开关柜局部放电暂态对地电压传播特性的仿真分析

Simulation of Transient Earth Voltages Aroused by Partial Discharge in Switchgears

在带电条件下的局部放电检测是反映封闭开关柜内部绝缘状况的有效手段。为此,首先根据电磁学基本原理分析了暂态对地电压(transient earth voltages,TEV)的产生机理,然后利用XFDTD软件仿真分析了TEV幅值和脉宽与激励源脉冲幅值、脉冲宽度、检测距离之间的关系。仿真结果表明:TEV的幅值与局部放电源的幅值成正比,且随着检测距离的增大而减小,随着局部放电源脉冲宽度的增加而减小;TEV的脉宽随局部放电源脉宽的增大而增大,与检测距离无关。为开展开关柜局部放电的带电检测工作提供了理论依据。

The principle of transient earth voltages （TEV） was analyzed by electromagnetics, and the finite-difference time-domain （FDTD） method was employed to simulate the propagation law of TEV in the switchgear. The simulation results show that, the TEV amplitude is proportional to the PD pulse amplitude, increases as PD pulse width decreases, and decreases as the distance between detection point and PD source increase. The TEV pulse width increases with that of excitation increasing, and is not affected by the amplitude of excitation or the detection distance.