本文提出了一種使用功率硬體迴路(PHIL)平台實現微電網功率轉換器之無縫轉換的方法。在系統模型中，使用回授電流濾波法(FCF)增加系統穩定性，並使用三相二階功率轉換器作為開關模式放大器，以便將即時模擬器中虛擬電網的電壓訊號放大到實際硬體上，使微電網中的功率轉換器能夠進行控制。在孤島偵測實驗中，使用正回授自動相移法(APS)作為孤島偵測法，並分別使用SOGI-FLL、DSOGI-FLL以及ROGI-FLL作為鎖頻迴路(FLL)，比較不同電網條件下不同GI-FLL的鎖頻情形。
在孤島實驗期間的模式轉換，我們使用無縫轉換，使系統在安全的情況下進行切換。並且設計了一種同步機制，使系統在進入孤島模式後，VSC能自動與修復完成的公用電同步，並且在系統修復完成後能夠順利切換回併網模式。最後，透過Matlab/Simulink模擬驗證方法之可行性，並使用OP5600即時模擬器和DSP28335進行硬體驗證。

This thesis presents a technique for achieving seamless transition of power converters in microgrid using a Power Hardware-in-the-Loop (PHIL) platform. The system model employs a feedback current filtering approach (FCF) to enhance the entire system stability, and uses a three-phase two-level power converter as a switch-mode amplifier, enabling the voltage signal of the virtual power grid in the real-time simulator to be amplified to the physical hardware, thus enabling control of the power converter within the microgrid. The islanding detection experiments utilize a positive feedback automatic phase-shift method (APS) for islanding detection and employs SOGI-FLL, DSOGI-FLL, or ROGI-FLL as frequency-locked loop (FLL) respectively to evaluate the locked frequency under various grid conditions.
In the course of islanding experiments, we employ a seamless transition strategy. A synchronization mechanism is also devised to enable the power converter to be automatically synchronized with the restored grid upon reaching the islanded mode, and smoothly transition back to the grid-connected mode once the main power grid is restored. The proposed approach is validated using Matlab/Simulink, and through hardware experiments on the OP5600 real-time simulator, and the DSP28335.

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