Estimating the Shortest Radius of Power System Security Region in Node Injection Space

A heuristic method for estimating the shortest radius of power system security region in node injection space is proposed based on sensitivities of the stability indexes to node injections. The closest boundary of security region in node injection space is approached step by step, and all kinds of power system operating constraints can also be considered. This method has no numerical convergence problem. Theoretically, this method can be used to estimate the shortest radius of all kinds of parameter security regions such as voltage security region, small-signal security region and transient security region, which provides a unified approach to estimate all kinds of power system security regions. Numerical results manifest that the proposed method is valid and effective.