Active Unintentional Islanding Detection Method for Multiple-PMSG-Based DGs

Penetration of small distributed generators (DGs) has been made possible in distribution systems owing to the advances in power electronics. However, it is not desired to energize the loads during an unintentional island formation. Hence, in this article, an active unintentional islanding detection method based on disturbance injection through a q-axis current controller is presented for converter interfaced multiple permanent-magnet-synchronous-generator (PMSG)-based DGs. The injected disturbance forces the frequency of the system to change meaningfully on the postislanding condition. Subsequently, a simple analyzing method is proposed based on the blend of a second-order bandpass filter and mean of absolute frequency variation to detect and also to differentiate the islanding from the nonislanding events. The proposed method detects the island formation within 178 ms for the most crucial islanding condition for PMSG-based DGs, whereas the minimum detection time among several international standards is 200 ms. And, also it distinguishes the nonislanding events from the islanding events precisely without destabilizing the system. The MATLAB R2019b/Simulink platform is used to validate the results in simulations.