Application of Phase-Shift PWM in EAST Fast Control Power Supply

EAST (Experimental Advanced Superconducting Tokamak) fast control power supply is a large capacity single phase inverter power supply, which traces displacement signal of plasma, and excites four fast-control coils in vacuum chamber to produce magnetic field that realizes plasma stabilization in large elongate model. To meet the requirement of large current and fast response, multi-inverters in parallel is presented. The technique of carrier wave Phase-shift PWM is applied to decrease switching loss of IGBT, raise equal switch-frequency of converter and improve performance of output wave. The system design scheme and control method are introduced, and the analysis of harmonic and simulation are carried out. The validity of proposed scheme and control strategy were confirmed by experiments, the power supply system can supply large current and has ability of fast response.