基于电热耦合的油纸绝缘套管内部压强变化特性

Internal Pressure Change Characteristics of Oil-impregnated Paper Bushing Based on Electro-thermal Coupling

油纸绝缘套管作为目前电力系统应用最广泛的套管类型,因在运行时无法掌握内部动态压强,不能及时发现内部缺陷,严重影响套管使用寿命。为此,提出了油纸绝缘套管内部压强的解析数学算法,建立了试验用油纸绝缘套管的电热耦合分析模型,考虑了导电杆载流量和外界环境温度对油纸绝缘套管内部压强的影响,通过搭建试验用油纸绝缘套管平台对所提算法模型进行了准确性验证。结果表明:套管内部压强解析数学算法具有较高的计算精度,套管油枕处呼吸腔中空气的压缩量是影响油纸绝缘套管内部压强变化的主要因素;结合仿真分析,呼吸腔内空气压强占套管内部压强的76.9%。研究成果对于掌握油纸绝缘套管内部压强分布,及时捕捉套管异常状态有重要的指导意义。

The oil-impregnated paper(OIP)bushing is currently the most widely used bushing type in power systems and its internal defects can not be timely found due to the unknown dynamic pressure during operation,which seriously im-pairs the service life of the bushing.Therefore,an analytical mathematical algorithm for the internal pressure of the OIP bushing is proposed in the paper.Then,an electro-thermal coupling model of the testing OIP bushing is established to an-alyze the influence of the conductive rod current and ambient temperature on the internal pressure.Moreover,the testing OIP bushing platform is used to verify the accuracy of the algorithm.The results show that the mathematical model of the bushing has high computational accuracy,and the air pressure inside the breathing chamber is the main factor affecting the internal pressure changes of the bushing.Combined with the analyses of the simulation,the air pressure accounts for 76.9%of the internal pressure of the bushing.The research results have important guiding significance for mastering the internal pressure distribution of OIP bushing and timely capturing abnormal states of OIP bushing.