Synthesis and operation of an FFT-decoupled fixed-order RFP plasma control system based on identification data

Erik Olofsson (1) , Per Brunsell (1) , Emmanuel Witrant (2) , Jim R. Drake (3)

1 Alvfèn lab
2 GIPSA-SLR - GIPSA - Systèmes linéaires et robustesse
3 Fusion Plasma Physics [Stockholm]

Recent developments and applications of system identification methods for the reversed-field pinch (RFP) machine EXTRAP T2R have yielded plasma response parameters for decoupled dynamics. These datasets are the fundament for a real-time implementable fast fourier transform (FFT) decoupled discrete-time fixed-order strongly-stabilizing synthesis as described in this work. Robustness is assessed over the dataset by bootstrap calculation of the sensitivity transfer function worst-case H1-gain distribution. Output-tracking and magnetohydrodynamic (MHD) mode m = 1-tracking is considered in the same framework simply as two distinct weighted traces of a performance channel output-covariance matrix as derived from the closed-loop discrete-time Lyapunov equation. The behaviour of the resulting multivariable controller is investigated with dedicated T2R experiments.

Domaines: Physique des plasmas [physics.plasm-ph]; Plasmas; Automatique / Robotique

Erik Olofsson, Per Brunsell, Emmanuel Witrant, Jim R. Drake. Synthesis and operation of an FFT-decoupled fixed-order RFP plasma control system based on identification data. Plasma Physics and Controlled Fusion, 2010, 52 (10), pp.104005. ⟨10.1088/0741-3335/52/10/104005⟩. ⟨hal-00562139⟩