Power balance modulation strategy for hybrid cascaded H-bridge multi-level inverter

Abstract Under the traditional hybrid modulation strategy, output powers of cascaded H-bridge inverter are not balanced between units. With a 13-level with DC side voltage ratio 1:1:1:3 (referred to as III-inverter in paper) research object, power equalization strategy based on carrier rotation is proposed. control which, inverters formed by superposition multiple basic waveforms. Firstly, adopted modulate so that high- and low-voltage units, respectively, operate low-frequency high-frequency states. Then, pulse sequence within 3/2 cycle made circulate among all units rotation. Finally, each contain waveforms, thus implementing balance Based simulation experiment, effectiveness verified, it shown under this waveform quality high, there no current backflow, can be cycles.