent magnetic induction machine.

  7. Converting Commodity Head-Mounted Displays for Optical See-Through Augmented Reality

    E-Print Network [OSTI]

    Pollefeys, Marc

    head-mounted display. Project achieves wide field of view and low latency augmented reality displayConverting Commodity Head-Mounted Displays for Optical See-Through Augmented Reality The Challenge The current market for fully immersive virtual reality head- mounted displays is rapidly expanding, however

  8. Sliding Mode Control of Boost Converter: Application to energy storage system via supercapacitors

    E-Print Network [OSTI]

    Boyer, Edmond

    Sliding Mode Control of Boost Converter: Application to energy storage system via supercapacitors the contract Hysbus through the competitive pole (Lyon Urban Truck and Bus 2015). Keywords «Energy storage of an energy storage system based on supercapacitors technology in order to regulate the output voltage. Given

  9. A DC-DC Converter-Based PEM Fuel Cell System Emulator

    E-Print Network [OSTI]

    Boyer, Edmond

    A DC-DC Converter-Based PEM Fuel Cell System Emulator Daoud Rezzak, Farid Khoucha, Mohamed Benbouzid, Abdelaziz Kheloui and Abdeslam Mamoune Abstract--The Proton Exchange Membrane Fuel Cell (PEMFC power supplies. Fuel cell systems are characterized by high costs and complex auxiliary devices

  10. TAS-2013-0043 1 Abstract--Fuel cells are electrochemical energy converters

    E-Print Network [OSTI]

    Boyer, Edmond

    TAS-2013-0043 1 Abstract--Fuel cells are electrochemical energy converters which allow generation. Fuel cells are then by essence low voltage sources , so that for most practical applications of the perfectly direct current relies upon a fuel cell fed by hydrogen. The main advantages to be taken from fuel

  11. Aalborg Universitet Ancillary Frequency Control of Direct Drive Full-Scale Converter Based Wind Power

    E-Print Network [OSTI]

    Hu, Weihao

    , integration of such a lot of wind energy into power grids presents a major challenge to power system operators more attentions all over the world. Large-scale wind power plants are increasingly integrated). Ancillary Frequency Control of Direct Drive Full-Scale Converter Based Wind Power Plants. In Proceedings

  12. Direct Power Control of Doubly-Fed Generator Based Wind Turbine Converters to Improve Low Voltage

    E-Print Network [OSTI]

    Kimball, Jonathan W.

    by an Industrial Power Corruptor (IPC) in the laboratory. I. INTRODUCTION The new grid code requirements for windDirect Power Control of Doubly-Fed Generator Based Wind Turbine Converters to Improve Low Voltage power integration state that doubly fed induction generator (DFIG) controllers should be capable

  13. One-way wave-equation migration of compressional and converted waves in a VTI medium

    E-Print Network [OSTI]

    Ursin, Bjørn

    One-way wave-equation migration of compressional and converted waves in a VTI medium Ørjan Pedersen- sure and shear-wave reflections, one can increase the amount of information obtained about the subsur- face than by recording pressure waves alone. Geo- logic structures which are not visible by using con

  14. A Universal Level Converter Towards the Realization of Energy Efficient Implantable Drug Delivery

    E-Print Network [OSTI]

    Mohanty, Saraju P.

    A Universal Level Converter Towards the Realization of Energy Efficient Implantable Drug Delivery VLSI Design and CAD Laboratory (VDCL), University of North Texas, Denton, TX 76203, USA. 2 Electrical many side effects, such as reduction in battery life time, increase in operating tempera- ture

  15. Harmonic Elimination in Multilevel Converters John Chiasson, Leon Tolbert, Keith McKenzie and Zhong Du

    E-Print Network [OSTI]

    Tolbert, Leon M.

    Converters, Harmonic Elimination, Resultants, Symmetric Polynomials I. Introduction Electric power production and information infrastructure. A shift will take place from a relatively few large, concentrated generation be obtained from solar cells, fuel cells, or ul- tracapacitors. Figure 1 shows a single-phase structure

  16. A Generalized Formula for Converting Chi-Square Tests to Effect Sizes for Meta-Analysis

    E-Print Network [OSTI]

    Rosenberg, Michael S.

    A Generalized Formula for Converting Chi-Square Tests to Effect Sizes for Meta-Analysis Michael S Sciences, Arizona State University, Tempe, Arizona, United States of America Abstract The common formula of the effect size. A corrected formula is provided. Citation: Rosenberg MS (2010) A Generalized Formula

  17. Low Switching Frequency Active Harmonic Elimination in Multilevel Converters with Unequal DC Voltages

    E-Print Network [OSTI]

    Tolbert, Leon M.

