A commom-ground enhanced-gain buck/boost converter with continuous currents,low voltage stress and reduced switches
The boost capability of conventional Buck/Boost converter is weak and the power switches suffer from high voltage stress(equals the voltage at the high-voltage side(HVS)),reducing the conversion efficiency.Further,since the HVS current pulsates greatly,large capacity capacitors are required to meet the requirements of current ripple,decreasing the system reliability.Therefore,this paper proposes an improved Buck/Boost converter.By introducing one switch,one inductor and two capacitors into the conventional topology,the proposed converter has continuous input and output current,which greatly reduces the current stress of HVS filter capacitor.The voltage gain in Boost mode is increased to(2-D1)/(1-D1),and all switches have the same low voltage stress,which equals the difference between the voltages at low-voltage side(LVS)and HVS,so it has higher conversion efficiency.The operation principle,steady-state characteristics,dynamic model and control strategy are analyzed in detail.Its feasibility is verified on a 100 W/120 kHz prototype.The experimental results demonstrate an enhanced efficiency performance over wide operating operations with a maximum efficiency of 95.6%.
bidirectional DC-DC convertervoltage stresscurrent stressvoltage gain
万方数据
维普
