改進型移相全橋PWM ZVS DC-DC變換器的研究

摘要：本文提出了一種副邊加箝位網絡的改進型移相全橋ZVS PWM DC-DC變換器。該箝位網絡減小了移相全橋變換器續流狀態時的原邊環流，在寬負載范圍內實現了滯后橋臂的ZCS開關，并可有效地減小副邊整流二極管上的振蕩尖峰。文章詳細分析了變換器的工作原理及各個工作模態。在此基礎上，研制了一臺輸出功率3KW(360V/8.5A)的DC-DC變換器樣機，實驗結果表明理論分析正確，變換器整機變換的效率高。 敘詞：反向恢復，環流，軟開關，全橋變換器 Abstract：This paper introduce an improved phase-shift ZVS-PWM converter.A simple auxiliary circuit, which consists of two small capacitors and three diodes, is added in the secondary to decrease the circulating current ,as well as to clamp secondary rectifier voltage .The converter achieves zero-current switching for the lag leg due to the minimized circulating current .The principle of the converter and the operation modal are analysied in detail .A 3kW DC-DC converter is designed based on this circuit .The experiment result verify the analysis ,and the efficiency of the converter is high . Keyword：diode recovery, circulating current, soft-switch, full-bridge converter