High step-up ZVS dual switches converter with three-winding-coupled inductor

A novel transformerless DC/DC converter is proposed in this paper to meet the high step-up, high efficiency and high power requirements. In the proposed converter, the dual switches structure is introduced to reduced the voltage and current stress of the power switches; the active clamping technology is utilized to realize the ZVS switching of all the switches; all the windings are coupled to simplify the magnetic components, the three-winding-coupled inductor can achieve a relatively high voltage conversion with an appropriate turns ratio, moreover, the reverse-recovery problem of the diodes is partly solved due to the leakage inductor. Firstly, this paper analyze the operation principle of the converter; secondly the characteristics of the converter is discussed; then a design guidance is given, with the guidance, a 30V-input 400-V output 500W operation with 100kHz switching frequency topology is established in the lab to verify the correctness of the proposed converter.