Islanding detection and over voltage mitigation using controllable loads

An islanding condition occurs when a distributed generation (DG) unit continues to energize a part of the grid while said part has been isolated from the main electrical utility. In this event, if the power of the DG exceeds the load, a transient over voltage (TOV) will occur. The adverse effects of TOVs and islanding require that sub-circuits within a power grid not only allow the detection of islanding and TOVs, but also mitigate the over voltages while having the ability to disconnect DG from the grid, if necessary. This paper proposes a solution based on wireless sensor networks and controllable loads. The controllable loads are utilized as fast-acting elements for the mitigation of TOVs.