TRANSP-based closed-loop simulations of current profile optimal regulation in NSTX-Upgrade

doi:10.1016/j.fusengdes.2019.01.021

This content will become publicly available on February 19, 2020

Title: TRANSP-based closed-loop simulations of current profile optimal regulation in NSTX-Upgrade

Full Record
Other Related Research

Abstract

Active control of the toroidal current density profile is critical for the upgraded National Spherical Torus eXperiment device (NSTX-U) to maintain operation at the desired high-performance, MHD-stable, plasma regime. Initial efforts towards current density profile control have led to the development of a control-oriented, physics-based, plasma-response model, which combines the magnetic diffusion equation with empirical correlations for the kinetic profiles and the non-inductive current sources. The developed control-oriented model has been successfully tailored to the NSTX-U geometry and actuators. Moreover, a series of efforts have been made towards the design of model-based controllers, including a linear-quadratic-integral optimal control strategy that can regulate the current density profile around a prescribed target profile while rejecting disturbances. In this work, the tracking performance of the proposed current-profile optimal controller is tested in numerical simulations based on the physics-oriented code TRANSP. Furthermore, these high-fidelity closed-loop simulations, which are a critical step before experimental implementation and testing, are enabled by a flexible framework recently developed to perform feedback control design and simulation in TRANSP.

Authors:

Ilhan, Zeki O. ^[1]; Boyer, Mark D. ^[2];

^[1]

Lehigh Univ., Bethlehem, PA (United States)
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)

Publication Date:: 2019-02-19

Research Org.:: Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)

Sponsoring Org.:: USDOE

OSTI Identifier:: 1503680

Grant/Contract Number:: AC02-09CH11466

Resource Type:: Accepted Manuscript

Journal Name:: Fusion Engineering and Design

Additional Journal Information:: Journal Name: Fusion Engineering and Design; Journal ID: ISSN 0920-3796

Publisher:: Elsevier

Country of Publication:: United States

Language:: English

Subject:: 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; Plasma control; Current profile control; Model-based control; Optimal control; TRANSP-based simulation

Citation Formats


                    Ilhan, Zeki O., Boyer, Mark D., and Schuster, Eugenio. TRANSP-based closed-loop simulations of current profile optimal regulation in NSTX-Upgrade.  United States: N. p., 2019. 
        Web.  doi:10.1016/j.fusengdes.2019.01.021.

Copy to clipboard


                    Ilhan, Zeki O., Boyer, Mark D., & Schuster, Eugenio. TRANSP-based closed-loop simulations of current profile optimal regulation in NSTX-Upgrade.  United States.  doi:10.1016/j.fusengdes.2019.01.021.

Copy to clipboard


                    Ilhan, Zeki O., Boyer, Mark D., and Schuster, Eugenio. Tue .  
        "TRANSP-based closed-loop simulations of current profile optimal regulation in NSTX-Upgrade".  United States.  doi:10.1016/j.fusengdes.2019.01.021.

Copy to clipboard


                    
@article{osti_1503680,

  title        = {TRANSP-based closed-loop simulations of current profile optimal regulation in NSTX-Upgrade},

  author       = {Ilhan, Zeki O. and Boyer, Mark D. and Schuster, Eugenio},

  abstractNote = {Active control of the toroidal current density profile is critical for the upgraded National Spherical Torus eXperiment device (NSTX-U) to maintain operation at the desired high-performance, MHD-stable, plasma regime. Initial efforts towards current density profile control have led to the development of a control-oriented, physics-based, plasma-response model, which combines the magnetic diffusion equation with empirical correlations for the kinetic profiles and the non-inductive current sources. The developed control-oriented model has been successfully tailored to the NSTX-U geometry and actuators. Moreover, a series of efforts have been made towards the design of model-based controllers, including a linear-quadratic-integral optimal control strategy that can regulate the current density profile around a prescribed target profile while rejecting disturbances. In this work, the tracking performance of the proposed current-profile optimal controller is tested in numerical simulations based on the physics-oriented code TRANSP. Furthermore, these high-fidelity closed-loop simulations, which are a critical step before experimental implementation and testing, are enabled by a flexible framework recently developed to perform feedback control design and simulation in TRANSP.},

  doi          = {10.1016/j.fusengdes.2019.01.021},

  journal      = {Fusion Engineering and Design},

  number       = ,

  volume       = ,

  place        = {United States},

  year         = {2019},

  month        = {2}

}

Copy to clipboard

Journal Article:

