A Four Switch Common Ground-based Single Phase Current-fed Boost Inverter

Single-stage boost inverters are gaining more attention in photovoltaic (PV) applications. These inverters utilize a shoot-through state to deliver power at the rated voltage. However, most of them require at least five controlled active switches and more than two passive reactive elements in the intermediate network. Also, the absence of galvanic isolation introduces a high-frequency common mode voltage, leading to a circulating current. To address these limitations, a compact four-switch common ground-based single-phase current-fed boost inverter is proposed in this paper. It utilizes four controlled active switches, two diodes, one inductor, and one capacitor. The common ground configuration of the inverter effectively eliminates the circulating current. The utilization of a single capacitor in the intermediate network, as well as the symmetrical operation of the inverter for both half cycles of AC output, reduces the DC offset. Further, the continuous input current and step-up nature of the inverter make it appropriate for PV applications. The design, operational modes, pulse width modulation (PWM) control strategy, and closed-loop control of the proposed inverter are presented. The steady-state and dynamic analyses are validated using MATLAB Simulink, while the thermal and power loss analyses are performed by PLECS software. Finally, the simulation results and performance of the inverter are verified with experimental results.