Exploration of voltage mode of the new fast control power supply for EAST

Aiming at the requirements of large current and fast response for the fast control power supply for EAST, the second generation supply could apply voltage control mode to achieve the maximum of current rising rate, while active feedback power of plasma's vertical displacement retained current control mode, which was used in the first generation of fast control power supply for EAST. To solve the problem of overvoltage protection caused directly by the reverse energy produced by the frequent overcurrent protection when the power supply outputs high voltage, current limiting protection was applied. Experimental results prove that voltage mode can greatly improve the ability of power supply to restrain plasma's vertical unstable displacement. (authors)