    The multilevel converter is a promising technology for renewable/distributed energy applications of power electronics because of its easy connection with renewable/distributed energy modules such as fuel cells, solar panels, and wind turbines. Other benefits also include its low electromagnetic interference (EMI

  18. The Effects of Wave Energy Converters on a Monochromatic Wave Climate

    E-Print Network [OSTI]

    Fox-Kemper, Baylor

    in wave energy converters as a possible means of providing renewable energy, the effects of a wave energy The interest in renewable energies is currently increasing due to the reported rise in global temperature and mean wave period of wave energy fields. There is tremendous energy potential in the ocean. Solar energy

  19. Multilevel Converters as a Utility Interface for Renewable Energy Systems Leon M. Tolbert Fang Z. Peng

    E-Print Network [OSTI]

    Tolbert, Leon M.

    interface, power quality I. INTRODUCTION Electric power production in the 21st Century will see dramatic suitable for flexible ac transmission systems (FACTS) and custom power applications [6, 7]. The useMultilevel Converters as a Utility Interface for Renewable Energy Systems Leon M. Tolbert Fang Z

  20. High Speed CMOS Output Stage for Integrated DC-DC Converters Wai Tung Ng*, Marian Changl

    E-Print Network [OSTI]

    Ng, Wai Tung

    to attain maximum channel width per unit area for low on-resistance. A typical MF layout and its equivalent DC/DC converters is characterized by power conversion efficiency, transient response, size and cost is introduced to enhance the switching speed and power conversion efficiency of low voltage integrated DC

  1. A short and simple explanation of how oil is converted into gasoline and then brought to

    E-Print Network [OSTI]

    A short and simple explanation of how oil is converted into gasoline and then brought to you Blending [Step 5] DiSTRibuTiON [Step 6] CONSumER uSE #12;3 SOuRCES 1 The most common method of obtaining the products produced from this petroleum, gasoline represents about half of the total product volume

  2. Using Pyrolysis to Convert Unused Urban Biotic Material into Bioenergy and Biochar

    E-Print Network [OSTI]

    Wolberg, George

    Using Pyrolysis to Convert Unused Urban Biotic Material into Bioenergy and Biochar Objective of pyrolysis (low-temperature anaerobic burning) that will generate bio-energy as well as biochar for enriching-explored technology is pyrolysis. Pyrolysis is a low temperature, anaerobic process that avoids incineration

  3. Regenerative Braking for an Electric Vehicle Using Ultracapacitors and a Buck-Boost Converter

    E-Print Network [OSTI]

    Catholic University of Chile (Universidad Católica de Chile)

    Regenerative Braking for an Electric Vehicle Using Ultracapacitors and a Buck-Boost Converter Juan situation (regenerative braking), the battery voltage goes up, and then the control needs to activate regenerative braking can be avoided #12;with the help of ultracapacitors. Besides, ultracapacitors allow

  4. Efficiency analysis of a pneu-mechanical Wave Energy Converter : model of the device losses,

    E-Print Network [OSTI]

    Psaltis, Demetri

    ENAC/ Efficiency analysis of a pneu-mechanical Wave Energy Converter : model of the device losses. Van Herle 1 Mots Clés: Efficiency Analysis, Power Take Off, Renewable Energy, WEC, Wave Energy. 1 have been focused on the efficiency of the different technologies on a test rig and building

  5. A 3-Bit Current Mode Quantizer for Continuous Time Delta Sigma Analog-to-Digital Converters 

    E-Print Network [OSTI]

    Sundar, Arun

    2012-02-14

    The summing amplifier and the quantizer form two of the most critical blocks in a continuous time delta sigma (CT ??) analog-to-digital converter (ADC). Most of the conventional CT ?? ADC designs incorporate a voltage summing amplifier and a voltage...

  6. Elimination of Harmonics in a Multilevel Converter using the Theory of Symmetric

    E-Print Network [OSTI]

    Tolbert, Leon M.

    of dc voltages. For example, the output of solar cells are dc voltages, and if this energy is to be fed for connecting such distributed dc energy sources (solar cells, fuel cells, the rectified output of wind turbines that the transcendental equations characterizing the har- monic content can be converted to polynomial equations which

  7. Dexpler: Converting Android Dalvik Bytecode to Jimple for Static Analysis with Soot

    E-Print Network [OSTI]

    Bartel, Alexandre; Monperrus, Martin; Traon, Yves Le

    2012-01-01

    This paper introduces Dexpler, a software package which converts Dalvik bytecode to Jimple. Dexpler is built on top of Dedexer and Soot. As Jimple is Soot's main internal rep- resentation of code, the Dalvik bytecode can be manipu- lated with any Jimple based tool, for instance for performing point-to or flow analysis.

  8. Method to Design General RNS Reverse Converters for Extended Moduli Sets

    E-Print Network [OSTI]

    Sousa, Leonel

    1 Method to Design General RNS Reverse Converters for Extended Moduli Sets Hector Pettenghi, Member, research on residue number systems (RNS) has targeted larger dynamic ranges in order to further explore-of-the-art, resulting in an improvement of the overall RNS performance at the cost of a slower reverse conversion

  9. Multiplier-based Binary-to-RNS Converter Modulo {2n +-k} Pedro Miguens Matutino

    E-Print Network [OSTI]

    Sousa, Leonel

    125 Multiplier-based Binary-to-RNS Converter Modulo {2n +- k} Pedro Miguens Matutino ISEL for binary- to-RNS conversion modulo {2n ± k} is proposed. The proposed structure is based on adders know to date. I. INTRODUCTION The modular characteristics of Residue Number System (RNS) offers

  10. RNS Reverse Converters based on the New Chinese Remainder Theorem I

    E-Print Network [OSTI]

    Sousa, Leonel

    RNS Reverse Converters based on the New Chinese Remainder Theorem I Hector Pettenghi Departamento number systems (RNS) has targeted larger dynamic ranges in order to further explore the inherent parallelism of these systems. In this paper, a performance analysis is presented for RNS

