基于多状态数据均衡与XGBoost的特高压换流阀运行状态评估  

Operation State Evaluation of UHV Converter Valve Based on Multi-state Data Equalization and XGBoost

作　　者：李轩[1] 梅飞[2] 沙浩源 郑建勇[1] LI Xuan;MEI Fei;SHA Haoyuan;ZHENG Jianyong(School of Electrical Engineering,Southeast University,Nanjing 211096,China;College of Energy and Electrical Engineering,Hohai University,Nanjing 211100,China)

机构地区：[1]东南大学电气工程学院,南京211096 [2]河海大学能源与电气学院,南京211100

出　　处：《高电压技术》2022年第2期644-652,共9页High Voltage Engineering

基　　金：国家重点研发计划(2018YFB1500800);国网江苏省电力有限公司科技项目(J2019010)。

摘　　要：为减少直流系统停运与检修时间,提高换流阀运行的稳定性,提出一种基于多状态数据均衡与极端梯度提升(extreme gradient boost,XGBoost)的特高压换流阀状态评估方法。首先,针对晶闸管换流阀的主要部件,提取晶闸管组件、阀冷却组件、阀避雷器以及外部环境等4类特征指标;然后,提出一种基于孤立森林与合成少数类过采样技术的数据预处理方法,剔除数据集中的离群样本;再对少数类样本进行过采样,以实现各状态数据集的有效性与均衡性;接着,利用预处理后的数据训练XGBoost分类器,结合K-fold交叉验证与网格搜索法获取模型的最优超参数。最后以江苏省某换流站的实测数据为例对所提方法进行验证,结果表明:计算评估模型的准确率达97.1%,较传统方法更能准确判断换流阀的运行状态,同时该模型能反应各状态量的特征贡献度,可为换流阀的检修提供依据。In order to reduce the downtime and maintenance time of a DC system and improve the stability of converter valve operation,a state evaluation method for UHV converter valve based on multi-state data equalization and extreme gradient boost(XGBoost)is proposed.Firstly,for the main components of the thyristor converter valve,the four characteristic indexes of the thyristor component,the valve cooling component,the valve arrester and the external environment are extracted.A data preprocessing method based on isolated forest and synthetic minority oversampling technology is proposed,where the outlier samples in the data set are removed,and then the minority samples are oversampled to achieve the effectiveness and balance of the data set in each state.The preprocessed data are utilized to train the XGBoost classifier,and the optimal hyperparameters of the model are obtained based on the K-fold cross-validation and grid search method.Finally,the measured data of a converter station in Jiangsu Province are taken as an example to verify the proposed method,and the results show that the accuracy rate of the evaluation model is 97.1%,which is more accurate than traditional methods for judging the operating state of the converter valve.In addition,the model can reflect the characteristic contribution of each state quantity,and provide a basis for the maintenance of the converter valve.

关 键 词：换流阀 状态评估 不平衡数据集 孤立森林 XGBoost 特征提取 

分 类 号：TM721.1[电气工程—电力系统及自动化] TP181[自动化与计算机技术—控制理论与控制工程]