基于改进时变电弧方程的直流覆冰闪络动态电路模型研究

Study on Dynamic Circuit Model of DC Icing Flashover Based on Improved Time-Varying Arc Equation

覆冰闪络的动态电路模型可用于模拟冰闪发展的动态变化过程,有助于深入探究覆冰绝缘子闪络发展的机理。针对现有动态模型中的时变电弧方程仅表征电弧在空气间隙发展的不足,充分考虑冰层表面对电弧发展的影响,对时变电弧方程进行改进,使其能够更加准确地描述实际冰闪电弧的动态变化。在此基础上,建立直流覆冰闪络的动态电路模型,将模型仿真结果与已有模型进行对比,同时在人工气候室内对等效玻璃平板进行覆冰闪络的试验验证。结果表明:建立的动态电路模型所预测的闪络电压值更接近试验值,两者最大相对误差为6.6%;预测泄漏电流与实测泄漏电流的动态变化规律具有较好的一致性。

The dynamic circuit model of icing flashover can be used for simulating the dynamic process of icing flashover,which contributes to further study of the flashover mechanism of ice-covered insulators.However,the arc equation used by existing models only describe the arc propagation in the air gap.In this paper,the influence of ice surface on the arc propagation is taken into account to improve the time-varying arc equation.Therefore,the dynamic changes of actual icing flashover arc can be described more accurately.On this basis,the dynamic circuit model of DC icing flashover is proposed.Furthermore,the simulation results of the model are compared with other existing models and icing flashover tests of equivalent glass plane are then carried out in artificial climate chamber.The results show that the flashover voltage forecasted by the improved model in this paper is closer to the test value and the maximum relative error is 6.6%.The dynamic process of simulated leakage current has a good consistency with the measured leakage current.