Analysis of A Transformerless Single Switch High Gain DC–DC Converter for Renewable Energy Systems

A new transformerless single switch high gain dc–dc converter for renewable energy systems is proposed in this paper. The proposed converter solves two main problems: the low voltage produced by Photovoltaic (PV) solar panels and the discontinuous input current caused by the switching power supplies by stepping up the voltage of the PV panel and providing a continuous input current, respectively. The proposed converter is derived by adding a switched capacitor/inductor cell and a voltage multiplier stage to the traditional boost converter. The advantages of the converter are: high voltage conversion ratio, reduced voltage stress on the active switch and diodes, reduced gate driver requirements due to using only one switch and continuous input current to increase the life time of the solar PV panel. A detailed analysis of the operating principal in the continuous conduction mode, boundary conduction mode, discontinuous conduction mode, design consideration, nonideality of the converter is discussed. A laboratory prototype is built to verify the performance of the converter. The prototype is tested with different output powers (50–150 W) with an input voltage of 20 V and a duty cycle of 50%. The proposed converter succeeds in stepping the 20 V up to 200 V while providing a continuous input current at a 96% efficiency when the output load draws 100 W.