A Bridgless Stacked Switches-Based AC-DC Converter with Reduced Storage Capacitances and Low-Frequency Voltage Ripple for HV EV Systems

This paper presents a fully soft-switched single-stage stacked switches-based AC-DC converter with significantly reduced storage capacitances and low-frequency voltage ripple for High Voltage (HV) Electric Vehicle (EV) application. In the proposed converter, a front-end duty ratio closed-loop control system based on the input current equation provides a high-quality sinusoidal input current. Moreover, a dual feedback control loops in both the primary and secondary side of the converter are responsible to minimize the low-frequency DC-link and output voltage oscillations, eliminating the need for bulky DC-link and output storage capacitors and enhancing the reliability, lifetime, and cost-effectiveness of the converter. Moreover, the output voltage of the converter is regulated through a Variable Frequency (VF) control algorithm. The performance of the proposed converter is verified through a 1kW, 120V
rms
/800V
dc
, 150kHz proof-of-concept hardware prototype.