基于ERF和BO-SVC的交流接触器触头故障识别方法

AC contactor fault recognition based on ERF and BO-SVC

针对交流接触器各状态样本不均衡导致故障状态识别精度低和特征冗余度高的问题,文中提出一种基于嵌入式随机森林(embedded random forest,ERF)和贝叶斯优化非线性支持向量机(Bayesian optimization-support vector classification,BO-SVC)的复合识别方法。首先,通过交流接触器全寿命试验平台提取接触器状态特征,并针对各状态样本间不均衡导致识别精度低现象,提出一种基于权重法的样本均衡处理策略。然后,使用ERF对均衡后样本进行特征选择和降维,提取最能表征触头状态变化规律的最优特征。最后,将最优特征输入到BO-SVC识别模型,与另外2种代表性模型作为对比,以精确率、召回率和F1-分数3个指标对各模型性能进行评估。在3个指标上,文中方法的结果分别达到95.22%、98.91%和97.01%,均高于对比模型。以F1-分数为指标,在4组样本上对各模型性能进行测试,结果表明文中方法的F1-分数平均高出对比模型0.56%和27.28%,验证文中研究有效解决了交流接触器特征冗余和故障识别精度低的问题。

In response to the challenges posed by imbalanced samples leading to low recognition accuracy and high feature redundancy in AC contactor,a novel composite recognition methodology which is leverages embedded random forest(ERF)and Bayesian optimization-support vector classification(BO-SVC)is introduced.Firstly,the extraction of contactor state features from the full life testing platform designed for contactor is initiated.To counteract the low recognition accuracy caused by the imbalance among different state samples,a sample balancing strategy based on the weighted method is proposed.Subsequently,the ERF is employed to perform feature selection and reduction on the balanced samples.This process leads to the extraction of optimal features that represent the dynamic patterns of AC contactor state changes.Following the feature extraction step,the selected optimal features are fed into BO-SVC recognition model.A comprehensive evaluation of BO-SVC′s fault recognition capabilities is undertaken,compared with two other representative models,the performance of each model is evaluated based on three indicators:accuracy,recall,and F1-score.The results of the proposed method reaches 95.22%,98.91%,and 97.01%,respectively,all of which are higher than the comparison models.Using F1-score as an indicator,the performance of each model is tested on four sets of samples,and the results showed that the F1-score of the proposed method is on average 0.56%and 27.28%higher than the compared models,respectively.The research in the article effectively solves the problems of redundant characteristics and low fault recognition accuracy of AC contactors.