Non-isolated high gain DC–DC converter with low device stress and input current ripple

摘要

In this article, a novel DC-DC converter with high voltage gain capability is presented. The proposed converter is synthesised from (i) a basic two-phase interleaved boost converter (IBC) which uses coupled inductors (CIs) instead of discrete inductors and (ii) diode-capacitor multiplier (DCM) cells to achieve higher voltage conversion ratio. The outputs obtained from the interleaved and the DCM stages are judiciously cascaded with the outputs obtained from the secondary winding of the CIs to enhance the voltage gain. The input current is almost ripple free due to the adopted interleaving mechanism. As voltage gain is extended using CIs and DCMs, the voltage stress on the semiconductor devices is minimal and only a fraction (10.5%) of the output voltage. Experimental results obtained from the 18V/380V, 150W prototype converter, operating at a maximum efficiency of 94% under full-load condition, validate the proposed concept. Further, practical results obtained under closed-loop condition confirm that the converter yields a constant output of 380V DC which is suitable for microgrid application.