High boost ratio DC-DC converter with ripple-free input current

A high boost ratio non-isolated converter with a ripple-free input current is proposed, which combines a zero-ripple boost cell and a coupled inductor to achieve a high output voltage step-up. A passive snubber is utilised to suppress voltage spike of the switch caused by the resonance of the leakage inductance of the coupled inductor and the parasitic capacitance of the switch. Therefore, a low-voltage-rated metal oxide semiconductor field effect transistor (MOSFET) with low r_DS(ON) can be used to improve the efficiency of the converter. In addition, a ripple-free input current can be achieved, making the electromagnetic interference (EMI) filter simple. Experimental results of a 100 W (40 V/200 V) prototype are presented to verify the analysis results of the proposed converter.