Islanding detection during intended island operation of nested microgrid

In the future, functionalities like islanding detection must also operate during intended island operation of (MV+MV or MV+LV) nested microgrids. In this paper, healthy and faulty islanding detection of LV network connected generation unit during nested (MV+LV) microgrid islanded operation were studied by simulations with PSCAD model from real-life smart grid pilot. Main focus in the simulations was on the study and comparison of usage possibilities of combined (high-speed communication based transfer trip & fault detection/direction + voltage vector shift) and multi-criteria (voltage total harmonic distortion & voltage unbalance) based islanding detection schemes also during intended island operation of nested microgrid consisting only from inverter based generation units.