基于迭代算法的功能梯度绝缘子介电常数分布优化

Permittivity Distribution Optimization of Functionally Graded Insulator Based on Iterative Method

为了改善气体绝缘输电管道绝缘子沿面电场分布,提出一种基于迭代算法的功能梯度绝缘子介电常数分布优化方法,该方法具有策略简单、迭代次数少、效率高等优点。通过对圆台绝缘子和盆式绝缘子的介电常数分布进行优化,得到主要结论如下:圆台绝缘子的沿面电场分布呈现出由高压电极三结合点向地电极递减的趋势。优化后,圆台绝缘子沿面电场强度最大值由2.3 kV/mm降至1.1 kV/mm,下降幅度超过50%。对盆式绝缘子的介电常数分布进行优化时,需要兼顾绝缘子凹面和凸面的沿面电场分布。经过优化的盆式绝缘子的相对介电常数分布在径向坐标上呈现出“中间低,两侧高”的趋势,绝缘子的凹面电场强度最大值下降幅度超过60%。考虑到实际应用中构造连续梯度非常困难,该文提出“等厚梯度”和“等差梯度”两种离散化方案,对最优的连续介电常数分布进行离散化处理。

To improve the electric field(E-field)distribution on insulator surfaces of gas insulated transmission lines,an iterative method is proposed in this paper to optimize the permittivity distribution in functionally graded insulators,which has the advantages of simple strategy,less iteration and high efficiency.Based on the cone-type and the basin-type insulators,some conclusions can be drawn:the Efield strength declines from the HV triple junction to the GND electrode on the cone-type insulator surface.After optimization,the maximum E-field strength of the cone-type insulator is reduced by over 50%,from 2.3 to 1.1 kV/mm.For the basin-type insulator,the E-field distributions along both convex and concave surfaces must be taken into consideration in the optimization process.The optimum permittivity distribution presents the“U”type to quality,low in the middle and high at each end.The maximum E-field strength on the concave surface of the basin-type insulator is reduced by over 60%.At last,two discretization methods are employed to discretize the optimum permittivity distribution considering that the gradient layer number of insulators is limited in practical application.