Out-of-step splitting framework based on adaptive separation detecting criterion

Proper splitting controls are necessary to prevent large blackouts. Traditional relays cannot cope with or confirm out-of-step for severe instable situations of very fast power swings. Based on the wide area measurement system (WAMS), an adaptive framework for out-of-step splitting which makes use of remote communication to obtain quick and selectable disconnecting actions is proposed in the paper. The main innovative principles of the new scheme are: detect the synchronism loss based on the curves characteristics of Ucos¿ ensure the reliability of splitting action with the assistant of angle difference of voltage phase criterion; capture the out-of-step center interface to split based on the information of other surfaces. Simulation results of the 10 machines 39 buses New England system have demonstrated that the proposed framework has the advantage both in terms of much higher probability of detection and speed to prevent the power system from going into cascading outages.