A Novel Voltage Balance Control Strategy of AC-DC-AC Converter

A general problem in the double PWM converter is the voltage unbalance of the dc-link capacitors. This unbalance distorts the waveforms of the output voltage and current. Furthermore, it will lead to instability of the inverter system. Based on the analysis for the unbalance problem, a novel feedback control strategy of DC capacitor voltage deviation is proposed in this paper. The method does not add extra circuit. Build an simulation model of AC-DC-AC converter, the results show that control strategy is correct.