臺灣博碩士論文加值系統

本論文之研究內容為分析一主動箝位返馳式轉換器，以與傳統使用被動緩振電路之返馳式轉換器作比較。本論文所研製之主動箝位返馳式轉換器，主要是利用變壓器之漏電感與開關之寄生電容產生諧振，利用此一諧振特性達到開關之零電壓切換，藉此提升電路之效率及消除開關之電壓突波，並作電路之損耗分析。最後實作輸出規格為24V/8A/200W之電源供應器，實驗結果之波形與理論和模擬結果十分相符。

This thesis aims at the analysis of an active-clamping flyback converter. The comparisons between the active-clamping flyback converter and the conventional flyback converters adopting passive snubbers are made. The resonant tank of the active-clamping flyback converter consists of the leakage inductance of the transformer and the parasitic capacitance of the switch. The zero-voltage swtiching can be achieved by adequately design the circuit parameters. The conversion efficiency can thus be raised and the voltage spike on the switch can be reduced. Also the loss distribution is derived. An active-clamping flyback converter with an output rating of 24V/8A/200W is implemented in the lab. The experimental results are closely conformed to the theoretical analysis and the simulations.

中文摘要 I
Abstract II
目錄 III
圖表索引 VII

第一章 緒論 1
1.1 簡介 1
1.2 問題描述 2
1.3 電源轉換器之簡介 3
1.3.1 線性電源供應器 3
1.3.2 切換式電源供應器 4
1.4 論文架構 5
第二章 硬性與柔性切換技術 6
2.1 脈波寬度調變 6
2.2 硬性切換 7
2.2.1 功率開關寄生元件 8
2.2.2 高頻變壓器寄生元件 9
2.2.3 切換損失 10
2.3 柔性切換 11
2.3.1 零電壓切換 12
2.3.2 零電流切換 14
第三章 電路架構 17
3.1 基本返馳式轉換器介紹 17
3.2 電路之動作原理 18
3.3 高頻振鈴突波電壓對電路之響 21
3.4 傳統緩振電路介紹 21
3.4.1 RCD緩振電路 21
3.4.2 RC緩振電路 23
3.5 主動箝位返馳式轉換器 23
3.6 基本、傳統緩振電路、主動箝位之優缺點比較 24
第四章 電路推導與分析 26
4.1 主動箝位返馳式轉換器電路架構 26
4.2 主動箝位之動作原理及電路推導 27
4.3 採用RC緩振電路之返馳式轉換器電路架構 41
4.4 RC緩振電路之工作原理與電路推導 41
4.5 採用RCD緩振電路之返馳式轉換器電路架構 52
第五章 設計實例 53
5.1 前言 53
5.2 基本、RC、RCD之電源規格 53
5.3 基本、RC、RCD之變壓器設計 53
5.3.1 輸出濾波電容器之設計 57
5.3.2 RCD緩振電路之設計 57
5.3.2 RC緩振電路之設計 58
5.4 主動箝位返馳式轉換器之電源規格 59
5.4.1 主動箝位之變壓器設計 59
5.4.2 諧振電感與箝位電容之設計 61
5.4.3 零電壓切換調件 62
第六章 電路模擬與實驗結果 63
6.1 主動箝位返馳式轉換器實測與模擬結果比較 63
6.1.1 主動箝位返馳式轉換器實際量測結果 66
6.1.2 主動箝位之效率與損耗分佈分析 71
6.2 RC緩振電路返馳式轉換器之實測與模擬波形 75
6.2.1 各種返馳式轉換器開關電壓實際量測結果比較 77
6.2.2 各種返馳式轉換器效率之比較 82
6.2.3 主動箝位返馳式轉換器損失分佈 83
6.3各種返馳式轉換器之優缺點比較 84
第七章 結論與未來研究方向 85
7.1 結論 85
7.2 未來研究方向 86
參考文獻 87

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