Theoretical Foundation for Residual Lifetime Estimation

抄録

This paper shows a method, in the Weibull-power model, of estimating the parameters and the residual lifetime of insulation which had been under the specified service voltage stress for a long period. The deterioration model is assumed to include a threshold stress below which a breakdown will not occur. When a presumptive threshold is higher than the service voltage stress, the insulation will not deteriorate at all. In such a case, a hypothesis test which determines whether the threshold is higher than the service stress is shown ; the test can also support the existence of a strictly positive threshold. These methods will be applicable to the residual lifetime analysis for cross-linked polyethylene insulated cables which had been used for decades. Some simulated examples are demonstrated.