基于S变换与RF算法的高压发电机定子单相接地保护  

Stator Single-phase-to-ground Fault Protection for Powerformers Based on S-transform and Random Forest Algorithm

作　　者：王媛媛[1] 殷惠 林成 黄路明 陈豪威 WANG Yuanyuan;YIN Hui;LIN Cheng;HUANG Luming;CHEN Haowei(Hunan Province Collaborative Innovation Center of Clean Energy and Smart Grid（Changsha University of Science and Technology）,Changsha 410004,China;Maintenance Company of State Grid Hubei Electric Power Co.Ltd.,Wuhan 430200,China)

机构地区：[1]湖南省清洁能源与智能电网协同创新中心(长沙理工大学),湖南省长沙市410004 [2]国网湖北省电力有限公司检修公司,湖北省武汉市430200

出　　处：《电力系统自动化》2018年第22期194-199,共6页Automation of Electric Power Systems

基　　金：国家自然科学基金资助项目(51777014);国家重点研发计划资助项目(2017YFB0902903);湖南省重点研发计划项目(2018GK2057)~~

摘　　要：为了解决现有并列运行的多台高压发电机定子单相接地保护无选择性的问题,文中提出了一种基于S变换与随机森林(RF)算法的高压发电机定子单相接地保护方案。该方案利用S变换构造高压发电机定子单相接地故障下暂态零序电流幅—时—频矩阵,提取S变换幅—时—频矩阵相关系数、S变换暂态能量特征和暂态零序有功功率特征作为特征向量,将特征向量输入到RF保护判别模型中得到判别结果,从而辨识出发生故障的高压发电机。仿真结果表明在不同的故障条件下该保护方案的故障判别准确率较高,有望改善高压发电机定子单相接地保护的性能,弥补了单一故障特征量判别法的不足,且无须设置整定值,有效减少了系统运行方式对保护的影响。At present, the single-phase-to ground fault protection has no selectivity when it is used for multiple Powerformers in parallel. To solve this problem, a new stator single-phase-to-ground fault protection scheme based on S-transform and random forest （RF） algorithm is proposed. The scheme uses S-transform to construct the amplitude-time-frequency matrix of transient zero sequence current in single-phase-to-ground fault of multiple Powerformers. The correlation coefficient of S-transform amplitude-time-frequency matrix, S-transform transient energy characteristic and zero-sequence active power characteristic are extracted as feature vectors which are input into the discriminant model of RF protection model to obtain the discriminant results, and then the fault Powerformer is identified. The simulation results show that the protection scheme has a high accuracy rate of fault identification under different fault conditions, which is expected to improve the performance of single-phase-to-ground protection of multiple Powerformers and make up for the deficiency about the discrimination method of the single fault characteristic quantity. In addition, the protection scheme does not need to set the setting value, which effectively reduces the impact of the system operation mode on the protection.

关 键 词：高压发电机 单相接地保护 S变换 随机森林算法 

分 类 号：TM31[电气工程—电机]