运行中变压器表面振动信号特征分析与提取

发布时间：2018-04-27 14:41

本文选题：变压器 + 振动信号　；参考：《华北电力大学》2017年硕士论文

【摘要】：变压器是电力系统的关键设备,其运行的可靠性影响着电网的运行安全。统计结果表明变压器绕组和铁芯是变压器故障的多发部件,变压器表面振动信号与绕组及铁芯运行状态密切相关,由此通过变压器表面振动信号的特征分析与提取,可准确反映绕组与铁芯的工作状态,进而实现振动法监测变压器运行状态。本文以运行中变压器表面三维振动信号为研究对象,结合负载电流和运行电压对不同方向振动信号的时域峰值特征、傅里叶变换频谱特征和依据小波包分解法得到的能量谱特征进行了分析总结。在特征分析的基础上,针对变压器表面振动信号特征提取的需求,结合变压器负载电流和运行电压数据对振动信号进行了能量、相关性和灵敏度分析,构造了可用来表征变压器绕组和铁芯运行状态变化的特征向量,该向量可用于定量表示变压器表面振动信号频点能量受负载电流和运行电压变化的影响,为变压器的特征提取提供新的思路。变压器运行工况复杂多变,对其表面振动信号具有显著影响,本文参考风电机组的区间划分方法,完成了对变压器运行工况的划分。结合特征向量和各工况下振动信号的能量分布,设定了变压器振动异常判定准则,用于变压器的在线监测。
[Abstract]:Transformer is the key equipment in power system. The reliability of transformer affects the safety of power system. The statistical results show that transformer windings and iron cores are the frequent components of transformer faults, and the vibration signals on the surface of transformers are closely related to the operating state of the windings and cores. Therefore, the characteristic analysis and extraction of the vibration signals on the surface of the transformers are carried out. It can accurately reflect the working state of winding and iron core, and then realize the vibration method to monitor the operating state of transformer. In this paper, three dimensional vibration signals of transformer surface in operation are taken as the research object, and the time domain peak characteristics of vibration signals in different directions are combined with load current and operating voltage. The spectrum features of Fourier transform and the energy spectrum obtained by wavelet packet decomposition are analyzed and summarized. Based on the characteristic analysis, the energy, correlation and sensitivity of the vibration signal are analyzed by combining the load current and the running voltage data of the transformer, aiming at the demand of feature extraction of the vibration signal on the surface of the transformer. The eigenvector, which can be used to represent the change of transformer winding and core operation state, is constructed. The vector can be used to quantitatively express the influence of load current and operating voltage on the frequency point energy of vibration signal on the surface of transformer. It provides a new idea for feature extraction of transformer. The operation conditions of transformers are complex and changeable, which have a significant effect on the surface vibration signals. This paper, referring to the partition method of wind turbine units, completes the partition of transformer operating conditions. Based on the eigenvector and the energy distribution of vibration signals under different working conditions, the criterion of transformer vibration anomaly is set up, which is used for on-line monitoring of transformers.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN911.7;TM41

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