Space Vector Rotation-Based Controlled Decaying Current Injection for Islanding Detection of Inverter-Interfaced DG

Abstract

Continuous injection-based islanding detection of Inverter-Interfaced Distributed Generator (IIDG) has been a general trend. The major issues in previous islanding detection methods are large Non-Detection Zone (NDZ), poor Power Quality (PQ), high implementation cost, and lack of real-time validation. Further, the threshold in most methods is not generic and depends on the system’s rating. Hence, this paper proposes a local voltage and current measurement-based islanding detection method for IIDGs. It utilizes parameters estimated from the fundamental phasors of voltage and current at the Point of Common Coupling (PCC) of IIDG using Space Vector Rotation (SVR) and a controlled self-decaying current injection. The proposed disturbance is injected only after disturbance detection by SVR parameters to mitigate the impact on PQ. Disturbance identification is easy due to the combined PCC voltage and current effects on parameter estimation. Real-Time Digital Simulator (RTDS) and Controller Hardware In the Loop (CHIL) setup-based results from the proposed method have been obtained and compared with previous methods. These results indicate the proposed method’s real-time efficacy (low islanding detection time) with no NDZ and negligible impact on PQ for different islanding events. Also, the proposed method is independent of the microgrid’s rating and reliable for non-islanding events.