Fuzzy control-based modular multilevel converter voltage equalizing method

Provided is a fuzzy control-based modular multilevel converter voltage equalizing method. According to the invention, numbers of modules put into the period are calculated according to a converter control and protection system; a valve control system calculates the cut modules put in the former period, calculates numbers which should be put into/cut and alternated in this period according to the bridge arm current direction and bridge current size of this period, and calculates numbers of modules which should be alternated according to the bridge arm current value and the subordinating degree function in the bridge arm current intra-area, thereby adjusting numbers of modules which should be alternated in real time and performing voltage equalizing control for a modular multilevel converter.