基于绕组短路冲击响应时频特性的多特征联合形变判定方法  

Multi-Feature Joint Deformation Determination Method Based on Time-Frequency Characteristics of Winding Short-Circuit Impulse Response

作　　者：张子康 耿江海[1] 汪鑫宇 吕安强[2] 高树国 Zhang Zikang;Geng Jianghai;Wang Xinyu;LüAnqiang;Gao Shuguo(Hebei Provincial Key Laboratory of Power Transmission Equipment Security Defense North China Electric Power University,Baoding 071003,China;Department of Electronic and Communication Engineering Hebei Province North China Electric Power University,Baoding 071003,China;State Grid Hebei Electric Power Research Institute,Shijiazhuang 050021,China)

机构地区：[1]华北电力大学河北省输变电设备安全防御重点实验室,保定071003 [2]华北电力大学电子与通信工程系,保定071003 [3]国网河北省电力有限公司电力科学研究院,石家庄050021

出　　处：《电工技术学报》2024年第20期6564-6576,6590,共14页Transactions of China Electrotechnical Society

基　　金：河北省自然科学基金资助项目(E2021521004)。

摘　　要：为研究变压器短路冲击信号包含的物理特征与绕组形变之间的关系,提出一种基于绕组冲击响应时频特性的特征提取及形变判定方法。基于单自由度系统的相对位移模型构建绕组的短路冲击响应谱,得到其响应点频率偏移特征。对Hilbert能量谱进行非均匀频率带宽划分,修正累积效应的影响,提取不同频带范围内的能量带熵并计算加权能量带熵,表征特定频带内的能量混乱度;构建时频矩阵,量化能量密度分布、短时能量衰减变化等细节特征,对该矩阵进行奇异值分解,根据奇异值分布特性计算每个元素的权重值。据此提出基于加权能量带熵及基频奇异值畸变率的联合绕组状态判定方法,经三组共17次短路冲击试验数据验证,冲击信号的相对能量带熵增量变化与绕组产生的累积微应变呈高度正相关,基频奇异值畸变率与绕组发生形变的规律一致,发生形变时,该畸变率的值会大于2.0,证明了该判定方法的有效性。该方法可在变压器发生短路后对绕组的状态进行预判,进而考虑是否需要进一步处理,对变压器绕组状态的在线监测具有一定的指导意义。The transformer will suffer many external short-circuit impact during long-term operation,and the winding will be affected by many accumulations,which will produce irreversible deformation.However,there are still some problems in the study of on-line monitoring of winding mechanical status.The operation of transformer is affected by the accumulative effect,and the relevant studies have not modified the relevant eigenvalues by de-accumulation.The fault diagnosis is mainly aimed at the fundamental frequency vibration signal of the transformer,but the frequency doubling component within 500 Hz is generally present in normal operation,and the transient state contains more higher harmonics.To solve these problems,a feature extraction and deformation determination method based on time-frequency characteristics of shock response of winding is proposed in this paper,which can accurately judge the deformation of winding.Firstly,based on the relative displacement model of the single degree-of-freedom system,the short-circuit shock response spectrum of the winding is constructed,and the distribution law of the vibration shock response of the winding considering the cumulative effect is obtained.The Fourier spectrum and shock response spectrum distribution of the measured signal are compared to determine the frequency analysis range.Secondly,the time-frequency energy distribution of the short-circuit impulse signal is calculated,and the frequency bands of the energy spectrum are divided according to the response distribution characteristics obtained by the impulse response spectrum to offset the influence of the cumulative effect,and the characteristic changes of the relative energy band entropy are obtained,and the weighted entropy increment is calculated.Thirdly,transform the energy spectrum into time-frequency matrix,decompose the signal by singular value decomposition(SVD),get the singular value vector,and calculate its weight according to the distribution characteristics of the singular value,can calculate the fundament

关 键 词：短路试验 绕组形变 累积效应 冲击响应 时频矩阵 

分 类 号：TM407[电气工程—电器]