多相交錯臨界模式功率因數修正電路之電容電流漣波及相電流不穩定效應分析

Abstract

近年來，臨界模式功率因數修正電路(PFC)在中高功率的應用上，已經開始採用多相交錯控制技術。採用此控制方式的好處在，輸出輸入電容上的漣波大小較傳統的控制模式小的許多，在效率上，因為沒有二極體的電流反向回復問題而且導通損失也較小，故在中高功率的應用上也會有比較好的表現。 本論文針對多相功率因數校正電路在臨界模式特性進行分析，主要分成三項：一為輸入及輸出電流漣波大小以及穩定性之分析，二為分析電感感值不匹配時對系統之影響，三為相位延遲電路的不準確時所產生之問題。分別針對所整理出的四種控制模式一一做討論，針對所發現的不穩定現象提出新的控制改善方法，並從理論分析以及軟體模擬兩方面證明提出方法之可行性。

In recent years, multi-phase interleaved critical-mode power factor correction (PFC) circuits have become popular for medium-to-high power level application. This circuit features low ripple current for both the input and the output capacitors, absence of diode reverse recovery problems and relatively high power efficiency. This thesis deals with three aspects of such a PFC converter configuration. The first aspect is the functional relationship of capacitor ripple currents to circuit parameters and working conditions. Analysis was performed to find out the functional relationship. The second aspect is the effects of converter inductance mismatched on the phase current. Discussions about phase current imbalance due to four different control methods were given. And the third aspect is effects of delay time error on the phase current imbalance due to different control methods. Four control methods were analyzed, and new control methods were proposed to reduce on alleviate the current balancing problems. In all three aspects, simulations were conducted to verify the results obtained my theoretical analysis.