A new optimized ZV-ZCS non-isolated high-gain boost converter for renewable energy systems

This paper proposes a novel zero-voltage zero-current transition (ZV-ZCT) DC/DC high gain coupled inductor based boost converter for applications in renewable energy systems. It employs an auxiliary resonant network to soft-switch transition of semiconductor switches and soft-recovery of power diodes over wide input voltage and output power range of the converter with high efficiency. The auxiliary cell of the proposed converter has negligible impact on the converter’s overall dynamics and it doesn’t contribute any extra current stress to the semiconductor switches compared to classical hard switched boost converters. A thorough theoretical analysis of each operating mode has been presented together with the converter’s steady-state performance. The mathematical equations illustrating the dynamic behaviour of the converter have been used to design the auxiliary cell components. The circulating current loss has been minimized and simultaneously soft-switched operation of the converter is maintained through optimal selection of auxiliary cell components. Additionally, a power loss study and the proposed converter’s advantages over existing traditional converters are discussed. The converter’s soft-switching behaviour is established by hardware testing on a 400 W, 100 kHz prototype model. The theoretically predicted behaviour of the converter has been well corroborated by experimental observations.