The Research On Condition Monitoring And Faults Diagnosis Of High Voltage SF6 Circuit Breaker

High voltage circuit breaker (HVCB) is one of the most important equipments for controlling and operating in power system. In order to increase the reliability and safety of power system, condition monitoring and failure diagnosis are necessary for HVCB. However, there are many difficulties in HVCB failure diagnosis. To solve this questions, this paper gives the items and characteristic parameters of condition monitoring based on statistic and analyses on the summary of CIGRE 13.06 working group world wide reliability data and maintenance cost data on high voltage circuit breakers above 63KV and the condition of installation and operation of high voltage circuit breaker above 63KV the nation wide power system in 1999-2003.With fuzzy diagnosis theory, a fault diagnosis model of high voltage SF6 circuit breaker is presented in this paper. And by analyzing the frequent and common failures, this paper confirms the items of online monitoring of HVCB. Moreover, it digs the relationship between the characteristic parameters and the failures. From the result of failures statistics and the analysis on the important signals of HVCB's operation, this paper defines the failures array, failure symptoms array and fuzzy relational matrix. Then, it gives the optimistic fuzzy operator and diagnosis rules. And to improve the veracity of fuzzy diagnosis system, this paper proposes adaptive correction methods of the fuzzy relational matrix. At last, the practical examples given in this paper shows that the algorithm is convenient to use, and the conclusion is exact. Futhermore, for improving the accuracy of fuzzy diagnosis, this paper gives another auxiliary diagnosis method based on radial basis function neural network (RBFNN). RBFNN makes sure correctness of the fuzzy diagnosis result of operating mechanism.Electrical endurance is the most important index of HVCB's life. In this paper, a way of forecasting electrical endurance of circuit breaker contacts by calculating the relative electrical abrasion is given. This way is convenient and reliable to master the electrical endurance of circuit breaker. This paper proposes SPC on failures defending for preventing the HVCB from going wrong.