基于线圈电流分析的操动机构故障诊断方法

Fault diagnosis method of circuit breaker operating mechanism based on coil current analysis

提出一种贝叶斯更新和DS证据理论相结合的分合闸线圈电流分析方法。运用线圈模型提取线圈电流理想特征,与实际电流特征进行校正得到特征残差,以补偿环境对线圈电流的影响;利用历史样本数据和贝叶斯方法对各个特征残差分布参数进行后验估计,降低测量误差的干扰;在后验分布结果上,依据不确定性规则对概率进行分割,使用DS证据理论融合分割结果,实现操动机构各类故障的有效评估.在实验平台上进行故障模拟与故障成因诊断实验,结果表明：该方法在故障征兆发生的1~2次内即可准确地识别出故障原因,说明改进方法能够有效减少系统测量误差带来的影响,具有较强诊断的敏感性与分类准确性,为视情维修提供较可靠依据.

A coil current analytical method for diagnosing circuit breaker（CB）operation mechanism malfunction was proposed based on the combination of Bayesian updating and Dempster/shafer（DS）theory.By obtaining ideal features of coil current from the coil model,the feature error was compensated with the comparison between ideal and real current features in order to offset the environment effect.On the purpose of reducing the influence of measurement error,the posteriori estimation was calculated with history sampling data for describing the distribution parameters of feature error by means of Bayesian updating.On the basis of posteriori distribution,the probability was segmented and fused by the way of uncertainty rules and DS methodology respectively,so that the malfunctions of operation mechanism can be assessed effectively.Experimented with the testing platform,malfunctions were simulated and diagnosed.The result illustrates that the proposed algorithm can quickly recognize fault within 1to 2times after the appearance of failure data,which means that the modified method can work against the impact of system measurement error effectively.The diagnosis and classification are sensitive and accurate,which provides maintenance with reliable basis.