Interleaved DC–DC Converter with High-voltage Gain and High-efficiency for Photovoltaic System

A high voltage gain DC–DC converter used in Photovoltaic system applications is proposed in this paper. The proposed topology can convert the low voltage of a Photovoltaic system into an increasing voltage and in fact, provide a high voltage gain. For this purpose, a combination of the structure of the coupled inductors and a voltage multiplier cell is used. Voltage gain boosting occurs while no extreme duty cycle or high turns ratio is imposed on the system. Due to the use of interleaved structure and equal current division in two phases, the current ripple is reduced. Also, since the voltage stress of the switches is lower than the output voltage, by selecting the low-voltage rated switches and small Rds (On), consequently the conduction loss is reduced. Other advantages of the converter include the soft-switching conditions for the power switches and alleviating the problem of reverse recovery. Recycling of the leakage energy due to the presence of the coupled inductors and no need for the clamp circuits is an important feature of this converter. With a series of physical changes in the structural material of the converter, such as the core and the type of wire used in the inductors and how to twist on the core, the losses were reduced and the efficiency was increased. A 350 W, 22 V/400 V prototype was built and implemented to verify the performance of the proposed converter. Experimental results indicate the desired operation of the structure.