Investigation Into Islanding Detection With Capacitor Insertion-Based Method

When islanding conditions arise, local distribution companies usually require the disconnection of all distributed generations from the isolated grid. For this purpose, mainly passive anti-islanding protections are used The most common and widely used, because of their low cost, are passive anti-islanding protections (e.g., frequency and voltage based). Unfortunately, passive schemes cannot detect islanding situations under certain system operating conditions, namely, when the active/reactive power imbalance in an island is low. To improve operation and to reduce the nondetection zone of this, the protection schemes capacitor insertion method is proposed. The capacitor bank switching strategy and effectiveness of the proposed method are demonstrated through simulation studies, conducted in the PSCAD/EMTDC software environment and real-time laboratory testing. The results may be useful for utility companies and distributed generators owners to enhance islanding condition identification efficiency.