节点解析法研究特高压廊管气体绝缘输电线路的热特性

摘要

根据能量守恒定理发展了一种求解廊管特高压气体绝缘输电线路(GIL)热特性的节点解析法,并基于已有文献中的实验数据验证了该方法具有较高的准确性.利用该方法,结合苏通GIL廊管工程运行工况特点,以国产1100 kV的GIL为研究对象,研究了GIL材质、环境温度(15～40℃)、负载电流(2～8 kA)、管道内压(0.1～1 MPa)等参数对GIL热特性的影响.结果表明:A类材料GIL传热性能优于B类材料GIL;环境温度与GIL温度呈线性正比关系;负载电流越大,GIL的温度越高,GIL温度与负载电流间的关系近似呈指数函数形式;管道内压只对导体温度有影响,对外壳温度无影响,同时随管道内压的增大导体温度降低,但是导体温降较小.该方法和计算结果为GIL热可靠性设计与温度监测系统设计提供了理论依据.%Based on the energy conservation theorem,a nodal analysis method for solving the thermal characteristics of EHV gas insulated transmission line (GIL) in pipe gallery is presented.According to the experimental data in the literature,it has been proved that this method has high accuracy.Using this method and combining with the characteristics of Sutong GIL pipe rack project running condition,the effects of environment temperature (15-40 ℃),load current (2-8 kA),pipe pressure (0.1-1 MPa) and other parameters on the thermal characteristics of GIL are studied with the domestic 1100 kV GIL as the research object.The results show that the GIL heat transfer performance of A-type materials is better than B-type materials.The ambient temperature is linear with the conductor and enclosure temperature.The higher the load current,the higher the temperature of the conductor and the enclosure,and the relationship between GIL temperature and load current approximates an exponential function.The internal pressure inside the pipe only affects the conductor temperature and has no effect on the enclosure temperature.The conductor temperature decreases with the internal pressure,but the temperature drop is relatively small.The proposed method and calculation results may provide a theoretical basis for the design of GIL thermal reliability and temperature monitoring system.