多场耦合作用下的高压绝缘子动态积污机理的研究

The flashover accident by HV insulator contamination leads to large-scale paralysis of the power system, which has caused serious losses to the national economy every year. With the construction of UHV and EHV lines, the prediction of insulator contamination is very important. Based on exiting studies of snow accretion on HV transmission line, and electric filed of HV transmission line and insulator under wind-sand flow, this project is from the perspective the multi-field coupling effect of atmospheric turbulence-pollutant particle-high voltage electric field, using ectro-hydro dynamics(EHD) and computational fluid dynamics(CFD) methods to study the mechanism of dynamic contamination on insulators surface. The main contents include the study of the motion law of the gas-solid two phase flow field and the distribution of the high-voltage ion current field under high-voltage electric field. The dynamic modeling of the dynamic contamination of the insulator surface is studied. To establish multi field coupling numerical analysis method of insulator, the numerical analysis program is developed to simulate the dynamic insulator contamination. The experimental study of the wind tunnel and the natural pollution deposit(NPD) is carried out, and the theoretical model and the numerical analysis method are supplemented and perfected. The implementation of this project not only lay the foundation for the dynamic contamination prediction of insulators, but also provide technical support for the safe operation of UHV power grid, so it has important scientific significance and practical application value.

高压绝缘子的积污导致电力系统大面积瘫痪的污闪事故，每年给国民经济带来严重损失。随着特高压和超高压线路即将全面建设，绝缘子积污的预测显得尤为重要。本项目拟在高压输电线积雪模拟和风沙流作用下的高压输电线、绝缘子的电场特性等已有的研究基础上, 从大气湍流－污染物颗粒－高压电场的多场耦合作用的角度，结合电流体动力学和计算流体力学方法，研究高压绝缘子动态积污的机理。主要研究内容包括在高压电场作用下，绝缘子周围的气固两相流场的运动规律和高压离子流电场的分布特性；研究绝缘子表面动态积污的动力学建模；建立绝缘子周围的多场耦合数值解析方法，开发绝缘子动态积污的数值模拟程序，实现绝缘子动态积污模拟；进行绝缘子的风洞和自然积污实验研究，对理论模型和数值计算方法进行补充和完善。本项目的实施不仅为绝缘子的动态积污预测奠定基础，而且为特、超高压电网的安全运行提供技术支持，因此具有重要科学意义和实际应用价值。

本项目针对高压绝缘子的积污导致电网停运的污闪发生机理展开了科学的研究探索。从大气湍流—雾霾颗粒—高压电场的多场作用的观点，运用电流体动力学理论和计算流体力学方法，实现了绝缘子周围的多场建模；基于颗粒碰撞能量耗散理论，提出了一种绝缘子表面动态积污的建模方法；开发了导电层单元，解决了网格畸变问题；首次实现了高压电场下的绝缘子的非均匀积污的数值模拟。开发了基于格子玻尔兹曼方法的多场作用下的绝缘子动态积污的数值模拟程序；进行了自然积污、风洞和电镜测试等实验研究，首次测得了雾霾颗粒在绝缘子表面的吸附力。通过比较数值模拟和实验结果，讨论了高压电场作用下，不同工况下绝缘子的积污规律；研究分析了非均匀积污情况下绝缘子的电场分布，揭示了污闪发生的主要机理—绝缘子非均匀积污产生的电场畸变。本项目的实施不仅为污闪的预警提供了一定的理论支持，而且对高压电场下的气固两相流模型和数值计算方法进行了一定的补充和完善。