  11. MO. RIY. MO. : ;. ' ~ . Dual A /D Converter Reliability Prediction ATM 905

    E-Print Network [OSTI]

    Rathbun, Julie A.

    the Reliability Prediction and Failure Modes Effects & Criticality Analysis of the Bendix designed Dual A/D Converter. The analysis reflects the final flight configuration for the Array D ALSEP System. Prepared simultaneously by the counter control (Block I, digital board). When the ramp voltage equals the analog input

  12. Fault Sensitivity Analysis and Reliability Enhancement of Analog-to-Digital Converters

    E-Print Network [OSTI]

    Koren, Israel

    1 Fault Sensitivity Analysis and Reliability Enhancement of Analog-to-Digital Converters Mandeep. The latter also enables an early analysis in the design phase thus eliminating costly redesign. Two types. This type of faults has been known to account for 85% or more failures in digital systems [1], [2]. Since

  13. Comparative Study of Power Factor Correction Converters For Single Phase Half-Bridge Inverters

    E-Print Network [OSTI]

    Tolbert, Leon M.

    of input current harmonic distortion and en- ergy efficiency. I. INTRODUCTION Uninterruptible power supplyComparative Study of Power Factor Correction Converters For Single Phase Half-Bridge Inverters Gui an isolation transformer, and sinu- soidal input currents if a power factor correction (PFC) con- verter

  14. Video Article Continuously-Stirred Anaerobic Digester to Convert Organic Wastes into

    E-Print Network [OSTI]

    Angenent, Lars T.

    Video Article Continuously-Stirred Anaerobic Digester to Convert Organic Wastes into Biogas: System, Bioenergy, Biogas, Methane, Organic Waste, Methanogenesis, Energy Crops, Date Published: // Citation: Usack Wastes into Biogas: System Setup and Basic Operation. J. Vis. Exp. (), e3978, DOI : 10

  15. High-Power Converters and AC Drives IEEE PESC2005 Tutorial

    E-Print Network [OSTI]

    Wu, Bin

    Overview · MV Drive Applications Industry Application Examples Petrochemical Pipeline pumps, gas Introduction Main Topics · Medium Voltage (MV) Drive Overview · High Power Converter Topologies · MV Industrial Topic 1 Introduction MV Drive Overview · MV Drive Market Survey Main purpose for high-power fan/pump

  16. Integrated Power Adapter: Isolated Converter with Integrated Passives and Low Material Stress

    SciTech Connect (OSTI)

    None

    2010-09-01

    ADEPT Project: CPES at Virginia Tech is developing an extremely efficient power converter that could be used in power adapters for small, lightweight laptops and other types of mobile electronic devices. Power adapters convert electrical energy into useable power for an electronic device, and they currently waste a lot of energy when they are plugged into an outlet to power up. CPES at Virginia Tech is integrating high-density capacitors, new magnetic materials, high-frequency integrated circuits, and a constant-flux transformer to create its efficient power converter. The high-density capacitors enable the power adapter to store more energy. The new magnetic materials also increase energy storage, and they can be precisely dispensed using a low-cost ink-jet printer which keeps costs down. The high-frequency integrated circuits can handle more power, and they can handle it more efficiently. And, the constant-flux transformer processes a consistent flow of electrical current, which makes the converter more efficient.

  17. Coordination of Converter and Fuel Cell Controllers Kyung-Won Suh and Anna G. Stefanopoulou

    E-Print Network [OSTI]

    Stefanopoulou, Anna

    Coordination of Converter and Fuel Cell Controllers Kyung-Won Suh and Anna G. Stefanopoulou following fuel cell systems depend on control of reactant flow and regulation of DC bus voltage during load (current) drawn from them. To this end, we model and analyze the dynamics of a fuel cell system equipped

  18. LABORATORY OBSERVATIONS AND NUMERICAL MODELING OF THE EFFECTS OF AN ARRAY OF WAVE ENERGY CONVERTERS

    E-Print Network [OSTI]

    Haller, Merrick

    1 LABORATORY OBSERVATIONS AND NUMERICAL MODELING OF THE EFFECTS OF AN ARRAY OF WAVE ENERGY of wave energy converters (WECs) on water waves through the analysis of extensive laboratory experiments absorption is a reasonable predictor of the effect of WECs on the far field. Keywords: wave- energy; spectral

  19. Wave Energy Converter Design Tool for Point Absorbers with Arbitrary Device Geometry Kelley Ruehl

    E-Print Network [OSTI]

    Siefert, Chris

    Wave Energy Converter Design Tool for Point Absorbers with Arbitrary Device Geometry Kelley Ruehl University Corvallis, OR, USA ABSTRACT In order to promote and support the wave energy industry, a Wave strategies. KEY WORDS: wave energy; point absorber; time-domain; design tool. INTRODUCTION Wave Energy

  20. Impedance Control Network Resonant dc-dc Converter for Wide-Range High-Efficiency Operation

    E-Print Network [OSTI]

    Perreault, Dave

    voltages and output power. The ICN converter architecture enables increase in switching frequency (hence to maintain desirable circuit waveforms (e.g., ZVS/ZCS switching and minimum conduction current) as power some widely-used design and control techniques. One common means of controlling resonant soft-switched

  1. Control development for an 18 MW pulsed power converter using a real-time simulation platform

    E-Print Network [OSTI]

    Genton, Charles-Mathieu; Boattini, Fulvio

    2015-01-01

    In the frame of the LHC Injectors Upgrade (LIU) project, a new main power supply (MPS) for the PSBooster accelerator is required. The largest element of the new MPS is the 18 MW main power converter (MPC). The paper presents the design of the MPC control software, using Rapid Control Prototyping.

