A New Lifetime Estimation Method Using the Combined Data of the Accelerated Test Data and the Inspection Data.

使用全新电气绝缘的加速寿命试验长期以来一直用于估计绝缘的寿命。尽管在加速寿命试验中对绝缘施加了各种类型的应力，但由于意外的劣化因素，绝缘通常比估计寿命更快地断裂。然后使用工作绝缘进行升压击穿电压测试，以评估绝缘的实际剩余寿命。然而，这两种测试方法之间的关系的理论解释还没有严格。联合收割机可以采用纳尔逊提出的累积暴露量模型，也可以采用通常用于短时加速寿命试验的Sedyakin模型，在研究累积暴露量模型时，我们发现模型参数估计的各种困难，因此我们首先研究了用升压法估计击穿电压的问题。升压 关于我们 方法被用来估计冲击击穿电压时，电气绝缘被打破后，它是不可用的。我们分析的可靠性估计的潜在的击穿概率分布的逐步上升的方法，当（1）所观察到的击穿电压本身是可用的，（2）它是不可用的。与后一种情况相比，前一种情况具有许多优点，例如（1）估计的置信区间变得更小，（2）可以稳定地获得估计。我们总结了三种情况下，潜在的概率分布的击穿电压被假定为正态分布，威布尔，和gumbel类型的结果。对各种分布模型的最优检验方法作了简明扼要的描述。在假定概率分布为若干可靠性分布模型时，推荐了一种新的递增试验方法。我们首先推荐使用基本概率分布的参数。其次，如果所观察到的击穿电压本身而不是击穿和非击穿的二值信息是可用的，则使用新的升压方法是有利的。与传统的逐步增加法相比，采用新的逐步增加法可以大大减少试验样本的数量，以获得相同的估计可靠度。升压测试获得50%击穿电压的最佳策略是将升压距离设置为大于基础分布的标准偏差的一半。少

Accelerated life tests using the brand-new electrical insulation have long been used to estimate the lifetime of the insulation. Although a variety of types of stresses are imposed on the insulation in the accelerated life tests, the insulation is often broken more quickly than the estimated lifetime due to unexpected deterioration factors. The step-up breakdown voltage tests using the working insulation are then performed to assess the actual remaining lifetime of the insulation. However, theoretical explanations of the relation between these two test methods have not been made rigorously. One way to combine these two may be the cumulative exposure model proposed by Nelson, or Sedyakin model which is usually applied to short time accelerated life testing.In studying the cumulative exposure model, we have found a variety of difficulties in parameter estimation for the model; thereby this fact leads us to study first the breakdown voltage estimation using the step-up method. The step-up … More method is used to estimate the impulse breakdown voltages when the electrical insulation is not usable after it is broken. We analyses the reliability of the estimates of the underlying breakdown probability distribution in the step-up method, when (1)the observed breakdown voltage itself is available and (2)it is not available. The former case has many advantages compared to the latter case such that (1)the confidence intervals of the estimates become smaller and (2)the estimates can be obtained in stable. We summarize the results of the three cases that the underlying probability distribution for the breakdown voltage is assumed to be normal, Weibull, and gumbel types. The optimal test method is simply and clearly described for various distribution models. The new step-up test method is recommended when the underlying probability distribution is assumed to be some reliability distribution models. We first recommend the use of the parameters of the underlying probability distribution. Second, it is advantageous to use the new step-up method if the observed breakdown voltage itself rather than the two-valued information of breakdown and non-breakdown is available. Using the new step-up method, the number of test specimens can be substantially reduced comparing to that in the conventional step-up method to obtain the same estimation reliability. The optimal strategy of the step-up test to obtain the 50% breakdown voltage is to set the step-up distance to larger than the half of the standard deviation of the underlying distribution. Less