Soft-Switching Mechanism for a High-Gain, Interleaved Hybrid Boost Converter

In this article, an auxiliary circuit-based soft-switching mechanism for a high-gain, nonisolated, four-phase interleaved hybrid boost converter is presented. The auxiliary circuit consists of only a single additional switch, four diodes, and a small auxiliary inductor, and ensures zero voltage transition (ZVT) of all four phases. Two variations of the ZVT circuit application are presented in this article, each having its own advantages and can be implemented without any significant modifications in the auxiliary circuit. The auxiliary switch operates with zero current switching, ensuring that the power loss in the auxiliary circuit is low for both cases. The timing of the ZVT circuit is adaptively controlled with changing load conditions. The proposed concepts are validated through a 2.5 kW hardware prototype operating at 100 kHz and achieving a high gain conversion from 46 V input to 850-V output. The converter is able to achieve a peak efficiency of 98.3% with silicon devices as main switches at 100-kHz switching frequency.