Novel bidirectional single-phase single-stage isolated AC-DC converter with PFC for charging of electric vehicles

This thesis proposes a novel bidirectional single-phase single-stage AC-DC converter for Electric Vehicle (EV) charging application. AC side of the proposed converter consists of a current-fed half bridge converter. This is connected to the full-bridge converter on secondary side of a high-frequency (HF) transformer. Power Factor Correction (PFC) can be attained by regulating the current at the input of the ac side. In addition to that, the proposed converter achieves Zero Current Switching (ZCS) of primary side switches and zero current turn-on for secondary side devices throughout the operation without any additional components. Furthermore, a novel modulation technique and control algorithm is implemented. This ensures soft-switching throughout the operation range of the converter during bidirectional power flow. Design equations are derived to help suitable selection of components for a given specification. The proposed converter is designed for 1.5KW capacity for EV charging application. The simulation and experimental results are presented.