High gain interleaved DC-DC converter with ripple-free input current and low device stress

A non-isolated DC-DC converter which yields high voltage gain and suitable for photovoltaic (PV) applications is described in this research article. The high gain converter proposed in this paper is synthesised by combining several voltage gain extension techniques viz. coupled inductors, voltage-lift capacitor, and diode-capacitor multiplier (DCM) cells. Since the input stage is interleaved, and the switches are operated complimentarily, the source current ripple is nullified and switch current rating is minimised. Due to the hybrid voltage gain extension techniques adopted while synthesising the converter, the voltage stress on the switches is only 10.5% of the output voltage. To validate the proposed concept, experimental results are obtained from 18 V-380 V, 150W prototype converter which is operated at 50 kHz. The proposed converter yields a voltage gain of 21.11 at 92.83% efficiency under full-load condition. During closed-loop operation, the proposed converter quickly settles down to its nominal output voltage of 380 V when the input voltage and load current values are subjected to step variations. The superior features of the proposed converter are highlighted by comparing it with similar and recent state-of-the art high gain converters.