Proof for The Equivalent Condition Score Method for Calculation of Power Transmission Equipment’s Failure Rate

Abstract

Condition maintenance is a kind of maintenance based on the advanced condition monitoring and diagnosis technology for collecting equipment’s condition information, and evaluating equipment’s condition score. The obtained condition score should be the foundation for the calculation of equipment’s failure rate. With the calculated failure rate, the decision of out-of-service maintenance (OM) could be made. After each OM, the same condition scores obtained before and after an OM could correspond to different failure rate values. Inspired by an all-state integration (ASI) method, an equivalent condition score (ECS) method, which converts the condition score obtained after an OM to an equivalent condition score, has been proposed in a previous work. Based on the equivalent condition score, the equipment’s failure rate can be calculated by the ECS method. This paper makes a contribution by providing a mathematical proof to show that the ACS and ECS methods are equivalent, which is important for wide applications of the ECS method.