基于短路电抗与振动信号联合分析的变压器绕组变形诊断

发布时间：2018-03-23 12:04

本文选题：变压器　切入点：绕组变形　出处：《高电压技术》2017年06期

【摘要】：通过单一信息对变压器绕组变形状态进行监测限制颇多,为使诊断结果更加准确可信,在变压器绕组电气特性与机械特性分析的基础上,结合变压器绕组短路电抗及油箱振动信号,从电气信息及振动信息中提取对绕组形变具有区分度的特征量,构建多信息诊断模型进行绕组变形诊断。具体方法为将短路电抗变化率、振动信号小波包分解后的"频段能量欧氏距离"及振动信号主频标准偏差相关量组成表征变压器绕组状态的特征向量,而后设定基准向量,求取特征向量与基准向量的夹角作为表征绕组变形程度的诊断量。针对该文试验变压器B相绕组,其正常状态、85%短路冲击电流冲击后、100%短路冲击电流冲击后、模拟故障状态的特征角度分别为0°、6.421 7°、17.820 5°、28.058 8°。试验结果表明该方法对绕组变形有较好的诊断效果,随着绕组状态的恶化,特征角度不断增大且梯度明显,对单独使用短路电抗变化率不能区分的较小形变也有区分度。
[Abstract]:In order to make the diagnosis results more accurate and credible, based on the analysis of the electrical and mechanical characteristics of the transformer windings, there are many limits to monitor the transformer winding deformation state by a single information. Combined with the short circuit reactance of transformer windings and the vibration signal of oil tank, the characteristic value of the winding deformation is extracted from the electrical information and vibration information. A multi-information diagnosis model is constructed to diagnose winding deformation. After the wavelet packet decomposition of vibration signal, the "Euclidean distance in frequency band" and the correlation between the main frequency standard deviation of vibration signal constitute the characteristic vector to characterize the winding state of the transformer, and then set the reference vector. The angle between the eigenvector and the reference vector is used as the diagnostic parameter to characterize the degree of winding deformation. In this paper, for the B phase winding of the transformer tested, its normal state is 85% short circuit impact current shock and 100% short circuit impact current impact. The characteristic angles of the simulated fault state are 0 掳/ 6.421 7 掳/ 17.820 5 掳/ 28.058 8 掳respectively. The test results show that the method has a good diagnostic effect on the winding deformation. With the deterioration of the winding state, the characteristic angle increases and the gradient is obvious. The smaller deformation which can not be distinguished by the rate of change of short-circuit reactance alone is also distinguished.
【作者单位】：沈阳工业大学电气工程学院;中国电力科学研究院;国网湖北省电力公司;
【基金】：国家电网公司基础性前瞻性科技项目(GY-71-14-009)~~
【分类号】：TM407

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