The reliability evaluation of configuration of bus arrangement in substations by the variable failure rate of power circuit breaker under time-based maintenance

this paper addresses the study of the variable failure rate of high-voltage circuit breaker by using the Weibull distribution method to set time-based maintenance schedule properly. Power circuit breaker is installed in the substation in varied configurations, the case study for compared with, Main and Transfer bus arrangement, and Breaker and A Half bus arrangement. These are used more in substation of Thailand. From the numbers of failure data of power circuit breaker in 230-kV level, recorded by maintenance engineers of Electricity Generating Authority of Thailand's transmission network in the period of 1991–2011. The Weibull distribution is the well-known method to analyze electrical equipment to calculate the failure rate and Mean Time Between Failure of each part of power circuit breaker. After getting Mean Time Between Failure, the parts can categorized and the time-based maintenance schedule can be set consequently. This schedule replacement of such subcomponents usually decreases the total failure rate designated as variable failure rate of high voltage equipment. The results from the table of maintenance schedule by categorizing each part of power circuit breaker with the new replacement subcomponent group show that the failure rate of power circuit breaker can be diminished and it helps to plan maintenance schedule, and also to store up parts of power circuit breaker properly, which will reduce the cost of power circuit breaker maintenance as well.