Fully Soft-Switched High Voltage Gain Quasi-Z-Source Converter With Continuous Input Current and Low Switch Voltage Stress

Abstract

In this article, a unique high voltage gain converter based on the quasi-Z-source structure is introduced. By integrating the basic structure and a new auxiliary circuit comprising the coupled inductors (CIs), switched capacitors, and active clamp method, several essential specifications are achieved. In the proposed converter, fully soft switching operation is established, capacitive turn-on losses are eliminated, and all diodes reverse recovery problem is solved. This converter achieves high voltage gain and low switch voltage stress at low CIs turns ratio, which consequence in lesser copper losses and a smaller magnetic core. Absorbing and recycling the leakage inductance energy, continuous input current with low ripple, and common ground between the source and load are the converter advantages. Possession of all mentioned features simultaneously has made the proposed converter superior to similar state of the art converters. The proposed structure is studied in detail, and comprehensively compared with the counterpart converters. A 200-W laboratory prototype is realized, which confirms the converter achieved advantages.