Congestion Management Ensuring Voltage Stability under Multicontingency with Preventive and Corrective Controls

For some operating conditions, secure operation of power systems is ensured by preventive controls. But for some other operating conditions, secure operation of power systems is ensured by corrective controls. Preventive and corrective controls have totally different technologic and economic implications. The N-1 contingency and N-2 contingency scenario should be dealt with different controls measures because of their financial impacts on power systems operation. Based on preventive and corrective controls, a congestion management method considering voltage stability under N-1 and N-2 multicontingency conditions is presented in this paper for day-ahead electricity markets. By decomposing operating and voltage stability constraints into two consecutive preventive and corrective congestion managements, secure operations of power system under N-1 and N-2 contingency are ensured and congestion cost in day-ahead markets is reduced at same time. The proposed method is tested on modified IEEE 30 bus system. The simulation results showed the effectiveness of the method.