  2. 5 kW Multilevel DC-DC Converter for Hybrid Electric and Fuel Cell Automotive

    E-Print Network [OSTI]

    Tolbert, Leon M.

    5 kW Multilevel DC-DC Converter for Hybrid Electric and Fuel Cell Automotive Applications Faisal H) for future hybrid electric vehicle and fuel cell automotive applications will be presented in this paper will impact if the 42V/14V dual bus system will be a successful and cost effective solution for future

  3. Integration of planar transformer and/or planar inductor with power switches in power converter

    DOE Patents [OSTI]

    Chen, Kanghua (Canton, MI); Ahmed, Sayeed (Canton, MI); Zhu, Lizhi (Canton, MI)

    2007-10-30

    A power converter integrates at least one planar transformer comprising a multi-layer transformer substrate and/or at least one planar inductor comprising a multi-layer inductor substrate with a number of power semiconductor switches physically and thermally coupled to a heat sink via one or more multi-layer switch substrates.

  4. Converted wave imaging in anisotropic media using sea-floor seismic data 

    E-Print Network [OSTI]

    Mancini, Fabio

    velocity ratio is derived conventionally by event matching in the P-wave and converted wave stacks. I present an attempt to use well-log derived velocity ratios to avoid this interpretative step. The velocity ratio derived from 4C seismic data is about 30...

  5. Instrumentation for Monitoring around Marine Renewable Energy Converters: Workshop Final Report

    SciTech Connect (OSTI)

    Polagye, B. L.; Copping, A. E.; Brown-Saracino, J.; Suryan, R.; Kramer, S.; Smith, C.

    2014-01-14

    To better understand the state of instrumentation and capabilities for monitoring around marine energy converters, the U.S. Department of Energy directed Pacific Northwest National Laboratory and the Northwest National Marine Renewable Energy Center at the University of Washington to convene an invitation-only workshop of experts from around the world to address instrumentation needs.

  6. Converting PETAL, the 25m solar collector, into an astronomical research facility

    E-Print Network [OSTI]

    Ribak, Erez

    1 Converting PETAL, the 25m solar collector, into an astronomical research facility Erez N. Ribak and Astronomy, Tel Aviv University, Israel ABSTRACT We propose to modify the solar collector PETAL (Photon, and using fibre optics to combine the light at a common focus. Keywords: Solar collectors, Large telescopes

  7. Optical antennas are devices designed to efficiently convert optical radiation into local-

    E-Print Network [OSTI]

    Novotny, Lukas

    Optical antennas are devices designed to efficiently convert optical radiation into local- ized the potential to boost the effi- ciency of optoelectronic devices ranging from light-emitting diodes to solar- ing data describe the spatial­spectral evolu- tion of characteristic antenna resonances

  8. High Efficiency Thermionics (HET-IV) and Converter Advancement (CAP) programs. Final reports

    SciTech Connect (OSTI)

    Geller, C.B.; Murray, C.S.; Riley, D.R. [Bettis Atomic Power Lab., West Mifflin, PA (United States); Desplat, J.L.; Hansen, L.K.; Hatch, G.L.; McVey, J.B.; Rasor, N.S. [Rasor Associates, Inc., Sunnyvale, CA (United States)

    1996-04-01

    This report contains the final report of the High Efficiency Thermionics (HET-IV) Program, Attachment A, performed at Rasor Associates, Inc. (RAI); and the final report of the Converter Advancement Program (CAP), performed at the Bettis Atomic Power Laboratory, Attachment B. The phenomenology of cesium-oxygen thermionic converters was elucidated in these programs, and the factors that had prevented the achievement of stable, enhanced cesium-oxygen converter performance for the previous thirty years were identified. Based on these discoveries, cesium-oxygen vapor sources were developed that achieved stable performance with factor-of-two improvements in power density and thermal efficiency, relative to conventional, cesium-only ignited mode thermionic converters. Key achievements of the HET-IV/CAP programs are as follows: a new technique for measuring minute traces of oxygen in cesium atmospheres; the determination of the proper range of oxygen partial pressures for optimum converter performance--10{sup {minus}7} to 10{sup {minus}9} torr; the discovery, and analysis of the cesium-oxygen liquid migration and compositional segregation phenomena; the successful use of capillary forces to contain the migration phenomenon; the use of differential heating to control compositional segregation, and induce vapor circulation; the development of mechanically and chemically stable, porous reservoir structures; the development of precise, in situ oxygen charging methods; stable improvements in emitter performance, up to effective emitter bare work functions of 5.4 eV; stable improvements in barrier index, to value below 1.8 Volts; the development of detailed microscopic models for cesium-oxygen reservoir dynamics and collector work function behavior; and the discovery of new relationships between electrode geometry and Schock Instability.

  9. convert program

    National Nuclear Security Administration (NNSA)

    %2A en Nuclear Material Removal http:www.nnsa.energy.govaboutusourprogramsdnnm3remove

    Pag...

