Partial discharge

About: Partial discharge is a research topic. Over the lifetime, 13997 publications have been published within this topic receiving 102058 citations. The topic is also known as: PD.

A new approach to partial discharge testing of HV cable systems

Abstract: This paper describes the application of an innovative partial discharge (PD) detection and analysis approach to the diagnosis of HV polymeric cable systems. The results of PD measurements performed off-line on cable systems, rated from 220 to 400 kV just after laying or after some time in operation, are presented. PD generating defect identification and location are discussed, also in relation to forensic observations

Detection of harmful metallic particles inside gas insulated switchgear using UHF sensor

Abstract: Gas insulated switchgears (GIS) are widely used as major substation equipment because of their excellent insulation and interruption performance. However, while a GIS is highly reliable, it is a concealed device, meaning diagnostic technology using various sensors is required to detect any insulation abnormality. Among various potential defects inside a GIS, the most problematic is caused by the existence of fine metallic particles, and thus the ability to detect harmful particles in tests at a factory and on site as well as in operation is becoming an important subject. This paper examines, on an experimental basis, the UHF sensor's characteristics of detecting partial discharge (PD) signals generated from particles inside the GIS with those placed freely on the bottom surface of the tank, having adhered to the insulating spacer's surface, and fixed on the center conductor, respectively. Based on previous reports, breakdown characteristics with the existence of particles were arranged in terms of the particle length, and the harmful particle length was estimated. Both results were compared with each other to evaluate the possibility of detecting harmful particles in each location with the UHF sensor. Consequently, it emerged that free particles were detected comparatively easily. However, while those having adhered to the spacer's surface and fixed on the center conductor could be detected in insulation tests at 2 pu at a factory, detection was difficult in many cases in the field.

Partial Discharge Automatic Monitor for Oil-Filled Power Transformer

Abstract: This paper describes a new type of partial discharge (PD) automatic monitor capable of detecting possible troubles caused by PD inside a transformer in the field and preventing the unfavorable phenomenon from expanding.

UHF PD-detection in a power transformer

Abstract: The detection of partial discharge (PD) in high voltage insulation is an effective way to determine dielectric faults in the early stages of development. Partial discharge detection in a power transformer was made possible by use of the acoustic detection technique and also by the UHF detection technique. Floating metal parts and partial discharges were detected in paper insulation in a 110/10 kV transformer. The discharge patterns and detection sensitivity obtained with several discharge sources in transformer oil were presented. The UHF technique is considered an ideal method for monitoring and for inspection because of the possibility for automatic classification of the type of discharge and because of its low sensitivity to external noise. It was shown that partial discharge in oil is short in duration and more irregular in time than partial discharge in gas. The UHF technique was also found to be more sensitive because of the lower wave attenuation and classification of the type of discharge. 3 refs., 5 figs.

Movement of particles in compressed SF/sub 6/ GIS with dielectric coated enclosure

Abstract: In compressed GIS (gas insulated switchgear), the control of wire particle contamination by dielectric coating of enclosure is demonstrated in this paper. Assuming that a particle acquires free charge through a partial discharge, the modeling of particle movement when the inside surface of a horizontal section of GIS/GITL (gas insulated transmission line) enclosure is coated is described. Under an applied 60 Hz ac voltage, the maximum height reached above the enclosure by a particle is much lower for a coated than for an uncoated enclosure. When the applied ac voltage varies, the maximum height reached depends on the magnitude of the applied voltage, phase and velocity at which the particle hits the enclosure. Typical results show that by coating the enclosure, the maximum height reached by a wire particle in a coaxial system can be reduced, thus inhibiting particle movement and minimizing the possibility of insulation breakdown.