Synchrophasor Based Transmission System Anti-Islanding Scheme

Unintended power system islanding means a portion of loads and generators become isolated from the rest of the grid. the islanded area is susceptible to severe power quality problems and may come across system instability. Islanding may occur in both distribution and transmission grids. Legacy existing anti-islanding schemes in sonic transmission utilities use signals of open breakers and switches, therefore are prone to human error. In this paper, a new scheme is proposed using synchrophasor data for islanding detection, which makes use of the frequency difference inside and outside the island measured by phasor measurement units (PMUs). Simulation results for different contingencies and different generation states using real time digital power system simulator (RTDS) show that the proposed scheme is capable of avoiding false tripping caused by inaccurate breaker/switch status and riding through all the non-islanding cases.