Neutral beam injection (NBI) is one of the most effective ways to heat plasma in tokomak. In order to construct and promote the mega watt level neutral beam injector on HL-2A tokomak, the power supplies and control sequence technology for the high beam current of ion source power are developed, including arc discharge, beam extraction and auxiliary power supplies, etc. Some important technologies such as digital signal processor control, current fast-shifting, IGBT in series modulator, high-frequency switched-mode power supply, core snubber, in...