noradin ghadimi - young researchers club,ardabil branch islamic azad university ardabil iran
rasoul ghadimi - ardabil province electricity distribution co ,ardabil ,iran
alireza alizade - ardabil province electricity distribution co ,ardabil ,iran

Due to the DGs advantages, including using of Renewable Energy which not polluting environment and has endless nature, the application of DGs can potentially reduce the need for traditional system expansion,controlling a potentially huge number of DGs creates a daunting new challenge for operating andcontrolling the network safely and efficiently. One problem that encountered with it when using with DGs, is an unwanted Islanding phenomenon. Anti-islanding protection schemes currently enforce the renewable distributed generators to disconnect immediately and stop generation for grid faults through loss of grid(LOG) protection system. In this paper, a novel technique in order to detecting islanding conditions has been present, and the proposed method based on total harmonic distortion and rate of change of phase angle difference, itsperformance is much more appropriate than that of previous techniques. The simulation results performed in MATLAB, clearly show improved operation of this method.

Distributed Generation- Islanding, -Switching- Passive Technique