基于小波分析的变压器转换性故障快速识别方法  

Research on Fast Identification Methods for Transformer Faults Based on Wavelet Transform

作　　者：孙广慧 郑楚韬 孔祥轩 刘杰荣 刘洪铭 王聃 马恒瑞 SUN Guanghui;ZHENG Chutao;KONG Xiangxuan;LIU Jierong;LIU Hongming;WANG Dan;MA Hengrui(Foshan Power Supply Bureau,Guangdong Power Grid Co.,Ltd.,Foshan 528200,Guangdong,China;Jiaxing Power Supply Company,State Grid Zhejiang Electric Power Co.,Ltd.,Jiaxing 314000,Zhejiang,China;Qide Institute of Renewable Energy,Qinghai University,Xining 810016,Qinghai,China)

机构地区：[1]广东电网有限责任公司佛山供电局,广东佛山528200 [2]国网浙江省电力有限公司嘉兴供电公司,浙江嘉兴314000 [3]青海大学启迪新能源学院,青海西宁810016

出　　处：《电网与清洁能源》2021年第2期23-29,41,共8页Power System and Clean Energy

基　　金：国家自然科学基金项目(51777142&51907096);青海省自然科学基金项目(2019-ZJ-950Q)。

摘　　要：当变压器发生区外故障时,会出现因电流传感器饱和而导致差动保护误动的问题。为解决这一问题,文中提出了基于小波分析的时差法,作为变压器差动保护判断区内、外故障的判据。首先,分析了电流互感器的饱和对变压器差动保护产生的影响;其次,利用模极大值原理研究了小波用于信号奇异性检测的方法,并选取合适的阈值规则对含噪声信号进行了消噪处理;然后,利用小波模极大值原理确定故障开始和差流出现的时刻;最后,提出了一种基于综合负序分量的变压器区外转区内故障时解除差动保护闭锁的新判据,并仿真验证了该方法的有效性。When a fault occurs outside the transformer zone,the differential protection misoperation will occur due to saturation of the current sensor.In order to solve this problem,this paper proposes a time difference method based on wavelet analysis as a criterion for determining the internal and external faults of the transformer differential protection.First,the effect of saturation of the current transformer on the differential protection of the transformer is analyzed.Second,the method of wavelet for signal singularity detection is studied using the principle of modulus maximum,and appropriate threshold rules are selected for de-noise processing for noise-containing signals.Third,the wavelet modulus maximum value principle is used to determine the start time of the fault and the time of the occurrence of the differential current.Finally,a new criterion based on the integrated negative sequence component to remove the differential protection lockout in the course of transferring of an out-of-zone fault to an inside-zone fault for transformers.transformer faults transferring from outside the zone to inside,and simulations verify the effectiveness of the method.

关 键 词：变压器故障 识别方法 小波分析 

分 类 号：TM452[电气工程—电器]