Preventive control method of electric power system based on on-line voltage stability monitoring index

To achieve a preventive control strategy, which realizes online decision and real-time matching, the speed of real-time stability assessment and selection of control measures is the key. The impedance module margin was applied to assess the level of voltage stability in this paper. Furthermore, the sensitivity of the index with respect to control variables was presented, which can avoid computing the left eigenvector of the zero eigenvalue of Jacobian matrix of power system. Based on aforementioned theory, this paper proposed a successive linear programming model for voltage preventive control. This method speeds up the updated time of preventive control greatly. In order to overcome the index can not exactly reflect the stability domain when the power system suffer a disturbance or operates near the critical point, the nonlinear equivalent principle was applied to implement rapid prediction of the maximum load ability point, the load margin was obtained to take as a complementary object for the control model. The proposed method is tested on a real power system in the south of China to verify its feasibility and effectiveness. © 2015 Chin. Soc. for Elec. Eng.