Implementation of a Non-Isolated, High Gain ZVS/ZCS DC- DC Converter

This paper presents implementations of a nonisolated, high voltage gain DC-DC converter. High voltage gain is achieved due to inclusion of resonance and transformer in the circuit. The performance of this converter is compared with two similar topologies namely coupled inductor-switched capacitor step-up converter and coupled inductor step-up converter. The proposed prototype is designed using a high frequency transformer providing both electrical and magnetic coupling, hence the converter is said to be non-isolated. The transformer provides hybrid switching technique which combines both conventional linear PWM and traditional resonant conversion, so that the converter achieves ZVS turn on of the switch and ZCS turn off of the diodes. The transformer transfers the inductive and capacitive energy simultaneously to increase the voltage gain of the converter and decreases the size of the magnetic component. Also switching losses of the proposed converter is reduced by incorporating the resonant mode, thereby increases the efficiency. The voltage stresses of all the devices are reduced. Keywords—High frequency transformer (HT), High voltage gain, Non-Isolated DC-DC converter, Zero voltage switching (ZVS), Zero current switching (ZCS).