以脈寬調變方法實現錯相式LLC諧振轉換電路之均流控制

Current Balancing Control of Interleaved LLC Resonant Converters by Pulse-Width Modulation Method

黃正二

指導教授 ： 吳黎明

健行科技大學/電資學院/電機工程系碩士班/碩士(2015年)

https://doi.org/10.6824/UCH.2015.00062

摘要

本論文提出以脈寬調變(PWM)替代頻率調變(FM)的方法，進行錯相LLC諧振轉換器之穩壓與模組均流控制。一般模組並聯的功率轉換器會因零組件參數誤差而產生不可避免的電流失衡問題，而諧振電路常用的FM控制法未能解決此問題。本論文結合基本波近似法與傅氏級數分析法，說明半橋諧振電路可用PWM方法進行操控的工作原理，並進行LLC半橋諧振電路模組與控制方法的分析與設計，其中電路控制採用兩組PWM控制迴路，一組內迴路以主僕控制方式實現模組電流平衡，另一組外迴路則控制輸出電壓。

本論文實作兩組模組並聯的300W/380Vin/19Vout錯相式LLC諧振電路一組，並以數位訊號處理器TMS320F28035為控制平台，以驗證所提方法。實驗結果顯示，模組的半橋開關皆可零電壓切換，模組均流改善率可達75%以上，電路最大效率為94%。

關鍵字

錯相式LLC諧振轉換器 ； 頻率調變 ； 脈寬調變 ； 電流平衡

並列摘要

This thesis proposes to use pulse-width modulation (PWM), instead of frequency modulation (FM), to regulate the output voltage and balance the module currents of an interleaved LLC resonant converter. The imbalance of module currents in power converters with modules connected in parallel is usually a problem caused by parameter errors of component, which is unavoidable and unsolvable by the regular FM method. The thesis combines the Fundamental component approximation method and the Fourier series analysis technique to explain the principle that a half bridge resonant converter can be controlled by the PWM method. Analysis and design of LLC resonant converter based on PWM control are performed. In addition, the control system is designed to include two PWM control loops. While the inner loop is to balancing the module currents by using the master-slave control logic, the outer loop is to regulating the output voltage of the converter.
A 300W/380Vin/19Vout interleaved LLC resonant converter with two modules connected in parallel had been realized in this thesis to verify the proposed method, in which the DSP TMS320F28035 was used as the control platform. As a result, the experimental measure showed that all the half bridge switches can be turned on with zero voltage, the current balancing effect can be improved at least 75%, and the maximum converter efficiency obtained is 94%.

並列關鍵字

Interleaved LLC Resonant Converter ； Pulse Width Modulation ； Frequency Modulation ； Current Balancing

參考文獻

[1] 梁成輝、梁從主、楊隆生、李祖聖、陳雅君、陳建富、林瑞禮等人，“錯相式LLC半橋諧振轉換器之研製”，中華民國第二十九屆電力工程研討會，台灣，台南，2008年12月5-6日。

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