基于最优FIR滤波器的小电流接地故障选线技术  

Low-current grounding fault line selection technology based on optimal FIR filter

作　　者：王喆 WANG Zhe(Southern Power Grid Digital Enterprise Technology(Guangdong)Co.,Ltd.,Guangzhou 510700,China)

机构地区：[1]南方电网数字企业科技(广东)有限公司,广东广州510700

出　　处：《粘接》2025年第3期150-153,共4页Adhesion

摘　　要：由于小电流接地系统的故障信号特征不明显,容易被其他干扰信号掩盖,导致故障选线不准确。为提升小电流接地故障定位准确度,提出基于最优FIR滤波器的小电流接地故障选线技术。通过分析小电流接地故障的暂态特征,获取电流接地故障原因。采用EMD分解方法对小电流接地系统各相电路实施零序电流分解,以高频分量为目标设计最优FIR滤波器。根据建立的最优FIR滤波器,计算线路频带信号相应幅值,确定暂态零序电流时频特征。依据时频特征的相似性度量结果,制定综合相关系数,确立判定条件实现小电流接地故障选线。实验结果表明,所提方法开展小电流接地故障选线时,选线判据灵敏度高且抗噪性较好。由此证明,所提方法在小电流接地故障选线时具有较高的应用效果。Because the fault signal characteristics of the low-current grounding system are not obvious,it is easy to be covered by other interference signals,resulting in inaccurate fault line selection.In order to improve the accuracy of low-current grounding fault location,a small-current grounding fault line selection technology based on the optimal FIR filter was proposed.By analyzing the transient characteristics of small current grounding faults,the causes of current grounding faults were obtained.The EMD decomposition method was used to decompose the zero-sequence current of each phase circuit of the low-current grounding system,and the optimal FIR filter wais designed with the high-frequency component as the goal.According to the established optimal FIR filter,the corresponding amplitude of the line band signal was calculated,and the time-frequency characteristics of the transient zero-sequence current were determined.According to the similarity measurement results of time-frequency characteristics,the comprehensive correlation coefficient was formulated,and the judgment conditions were established to realize the line selection of small current grounding faults.Experimental results showed that the proposed method had high sensitivity and good noise immunity when carrying out line selection for low-current grounding faults.The proposed method has a high application effect in the line selection of small current grounding faults.

关 键 词：最优FIR滤波器 小电流接地故障 选线技术 特征提取 电流时频分解 

分 类 号：TM711.2[电气工程—电力系统及自动化]