DocumentCode :
574822
Title :
First-principles model-based robust control of the current profile evolution in the DIII-D tokamak
Author :
Barton, Justin E. ; Boyer, Mark D. ; Wenyu Shi ; Schuster, Eugenio ; Luce, Tim C. ; Ferron, John R. ; Walker, Michael L. ; Humphreys, David A. ; Penaflor, B.G. ; Johnson, R.D.
Author_Institution :
Dept. of Mech. Eng. & Mech., Lehigh Univ., Bethlehem, PA, USA
fYear :
2012
fDate :
27-29 June 2012
Firstpage :
2134
Lastpage :
2140
Abstract :
Setting up a suitable toroidal current profile in a fusion tokamak reactor is vital to the eventual realization of a commercial nuclear fusion power plant. Creating the desired current profile during the ramp-up and early flat-top phases of the plasma discharge and then actively maintaining this target profile for the remainder of the discharge is the goal at the DIII-D tokamak. The evolution of the toroidal current profile in toka-maks is related to the evolution of the poloidal magnetic flux profile, which is modeled by the magnetic diffusion equation. A simplified first-principles-driven, nonlinear, dynamic, control-oriented, partial differential equation model of the poloidal flux profile evolution is obtained by combining the magnetic diffusion equation with empirical correlations obtained from experimental data at DIII-D and is used to synthesize a robust H feedback controller to track a desired reference trajectory of the poloidal magnetic flux gradient profile. We employ a singular value decomposition of the static gain matrix of the plant model to identify the most relevant channels which we control with the feedback controller. A framework for real-time feedforward + feedback control was implemented in the DIII-D Plasma Control System and experimental results in the DIII-D tokamak are presented to illustrate the capabilities of the feedback controller. These experiments mark the first time ever a first-principles-driven model-based magnetic profile controller was successfully implemented and tested in a tokamak device.
Keywords :
H control; Tokamak devices; feedback; matrix algebra; robust control; singular value decomposition; DIII-D plasma control system; DIII-D tokamak device; current profile evolution; first principles model based robust control; fusion tokamak reactor; magnetic diffusion equation; model based magnetic profile controller; nuclear fusion power plant; partial differential equation model; plasma discharge; poloidal flux profile evolution; poloidal magnetic flux gradient profile; poloidal magnetic flux profile; reference trajectory; robust H infinity feedback controller; singular value decomposition; static gain matrix; toroidal current profile; Adaptive control; Feedforward neural networks; Mathematical model; Steady-state; Tokamaks; Toroidal magnetic fields;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
American Control Conference (ACC), 2012
Conference_Location :
Montreal, QC
ISSN :
0743-1619
Print_ISBN :
978-1-4577-1095-7
Electronic_ISBN :
0743-1619
Type :
conf
DOI :
10.1109/ACC.2012.6315491
Filename :
6315491
Link To Document :
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