Research on Resonant Frequency Feedback Control Strategy of EAST Fishtail Divertor Magnet Coil Power Supply

Fishtail divertor (FTD), a new divertor concept, is a significant research object of EAST tokamak divertor system. Considering the requirement of sinusoidal current precision and stable output with variable frequency (10-3800Hz) and adjustable amplitude (0-5000A) in complex and arguable electromagnetic environment, a resonant frequency feedback control strategy is proposed for FTD magnet coil power supply. The equivalent mathematical model of the FTD coil PS and control process is set up. Through detailed theoretical analysis and simulation, the conclusion of performance optimization based on control strategy is obtained. At the work of frequency feedback control strategy, the power supply can promptly identify the resonant network frequency deviation caused by the interference of electromagnetic environment on the equivalent load characteristics within 1.5S, and actively correct the excitation voltage frequency, so as to ensure the accuracy of the FTD magnet coil current. Finally, the correctness of the design is verified through experimental tests.