  10. convert program

    National Nuclear Security Administration (NNSA)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield Municipal GasAdministration Medal01 Sandia4) August 20123/%2A en46A NAME6/%2A en

  11. Efficiency Analysis of a High Frequency Buck Converter for On-Chip Integration with a Dual-VDD Microprocessor

    E-Print Network [OSTI]

    Friedman, Eby G.

    Efficiency Analysis of a High Frequency Buck Converter for On-Chip Integration with a Dual that simultaneously permits monolithic integration and high efficiency. A parasitic model of the buck converter devices on the same die for a target technology. An efficiency of 88.4% at a switching frequency of 477

  12. 36 IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS, VOL. 35, NO. 1, JANUARY/FEBRUARY 1999 Multilevel Converters for Large Electric Drives

    E-Print Network [OSTI]

    Tolbert, Leon M.

    . Multilevel converters: 1) can generate near- sinusoidal voltages with only fundamental frequency switching; 2 Converters for Large Electric Drives Leon M. Tolbert, Senior Member, IEEE, Fang Zheng Peng, Senior Member multilevel con- verters as an application for high-power and/or high-voltage electric motor drives

  13. Aalborg Universitet Harmonic models of a back-to-back converter in large offshore wind farms compared

    E-Print Network [OSTI]

    Bak, Claus Leth

    Aalborg Universitet Harmonic models of a back-to-back converter in large offshore wind farms-to-back converter in large offshore wind farms compared with measurement data. In Proceedings of Nordic Wind Power from vbn.aau.dk on: juli 04, 2015 #12; Abstract--The offshore wind farm with installed back-to- back

  14. Merged Two-Stage Power Converter With Soft Charging Switched-Capacitor Stage in 180 nm CMOS

    E-Print Network [OSTI]

    Pilawa-Podgurski, Robert C. N.

    In this paper, we introduce a merged two-stage dc-dc power converter for low-voltage power delivery. By separating the transformation and regulation function of a dc-dc power converter into two stages, both large voltage ...

  15. Hybrid Control Method for Optimal Transient Response and Output Filter Minimization for Buck-Boost type Converters

    E-Print Network [OSTI]

    transfer systems, such as a boost, buck-boost, or flyback converters, this is not the case. Here, the timeHybrid Control Method for Optimal Transient Response and Output Filter Minimization for Buck-Boost type Converters Mor Mordechai Peretz Power Electronics Laboratory Dept. of Electrical and Computer

  16. Abstract--A design method for digital controller of PWM DC-DC converters was developed, tested by simulations and

    E-Print Network [OSTI]

    domain transformation and discretization. A digital PID controller for a Buck type converter domain and the sampled data domain (via the various transformation algorithms), a digital compensatorAbstract-- A design method for digital controller of PWM DC-DC converters was developed, tested

  17. A three-level buck converter to regulate a high-voltage DC-to-AC inverter

    E-Print Network [OSTI]

    Schrock, Kenneth C

    2008-01-01

    A three-level buck converter is designed and analyzed, and shown to be suitable as a high-voltage down converter as a pre-regulation stage for a 600 watt DC-to-AC power inverter. Topology selection for the inverter is ...

  18. GOCEXML2ASCII an XML to ASCII converter for GOCE level EGG_NOM and SST_PSO data

    E-Print Network [OSTI]

    Stuttgart, Universität

    GOCEXML2ASCII ­ an XML to ASCII converter for GOCE level EGG_NOM and SST_PSO data Ma hias Roth SST_PSO_2 file (a typical SST_PSO_2 file has a size of ~ MB). The advantage of this parser Institute (Arsov, ) is implemented in C++. According to Arsov, the GOCEPARSER needs ~ min to convert a SST_PSO

  19. IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, VOL. 63, NO. 4, MAY 2014 1581 Design Methodology of LLC Resonant Converters

    E-Print Network [OSTI]

    Mi, Chunting "Chris"

    Resonant Converters for Electric Vehicle Battery Chargers Junjun Deng, Student Member, IEEE, Siqi Li-ion battery charger of a plug-in hybrid electric vehicle (PHEV) is presented. Unlike traditional resistive of 250­450 V at 3.3 kW with a peak efficiency of 98.2%. Index Terms--Battery charger, DC­DC converter

  20. Abstract Designers of advanced power converters may choose from a variety of switching device models for simulation. Some

    E-Print Network [OSTI]

    Kimball, Jonathan W.

    Abstract ­ Designers of advanced power converters may choose from a variety of switching device to the design of a typical power converter than voltage transients. Averaging is used in [7] to create a power dissipation model. The present work instead inserts power dissipating elements at each switching edge

  1. THE FORCE OF A TSUNAMI ON A WAVE ENERGY CONVERTER LAURA O'BRIEN, PAUL CHRISTODOULIDES, EMILIANO RENZI, DENYS DUTYKH,

    E-Print Network [OSTI]

    THE FORCE OF A TSUNAMI ON A WAVE ENERGY CONVERTER LAURA O'BRIEN, PAUL CHRISTODOULIDES, EMILIANO waves. The question posed here is whether a nearshore wave energy converter (WEC) could withstand Acknowledgements 10 References 10 1. Introduction Wave energy devices are slowly becoming a reality. Various

  2. A Transformer-less Partial Power Boost Converter for PV Applications Using a Three-Level Switching Cell

    SciTech Connect (OSTI)

    Mohammed Agamy; Maja Harfman-Todorovic; Ahmed Elasser; Somasundaram Essakiappan

    2013-03-01

    Photovoltaic architectures with distributed power electronics provide many advantages in terms of energy yield as well as system level optimization. As the power level of the solar farm increases it becomes more beneficial to increase the dc collection network voltage, which requires the use of power devices with higher voltage ratings, and thus making the design of efficient, low cost, distributed power converters more challenging. In this paper a simple partial power converter topology is proposed. The topology is implemented using a three-level switching cell, which allows the use of semiconductor devices with lower voltage rating; thus improving design and performance and reducing converter cost. This makes the converters suitable for use for medium to high power applications where dc-link voltages of 600V~1kV may be needed without the need for high voltage devices. Converter operation and experimental results are presented for two partial power circuit variants using three-level switching cells.

