Performance Evaluation of Islanding Detection for Distributed Energy Resources With Grid Support Functions

With the proliferation of Distributed Energy Resources (DER), Grid Support Functions (GSFs) have been widely deployed. With the object to maintain the frequency and voltage stability during the grid-connected operation, GSFs, however, has raised great concerns on the effectiveness degradation of islanding prevention. Focusing on it, this paper evaluates the performance of the widely used islanding detection method, Slip-Mode Frequency Shift (SMS) operating together with GSFs. First, a small-signal model for this control combination is firstly derived, facilitating the investigation of interaction mechanism between GSFs and SMS. Accordingly, the optimal range of SMS coefficient is identified to guarantee both a successful islanding detection when an island forms and a stable operation during the grid-connected condition. It is observed that several key parameters, especially the slope and the open-loop response time of GSFs, as well as the SMS coefficient, jointly dominate the effectiveness of the islanding detection and should be deliberately designed. Finally, extensive simulations and controller hardware-in-the-loop (HIL) tests are performed to validate the above analysis.