Contactors and fast-cut protection can not effectively protect power electronics in device when high-voltage power failure of chopper cascade speed control system. To this end

we designed the main circuit topology with electronic protection circuit

and analyzed the transient process of chopper cascade speed control system. Conventional chopper cascade speed control system with electronic protection circuits for high-voltage power failure conditions were tested on the simulated load test platforms. The experimental results show that the fault surge current of the chopper cascade speed control system is about 10 to 12 times of rated current

and the current of the chopper cascade speed control system with electronic protection circuits fault surge currents is about 2 to 3 times of rated current. The higher the limiting-resistance is

the lower the fault current will be. Theoretical value and actual measured values are basically the same and the relative error is less than 3%. It is verified that electronic protection circuits can effectively solve the problem of high-voltage power failure under active inverter structure and inverter subversion.