Free Publicly Available Full Text

This content will become publicly available on February 19, 2020

Publisher's Version of Record

DOI: 10.1016/j.fusengdes.2019.01.021

Other availability

Search WorldCat to find libraries that may hold this journal

Save / Share:

Export Metadata

Save to My Library

Similar Records in DOE PAGES and OSTI.GOV collections:

Physics-based control-oriented modeling of the current density profile evolution in NSTX-Upgrade

Journal Article Ilhan, Zeki O. ; Barton, Justin E. ; Schuster, Eugenio ; ... - Fusion Engineering and Design

Active control of the toroidal current density profile is among those plasma control milestones that the National Spherical Torus eXperiment-Upgrade (NSTX-U) program must achieve to realize its next-step operational goals. Motivated by the coupled, nonlinear, multivariable, distributed-parameter plasma dynamics, the first step towards control design is the development of a physics-based, control-oriented model for the current profile evolution in response to non-inductive current drives and heating systems. The evolution of the toroidal current density profile is closely related to the evolution of the poloidal magnetic flux profile, whose dynamics is modeled by a nonlinear partial differential equation (PDE) referred tomore »« less
DOI: 10.1016/j.fusengdes.2017.04.028

Full Text Available
Central safety factor and β _N control on NSTX-U via beam power and plasma boundary shape modification, using TRANSP for closed loop simulations

Journal Article Boyer, M. D. ; Andre, R. ; Gates, D. A. ; ... - Nuclear Fusion

The high-performance operational goals of NSTX-U will require development of advanced feedback control algorithms, including control of ßN and the safety factor profile. In this work, a novel approach to simultaneously controlling ßN and the value of the safety factor on the magnetic axis, q0, through manipulation of the plasma boundary shape and total beam power, is proposed. Simulations of the proposed scheme show promising results and motivate future experimental implementation and eventual integration into a more complex current profile control scheme planned to include actuation of individual beam powers, density, and loop voltage. As part of this work, amore »« less
DOI: 10.1088/0029-5515/55/5/053033

Full Text Available
Central safety factor and β _N control on NSTX-U via beam power and plasma boundary shape modification, using TRANSP for closed loop simulations

Journal Article Boyer, M. D. ; Andre, R. ; Gates, D. A. ; ... - Nuclear Fusion
Cited by 7
DOI: 10.1088/0029-5515/55/5/053033
Feedback control design for non-inductively sustained scenarios in NSTX-U using TRANSP

Journal Article Boyer, M. D. ; Andre, R. G. ; Gates, D. A. ; ... - Nuclear Fusion

This paper examines a method for real-time control of non-inductively sustained scenarios in NSTX-U by using TRANSP, a time-dependent integrated modeling code for prediction and interpretive analysis of tokamak experimental data, as a simulator. The actuators considered for control in this work are the six neutral beam sources and the plasma boundary shape. To understand the response of the plasma current, stored energy, and central safety factor to these actuators and to enable systematic design of control algorithms, simulations were run in which the actuators were modulated and a linearized dynamic response model was generated. A multi-variable model-based control schememore »« less
Cited by 3
DOI: 10.1088/1741-4326/aa68e9

Full Text Available
Dynamic analysis of concentrated solar supercritical CO2-based power generation closed-loop cycle

Journal Article Osorio, Julian D. ; Hovsapian, Rob ; Ordonez, Juan C. - Applied Thermal Engineering

Here, the dynamic behavior of a concentrated solar power (CSP) supercritical CO ₂ cycle is studied under different seasonal conditions. The system analyzed is composed of a central receiver, hot and cold thermal energy storage units, a heat exchanger, a recuperator, and multi-stage compression-expansion subsystems with intercoolers and reheaters between compressors and turbines respectively. Energy models for each component of the system are developed in order to optimize operating and design parameters such as mass flow rate, intermediate pressures and the effective area of the recuperator to lead to maximum efficiency. Our results show that the parametric optimization leads themore »« less
Cited by 12
DOI: 10.1016/j.applthermaleng.2015.10.039

Full Text Available

Similar Records