Low Pressure Partial Discharge Investigation with FEM Modeling for a Twisted Pair of Insulated Conductors

Partial discharge (PD) phenomena with a twisted pair configuration of insulated conductors have been investigated in a low pressure environment. The pressure range was from 2 to 760 Torr. PD waveforms were recorded using a 50-Omega viewing resistor. Representative PD waveforms at various pressures are presented. Three-dimensional two-variable histograms of PD amplitude and rise time vs. phase angle of the 60 Hz source voltage were developed. Visual phenomena of PD manifestation at low pressure were observed in the laboratory. Several two-dimensional cross-section modeling of the twisted pair of insulated conductors were constructed to study the electric field distribution of the electrode configuration. Correlations between the PD waveform characteristics and the physical PD mechanisms were investigated with the help of the finite element method (FEM) modeling techniques.