A Novel Soft-Switched Quasi-Resonant Bidirectional DC/DC Converter for Electric Vehicle Application

In this paper, a novel high gain, non-isolated, coupled-inductor (CL) based, bidirectional DC/DC converter (CLBDC) is presented. In step-up mode, the CLBDC operates in quasi-resonance (QR) mode due to the leakage inductance (Lk) of the CL. QR operation offers several advantages, such as soft-switching conditions of boost switch turn-on (ZVS) and diodes turn-off (ZCS), which significantly reduce switching losses and increase the converter’s efficiency. The CLBDC benefits from a wide range of high voltage gain in both step-up and step-down modes due to the presence of the CL and boost capacitor. Furthermore, the CLBDC’s input current has a low ripple. These features make this converter useful for electric vehicle applications and two-way power flow. The operating principles and steady-state analysis are discussed for both boost and buck modes. To verify the CLBDC feasibility, simulations are performed in Simulink/MATLAB software. The simulation results prove the validity of the converter specifications well.