中压电缆瞬时电弧击穿故障行波测距研究
Research on Traveling Wave Ranging of Transient Arc Breakdown Faults in Medium Voltage Cables
郭王勇 1王毅松 2黄墀志 1秦卉 1张军 1石超群 2徐阳2
作者信息
- 1. 国电南瑞科技股份有限公司,江苏 南京 211161
- 2. 西安交通大学电工材料电气绝缘全国重点实验室,陕西 西安 710049;西安交通大学电气工程学院,陕西 西安 710049
- 折叠
摘要
中压电力电缆瞬时性电弧可为永久性故障提供预警.为研究中性点经低电阻接地系统的电缆瞬时性电弧故障信号与行波测距,提出一种基于磁流体动力学与曲线拟合的电弧非线性时变电阻等效方法.首先,通过多物理场仿真获取瞬时性电弧的信号与燃弧时长,并分析电导与温度变化.然后,对电导变化曲线进行拟合,获取数学解析式,构建中性点经低电阻接地的 10 kV电缆线路模型,使用可变电阻元件代替电弧,并通过解析式计算得到等效电阻.最后,对电缆线路的瞬时性电弧故障信号进行仿真,并通过监测电缆双端金属屏蔽层电流行波,基于小波变换提取行波到达时间,实现故障点定位.通过仿真分析,结果表明该方法定位误差小于0.5%.
Abstract
The instantaneous arc of medium voltage power cables can serve as an early warning for permanent faults.To delve into the instantaneous arc fault signal and traveling wave location of cables in the low resistance grounded neutral system,we introduce an equivalent method of arc nonlinear time-varying resistance based on magneto hydro dynamics and curve fitting.Firstly,the instantaneous arc signal and duration time are obtained by multi-physics simulation,and the arc conductance and temperature are analyzed.Secondly,electric conductance curves are fitted to obtain the mathematical analytical expressions.A 10 kV cable line model with low resistance grounded neutral is constructed with the arc replaced by the variable resistor element,and the equivalent resistance is obtained through analytical expression.Finally,the instantaneous arc fault signal of the cable line is simulated.The traveling wave arrival times are extracted based on the wavelet transform by monitoring the current of the metal sheath layer of the cable,and the fault location is realized.The simulation results show that the positioning error by this method is less than 0.5%.
关键词
瞬时性电弧/行波测距/非线性电阻等效/磁流体动力学模型/中压电力电缆Key words
instantaneous arc/traveling wave location/nonlinear resistance equivalent/magneto hydro dynamics model/medium voltage power cable引用本文复制引用
出版年
2024
NETL
NSTL
万方数据