热效应对胶浸纸套管绝缘性能的影响及温度反演方法

Influence of Thermal Effect on Insulation Performance of Resin Impregnated Paper Bushing and Temperature Inversion Method

为研究热效应对胶浸纸(resin impregnated paper,RIP)套管绝缘特性的影响,首先搭建串联RIP套管模型温升试验平台,进行不同载流条件下RIP套管模型的频域介电谱(frequency domain spectroscopy,FDS)测试和内部温度测量,然后建立扩展德拜模型研究热效应对RIP套管模型绝缘性能的影响,最后针对套管内部温度检测的难题,提出一种基于“介质损耗”的套管内部温度反演方法。结果表明:套管模型承载的电流最终体现为内部温度的变化;复电容实部C′(ω)和虚部C″(ω)在低频段(5 mHz~5 Hz)随载流量的增加而显著增大;扩展德拜模型参数对RIP绝缘内部温度变化较为敏感,根据“介质损耗”在不同频段的表现形式,提取介质损耗面积Sp和介质损耗斜率Kp作为反演RIP套管最高温度的特征参量,该特征参量与最高温度均存在拟合优度较高的二次函数关系,据此可实现RIP套管最高温度的间接测量。该方法为检测套管内部温度提供了一条新思路。

In order to study the influence of thermal effect on the insulation characteristics of resin impregnated paper(RIP)bushing,firstly,a series RIP bushing model temperature rise test platform is built to test the frequency domain spectroscopy(FDS)and internal temperature of RIP bushing model under different current carrying conditions.Then,the extended Debye model is established to study the influence of thermal effect on the insulation performance of RIP bushing mode.Finally,for the problem of bushing internal temperature detection,a bushing internal temperature inversion method is proposed based on dielectric loss.The results show that the current carried by the bushing model is ultimately reflected in the change of internal temperature;The real part C′(ω)and the imaginary part C″(ω)of the complex capacitor increase significantly in the low frequency band(5 mHz~5 Hz)with the increase of current;The parameters of the extended Debye model are sensitive to the internal temperature change of the RIP insulation;According to the manifestation of"dielectric loss"in different frequency bands,the characteristic parameters dielectric loss area Sp and dielectric loss slope Kp are extracted to estimate the maximum temperature of the RIP bushing.The characteristic parameters and the maximum temperature have a quadratic function relationship with a high degree of goodness of fit.Based on the above relationship,the indirect measurement of the maximum temperature of RIP bushing can be realized.This method provides a new idea for detecting the internal temperature of the bushing.