Research Of Algorithm Of Static Reliability Evaluation For Transmission Systems

With the development of the domestic economy, power grid is developing to the mode of high voltage level and high capacity. The domestic power grid will enter a period of rapid development and it is becoming more and more complex. With the number of components keep growing, the blackout often results in huge economic losses and social benefits, and the consequences is becoming more and more serious. These years, several large-scale outages has occurred around the word and result in huge economic losses. So reliability evaluation of transmission systems become urgent and necessary.Two algorithms are realized in this paper to calculate the load point reliability indices and the system reliability indices. The algorithm to calculate the load point indices devided the transmission networks into several power supply zones by voltage level and power supply condition, then use the minimum cut sets method to calculate the reliability parameters of each zone. When calculating the system reliability indices, the analytical method is used to enumerate the failure states of transmission system. Network topology and its analysis is represented by means of the storage of connection matrix and the breadth first search technique is used to identify whether the multiple failure lead to break apparatus of networks. The AC power flow model is used to judge the line overload and voltage violation more accurately. The optimal load shedding nonlinear programming model is established and the primal-dual interior point algorithm based on the perturbed Kuhn-Tucker condition is used to solve the corrective action of the active power and the reactive power. Furthermore, the contingency selection techniques base on calculating the Performance Index of each states can make the algorithm more effective.The programs based on the algorithms described in this article have been written. The correctness and effectiveness of these algorithms and the sub module have been verified by evaluating the reliability of IEEE-RTS79system.