10kV交联聚乙烯电缆内部多形态间歇性电弧故障建模

Modeling of Internal Multiform Intermittent Arc Fault for 10kV XLPE Cable

间歇性电弧是电缆故障初期发展阶段的重要过程,该文以我国配电网中广泛使用的10kV交联聚乙烯电缆为研究对象,通过实验分析发现,电缆内部电弧与常规弧光对地击穿电弧波形存在明显差异,并在其发展过程中呈现出多种波形形态。该文通过梳理总结电缆内部间歇性电弧在随机演变中的共性,将其归结出振荡间歇性电弧、稳态间歇性电弧、半稳态间歇性电弧三类主要形态。从帮助电缆故障分析的外特性重现角度,以黑箱建模思路分别基于高斯随机脉冲、弧隙能量平衡理论和占比控制,构建出三类主要电弧形态的控制模型,并根据实验样本数据统计出各模型控制参数的分布范围。所提模型利用PSCAD仿真软件得到实现,与实验波形的对比表明,该文所构建的多形态电弧模型能有效模拟出三类间歇性电弧的主要特征。该多形态间歇性电弧的发掘丰富了电缆电弧的随机多样性,为电缆初期故障分析提供了新的模型基础。

Intermittent arc is an important process in the initial development stage of cable fault.This paper takes 10kV XLPE cable widely used in China’s distribution network as the research object.Through experimental analysis,it is found that there are obvious waveform differences between the arc inside the cable and the arc breakdown to the ground,and it presents a variety of waveform forms in its development process.This paper combs and summarizes the commonness in the random evolution of the intermittent cable arc,and summarizes them into three main forms:oscillating intermittent arc,steadystate intermittent arc and semi-steady-state intermittent arc.From the perspective of external characteristic reproduction to help cable fault analysis,the control models of three main arc forms are constructed based on Gaussian random pulse,arc gap energy balance theory and proportion control respectively with the idea of black box modeling.The distribution range of the control parameters of each model is calculated according to the experimental sample data.The proposed model is realized by PSCAD simulation software,and the comparison with the experimental waveform shows that the multiform arc model constructed in this paper can effectively simulate the main characteristics of the three types of intermittent arc.The discovery of the multi-form intermittent arc enriches the random diversity of cable arc,and the arc model provides a new basis for cable incipient fault analysis.