考虑频变参数的油浸式变压器绕组分数阶传输线模型  

Fractional Transmission Line Model of Oil-Immersed Transformer Winding Considering Frequency-Dependent Parameters

作　　者：梁贵书[1] 王雁超[1] 

机构地区：[1]华北电力大学电气工程学院,保定071003

出　　处：《电工技术学报》2016年第17期178-186,共9页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金(51177048;51407073);河北省自然科学基金(E2012502009);河北省科技指导性计划(Z2012033)资助项目

摘　　要：建立精确的变压器绕组模型对于准确分析研究绕组各处的电压分布具有重要意义。导线的趋肤效应和油纸介电常数的频变特性分别是造成变压器绕组传输线模型的阻抗和导纳参数频变的主要因素。然而,以往的变压器绕组传输线模型通常将油纸介电常数的频变特性和导线的趋肤效应忽略,影响暂态过电压分布计算的准确性。该文以具有单弛豫过程的Cole-Cole模型为基础,对油浸纸样品的实测介电常数进行拟合,利用拟合模型和平行板电容公式,推导出变压器绕组传输线模型的分数阶导纳参数,进而建立变压器绕组的分数阶传输线模型。通过对分数阶传输线模型进行仿真计算,得到绕组上的过电压波形,将仿真值与实验实测值以及未考虑频变参数时建立的整数阶传输线模型仿真值进行对比,验证了所提分数阶模型的准确性。Establishing the precise model of the transformer windings has the vital s ignificance for analyzing the voltage distribution on the windings. The frequency-dependent characteristics of the impedance parameter and the admittance parameter in the transmission line model of the transformer windings are mainly caused by the skin effect and the frequency-dependent characteristics of the permittivity of the oil-paper respectively. However, traditional transmission line models of the transformer windings often ignore the frequency-dependent characteristics of the permittivity of oil-paper and the skin effect, which influence the accuracy of calculating of transient overvoltage distribution. The measured permittivity of the oil paper samples are fitted based on the Cole-Cole model with one dielectric relaxation process. By combining the model with the capacitance formula of parallel plate, the fractional admittance parameters are derived. Then, the fractional transmission line model of the transformer windings is established. Through the simulation of the fractional transmission line model , the overvoltage waveform on the windings is obtained. It is then compared with the experimental waveform and the simulation waveform of the transmission line model without considering the frequency-dependent characteristics of the impedance parameter and the admittance parameter. The results confirm the validity of the proposed fractional model.

关 键 词：油纸 介电常数 趋肤效应 COLE-COLE模型 分数阶模型 

分 类 号：TM411[电气工程—电器]