Islanding Detection Method for Grid-Forming Inverter Using Voltage Reference Perturbation

Traditional islanding detection methods have been developed for the grid-following inverters. However, these methods are not directly applicable to grid-forming inverters because they regulate voltage and frequency. This paper proposes an islanding detection method specifically desinged for grid-forming inverters. Unintentional islanding scenarios are simulated using PSCAD/EMTDC witin the IEEE Std. 929-2000 test system. The proposed approach initially detects abnormal conditions by monitoring the rate of change of frequency. Subsequently, the voltage reference of the grid-forming inverter is finely adjusted within the nomial voltage range to determine whether the inverter operates in islanding mode. This perturbation-based method can distinguish islanding events from non-islanding transients such as faults.