Backward and forward sweep method 1 Detection time 1 Distributed generation 1 Forward sweep method 1 Frequency index 1 Islanding detection 1 Islanding detection time 1 Islanding prevention 1 Non detection zones 1 Non-detection zone 1 Passive islanding detection 1 V-F (voltage–frequency) index 1 Voltage frequency 1 Voltage–frequency index 1 backward and forward sweep (BFS) method 1 distributed generation (DG) 1 islanding detection time 1 islanding prevention non-detection zone (NDZ) 1 passive islanding detection 1