新型式單相單級交流轉直流且具有輸入電流修飾的電源轉換器

Abstract

本論文研製之新型輸入電流修飾器應用於交流轉直流電源轉換器，此轉換器具有輸入電流諧波校正功能以及輸出電壓快速反應特性。在文中所介紹的輸入電流修飾器應用在兼具電流校正功能的反馳式架構，順向式架構和橋式架構。明顯改善了傳統交流轉直流電源轉換器中輸入電流的諧波電流，若經過適當設計功率因數可高達90%以上，且只要選用傳統控制器既可完成穩定輸出電壓與電流，是一項精巧而實用的研究成果。所有文中提及的電路都是在穩態情況作分析與考量。所做的分析研究包括操作原理分析、重要參數分析、電路設計步驟最後還有電路模擬或雛型電路實作驗證性能。 這論文研究的交流轉直流電源轉換器中利用變壓器加繞一線圈達到兩個主要優點： (i) 本設計大大減小舊有單級Boost-型功率因數校正單元中的大電感。 在同樣輸出瓦特數， 舊有單級具功率因數校正轉換器中的boost電感有高至1.7倍於磁化電感的感值，或是1.4mH的感值。在論文中所研究的電路所使用的電感L1其電感值可低至0.1倍於磁化電感或是30μH的電感值。(ii) 另一優點是在輸入端整流用的大電容電壓差可以控制在450V以下， 經由調整變壓器線圈的圈數比可以達成即便是在全範圍輸入電壓也適用(90V~265V)。雖然這幾年有不少類似技術文獻的出現，其中有些要用到較複雜的控制電路達到高的功率因數、非固定切換頻率作高功率因數調整或是在電路前段的升壓部分仍具有大體積的電感，過去所提的這些方法固然有其個別優點，可是在競爭激烈的切換式電源市場角度評量，電路架構簡單、高信賴度、以及成本是主要考量因素。 本文中所新提出的轉換器即使在輸入功率高至600W應用範圍也能滿足規範IEC61000-3-2 class D的要求，且具有輸出電壓快速動態反應的性能。 文中所研究的電路具有結構簡單，高信賴度，與低的成本。其中的切換頻率是定頻式，對於變壓器設計和電磁干擾防治可有較好的效果。且論文中研究的電路可以用最普通的控制器UC3842或TL494來完成應用設計而且電氣性能表現符合電流諧波規範。

This dissertation presents a new input current shaper (ICS) for single-phase single-stage AC/DC converters with harmonic current correction and fast output voltage regulation. The proposed ICS are applied in flyback structure, forward structure, and bridge structure with the function of harmonic current correction. All the circuits are analyzed in steady state consideration. The study contains operation principle analysis, critical parameters analysis, design procedure. Finally, simulations and experiment results are shown for verifications. In the proposed AC/DC converters, an extra winding wound in the transformer provides two key advantages: (i) The size of the bulk inductor used in the conventional boost-based PFC cell can be significantly reduced in the proposed converters. In same output power application, the main transformer should has similar size but the boost inductor in prior single-stage PFC converter will be up to 1.7Lm or 1.4mH, and the inductor L1 in the proposed circuit can be down to 0.1Lm or 30μH. (ii) The voltage across bulk capacitor can be held under 450V by tuning the transformer windings ratio even though the converter operates in a wide range of input voltages (90V~265V/ac). Similar technique has been reported in recent years, but complex control circuit is needed to achieve high power factor or still use a bulk inductor in the boost-cell in the front stage of the converter. In a competitive market of switching power supply, the main consideration includes a simple, reliable, and cost-effective. Therefore, there is an improved opportunity in those presented solutions. These new converters comply with IEC 61000-3-2 class D from the load range up to 600W, and can achieve fast output voltage regulation. The proposed circuit has a simple, reliable, and cost-effective structure. The switching frequency is fixed in the proposed converters, which benefits the design of transformer and EMI filter. The proposed solution employs conventional controller, UC3842 or TL494, to implement the circuits and the solution can comply with the agent’s standards.