基于电路网络的绝缘子交流污闪动态模型研究

Study on the Dynamic Model of Polluted Insulators Under AC Voltage Based on the Circuit Network

绝缘子污秽闪络动态模型的建立能模拟污闪发展的动态变化过程,有助于深入地理解污秽闪络发展的机制。将电弧用电路网络来等效,建立起基于电路网络的污秽绝缘子交流闪络动态模型。模型中,电弧通道各参数值由电弧周围的电磁场分布以及气体放电理论决定。由于引入了电弧发展速度,模型具有时间特性,各个电路参数需要进行实时循环计算。该污闪动态模型考虑了电弧发展过程中电弧通道对地支路的影响,能更为精确地描述局部电弧发展的实际情况。仿真结果表明:局部电弧的发展过程与实际情况基本一致,得到的临界闪络值较现有交流污秽闪络模型在一定程度上更为精确,这对于深入研究污闪机制具有参考价值。

The flashover dynamic model of polluted insulators can simulate the real change of arc propagation, which is helpful to understanding the flashover mechanism of polluted insulators. In this paper, the arc was equivalent to a circuit network and then a new AC flashover dynamic model based on the circuit network was proposed. In the model, the parameters of arc channel were determined by electromagnetic field and gas discharge theories. Due to the velocity introduced, the dynamic model had time-dependent characteristic and the parameters of the circuit required to be calculated circularly in real-time. Taking the surface branch beneath the arc channel into consideration, this new model can describe the actual process of the arc propagation exactly. The simulation result indicated that the simulated process of the arc propagation matched with the actual process and the critical values were more accurate than those of existing AC models to a certain extent. This provides a reference for studying the flashover mechanism deeply.