Comparative Research on Current Pulse Method and UHF Measurements of Partial Discharge in Mineral Oil

In order to explore the relationship between parameters of UHF signals and discharge magnitude of pulse current in partial discharge(PD)detection in oil-paper insulating power equipment,the differences of principle between current pulse measurement and UHF measurement in PD is introduced.Four typical PD models are constructed,such as inherent vice discharge,oil-barrier discharge,surface discharge,floating electric potential metallic particle discharge,and pulse current signals and UHF signals are recorded simultaneously using an oscilloscope.The relationship of parameters between UHF and pulse current measurement is analyzed,and the calibration method for UHF with current pulse is discussed.The results show that UHF measurement and pulse current measurement have the same trend reflecting the change of PD level,but there is not direct linear relationship between parameters of UHF and pulse current measurement.