多組 LLC諧振轉換器之並聯與均流研製

Realization study of Parallel and current sharing of multiple LLC resonant converters

周志明(Chih-Ming Chou)

指導教授 ： 謝冠群 ； 謝宏毅

中原大學/電機資訊學院/電機工程研究所/碩士(2020年)

https://doi.org/10.6840/cycu202000202

摘要

本文旨在研究多組LLC諧振轉換器的並聯均流系統，使用外迴路和最大電流均流控制，可以確保負載電流均勻分配到每個模塊。另外，此並聯系統還具有熱插拔功能，可以在不斷電情況下進行系統負載擴充或維護，從而提高了系統的擴充性和可靠性。首先，分析了LLC諧振轉換器的小信號模型，由於在並聯系統中增加均流環路會導致電壓環路的複雜性，因此，傳遞函數的波特圖用於分析並聯系統環路的穩定性，這也有助於最大電流均流電路的補償器設計。最後，設計並實現了三個並聯的1kW LLC諧振轉換器，其輸出電壓/電流約為48V/21A，並聯均流誤差率在±5％以內，且所有負載電流在負載波動或熱插拔期間都可以均勻分佈。

關鍵字

LLC諧振轉換器並聯 ； 小訊號模型 ； 外迴路控制法 ； 最大電流均流控制

並列摘要

This thesis aims to develop the parallel current sharing system of multiple groups of LLC resonant converters. An external loop control and the maximum current sharing control are used that can ensure the load currents evenly distributed to each module. In addition, this parallel system has a function of hot swap, which can expand or maintain the system load under the condition of continuous power, thus improving the system scalability and reliability.Firstly, the small-signal model of the LLC resonant converter is analyzed. Because the addition of current sharing loop into the parallel system will cause the complexity of the voltage loop, the Bode plot of transfer function is used to analyze the stability of the parallel system loop, which also help the compensator design of the maximum current sharing circuit. Finally, three 1-kW LLC resonant converters in parallel were designed and implemented, the output voltage/current of which is around 48V/21A, the parallel current sharing error rate is within ±5%, and all load currents can be evenly distributed during load fluctuations and hot swapping.

並列關鍵字

LLC resonant converters in parallel ； Small-signal model ； external loop control method ； Maximum current sharing control

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