Compact power supplies for tokamak heating

As extension of power transformers, efficient large-scale contactless power transfer between stationary and reference frames is a problem of world-wide importance, to such applications as electric vehicles, materials handling and plasma heating for fusion science. Tokamak is the common developed fusion device where heating is recognized as one of its key technologies for its future reactor roadmap. Snubber is often used as protection device in NBI system for Tokamak heating [1-3]. The present NBI generally use 50/60 Hz High Voltage (HV) Insulation Transformers to configure its dc power supply to offer the bias current to the snubber, which could use the full flux swing of the core from the negative saturation point to the positive one of its BH major loop. The snubber weight could then be decreased to its half by using the bias power supply. But this 50/60Hz HV insulation transformer is much heavier than High Frequency (HF) High Voltage (HV) Insulation system. The paper gives the requirement, design and test of this Compact Power Systems based on HF HV Zero Current Switching (ZCS) technologies for Experimental Advanced Superconducting Tokamak (EAST) NBI snubber as well as its potential for its compact HVDC power supply. Its new control strategy is also implemented with one macro pulse composed by the digital defined continuous micro pulses. Some experimental evaluations have been done to verify the analysis results, which have been extended to over 100s and could be used for detail engineering design of power supplies for EAST based on IGBT.