A High-Efficiency DC/DC Converter for High-Voltage-Gain, High-Current Applications

A new class of high-voltage-gain dc-dc converters for high-efficiency and transformer-less dc-dc applications, where large voltage step-up ratios are required, is presented in this paper. The converter is derived from the hybrid integration of a switched-capacitor converter and a boost converter. It features high step-up voltage conversion ratio with a moderate duty cycle, nonpulsating input current, low-voltage stress on all of the switches, easy implementation of control and driving circuits, scalability for high-current high-power applications, and low cost due to reduced components via combination of a two-stage converter into a single-stage converter. Full soft-charging operation and minimal device voltage stresses are achieved under all operating conditions. Steady-state operations of the converter are comprehensively analyzed. A 300-W prototype of a 19-time converter achieving the peak efficiency of 96.1% is built. Both simulation and experimental results validating the theoretical analysis and operation of the converter are provided.