A high-efficiency single-phase bidirectional AC-DC converter with miniminized common mode voltages for battery energy storage systems

This paper presents a new high-efficiency single-phase bidirectional ac-dc converter with the application for battery energy storage systems. The proposed converter utilizes two split ac-coupled inductors that operate separately for positive and negative half grid cycles in both inversion and rectification operations. The circuit avoids the slow body diode reverse recovery issue of the high-voltage silicon MOSFETs, and thus allowing the use of the latest low R_ds(on) superjunction MOSFET and zero reverse recovery SiC diode devices to form the phase-leg for high-efficiency power conversion. The proposed converter works as an ac-switch transformerless inverter in inversion mode and bridgeless power factor corrector (PFC) in rectification mode with minimized common mode (CM) voltages. Experimental results demonstrate the high efficiency and minimized CM voltages of the proposed topology.