车载电缆终端非线性应控管改善畸变电场分布的优化研究

Optimal Research on Improving Distorted Electric Field Distribution by Nonlinear Stress Tube of Vehicle Cable Terminal

电缆柔性终端对高速动车组供电系统的安全、稳定运行有着极为重要的作用。电缆终端内部存在气隙、导电微粒等杂质或遭受雷击过电压作用时,其内部电场畸变严重,在运行过程中发生爆炸事故,严重影响高铁列车的安全运行。为了优化电缆终端内部电场畸变问题,建立电缆终端模型,提出使用一种与电导率参数相关的非线性材料替换高介质材料,研究两种材料用作应控管时在不同运行条件下的电场分布。仿真研究表明:使用非线性应控管能有效均匀终端内部电场,削弱电场畸变程度。同时,对使用两种应控管材料的电缆终端试样进行耐压性实验,对比局部放电结果和内部解剖情况。分析发现,采用高介质材料的应控管终端出现明显局部放电现象。研究表明,使用非线性材料应控管的电缆终端能够有效解决电场畸变,增强电缆绝缘性。

Flexible cable terminal plays an extremely important role in the safe and stable operation of the power supply system of the high speed EMU.Air gap,conductive particles and other impurities inside the cable terminal or lightning overvoltage cause serious internal electric field distortion,and may lead to explosion accidents during the operation,which seriously affects the safe operation of the high speed train.In order to optimize the electric field distortion in the cable terminal,a flexible cable terminal model was established.In this paper,a nonlinear material related to the electrical conductivity parameters was used to replace the high dielectric material to study the problem of the electric field distribution under different operating conditions by using two materials as stress control tubes.The simulation results show that the use of chloroprene or neoprene rubber of nonlinear stress control tubes can effectively and uniformly reduce the electric field inside the cable terminal,and weaken the distortion degree of the electric field.At the same time,in order to compare the results of partial discharge and internal anatomy,the voltage endurance test of cable terminal sample using two kinds of chloroprene or neoprene rubber materials of stress control tubes was carried out.It was found that partial discharge is evident at the terminal of the chloroprene or neoprene rubber with high dielectric material.The research shows that the cable terminal with stress control tubes of nonlinear materials can effectively solve the electric field distortion and enhance the cable insulation.