针-板局部放电VHF信号与放电量之间的等量关系

Relationship Between VHF Signals and Discharge Magnitude of Partial Discharge from Needle Plate Electrode

为研究局部放电高频信号与视在放电量之间的关系,系统推导了针板空气间隙局部放电甚高频(VHF)信号的峰峰电压、累积能量与视在放电量分别存在的线性函数和二次函数关系,通过大量的实验数据进行了验证,从理论和实验上证明了用标定的方法可解决高频法测量局部放电的定量问题。比对研究表明,在极不均匀电场的情况下,由于存在的空间电荷对放电的发展有阻碍,使得空气间隙距离越大其临近间隙击穿电压时的局部放电量越小。该研究结果对用高频法定量检测电力设备局部放电具有重要的参考价值和指导作用。

In order to explore the relationship between very-high frequency（VHF） signals and apparent discharge magnitude with needle-plate electrodes within different air-gap distance,the VHF method combined with pulse current（IEC 60270）in partial discharge（PD） was used.A linear relationship between peak to peak voltage of VHF signals and apparent discharge magnitude was obtained,and quadratic relationship between cumulative energy from VHF signals and apparent discharge magnitude was also obtained.It was proved that calibration on PD measurement using high-frequency method could be solved theoretically and practically.On the premise of severe non-uniform electric field,the longer the distance of the air-gap is,the lower PD magnitude will be,when the voltage is close to breakdown,as the development of the discharge will be hindered by existing space charge.The theoretical derivation agrees with experimental results.