Pre-study of grey prediction control for EAST vertical displacement control power supply

Abstract

The ability of magnetic confinement to plasma can be improved by elongating plasma cross-section in Tokamak device, but elongated plasma has potential instability in the vertical direction, so feedback control system is needed to restrain plasma vertical displacement. In Experimental Advanced Superconducting Tokamak (EAST for short), active feedback control power supply excites coils in vacuum, generates fast-changing magnetic field to inhibit vertical displacement of plasma. For improving the response performance of power supply, the grey prediction is combined with conventional PID control. The grey prediction GM(1,1) can amend PID parameter of controller online, and realize metabolic grey filtering and prediction of active feedback control signal. The prediction results were used in control operation in place of the measured value, which can shorten the delay time of sampling and controlling in power supply. The results of simulation and experiment of prototype show that the algorithm can realize ahead of adjustment and improve the performance of active feedback control response.