Single-Phase Common-Ground Dual-Buck Inverters With No Leakage Current

This article presents two unique common-ground high-reliability dual-buck single-phase inverters suitable for photovoltaic applications. The proposed inverters directly connect the source and load, excluding the inverters from leakage current. The first proposed inverter works only for unity power factor operation. In its operation, the inverter employs only one high-frequency switching device, thus presenting low switching losses and improving overall efficiency. The second proposed inverter works for any power factor. In its operation, the inverter utilizes two high-frequency switching devices, resulting in minimal switching losses. The proposed inverters have no reverse recovery loss and related issues since the body diodes of the power metal-oxide-semiconductor field-effect transistors are disabled. The proposed inverters are devoid of short-circuit issues, resulting in high reliability. The detailed modes and operating principles together with the pulsewidth-modulated strategy for the proposed inverters are described. Experiments were carried out on 0.6-kW laboratory prototypes, operating at a switching frequency of 50 kHz and an output voltage of 110 V-rms. The experimental results verified the robustness of the proposed inverters.