本論文提出新的電感-電容濾波器架構改良換流器之共模電流，應用於三相非隔離倂網型太陽能功率轉換器，以降低太陽能光電板負極對地的電壓變動與功率轉換器輸出端之三相共模電流，避免縮短太陽能光電板的使用壽命及危害到人員的安全。在太陽能板側採用昇壓型直流-直流功率轉換器架構，將太陽能光電板的直流電壓560V提昇至670V，提供給直流-交流功率轉換器使用，由三相全橋型直流-交流功率轉換器搭配使用電壓空間向量脈波寬度調變將直流鏈電壓轉換為三相交流電流饋入市電。
　　本文採用32位元的數位信號處理器作為系統控制核心，以減少硬體電路。並利用電力電子模擬軟體Powersim進行分析改良型電感-電容濾波器策略的抑制效果。本文已完成10 kW三相非隔離倂網型太陽能功率轉換器之系統雛型，由實驗結果顯示，其太陽能光電板負極對地變動量的實測值由1,793V降至181V，而對應之三相共模電流變動量由253 mA降至99 mA。故本文提出的電感-電容濾波器較現有被動式抑制法的共模電流抑制效果佳，適用於非隔離倂網型太陽能功率轉換器之倂網系統。

　　This thesis proposes a novel inductance-capacitance filter to improve the common-mode current for transformerless grid-connected photovoltaic (PV) inverters. Reduction of the voltage of PV negative electrode with respect to ground is then resulted to avoid shortening the service life of PV array and harming the personnel safety. A boost-type dc-dc converter is introduced to boost the PV array voltage from 560V to 670V on output side of PV array for inverter input. The three-phase full-bridge inverter designed uses voltage space vector pulse-width modulation to convert dc-link voltage to three-phase alternating current for grid-connection.
　　In this thesis, a 32-bit digital signal processor is adopted as the control core for reducing the circuit complexity. The Powersim simulation software is used to analyse the suppression effect of the proposed inductance-capacitance filter. A 10 kW prototype of transformerless grid-connected three-phase PV inverter is built. Experimental results show that the voltage of PV negative electrode to ground is reduced from 1,793V to 181V, and the corresponding common-mode current is reduced from 253 mA to 99 mA, respectively. The proposed inductance-capacitance filter is better than current passive techniques in the suppression effect of common-mode current. Thus it is applicable for transformerless grid-connected photovoltaic inverters.

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