高压XLPE电缆高频损耗对局部放电脉冲波形的影响

为研究局部放电信号沿电缆传播产生的高频损耗(包括幅值衰减和散射变形),应用结构共振法拟合出电缆半导电层复介电常数的经验公式并应用于分析解法的仿真计算,解决了电缆半导电层复介电常数难以估算的问题。其次,应用传递函数校正测量法避开测量系统与电缆的波阻抗不匹配问题;并试验验证了电缆高频损耗对局部放电脉冲波形的影响。结果表明,衰减因子使波形幅值衰减、脉冲展宽,原始脉冲越窄衰减越严重;相位因子使高斯脉冲向非对称变化,并出现逆峰。

Influence of High Frequency Loss on Waveform of Partial Discharge Pulses of High Voltage XLPE Cables

The partial discharge signals propagation along the cable will generate high frequency losses including amplitude attenuation and scattering distortion. In this paper, the high frequency loss of the propagation of the pulse along the shielded cable is studied. The empirical formula of the complex dielectric constant of the cable semi-conductive layer is fitted by the structural resonance method and the simulation calculation is applied to analyze the solution that the complex permittivity of the cable is difficult to estimate. Secondly, the measurement method is used to avoid the mismatch between the measuring system and the wave impedance of the cable. The impact of high frequency loss of the cable on the partial discharge pulse is verified by experiment. The results show that the attenuation factor makes waveform amplitude attenuation and pulse broadening, and the attenuation is more serious when the original pulse is narrower; phase factor causes the wave to appear the inverse peak, and the waveform will become asymmetrically.