本論文提出功率潮流優化控制策略,對三相背靠背(Back-to-Back; BTB)轉換器兩級間之功率潮流進行調控。本論文提出之功率潮流優化控制策略可分為電流優化調變策略及動態直流電壓調變策略兩部分。電流優化調變策略能以適當之調變電流對兩級間之功率潮流進行調整,使三相BTB轉換器之直流匯流排電壓能迅速的穩在預設之磁滯區間內。而動態直流電壓調變策略則能隨三相BTB轉換器之輸出功率的多寡,對直流匯流排電壓之磁滯區間進行調整,在輸出功率驟變時,能防止不必要的直流匯流排電壓保護觸發,或是降低匯流排電容值。本論文採用的三相BTB轉換器能做為主動式電力調節器,控制交流微電網間之功率潮流,以提升微電網之電力品質。配合本論文提出之功率潮流優化控制策略,主動式電力調節器能準確的對交流微電網間之功率潮流進行調整。最後以實測波形來驗證本論文所提出之功率潮流優化控制策略的性能表現。
This thesis proposes an optimal power flow control strategy to regulate the power flow of a three-phase back-to-back (BTB) converter. The proposed optimal power flow control consists of the optimal ac-line current regulation strategy and the dynamic dc-bus voltage regulation strategy. With the optimal ac-line current regulation strategy, the appropriate input current can be determined quickly to stabilize the dc-bus voltage of the BTB converter. The dynamic dc-bus voltage regulation strategy can alter the reference of the dc-bus voltage to prevent triggering of the DC voltage protection mechanism when an abrupt power change of the BTB converter occurs. The proposed BTB converter can be adopted as an active power conditioner to improve the power quality of the AC micro-grids. The active power conditioner with the proposed optimal power flow control strategy can regulate the power flow between different AC micro-grids accurately. Finally, experimental results measured from a prototype circuit are presented to demonstrate the performances of the optimal power flow control strategy.