【作者】 张锋；

【导师】 李剑；

【作者基本信息】 重庆大学 ， 电气工程， 2008， 硕士

【摘要】 油纸绝缘是油浸式变压器内绝缘的重要组成形式,在长期的运行过程中受到以电热应力为主的多因子老化影响,绝缘性能下降,直接威胁到变压器的安全运行。老化问题一直是绝缘学科的重要研究课题,对电气设备进行绝缘诊断和寿命预测与电力系统运行的安全性及经济性密切相关。本文首先设计了油纸绝缘电热老化试验油箱;设计了新的油纸绝缘缺陷模型,模拟了变压器匝间绝缘缺陷在绝缘油纸中放电的情况;合理地选择老化条件,对多个绝缘油纸试样进行加速电热老化试验,老化过程中定期采集缺陷模型的局部放电信号及绝缘纸样本聚合度。从局部放电信号中提取了27个局部放电统计算子,分析特征算子在老化过程中的变化规律。采用主成分因子分析方法,从局部放电统计算子中提取一组新的局部放电主成分因子,组成主成分因子统计矩阵,并分析主成分因子在老化过程中的变化规律。基于局部放电统计算子参数矩阵和主成分因子参数矩阵,采用c-均值聚类算法、模糊c-均值聚类算法、可能性c-均值聚类算法和核可能性c-均值聚类算法分别对两种参数矩阵进行聚类分析,聚类结果表明,主成分因子能够对油纸绝缘的老化状态进行有效判别,与27个统计因子相比,具有类似的聚类效果;利用主成分因子向量的可能性c-均值聚类算法和核可能性c-均值聚类算法对油纸绝缘老化状态的判别结果可以为绝缘状态诊断提供具有重要参考价值的信息。更多还原

【Abstract】 As the main insulation used in oil-immersed transformer, oil-paper suffers from thermal and electrical aging stress in the long-term running, which deteriorate the insulating performance and threaten the reliability of transformer directly. Aging research work is of vital importance in insulation subject, which ensures the secure and economy are reliable operation of power system.The oil tank is designed for the oil-paper under electrical and thermal thermal stresses. This paper presents a new oil-paper cavity modle to simulate the turn-to-turn insulation defects in transformers. A total of impregnated specimens are placed in the oil tank for the accelerated aging experiment.Aging experiment of this modle under electrical and thermal stresses are taken and partial discharges and degree of polymerization of specimens are measured during the experiment. There are 27 statistical operators are extracted from the partial discharge. The change law of statistical operators is analysed. There are principal parameters are extracted from the 27 statistical operators by factor analysis and compose the parameter matrix. The change law of principal parameters is analysed.The PD parameter vectors composed by either the statistical operators or the principal parameters are clustered by four types of clustering analysis methods, the c-mean clustering, the fuzzy c-mean clustering, the possibilistic c-means clustering and the kernel-based possibilistic c-mean clustering. The clustering results show that the robust clustering results can be obtained by using clustering algorithms with both the PD statistical operators and principal parameters. The possibilistic c-means clustering and the kernel-based possibilistic c-mean clustering show advantages to the c-mean clustering and the fuzzy c-mean clustering method for oil-paper aging diagnosis.更多还原