Coupled-Inductor-Based Buck-Boost Inverter with Leakage Current Suppression Capability

This article presents a novel transformer-less single-stage buck-boost inverter (SSBBI) utilizing coupled inductors and its dual-mode time-sharing control method. The leakage current can be completely suppressed by connecting the neutral of the electrolytic capacitors to the common ground of the power grid. Besides, only one MOSFET operates at high-frequency in Buck and Boost mode. As a result, in theory, high conversion efficiency can be guaranteed for the proposed inverter. Moreover, compared with conventional Aalborg inverters, the number of switches, diodes, and inductors is further reduced to reduce cost and increase power density. In addition, the operating principle based on equivalent circuits and the control strategy of the proposed inverter are given in this article. As a proof of concept, the simulation results based on PSIM of the proposed SSBBI with different input voltages and output powers and a 110 V power grid are provided.