Reliability estimation of high voltage SF6 circuit breakers by statistical analysis on the basis of the field data

Abstract In order to estimate the reliability of high voltage SF 6 circuit breakers, it is necessary to develop a statistical approach which can provide the failure probability, the failure rate and the remaining lifetime for the equipment and components. Useful information about the failure occurrences of 550 kV SF 6 circuit breakers is collected from the East China Grid with the operating history. Even if the statistical survey is linked to data records of the unfailed components and maintenance measures, the statistical approach can accurately estimate the reliability of the components assembled in the circuit breakers. It is demonstrated by individual characteristics of 550 kV SF 6 circuit breakers such as N 2 leakage, SF 6 leakage, overheat of primary terminal and defect of protection- and control system, etc. that the statistical approach is able to assess the reliability of equipment and components with reasonable and accurate results.