  3. Boost Converters for Gas Electric and Fuel Cell Hybrid Electric Vehicles

    SciTech Connect (OSTI)

    McKeever, JW

    2005-06-16

    Hybrid electric vehicles (HEVs) are driven by at least two prime energy sources, such as an internal combustion engine (ICE) and propulsion battery. For a series HEV configuration, the ICE drives only a generator, which maintains the state-of-charge (SOC) of propulsion and accessory batteries and drives the electric traction motor. For a parallel HEV configuration, the ICE is mechanically connected to directly drive the wheels as well as the generator, which likewise maintains the SOC of propulsion and accessory batteries and drives the electric traction motor. Today the prime energy source is an ICE; tomorrow it will very likely be a fuel cell (FC). Use of the FC eliminates a direct drive capability accentuating the importance of the battery charge and discharge systems. In both systems, the electric traction motor may use the voltage directly from the batteries or from a boost converter that raises the voltage. If low battery voltage is used directly, some special control circuitry, such as dual mode inverter control (DMIC) which adds a small cost, is necessary to drive the electric motor above base speed. If high voltage is chosen for more efficient motor operation or for high speed operation, the propulsion battery voltage must be raised, which would require some type of two-quadrant bidirectional chopper with an additional cost. Two common direct current (dc)-to-dc converters are: (1) the transformer-based boost or buck converter, which inverts a dc voltage, feeds the resulting alternating current (ac) into a transformer to raise or lower the voltage, and rectifies it to complete the conversion; and (2) the inductor-based switch mode boost or buck converter [1]. The switch-mode boost and buck features are discussed in this report as they operate in a bi-directional chopper. A benefit of the transformer-based boost converter is that it isolates the high voltage from the low voltage. Usually the transformer is large, further increasing the cost. A useful feature of the switch mode boost converter is its simplicity. Its inductor must handle the entire current, which is responsible for its main cost. The new Z-source inverter technology [2,3] boosts voltage directly by actively using the zero state time to boost the voltage. In the traditional pulse width modulated (PWM) inverter, this time is used only to control the average voltage by disconnecting the supply voltage from the motor. The purpose of this study is to examine the Z-source's potential for reducing the cost and improving the reliability of HEVs.

  4. Interconnected High-Voltage Pulsed-Power Converters System Design for H? Ion Sources

    E-Print Network [OSTI]

    Aguglia, D

    2014-01-01

    This paper presents the design and experimental validations of a system of three new high-voltage (HV) pulsedpower converters for the H? sources. The system requires three pulsed voltages (50, 40, and 25 kV to ground) at 2-Hz repetition rate, for 700 ?s of usable flat-top. The solution presents ripplefree output voltages and minimal stored energy to protect the ion source from the consequences of arc events. Experimental results on the final full-scale prototype are presented. In case of short-circuit events, the maximal energy delivered to the source is in the Joule range. HV flat-top stability of 1% is experimentally achieved with a simple Proportional-Integral- Derivative regulation and preliminary tuned H? source (e.g., radio frequency control, gas injection, and so forth). The system is running since more than a year with no power converter failures and damage to the source.

  5. Design of a High Power Continuous Source of Broadband Down-Converted Light

    E-Print Network [OSTI]

    Avi Pe'er; Yaron Silberberg; Barak Dayan; Asher A. Friesem

    2006-08-29

    We present the design and experimental proof of principle of a low threshold optical parametric oscillator (OPO) that continuously oscillates over a large bandwidth allowed by phase matching. The large oscillation bandwidth is achieved with a selective two-photon loss that suppresses the inherent mode competition, which tends to narrow the bandwidth in conventional OPOs. Our design performs pairwise mode-locking of many frequency pairs, in direct equivalence to passive mode-locking of ultrashort pulsed lasers. The ability to obtain high powers of continuous \\textit{and} broadband down-converted light enables the optimal exploitation of the correlations within the down-converted spectrum, thereby strongly affecting two-photon interactions even at classically high power levels, and opening new venues for applications such as two-photon spectroscopy and microscopy and optical spread spectrum communication.

  6. Efficient Power Converters for PV Arrays : Scalable Submodule Power Conversion for Utility-Scale Photovoltaics

    SciTech Connect (OSTI)

    2012-02-23

    Solar ADEPT Project: SolarBridge is developing a new power conversion technique to improve the energy output of PV power plants. This new technique is specifically aimed at large plants where many solar panels are connected together. SolarBridge is correcting for the inefficiencies that occur when two solar panels that encounter different amounts of sun are connected together. In most conventional PV system, the weakest panel limits the energy production of the entire system. That’s because all of the energy collected by the PV system feeds into a single collection point where a central inverter then converts it into useable energy for the grid. SolarBridge has found a more efficient and cost-effective way to convert solar energy, correcting these power differences before they reach the grid.

