High efficiency resonant dc/dc converter utilizing a resistance compression network

Abstract

This paper presents a new topology for a high efficiency dc/dc resonant power converter that utilizes a resistance compression network to provide simultaneous zero voltage switching and near zero current switching across a wide range of input voltage, output voltage and power levels. The resistance compression network (RCN) maintains desired current waveforms over a wide range of voltage operating conditions. The use of on/off control in conjunction with narrowband frequency control enables high efficiency to be maintained across a wide range of power levels. The converter implementation provides galvanic isolation and enables large (greater than 1∶10) voltage conversion ratios, making the system suitable for large step-up conversion in applications such as distributed photovoltaic converters. Experimental results from a 200 W prototype operating at 500 kHz show that over 95% efficiency is maintained across an input voltage range of 25 V to 40 V with an output voltage of 400 V. It is also shown that the converter operates very efficiently over a wide output voltage range of 250 V to 400 V, and a wide output power range of 20 W to 200 W. These experimental results demonstrate the effectiveness of the proposed design.