基于有限元法的绝缘子污闪动态电弧模型研究

Research on Dynamic Arc Model of Insulator Pollution Flashover Based on Finite Element Method

现有电弧发展模型均存在一定的缺陷,且对沿面电弧发展延伸过程进一步建模是深入研究绝缘子污闪机制的前提。对此,基于有限元法对绝缘子污闪动态电弧模型进行改进,利用COMSOL-MATLAB联合建立电弧延伸场路模型,考虑弧根电位、尺寸以及电弧延伸的动态过程,并通过人工污秽试验从动态剩余污层电阻和污闪电压2个参量入手验证该模型的有效性。研究结果表明:矩形平板模型对复杂外形绝缘子的展开有良好等价性;在直流污闪过程中,绝缘子剩余污层电阻值动态变化趋势与所提模型的计算结果基本一致,实测值与计算值的相对误差在12%以内;模型计算的绝缘子闪络电压与实际绝缘子试验值比较,误差在8%以内。

Existing arc development models have certain defects,and further modeling of the creeping arc development and extension process is a prerequisite for in-depth research on the pollution flashover mechanism of insulators.Based on the finite element method,this paper improves the dynamic arc model of insulator pollution flashover and uses COMSOL-MATLAB to jointly establish the arc extension field-circuit model.Meanwhile,it considers the arc root potential,size and the dynamic process of arc extension,and verifies the effectiveness of the model in two aspects of layer resistance and pollution flashover voltage through artificial pollution test from the dynamic residual pollution.The research results show that the rectangular plate model has good equivalence to the development of complex-shaped insulators.In addition,during the DC pollution flashover process,the dynamic change trend of the residual pollution layer resistance of the insulator is basically consistent with the calculation results of the proposed model.The measured value is less than the calculated value.The relative error of the measured value and the calculation value is within 12%,and the error of the insulator flashover voltage calculated by the model and the actual insulator test value is within 8%.