  7. Design of a high efficiency 30 kW boost composite converter

    SciTech Connect (OSTI)

    Kim, Hyeokjin; Chen, Hua; Maksimovic, Dragan; Erickson, Robert W.

    2015-09-20

    An experimental 30 kW boost composite converter is described in this paper. The composite converter architecture, which consists of a buck module, a boost module, and a dual active bridge module that operates as a DC transformer (DCX), leads to substantial reductions in losses at partial power points, and to significant improvements in weighted efficiency in applications that require wide variations in power and conversion ratio. A comprehensive loss model is developed, accounting for semiconductor conduction and switching losses, capacitor losses, as well as dc and ac losses in magnetic components. Based on the developed loss model, the module and system designs are optimized to maximize efficiency at a 50% power point. Experimental results for the 30 kW prototype demonstrate 98.5%peak efficiency, very high efficiency over wide ranges of power and voltage conversion ratios, as well as excellent agreements between model predictions and measured efficiency curves.

  8. FISSION TARGET DESIGN AND INTEGRATION OF NEUTRON CONVERTER FOR EURISOL-DS PROJECT

    E-Print Network [OSTI]

    J. Bermudez, O. Alyakrinskiy, M. Barbui, F. Negoita, L. Serbina, L.B. Tecchio, E. Udup

    A study of a new fission target for EURISOL-DS is presented with a detailed description of the target. Calculations of several configurations were done using Monte Carlo code FLUKA aimed to obtaining 1015 fissions/s on single target. In Eurisol, neutrons inducing the fission reactions are produced by a proton beam 1GeV-4mA interacting with a mercury converter. The target configuration was customized to gain fission yield from the large amount of low energy neutrons produced by the Hg converter. To this purpose, the fissile material is composed by discs of 238-Uranium carbide enriched with 15 g of 235-U. Studies of several geometries were done in order to define the shape and composition of uranium target, taking into account the mechanical and space constraints

  9. Analysis and Control of Period-Doubling Bifurcation in Buck Converters Using Harmonic Balance

    E-Print Network [OSTI]

    Chung-Chieh Fang; Eyad H. Abed

    2012-10-27

    Period doubling bifurcation in buck converters is studied by using the harmonic balance method. A simple dynamic model of a buck converter in continuous conduction mode under voltage mode or current mode control is derived. This model consists of the feedback connection of a linear system and a nonlinear one. An exact harmonic balance analysis is used to obtain a necessary and sufficient condition for a period doubling bifurcation to occur. If such a bifurcation occurs, the analysis also provides information on its exact location. Using the condition for bifurcation, a feedforward control is designed to eliminate the period doubling bifurcation. This results in a wider range of allowed source voltage, and also in improved line regulation.

  10. Propulsion system for a motor vehicle using a bidirectional energy converter

    DOE Patents [OSTI]

    Tamor, Michael Alan (Toledo, OH); Gale, Allan Roy (Livonia, MI)

    1999-01-01

    A motor vehicle propulsion system includes an electrical energy source and a traction motor coupled to receive electrical energy from the electrical energy source. The system also has a first bus provided electrical energy by the electrical energy source and a second bus of relatively lower voltage than the first bus. In addition, the system includes an electrically-driven source of reaction gas for the electrical energy source, the source of reaction gas coupled to receive electrical energy from the first bus. Also, the system has an electrical storage device coupled to the second bus for storing electrical energy at the lower voltage. The system also includes a bidirectional energy converter coupled to convert electrical energy from the first bus to the second bus and from the second bus to the first bus.

  11. Resonant behaviour of an oscillating wave energy converter in a channel

    E-Print Network [OSTI]

    E. Renzi; F. Dias

    2012-04-10

    A mathematical model is developed to study the behaviour of an oscillating wave energy converter in a channel. During recent laboratory tests in a wave tank, peaks in the hydrodynamic actions on the converter occurred at certain frequencies of the incident waves. This resonant mechanism is known to be generated by the transverse sloshing modes of the channel. Here the influence of the channel sloshing modes on the performance of the device is further investigated. Within the framework of a linear inviscid potential-flow theory, application of the Green theorem yields a hypersingular integral equation for the velocity potential in the fluid domain. The solution is found in terms of a fast-converging series of Chebyshev polynomials of the second kind. The physical behaviour of the system is then analysed, showing sensitivity of the resonant sloshing modes to the geometry of the device, that concurs in increasing the maximum efficiency. Analytical results are validated with available numerical and experimental data.

  12. Resonant behaviour of an oscillating wave energy converter in a channel

    E-Print Network [OSTI]

    Renzi, E

    2012-01-01

    A mathematical model is developed to study the behaviour of an oscillating wave energy converter in a channel. During recent laboratory tests in a wave tank, peaks in the hydrodynamic actions on the converter occurred at certain frequencies of the incident waves. This resonant mechanism is known to be generated by the transverse sloshing modes of the channel. Here the influence of the channel sloshing modes on the performance of the device is further investigated. Within the framework of a linear inviscid potential-flow theory, application of the Green theorem yields a hypersingular integral equation for the velocity potential in the fluid domain. The solution is found in terms of a fast-converging series of Chebyshev polynomials of the second kind. The physical behaviour of the system is then analysed, showing sensitivity of the resonant sloshing modes to the geometry of the device, that concurs in increasing the maximum efficiency. Analytical results are validated with available numerical and experimental d...

