Robust control of the current profile and plasma energy in EAST
Abstract
Integrated control of the toroidal current density profile, or alternatively the q-profile, and plasma stored energy is essential to achieve advanced plasma scenarios characterized by high plasma confinement, magnetohydrodynamics stability, and noninductively driven plasma current. The q-profile evolution is closely related to the evolution of the poloidal magnetic flux profile, whose dynamics is modeled by a nonlinear partial differential equation (PDE) referred to as the magnetic-flux diffusion equation (MDE). The MDE prediction depends heavily on the chosen models for the electron temperature, plasma resistivity, and non-inductive current drives. To aid control synthesis, control-oriented models for these plasma quantities are necessary to make the problem tractable. However, a relatively large deviation between the predictions by these control-oriented models and experimental data is not uncommon. For this reason, the electron temperature, plasma resistivity, and non-inductive current drives are modeled for control synthesis in this work as the product of an “uncertain” reference profile and a nonlinear function of the different auxiliary heating and current-drive (H&CD) source powers and the total plasma current. The uncertainties are quantified in such a way that the family of models arising from the modeling process is able to capture the q-profile and plasma stored energy dynamics frommore »
- Authors:
-
- Lehigh Univ., Bethlehem, PA (United States)
- Publication Date:
- Research Org.:
- Lehigh Univ., Bethlehem, PA (United States)
- Sponsoring Org.:
- USDOE Office of Science (SC), Fusion Energy Sciences (FES)
- OSTI Identifier:
- 1611441
- Alternate Identifier(s):
- OSTI ID: 1557895
- Grant/Contract Number:
- SC0010537
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Fusion Engineering and Design
- Additional Journal Information:
- Journal Volume: 146; Journal Issue: A; 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; plasma stored energy control; model-based control; robust control; EAST
Citation Formats
Wang, Hexiang, and Schuster, Eugenio. Robust control of the current profile and plasma energy in EAST. United States: N. p., 2019.
Web. doi:10.1016/j.fusengdes.2019.01.056.
Wang, Hexiang, & Schuster, Eugenio. Robust control of the current profile and plasma energy in EAST. United States. https://doi.org/10.1016/j.fusengdes.2019.01.056
Wang, Hexiang, and Schuster, Eugenio. Wed .
"Robust control of the current profile and plasma energy in EAST". United States. https://doi.org/10.1016/j.fusengdes.2019.01.056. https://www.osti.gov/servlets/purl/1611441.
@article{osti_1611441,
title = {Robust control of the current profile and plasma energy in EAST},
author = {Wang, Hexiang and Schuster, Eugenio},
abstractNote = {Integrated control of the toroidal current density profile, or alternatively the q-profile, and plasma stored energy is essential to achieve advanced plasma scenarios characterized by high plasma confinement, magnetohydrodynamics stability, and noninductively driven plasma current. The q-profile evolution is closely related to the evolution of the poloidal magnetic flux profile, whose dynamics is modeled by a nonlinear partial differential equation (PDE) referred to as the magnetic-flux diffusion equation (MDE). The MDE prediction depends heavily on the chosen models for the electron temperature, plasma resistivity, and non-inductive current drives. To aid control synthesis, control-oriented models for these plasma quantities are necessary to make the problem tractable. However, a relatively large deviation between the predictions by these control-oriented models and experimental data is not uncommon. For this reason, the electron temperature, plasma resistivity, and non-inductive current drives are modeled for control synthesis in this work as the product of an “uncertain” reference profile and a nonlinear function of the different auxiliary heating and current-drive (H&CD) source powers and the total plasma current. The uncertainties are quantified in such a way that the family of models arising from the modeling process is able to capture the q-profile and plasma stored energy dynamics from a typical EAST shot. A control-oriented nonlinear PDE model is developed by combining the MDE with the “uncertain” models for the electron temperature, plasma resistivity, and non-inductive current drives. This model is then rewritten into a control framework to design a controller that is robust against the modeled uncertainties. The resulting controller utilizes EAST's H&CD powers and total plasma current to regulate the q profile and plasma stored energy even when mismatches between modeled and actual dynamics are present. The effectiveness of the controller is demonstrated through nonlinear simulations.},
doi = {10.1016/j.fusengdes.2019.01.056},
journal = {Fusion Engineering and Design},
number = A,
volume = 146,
place = {United States},
year = {Wed Jan 23 00:00:00 EST 2019},
month = {Wed Jan 23 00:00:00 EST 2019}
}
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Works referenced in this record:
Toroidal current profile control during low confinement mode plasma discharges in DIII-D via first-principles-driven model-based robust control synthesis
journal, November 2012
- Barton, Justin E.; Boyer, Mark D.; Shi, Wenyu
- Nuclear Fusion, Vol. 52, Issue 12
Towards model-based current profile control at DIII-D
journal, October 2007
- Ou, Y.; Luce, T. C.; Schuster, E.
- Fusion Engineering and Design, Vol. 82, Issue 5-14
Control of the tokamak safety factor profile with time-varying constraints using MPC
journal, January 2015
- Maljaars, E.; Felici, F.; de Baar, M. R.
- Nuclear Fusion, Vol. 55, Issue 2
Neoclassical conductivity and bootstrap current formulas for general axisymmetric equilibria and arbitrary collisionality regime
journal, July 1999
- Sauter, O.; Angioni, C.; Lin-Liu, Y. R.
- Physics of Plasmas, Vol. 6, Issue 7
Receding-horizon optimal control of the current profile evolution during the ramp-up phase of a tokamak discharge
journal, January 2011
- Ou, Y.; Xu, C.; Schuster, E.
- Control Engineering Practice, Vol. 19, Issue 1
Physics-based control-oriented modeling and robust feedback control of the plasma safety factor profile and stored energy dynamics in ITER
journal, September 2015
- Barton, Justin E.; Besseghir, Karim; Lister, Jo
- Plasma Physics and Controlled Fusion, Vol. 57, Issue 11