VOLTAGE BALANCE CONTROL METHOD FOR FLYING-CAPACITOR MULTILEVEL CONVERTER

摘要

A voltage balance control method for a flying-capacitor multilevel converter (1) is provided. If the amplitude of the resultant current of the inductor currents from a plurality of output inductors (Lf) is lower than or equal to a threshold current value, the flowing direction of the inductor current of at least one flying-capacitor multilevel branch circuit (10) is controlled to be changed. Consequently, the problem of erroneously judging the current direction is avoided. Moreover, when the inductor current is low, the voltage of the flying capacitor (C1, C2) is correspondingly controlled. Consequently, the voltage balance of the flying capacitor (C1, C2) of the flying-capacitor multilevel converter (1) can be achieved more easily.