The power supply of Neutral Beam Injector (NBI) Suppressed grid is an integral part of the NBI power system. Its output voltage can be changed in the range of 1 to 5 kV with pulsed load based on the experimental desire, the rise time and the fall time of pulse are not more than 20μs. The project presented in the paper implement the high-voltage DC platform by the technology of phase-shifted PWM and series resonant converter, and then the vacuum tetrad is applied to modulate. The main circuit topology and control method are analyzed. The prelim...