Design and implementation of a novel non-isolated DC-DC converter with high voltage gain and low voltage stress

In this paper, a non-isolated high step-up DC-DC converter with an interleaved structure is presented that is suitable for photovoltaic energy conversion systems. In the proposed topology, coupled inductors and the switched capacitor cells have been used to increase the output voltage. Achieving this purpose is in a situation where no extreme duty cycle or high turns ratio will be required. Due to the use of the 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, selecting the low-voltage rated switches and small Rds (On) reduces the conduction loss. Other advantages of the proposed converter include providing the soft-switching conditions for the power switches and alleviating the reverse recovery problem. 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 the proposed converter. The experimental results, using prototype 350 W, 18 V input, and 400 V output, verify the effective performance of the proposed converter.