This paper presents a hybrid modulation method for single phase full bridge critical conduction mode (CRM) inverter aimed at improving the reactive power capability. The conventional unipolar modulation method causes a current distortion issue under non-unity power factor operation and faces an extremely high switching frequency problem at line current i_ac zero-crossing point. The proposed approach combines the benefits of unipolar modulation and bipolar modulation and resolves the current distortion problem. The discontinuous current mode (DCM) modulation is applied during i_ac zero-crossing area to eliminate the high switching frequency problem. The efficacy of the proposed modulation method is validated through both simulation and hardware experimentation.
