Neutral-point voltage waveform control method for mitigating the low-frequency ripple current in E-capless full-bridge inverter

Ripple current at twice the output frequency exists at dc side in single phase inverter due to the instantaneous power imbalance between input and output power. Neutral-point voltage waveform control method is proposed in this paper to eliminate the ripple current in E-capless full-bridge inverter. With the proposed method, the pulsation power is controlled to only flow through ac capacitors and the load, so that the dc source just supplies the average dc output power. Theoretical analysis, simulation and experiment results validated the proposed method.