Study Of Fuzzy Performance Index Method For Transient Stability Contingency Screening Of Power Systems

Security of power system is becoming more and more important under the condition of the interconnection of power systems and the construction of electric market. And people have paid more and more attention on the security of power system nowadays. With the development of computer technology and high performance computation method, the primary condition of online dynamic security assessment, an important means to improve the security of power system, has been afforded. Contingency screening, which is also called contingency filtering and ranking, is an important part of dynamic security analysis. It is essential for online transient stability analysis, and is significant for the implementation of security alarming.This thesis is focused on the study of contingency screening method of power system. The main work fulfilled is as follows.1) Various performance indexes which represent severity degree of contingencies are proposed and analyzed. These indexes are gotten system state before and after contingency clearing obtained by the means of time domain simulation. They can be computed conveniently and immediately and can meet the need of online transient stability analysis.2) A contingency screening algorithm using various performance indexes and adopting fuzzy method and statistics method is proposed. It is validated with the New England 10-generator 39-bus Power System.3) An Interval Fuzzy C-means clustering algorithm (IFCM) is also discussed for contingency screening. In comparison with traditional Fuzzy C-means clustering algorithm (FCM), it is more reliable when clustering patterns are somewhat mixed. Its application prospect is explored and expected with the test on the New England 10-generator 39-bus power system.