开关柜表面暂态地电压信号频谱特征

Spectrum Characteristics of Transient Earth Voltages Aroused by Partial Discharge in Switchgear

为指导暂态地电压(TEV)检测装置频段选择,研究了开关柜内部发生局部放电时,开关柜外表面暂态地电压信号的频域特性。基于有限积分方法研究了开关柜结构,表面缝隙尺寸和局放电流方向对暂态地电压信号频谱的影响。仿真结果显示:开关柜内部的结构会对表面的TEV信号能量分布产生明显的影响,TEV信号的频谱与开关柜自身的谐振频率密切相关;开关柜的缝隙尺寸及局放电流方向均会对TEV信号频谱的强度产生影响,但对频谱的分布影响较小。

In order to guide the frequency selection of transient earth voltages （TEV） detection device, we researched the frequency domain characteristics of TEV aroused by partial discharge in switchgears. The finite integration theory （FIT） was employed to simulate the influences of the switchgear size, surface aperture size and PD current direction on the spectrum of TEV signal. The simulation results show that the internal structure of switchgear has significant effects on the energy distribution of TEV signal. The TEV spectrum is closely related to the switchgear resonant frequency. The aperture size and PD current direction affect the strength of the TEV spectrum, but slightly affect the frequency distribution of TEV signal.