絶縁診断による電力機器のライフサイクル管理の検討

抄録

This paper deals with the statistical estimation of the maintenance cost reduction when insulation diagnosis for power apparatus is performed. A failure loss is expected if a proper alert has not been made because of “too loose diagnosis”. On the other hand, prematurity loss is expected if the apparatus has been replaced because of too early alert made by “too severe diagnosis”. The expected total loss is estimated as a function of risk ratio of the diagnosis. The loss depends on the precision of diagnosis and age of the apparatus as well. The minimum cost condition is realized by selecting a proper risk ratio. The cost reduction effect by diagnosis is also estimated by comparing with the maintenance costs without diagnosis. If the loss is lower than both “expected prematurity loss with immediate replace” and “expected failure loss with continuous operation”, the cost benefit is brought by the diagnosis. The better diagnosing precision brings the lower loss. A case study was performed assuming some realistic parameters.