高效率LLC電源轉換器之研製

Design of the High Efficiency LLC Power Converter

梁繼宗(Chi-Tsung Liang)

指導教授 ： 王文壽

崑山科技大學/工程學院/電子工程研究所/碩士(2008年)

摘要

本論文提出一種降低LLC諧振轉換器輸出電流漣波之方法。LLC諧振轉換器由於具有軟性切換特性，因此具有高轉換效率與低電磁干擾，故非常適合應用在高頻電源轉換器上。但也由於輸出電流漣波較大，因此轉換器的輸出通常需使用較大電容器，以滿足高直流輸出品質之特性。為了改善此一缺點，本論文提出利用在諧振槽中並聯一被動元件網路之電流修飾技術，以達到降低輸出電流漣波，進而減少使用輸出電容之方法。最後；本論文中以一個輸入為直流電壓400V，輸出為24V/8A的LLC諧振轉換器之模擬及實測結果，以驗證本論文所提方法之可行性。

關鍵字

LLC諧振轉換器 ； 輸出電流漣波 ； 諧振槽 ； 電流修飾

並列摘要

This thesis presents an output-current ripple reduction method for LLC resonant converter. Based on soft-switching, high efficiency and low electromagnetic interference, LLC resonant converter has been widely used for high switching frequency power conversion applications. However, the high output ripple current is the main drawback. Besides, for the large output current ripple of LLC resonant converter, the large output capacitance is necessary to reduce output current ripple for the high quality DC output voltage. In order to solve this problem, a current shaping technique is presented in this thesis. By using the resonant tank with a parallel passive network, the output ripple current can be improved. Also, the values of the output capacitance can be reduced. Finally, a 400V input voltage, 24V/8A output prototype of LLC resonant converter has been simulated and implemented. The simulation and experimental results demonstrated the feasibility of proposed method.

並列關鍵字

LLC resonant converter ； output current ripple ； resonant tank ； current shaping

參考文獻

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[3] K. Siri, C. Q. Lee, “Constant switching frequency LLC-type series resonant converter,” IEEE Circuits and Systems, vol.1 ,1989.

[4] R. Severns, “Topologies For Three Element Resonant Converters,” Proc. IEEE APEC ,’90, 1990, pp. 712-722.

[5] T. Higashi, H. Tsuruta, M. Nakahara, “Comparison of Noise Characteristics for Resonant and PWM Flyback Converters,” Proc. IEEE PESC ,’98, 1998, pp. 689-695.