A new MVA sensitivity method for fast accurate contingency evaluation

A new fast algorithm of calculating node voltage and branch power flow under N − 1 network topology is proposed based on MVA power sensitivity in this paper. The voltage of system under base network topology is calculated based on Newton power flow approach. The branch outage is represented by the branch outage parameter. The first order derivative of voltage with respect to branch outage parameter is calculated by using the convergent power flow equation of the base network topology, further the voltage derivative with respect to branch MVA power can easily be obtained. The voltage under N − 1 network topology can be obtained by correcting the voltage at base network topology using the sensitivity. The advantage of the proposed approach is its high speed and high accuracy, especially for the branch MW power flow. The proposed sensitivity is justified theoretically. The proposed method can be used very quickly to obtain the accurate node voltage under different N − 1 network topologies, and then branch power flow violation and voltage violation can be obtained. Tests on IEEE 14, 30, 118, 300 bus systems and Hunan power system in China verify the correctness and practical utility of the approach.

► The derivative of voltage to branch parameter is obtained under base network. ► Further the node voltage derivative with respect to branch MVA power is derived. ► The post-contingency node voltage and the branch power flows are obtained. ► The proposed method is better than the other methods suggested. ► Theoretical analysis justified the proposed sensitivity method.