홀드업 시간 보상을 위한 부스트 컨버터가 통합된 새로운 2-트랜스포머 위상 천이 풀 브리지 컨버터

초록

This paper proposes a two-transformer phase-shift full-bridge(2-TR PSFB) converter with an integrated boost converter for server power systems to meet hold-up time requirements. The 2-TR PSFB converter features a small RMS current, clamped voltage stress on the primary switches, and zero-voltage switching capability. However, it suffers from circulating current in the freewheeling state and high voltage stress on secondary rectifier diodes under a wide input voltage range. These issues are addressed by integrating a boost converter into the proposed converter, which enhances voltage gain, allows for maximum duty ratio operation at the nominal input voltage, reduces primary side RMS current, and utilizes lower-voltage-rated diodes to minimize conduction loss. A 250–400V input, 12V/400W output prototype validates its performance, demonstrating improved efficiency, particularly under nominal input voltage conditions compared to the conventional 2-TR PSFB converter.

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