A Soft Switched Bidirectional DC-DC Converter for Energy Storage Systems

This paper presents an interfacing circuit which acts as a bidirectional dc dc converter between battery or ultra capacitor and DC bus with zero voltage transition (ZVT) auxiliary circuit in electric vehicle (EV), fuel cell electric vehicle (FCEV) and hybrid electric vehicle (HEV). The auxiliary circuit provides soft switching to the switching element and the circuit uses a simple PWM control. So, the energy conversion through the converter is highly efficient. The converter operates in ZVT Buck to charge ultracapacitor or battery and in ZVT Boost to discharge ultracapacitor or battery. The performance of the proposed converter was simulated using PSPICE software. The dynamic response of the converter with respect to abrupt load changes and operating mode change is shown through PSim simulation result. The results confirm aforementioned advantages and features of the proposed converter.