动车组高压隔离开关电极结构优化

Optimization of High-voltage Isolating Switch Electrode of China Railway High-speed

国内外针对动车组高压系统绝缘特性研究甚少,分析动车组隔离开关电场分布并选择结构合理的电极参数,对动车组安全、稳定运行具有重要的工程意义。因此基于仿真分析和实验研究相结合的方法开展动车组隔离开关高压侧电极结构优化策略研究。建立动车组隔离开关3维模型,分析高压端电极结构优化前后复合绝缘子电位、电场分布变化趋势。仿真分析电极结构参数(环半径R,管半径r)对电位、电场分布的影响。实验比较电极结构优化前后耐压性能变化趋势,在高速风洞试验室验证了优化后的电极机械连接可靠性。研究结果表明,现有动车组隔离开关高压端电极边缘存在明显的棱角,复合绝缘子伞裙四周电位分布不均匀。优化后的电极可有效降低电位梯度,优化后的轴向及沿面电场强度最大值小于0.45 kV/mm。结构优化后的隔离开关工频、雷电冲击耐压值及机械强度均满足要求。

Few investigations focus on China Railway High-speed（CRH） high-voltage system insulation characteristics both at home and abroad. It is very important to analyze the electric field distribution of CRH isolating switch and select reasonable parameters of the fitting. Consequently, we researched the optimization strategy of the fitting structure on the high-voltage side of the CRH isolating switch by using the method of the combination of simulation calculation and expe- rimental verification, and established a CRH isolating switch 3D model Moreover, we analyzed the variation trend of electric potential and field distribution for the composite insulator before and after the optimization, and simulated and analyze the influences of the fitting＇s structure parameters （R as ring radius, r as pipe radius） on the electric potential and field distribution. The flashover performance of optimized electrode is compared with the original one in the tests. The mechanical connection reliability of the fitting after optimization is demonstrated in high speed wind tunnel test. The re- sults show that the fitting on the high-voltage side of the existing CRH isolating switch has obvious comer angle on the edge, the distribution of the electric potential around the composite insulator sheds is uneven. The electric potential gra- dient is decreased and the maximum electric field intensity is less than 0.45 kV/mm after the optimization of the fitting. The power frequency, lighting impulse, and mechanical strength tests are all qualified, and the optimized fitting can be in- stalled on the CHR for further test.