考虑温度梯度的高压直流GIL盆式绝缘子空间电荷仿真

Space Charge Simulation for Basin Insulator of High Voltage DC GIL Considering Temperature Gradient

在直流电压和温度梯度作用下,直流气体绝缘输电线路(gas-insulated transmission line,GIL)中盆式绝缘子内部易积聚空间电荷,引起局部电场畸变。因此,研究直流电压下盆式绝缘子内空间电荷积聚特性,对提高直流GIL的绝缘性能具有重要意义。以直流GIL盆式绝缘子为研究对象,基于2维双极性载流子模型,建立了电-热-流-电荷多物理场耦合模型,研究了不同温度分布、不同电压等级和不同极性电压下盆式绝缘子内空间电荷分布特性和电场分布规律。仿真结果表明:仿真模型能够有效地模拟盆式绝缘子内空间电荷和电场分布,在盆式绝缘子工作条件下,空间电荷主要积聚在金属与绝缘材料界面处,最大电荷密度为156.59 mC/m^(3),在一定程度上造成设备内部电场畸变。绝缘子在复杂工况下的空间电荷仿真可以解决电力设备难以直接测量空间电荷分布的难题,研究方法和结果可为直流GIL的绝缘优化设计和可靠运行提供理论支撑。

Under DC voltage and temperature gradient,space charge is easy to accumulate inside the basin-type insulator of DC gas-insulated transmission line(GIL),leading to local electric field distortion.Therefore,it is of great significance to study the space charge accumulation characteristics of basin-type insulators under DC voltage to improve the insulation performance of DC GIL.DC GIL basin insulator is taken as the research object,and a multi-physical field coupling model of electric-heat-fluid-charge based on two-dimensional bipolar carrier model is established to study the space charge characteristics and electric field distribution of basin insulators under different temperatures,voltage levels and voltage polarities.The results show that the model can effectively simulate the distribution of space charge and electric field in basin insulator.Under the working condition of the basin insulator,the space charge mainly accumulates at the interface between the metal and the insulating material,and the maximum space charge density is 156.59 mC/m^(3),which causes the internal electric field distortion to a certain extent.The space charge simulation of insulators under complex working con-dition can solve the current situation that it is difficult to measure space charge directly in power equipment.Besides,the simulation method and results can provide theoretical support for insulation optimization design of DC GIL.