基于电抗器开断过电压特征分析的匝间绝缘短路故障在线辨识

On-Line Identification of Inter-Turn Insulation Short Circuit Faults Based on Analysis of Reactor Breaking Overvoltage Characteristics

干式空心电抗器内部包封固化不易拆卸,当出现匝间绝缘短路故障时难以发现,停电检修维修成本较大周期较长,为了能利用运行中的信号在线检测出匝间绝缘故障,提出一种基于电抗器开断过电压特征分析的匝间绝缘故障辨识方法:在电抗器匝间绝缘短路故障分布式参数模型基础上,建立了带有匝间绝缘短路故障的电抗器开断过电压模型,分析匝间绝缘短路故障对电抗器开断过电压波形的影响作用,并利用变分模态分解算法对过电压波形进行频谱分析,最后搭建计及匝间绝缘故障开断过电压仿真模型,对存在不同程度的绝缘短路的电抗器进行开断模拟,获取电抗器开断电压波形及其振荡频率等数据,对波形数据进行分析和特征提取,量化开断过电压最大幅值及振荡频率与绝缘之间的差值,可以有效辨识出匝间短路故障。

In order to detect the inter-turn insulation fault online,this paper proposes an identification method of inter-tun insulation faults based on the analysis of reactor breaking overvoltage characteristics. Based on the distributed parameter model of the inter-turn insulation short-circuit fault of the reactor,the overvoltage model of the reactor with inter-turn insulation short-circuit fault is established. The influence of the inter-turn insulation short-circuit fault on the breaking overvoltage waveform of the reactor is analyzed. The frequency spectrum of the overvoltage waveform is analyzed by the variational mode decomposition algorithm. Finally,the reactor breaking overvoltage simulation model considering inter-turn insulation faults is established to simulate the reactor with different degrees of insulation short-circuit,obtain the data of the reactor breaking voltage waveform and its oscillation frequency,analyze the waveform data and extract its features,and quantify the difference between the maximum amplitude of breaking overvoltage and the oscillation frequency and insulation so that the inter-turn short-circuit fault can be identified effectively.