  13. Relations for a periodic array of flap-type wave energy converters

    E-Print Network [OSTI]

    Renzi, Emiliano

    2012-01-01

    This paper investigates the interaction of plane incident waves with a wave farm in the open ocean. The farm consists of a periodic array of large flap-type wave energy converters. A linear inviscid potential-flow model, already developed by the authors for a single flap in a channel, is considered. Asymptotic analysis of the wave field allows to obtain new expressions of the reflection, transmission and radiation coefficients of the system. It is shown that, unlike a line of heaving buoys, an array of flap-type converters is able to exploit resonance of the system transverse modes in order to attain high capture factor levels. Relations between the hydrodynamic coefficients are derived and applied for optimising the power output of the wave farm.

  14. High-efficiency, monolithic, multi-bandgap, tandem, photovoltaic energy converters

    DOE Patents [OSTI]

    Wanlass, Mark W

    2014-05-27

    A monolithic, multi-bandgap, tandem solar photovoltaic converter has at least one, and preferably at least two, subcells grown lattice-matched on a substrate with a bandgap in medium to high energy portions of the solar spectrum and at least one subcell grown lattice-mismatched to the substrate with a bandgap in the low energy portion of the solar spectrum, for example, about 1 eV.

  15. Processes for converting methane to higher molecular weight hydrocarbons via sulfur-containing intermediates

    SciTech Connect (OSTI)

    Han, S.; Palermo, R.E.

    1989-09-05

    This patent describes a process for converting methane to higher molecular weight hydrocarbons. The process comprising the steps of contacting methane with carbonyl sulfide in the presence of UV light under conditions sufficient to generate Ch/sub 3/SH; and contacting CH/sub 3/SH with a catalyst under conditions sufficient to produce hydrogen sulfide and a mixture of hydrocarbons having at least two carbon atoms.

  16. Identification of sorghum midge (Diptera: Cecidomyiidae): resistant lines among converted exotic sorghum 

    E-Print Network [OSTI]

    Ali, Ali El Badawi

    1986-01-01

    . Teetes (Chairman) Gary C. Peterson (Member) J eph C. Schaff r (Member) Fowden G. Maxwell (Head of Department) August 1986 ABSTRACT Identification of Sorghum Midge (D iptera: Cecidomy iidae) Resistant Lines Among Converted Exotic Sorghum (August... 1986) Ali E 1 Badawi Ali, B. S. , University of Khartoum, Khartoum, Sudan. Chairman of advisory cotmnittee: Dr. george L. Teetes. In an attempt to identify additional sorghum lines tant to so gh Sdg, t t ~ rtnt ~ ~so htd t (C q Stlott), field...

  17. Thermionic converter with differentially heated cesium-oxygen source and method of operation

    DOE Patents [OSTI]

    Rasor, Ned S. (Cupertino, CA); Riley, David R. (West Newton, PA); Murray, Christopher S. (Bethel Park, PA); Geller, Clint B. (Pittsburgh, PA)

    2000-01-01

    A thermionic converter having an emitter, a collector, and a source of cesium vapor is provided wherein the source of cesium vapor is differentially heated so that said source has a hotter end and a cooler end, with cesium vapor evaporating from said hotter end into the space between the emitter and the collector and with cesium vapor condensing at said cooler end. The condensed cesium vapor migrates through a porous element from the cooler end to the hotter end.

  18. Converting among fractions, decimals, and percents: an exploration of representational usage by middle school teachers 

    E-Print Network [OSTI]

    Muzheve, Michael Tapfuma

    2009-05-15

    , Robert M. Capraro Committee Members, Mary M. Capraro Gerald Kulm J. Maurice Rojas Radhika Viruru Head of Department, Dennie Smith August 2008 Major Subject: Curriculum and Instruction iii ABSTRACT Converting among Fractions... ACKNOWLEDGEMENTS I would like to thank my committee chair, Dr. R. M. Capraro, and my committee members, Dr. M. M. Capraro, Prof. Kulm, Dr. Rojas, and Dr. Viruru, for their guidance and support throughout the course of this research. This research would never...

  19. Efficiency of Switched-inductor DCDC Converter ICs across Process Technologies

    E-Print Network [OSTI]

    Rincon-Mora, Gabriel A.

    . For that purpose, switches (SI and SEN in Fig. 1a) energize and (SO and SDE in Fig. 1b) de-energize an inductor LXO) to lower iL and steer energy to vO. In buck converters, when vO is always below VIN, LX can energize than VIN, LX can de-energize directly from VIN, so SI and SDE are often absent in boost implementations

  20. 1 ADS1210, 1211 24-Bit ANALOG-TO-DIGITAL CONVERTER

    E-Print Network [OSTI]

    Hochmuth, Olaff

    ® 1 ADS1210, 1211 ® ADS1210 ADS1211 24-Bit ANALOG-TO-DIGITAL CONVERTER FEATURES q DELTA-SIGMA A/D-OFF FREQUENCY UP TO 15.6kHz q INTERNAL/EXTERNAL REFERENCE q ON CHIP SELF-CALIBRATION q ADS1211 INCLUDES 4 CHANNEL MUX DESCRIPTION The ADS1210 and ADS1211 are precision, wide dynamic range, delta-sigma analog