Analysis and Synthesis for A Novel ZVT-PWM Diagonal Half-Bridge Forward DC/DC Converter with Synchronous Rectification
| Autor: | Hao-Bin Su, 蘇豪斌 |
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| Rok vydání: | 2006 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 94 Based on the Diagonal Half-Bridge Forward (DHBF) DC/DC converter and soft switching technique, a novel Zero-Voltage-Transition Pulse-Width Modulation (ZVT-PWM) DHBF DC/DC converter is proposed in this thesis. It has high power conversion efficiency. The diagonal switches of the conventional DHBF converter exhibits hard switching. To achieve soft-switching operation, the voltages of the diagonal switches must resonate down to zero before switching. The proposed converter is developed by paralleling an auxiliary circuit at primary side of the transformer of the DHBF converter. The auxiliary circuit comprises a resonant inductor, a resonant capacitor and an auxiliary switch, which is used to control resonant occurrence. The diagonal switches of the proposed converter can operate under zero-voltage switching (ZVS) and the auxiliary switch can also operate under zero-current switching (ZCS). It is effective to increase the efficiency of the converter. Moreover, the synchronous rectification technique is also employed to reduce the conduction losses of the output rectifier. As a result, the proposed converter still exhibits high efficiency at heavy load. The operation principle and theoretical analysis of the proposed converter are presented herein. They are validated by IsSpice simulations and experimental results. A prototype of ZVT-PWM DHBF converter for input and / output is finally implemented. The overall efficiency of the proposed converter achieves at full load. The efficiency of the soft switching technique and the synchronous rectification technique is demonstrated by the proposed ZVT-PWM DHBF DC/DC converter. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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