H橋Buck變換電路輸出電壓幅相特性的研究

摘要：帶二階濾波的單相橋式Buck變換電路存在輸出紋波電壓移相的問題。本文結合單相橋式Buck電路模型，通過研究其降壓原理及輸出電壓特性，分析了開關管占空比對輸出電壓紋波相移的影響，結合元器件的電學特性做出了定性分析，并利用數學推導給出了定量計算公式，便于變流器的器件選擇和參數設計。最后，建立了基于MATLAB/SIMULINK的單相橋式Buck電路的仿真模型，仿真結果證實了理論分析方法和定量分析結果的正確性。 敘詞：H橋 Buck電路 紋波電壓 移相 Abstract： Output ripple voltages phase shifting exists in single phase Buck circuit with a second-order filter. Single phase Buck circuit is modeled, and its step-down principle and output character are researched. Duty cycles effect on output ripple voltages phase shifting is analyzed. Qualitative analysis combined with devices electric properties is given, and qualitative calculation formula is derived, both of which are beneficial to choose devices and design their parameters. Single phase Buck circuits model is simulated by MATLAB/SIMULINK, and simulation results verify the correctness of theoretical analysis method and qualitative calculation results. Keyword：H bridge, Buck circuit, Ripple voltage, Phase shifting