- 學位論文
背對背主動式電力調節器之反向零序電流補償方法
The Reverse Zero-Sequence Current Compensation Method for Back-to-Back Active Power Conditioners
摘要
本論文提出應用於三相四線式背對背主動式電力調節器之反向零序電流補償方法。背對背主動式電力調節器之功能為調節兩個獨立微電網之間的功率潮流，然而，當電壓故障發生時，因電壓不平衡造成的二倍頻振盪會反應在主動式電力調節器之輸出功率上。因此，本論文透過同時控制正序、負序及零序電流來消除輸出實虛功之二倍頻振盪。但大量的零序電流會在直流匯流排之分離電容(Split capacitor)上產生很大的電壓漣波，此大幅度的電壓漣波不僅會加速電解電容老化，其最大值可能會超過電容耐壓而損毀電容。反之，其最小值若低於前級整流器所連接之微電網之交流電壓峰值，可能會導致輸入電流失真，甚至使整個背對背主動式電力調節器無法正常運作。因此，本論文提出反向零序電流補償方法，透過前級整流器補償適當的零序電流，來減小分離式電容上之電壓漣波。本論文說明了主動式電力調節器於電壓不平衡下之功率潮流控制策略，並推導出反向零序電流方法，兩者皆經電腦模擬驗證。最後，實際研製一組5kVA之主動式電力調節器原型機來進行實作。
並列摘要
In this thesis, a novel reverse zero-sequence current (RZSC) compensation method for three-phase four-wire back-to-back active power conditioner (APC) is proposed. The objective of the APC is to achieve the active and reactive power transmission between two micro-grids. However, for the unbalanced voltage sag micro-grid system, the double-line frequency oscillation exists in the output active/reactive power of the APC. Therefore, this thesis utilizes the positive-/negative-/zero-sequence current to eliminate these oscillation, but the zero-sequence current produces the line frequency ripple voltage on the split capacitors of the dc-bus. The capacitor ripple voltage speeds up the aging process and reduces its life-time. Also, it may exceed the maximum operating voltage and damage the split capacitors, distort the output current of the inverter, or even cause the malfunction of the APC. Therefore, the RZSC method is proposed to compensate the impact of the ripple voltage to the split capacitors. The operation principle of the back-to-back APC under the unbalanced grid voltage is introduced, and the mathematical equation derivation of the proposed RZSC method is presented. Both computer simulations and hardware experimental results are presented to verify the performance of the back-to-back APC with the proposed RZSC method.