High Step-Up Interleaved Converter With Three-Winding Coupled Inductors and Voltage Multiplier Cells

Abstract

In this paper, a novel interleaved high step-up DC-DC converter with three-winding coupled inductors and voltage multiplier cells is proposed for renewable energy systems. The voltage-lift and voltage-stack methods are used to extend the voltage conversion ratio. The converter achieves high voltage gain without operating at extreme duty ratio. The voltage stress on the power switches is greatly lower than the output voltage. As a result, the low-voltage-rated MOSFETs with low conducting resistances can be employed to reduce the conduction losses. The diodes reverse-recovery problem can be alleviated by the leakage inductances of the coupled inductors. The input current ripple is reduced by the interleaved operation. The leakage energy of the coupled inductors is recycled such that the switch turn-off voltage spikes are avoided. The operating principles and performance analysis of the proposed converter are presented in detail. Finally, a 1000 W experimental prototype with 28 V input and 380 V output is built and tested. The experimental result are provided to validate the theoretical analysis and effectiveness of the proposed converter.