Stability analysis and model-based control in EXTRAP-T2R with time-delay compensation

Abstract : In this paper, we investigate the stability problems and control issues that occur in a reversed-field pinch (RFP) device, EXTRAP-T2R (T2R), used for research in fusion plasma physics and general plasma (ionized gas) dynamics. The plant exhibits, among other things, magnetohydrodynamic instabilities known as resistive-wall modes (RWMs), growing on a time-scale set by a surrounding non-perfectly conducting shell.We propose a novel model that takes into account experimental constraints, such as the actuators dynamics and control latencies, which lead to a multivariable time-delay model of the system. The openloop field-error characteristics are estimated and a stability analysis of the resulting closed-loop delay differential equation (DDE) emphasizes the importance of the delay effects. We then design a structurally constrained optimal PID controller by direct eigenvalue optimization (DEO) of this DDE. The presented results are substantially based on and compared with experimental data.
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Contributor : Emmanuel Witrant <>
Submitted on : Friday, November 21, 2008 - 1:54:05 PM
Last modification on : Tuesday, June 4, 2019 - 11:08:06 AM
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  • HAL Id : hal-00329874, version 1


Erik Olofsson, Emmanuel Witrant, Corentin Briat, Silviu-Iulian Niculescu, Per Brunsell. Stability analysis and model-based control in EXTRAP-T2R with time-delay compensation. 47th IEEE Conference on Decision and Control, CDC 2008, Dec 2008, Cancun, Mexico. ⟨hal-00329874⟩



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