A Novel ZVS High-Step-Up Converter With Built-In Transformer Voltage Multiplier Cell

This article proposes a novel interleaved high-step-up dc–dc converter with zero voltage switching (ZVS). Through a built-in transformer voltage multiplier cell (VMC) the high voltage conversion ratio is achieved without the narrow duty. By applying active clamp scheme, all of the power
MOSFET
s are switched with ZVS which minimizes the switching losses of the proposed converter. Besides the voltage stress across the switches is decreased and can be controlled by the built-in transformer turns ratio enabling utilization of low
on
-state resistance and low forward voltage drop semiconductors. Due to the interleaved structure, the input current ripple is minimized and the thermal stress is shared between the phases. Meanwhile, the charge balance of the capacitors give rise to equal current sharing performance for the two input inductors. All of these factors reduce the power losses and improves the performance of the proposed converter. Finally, in order to verify the operation of the proposed converter, a 35-V input voltage to 500-V output voltage prototype with the rated power of 1 kW is fabricated and tested in the laboratory.