浮电位类型局部放电的高频传感特性的试验研究

为了了解局部放电类型对UHF传感方法灵敏度的影响,笔者采用10～80MHz、150～250MHz、300～800MHz3种频段的高频放大器对浮电位局部放电进行测量。试验选择了0.2、0.8、1.4mm3种浮电位放电间隙。随着放电间隙的增大,局部放电量增大,但300～800MHz频段检测信号的幅值减小。结果表明,UHF检测信号的幅值并不能准确反映局部放电的严重程度,建议采用多频段信号传感,根据多频段检测信号幅值的相对关系进行局部放电严重程度判别。

Experimental Investigation on High Frequency Sensing Characteristis of Floating Type Partial Discharge

In order to understand the influence of partial discharge types on sensitivity of UHF sensing method, the floating type partial discharge was produced with a testing model, and detected via HF amplifiers in three frequency bands of 10～80 MHz, 150～250 MHz and 300～800 MHz. The discharge gap was set at 0.2, 0.8 and 1.4 mm, respectively. With the increasing discharge gap, the PD quantity increased, however the amplitude of the PD signals detected in 300～800 MHz frequency band decreased. This result indicates that the UHF PD signals can not be used to assess the severity of a PD effectively. It is suggested to make the assessment based on the relative amplitudes of the signals from different frequency bands.