A Two-Phase Interleaved High-Voltage Gain DC-DC Converter with Coupled Inductor and Built-in Transformer for Photovoltaic Applications

This paper presents a two-phase interleaved high-voltage gain DC-DC converter for photovoltaic (PV) energy harvesting. Utilizing double two-winding coupled inductors (CIs) and a two-winding built-in transformer (BIT) with switched-capacitor (SC) cells, the proposed converter achieves higher voltage gains than the similar converters in the previous studies. In addition, a continuous input current with the reduced ripple and low current stresses on the components are obtained due to the interleaved configuration of the converter. Furthermore, thanks to the reduced voltage stresses of the switches, low-voltage-rated MOSFETs with low RDs(on) are selected, which helps to reduce conduction losses. Moreover, a resistor-capacitor-diode (RCD) snubber is considered to absorb the energy of the leakage inductances of the CIs. Also, the reverse-recovery problem of the diodes is solved by the leakage inductances that provide zero-current switching (ZCS) turn-off for the diodes. The operating modes and steady-state analysis of the proposed converter are presented. In addition, a performance comparison is carried out, and a 200 W converter with a voltage gain of 25 and output voltage of 400 V is simulated in PLECS Blockset to prove the effectiveness and validity of the proposed converter.