High Voltage Gain Switched-Z-Source Bidirectional DC-DC Converter

The DC-DC converters are the essential modules in electric vehicles, grid interface of renewable energy sources and DC power supplies. This paper presents a novel high gain bidirectional switched Z-source DC-DC converter. The proposed bidirectional converter utilizes a switched-capacitor concept with inductors for high voltage gain. The proposed bidirectional converter has high voltage conversion ratio over a wide duty cycle range in both the boost and buck modes of operation. It has common ground between input and output, and uses only 5 active switches and 4 passive elements with reduced switch voltage stress. The current drawn from the low voltage side input source is continuous with reduced ripple. The operating principle, circuit analysis, design, mathematical model and closed-loop operation of the proposed converter are presented. The proposed converter is verified through computer simulation and laboratory experiments. The simulation and experimental results are presented.