Low Switching Loss Non-isolated DC-DC Buck-Boost Converter with ZCS Characteristics

This paper presents a low switching loss non-isolated DC-DC buck-boost converter with zero current switching characteristics. The proposed circuit uses the quasi-resonance method for both buck and boost operations with controlled complexity of auxiliary circuit. Both theoretical analysis and simulink simulations verify the zero current switching characteristics under PWM working state. Results show that in the buck operation, switching loss accounts for less than 0.1° of the total power; in the boost operation, switching loss accounts for 1.87°. In addition, simulated voltage and current waveforms of critical parameters are in good agreement with theoretical predictions. The performance of the proposed circuit is conducive for achieving smaller and highly efficient DC-DC converters.