Lifetime Estimation of Switching Devices Using Weibull Distribution Analysis

Abstract

In this paper, the failure events of power circuit breaker and disconnecting switch in a utility in Thailand recorded during installation, operation and maintenance are analyzed by using statistical method. The major components and subcomponents of power circuit breaker and disconnecting switch were firstly classified. Then, the failure rate and useful lifetime of all major parts and all components were calculated by using Weibull distribution analysis. The obtained result can be subsequently used to determine the proper time-base repair or replacement in order to reduce the unplanned outage and improve the efficiency of preventive maintenance by replacing the component of switching device in time. This could improve system reliability, prevent unplanned outage, extend the lifetime of the equipment, properly manage the spare part, and etc.