基于微分域电流过零点偏移特征的电抗器匝间保护新方法  

Novel method of shunt reactor inter-turn protection based on current zero-crossing offset characteristic in differential domain

作　　者：陈继瑞[1] 李宝伟[1,2] 田宝江 朱云峰[1] 王智勇[1] 王瑞彬 CHEN Jirui;LI Baowei;TIAN Baojiang;ZHU Yunfeng;WANG Zhiyong;WANG Ruibin(XJ Group Co.,Ltd.,Xuchang 461000,China;State Key Laboratory of Advanced Electromagnetic Engineering and Technology,Huazhong University of Science and Technology,Wuhan 430074,China;State Grid Henan Electric Power Dispatching Control Center,Zhengzhou 450052,China)

机构地区：[1]许继集团有限公司,河南许昌461000 [2]华中科技大学强电磁工程与新技术国家重点实验室,湖北武汉430074 [3]国网河南省电力公司电力调度控制中心,河南郑州450052

出　　处：《电力自动化设备》2023年第2期212-217,共6页Electric Power Automation Equipment

基　　金：国家电网公司总部科技项目(5100-202255011A-1-1-ZN)。

摘　　要：以中性点不带小电抗的高压并联电抗器为研究对象,在分析电抗器空投励磁涌流特征的基础上,指出了并联电抗器不带中性点小电抗时涌流会更加严重,是引起匝间保护误动的主要原因。分析了并联电抗器空投饱和的机理,指出了电抗器绕组磁通饱和后微分域相电流过零点前后采样峰值间距会发生偏移,在此基础上提出一种基于微分域电流过零点偏移特征的电抗器匝间保护新方法。利用工频特征下相电流过零点前后峰值间距与微分域相电流过零点前后采样峰值间距的偏移程度,结合相电流线性区内各时刻电感的均方根值与额定电感之间的特征关系来识别电抗器空投饱和与匝间故障,若识别为电抗器空投饱和则闭锁匝间保护,若识别为匝间故障则经短延时开放匝间保护。仿真结果验证了所提方法的正确性和有效性。Taking the high voltage shunt reactor without neutral small reactor as the research object,based on the characteristic analysis of magnetizing inrush current of reactor under no-load closing,it is pointed out that the inrush current will be more serious in case of shunt reactor without neutral small reactor,which is the main cause of inter-turn protection maloperation. The no-load closing saturation mechanism of shunt reactor is analyzed,it is pointed out that after reactor winding flux saturation,the sampling peak distance before and after zero-crossing point of differential domain phase current will shift. On this basis,a novel method of shunt reactor inter-turn protection based on current zero-crossing offset characteristic in differential domain is proposed. By using the offset degree of the peak distance before and after zero-crossing point of phase current in power frequency characteristics and differential domain,and combining the characteristics relationship between the root mean square of inductors and rated inductance in the linear region of the phase current,the shunt reactor no-load closing saturation and inter-turn short circuit fault can be identified. If it is identified as shunt reactor no-load closing saturation,lock the inter-turn protection. If it is identified as inter-turn short circuit fault,set the inter-turn protection after short delay. The correctness and effectiveness of the proposed method are verified by simulative results.

关 键 词：中性点小电抗 并联电抗器 匝间保护 微分域电流 线性区电感 空投饱和 

分 类 号：TM47[电气工程—电器]