考虑CT饱和干扰的电力变压器励磁涌流识别方法  

Magnetizing Inrush Identification Method of Power Transformer Considering CT Saturation Interference

作　　者：刘鹏辉 焦兵豪 郭向伟 LIU Penghui;JIAO Binghao;GUO Xiangwei(School of Electrical Engineering and Automation,Henan Polytechnic University,Jiaozuo 454000,Henan Province,China)

机构地区：[1]河南理工大学电气工程与自动化学院,河南省焦作市454000

出　　处：《电网技术》2022年第9期3633-3641,共9页Power System Technology

基　　金：河南省科技攻关计划项目(212102210248,202102210092)。

摘　　要：为了进一步提升励磁涌流识别技术,减少电流互感器(current transformer,CT)饱和干扰下电力变压器差动保护的误动与拒动情况,分析了CT饱和对传统方法的干扰问题,提出了一种基于特征数据判定的励磁涌流识别方法。首先,根据差动电流波形变化率差异,采用特征数据识别常规故障电流。其次,针对部分励磁涌流波形呈现单向性这一区别于故障电流的特性,通过辨识电流形式,识别单向励磁涌流。然后,针对饱和故障电流的识别问题,借助特征数据剔除干扰波形区段后,对特定取值区域内的波形数据进行多元线性回归拟合,利用判定系数区分饱和故障电流与双向励磁涌流。最后,仿真测试结果与录波数据测试结果均验证了所提方法的可行性,同时表明该方法相比于传统方法更具抗CT饱和干扰能力。In order to improve the performance of inrush current identification and reduce the misoperation and rejection of the power transformer differential protection under the current transformer(CT) saturation interference,the interference of CT saturation with the traditional methods is analyzed and a novel inrush current identification based on the characteristic data judgment for discrimination between the magnetizing inrush and internal faults in the power transformers is presented.Firstly,according to the differences of variation rates of the differential current waveforms,the characteristic data are used to identify the conventional fault currents.Secondly,in view of the unidirectional characteristic of some inrush current waveforms which is different from the fault currents,the unidirectional inrush current is identified by identifying the current forms.Then,aiming at the identification of the saturated fault currents,after eliminating the interference waveform sections with the help of the characteristic data,the waveform data in the specific value area is fitted by the multiple linear regression,and the judgment coefficient is used to distinguish the saturated fault currents from the bidirectional inrush currents.Finally,both the simulation test and the recorded data test results verify the feasibility of the proposed method,showing that this method has more anti-CT saturation interference ability than the traditional method.

关 键 词：励磁涌流 故障电流 电流形式 特征数据 判定系数 

分 类 号：TM721[电气工程—电力系统及自动化]