基于智能优化电场计算与空间电荷积聚规律的直流复合绝缘子表面电弧发展机理研究

Insulator flashover interrupts the power transmission by causing line to ground fault. This project intends to investigate the mechanism of arc around HVDC composite insulator by modeling arc propagation process. Since arc propagation is a stochastic process rather than deterministic one, new arc propagation model improves the traditional flashover model by introducing Random Walk theory. The model simulates the arc growth in a micro perspective based on arc physical principle. The electric field and space charge distribution are calculated at each step of arc propagation. An accurate and efficient electric field calculation method is designed by combining neutral network and charge simulation method. The arc propagation model is capable of simulating the arc propagation process from ignition to extinguish. The project intends to sample multiple arc propagation processes based on Monte Carlo theory. The arc tracks are recorded and the phenomena of arc jumping between sheds are analyzed to optimize the structure of HVDC composite insulator. The model could be used to design arc propagation simulation platform for other high voltage equipment in order to provide the theoretical reference to flashover prediction.

在高压输电中，绝缘子表面电弧易在两极间引发闪络继而导致保护装置动作，造成系统跳闸和故障重启，极大地影响电网安全稳定运行。本项目针对直流复合绝缘子周围电弧发展物理规律，拟将人工智能算法与模拟电荷法相结合，设计一种高效准确的绝缘子与电弧附近电场计算方法，建立在强电场作用下空气发生电离产生新空间电荷的模型，以随机漫步理论为基础，从微观角度探索电弧放电机理。本项目创新性地将传统定性污闪模型改进为电弧随机发展模型，通过统计量化电弧在绝缘子伞裙间的跳跃现象，研究电弧动态发展规律，并描述其从产生到熄灭的过程。本项目依据蒙特卡罗原理对该随机过程进行多次采样，分析整体电弧路径分布，从减少电弧产生和降低击穿概率两个角度提出直流复合绝缘子结构优化方法，并建立电弧产生与发展模拟平台。项目科学问题的解决对其他不同类型高压设备的绝缘优化设计也有重要意义，同时为高压设备的安全稳定运行及故障预测提供理论依据。

本项目着重研究了直流复合绝缘子表面及周围的电弧发展路径规律和机理，针对绝缘材料附近沿面放电的现象，将深度学习与模拟电荷法结合，设计了一种高效计算电弧附近关键区域电场的方法，建立了在强电场作用下空气发生电离形成导电通道的模型。本项目以随机漫步理论为基础将传统定性污闪模型改进为电弧随机发展模型，通过统计量化电弧在绝缘子伞裙间的跳跃现象，总结了电弧动态发展规律，并描述了其从产生到熄灭再到重燃的过程。本项目分析了整体电弧路径分布，从减少电弧产生和降低击穿概率两个角度提出了直流复合绝缘子结构优化方法，并建立了基于模拟电荷法和随机漫步理论的复合绝缘子闪络模拟与预测平台。项目成果可推广至电缆等固体绝缘内部电树、水树发展等机理研究和结构优化，为高压设备的安全稳定运行及故障预测提供理论依据。