A Ripple-Free Input Current Quasi-Z-Source DC-DC Converter with High Voltage Gain and Soft-Switching Technology

A high-voltage-gain dc-dc converter with soft-switching and input-current-ripple-free is presented in this article. It achieves zero input current ripple by introducing an extra inductor, a winding coupling, and a capacitor to parallel at the input power supply. At the same time, all switches in the converter achieve ZVS-on, and all diodes achieve ZCS-off, which can reduce the losses of the switches and the diodes. The coupled-inductor with a smaller inductance value corresponds to a smaller copper loss and volume, thereby improving the efficiency of the presented circuit. Finally, a 100 kHz 200 W 38–380 V experimental prototype was designed, and the efficiency of the circuit at rated power was 95.1%. The experiments verify the correctness of theoretical research, indicating the feasibility of the presented circuit.