基于改进平均秩次法的保护装置可靠性评估

针对保护装置可靠性分析中模型的精度问题,提出了一种综合改进平均秩次法与最小二乘法的威布尔分布模型参数估计新方法。该方法克服了平均秩次法只计及每个数据删失点的位置,而未考虑到每个失效区间的长度对结果影响的不足。在对保护装置的故障数据与删失数据预处理的基础上,分别采用平均秩次法与改进的平均秩次法对威布尔分布的形状参数与尺度参数进行估计,进一步得到可靠度函数及失效率函数等并进行了相关分析。以某型号继电保护装置的故障数据和删失数据为例,对比两种方法的参数估计结果,验证了提出的新方法比传统方法所得结果更加贴近实际的优点。

Reliability evaluation of protective device based on improved average rank order method

Aiming at improving the model accuracy for reliability assessment of protective devices, a new approach to estimate the parameters of the Weibull distribution model, integrating improved mean-rank method and the least square method, is proposed. It overcomes the shortcoming that the mean-rank method only considers the truncation-point position of each datum, and does not take into account the impact of the length of each failure interval on the analysis result. Based on pretreatment of failure data and censored data of protective devices, the shape and scale parameters of the Weibull distribution are estimated with the mean-rank method and the improved mean-rank method respectively, and the reliability function and the failure-rate function are obtained and analyzed. Taking the failure data and the censored data of a type of protective device as examples, parameter-estimation results of these two methods are compared, which verifies that the results obtained by the proposed method are more closely aligned with the practical operation status of the protective device. This work is supported by National Natural Science Foundation of China (No. 51877084), Natural Science Foundation of Hebei Province (No. E2018502063), and Fundamental Research Funds for the Central Universities (No. 2017MS096).