高速列车车顶抗偏折硅橡胶复合绝缘子伞裙参数的优化研究

Sheath parameters optimization of anti-deflection silicone rubber composite insulator installed on the roof of high-speed train

高速列车运行期间的气流会导致车顶硅橡胶复合绝缘子伞裙发生偏折,反复偏折会造成绝缘子伞裙机械强度下降,严重时伞裙表面会出现凹坑或裂缝,水分通过凹坑或裂缝侵入芯棒界面可引发绝缘子绝缘性能降低甚至闪络等故障,影响高速列车的安全稳定运行。为了研究车顶绝缘子在高速气流环境下的伞裙形变特性,基于流固耦合方法,仿真分析了伞裙形变产生原因及伞裙根部厚度、伞裙直径、伞裙倾角等参数的变化对车顶绝缘子伞裙形变量的影响规律,开展正交试验获取抗偏折性最优的伞裙参数组合。在满足车顶绝缘子爬电距离要求的前提下,设计制造一种芯棒加装伞骨的真型抗偏折硅橡胶复合绝缘子,最后通过仿真试验相结合的方式获取了优化模型的形变量。仿真及试验结果表明:车顶绝缘子伞裙形变量随伞裙直径的增大而增大,随伞裙根部厚度的增大而减小,适当改变伞裙上倾角等结构参数均可改变绝缘子伞裙形变量。新型抗偏折硅橡胶复合绝缘子在90m/s仿真风速下伞裙最大形变量不超过0.18mm;在0~110m/s试验风速下伞裙最大形变量不超过0.5mm,试验结束后绝缘子伞裙均未出现撕裂等现象。文中优化设计的抗偏折硅橡胶复合绝缘子可为极端环境中车顶绝缘子的伞裙结构设计与优化提供参考。

The airflow during the running of high-speed train would cause the deflection of silicone rubber composite insulator sheath on the roof,and the mechanical strength of the insulator sheath would decrease after repeated deflection.In severe cases,pits or cracks would appear on the surface,and water intrusion into the core bar interface through pits or cracks can cause faults such as reduced insulation performance of insulators or even flashover,affecting the safe and stable operation of the high-speed train.In order to study the deformation characteristics of the sheath of the roof insulator in the high-speed air flow environment,based on the fluid-structure coupling method,the causes of the deformation of the sheath and the influence of the changes of the root thickness of the sheath,the diameter of the sheath,the Angle of the sheath and other parameters on the shape variable of the roof insulator were simulated and analyzed.Meanwhile,based on the simulation results,the optimal anti-deflection sheath parameter combination was first obtained in the orthogonal test;and then on the premise of meeting the creepage distance requirements of the roof insulator,a type of authentic anti-resistant silicone rubber composite insulator with mandrake and umbrella was designed and made.Finally,the deformation size of the optimized model was obtained by combining with the simulation test.The results show that the sheath shape variable of the roof insulator increases with the increase of the sheath diameter,decreases with the increase of the thickness of the sheath root,and appropriately variations in the sheath angle and other structural parameters can change the sheath shape variable of the roof insulator.The simulation and test results also show that the maximum shape variable of the new anti-resistant silicone rubber composite insulator sheath is less than 0.18 mm at the simulated wind speed of 90 m/s.Under the test wind speed of 0~110 m/s,the maximum shape variable of the sheath is no more than 0.5 mm,and the insulator's sheath does not tear after the test.The optimized design of deflection-resistant silicone rubber composite insulator provides a reference for structure design and optimization of roof insulator of the sheath in extreme environment.