“…Rate of change of frequency (ROCOF) [25], [35], the rate of change of active power (ROCOAP) [26], phase angle difference [27], the rate of change of voltage (ROCOV) [28], the rate of change of reactive power ROCORP [29], over under voltage / over under frequency (OUV/OUF) [30] are some passive methods, they are suffering with the large NDZ, and fails to detect islanding at low or zero power imbalance conditions. The combination of any two passive parameters is used to reduce the NDZ, like ROCOF and output power [31], ROCOV and THD [32], ROCOV and power factor [6], [28], ROCOV and ROCOF [33], ROCOAP combination with ROCORP [34]. These methods will reduce the NDZ to less compare to single parameter passive techniques.…”