电缆接头偏心情况下的表面温度分布及统计特性研究

电缆接头偏心导致绝缘性能变差和局部过热,加速绝缘老化和击穿,严重时会造成电缆爆炸。因此,文中提出了一种基于表面温度统计特性的表征电缆接头偏心情况的方法,首先建立了电缆接头的电磁-热多物理场模型,在验证模型准确性的基础上,仿真验证了利用表面温度统计特性表征电缆接头偏心程度的有效性;其次,搭建了电缆接头偏心模拟试验平台,试验分析了不同偏心度下的温度概率密度曲线分布规律。结果表明:利用电缆接头表面温度统计特性能够较好的反映电缆接头偏心情况,且可利用统计参数与电缆偏心程度间的数学关系逆向推知电缆接头偏心度。

Surface Temperature Distribution and Statistical Characteristics of Cable Joints Under Eccentric Conditions

The eccentricity of cable joint may cause local overheating and variation of insulation performance,which will accelerate insulation aging,cause insulation breakdown and explosion of the cable in severe case.As a result,this paper puts forward the method to judge the eccentricity of the cable,which is based on the statistical characteristics of surficial temperature.This paper carries out the following work.Firstly,the electromagnetic-thermal field coupling model of cable joint is built.On the basis of verifying the accuracy of the model,the validity of the statistical characteristics of surface temperature to characterize the degree of eccentricity of cable joints is verified by simulation.Secondly,a simulation test platform for cable joint eccentricity is built,and the distribution regulation of temperature probability density curve under different eccentricity is tested and analyzed.The result shows that the statistical characteristics of cable’s surficial temperature could reflect the eccentricity of the cable joint well.What’s more,through mathematical relationship between the statistical parameter and the degree of cable’s eccentricity,we could judge the degree of cable’s eccentricity.