A system approach to emergency load shedding in case of voltage instability

In this paper, the load shedding algorithm based on system approach to prevent voltage instability is presented. The main point of the algorithm is the on-line linear optimization model, which produces the amounts of the load that need to be shed in the case of emergency voltage condition. Thus, the load shedding is simultaneously performed at all regional buses which enables voltage recovery at the jeopardized critical bus. Within the proposed optimization model, special attention is paid to the directly controlled loads since their disconnection does not significantly disturb the operating policy. The proposed procedure is verified on the example of the real high-voltage power system.