Partial discharge

About: Partial discharge is a(n) research topic. Over the lifetime, 13997 publication(s) have been published within this topic receiving 102058 citation(s). The topic is also known as: PD.

Electrical breakdown of gases

Abstract: A collection of individual works on electrical discharges is presented. Topics covered include: fundamental processes in the electrical breakdown of gases; vacuum breakdown; spark breakdown in uniform fields; corona discharge; spark breakdown in non-uniform fields; breakdown voltage characteristics; irradiation and time lags; high-frequency breakdown of gases; laser-induced electrical breakdown of gases; spark channels; and electrode phenomena. (GHT)

A generalized approach to partial discharge modeling

Abstract: An important tool for improving the reliability of HV insulation systems are partial discharge (PD) measurements. The interpretation of such measurements aims at extracting from the measured data information about insulation defects which then are used for estimating the risk of insulation failure of the equipment. Because the physical understanding of PD has made substantial progress in the last decade, it can now be exploited to support interpretation. In this paper a concept is presented which merges the available physical knowledge about various PD types into a generalized model which can be applied to arbitrary insulation defects. This approach will be restricted to PD of the streamer type in gases and at gas-insulator interfaces which cover a large fraction of the cases encountered in technical insulation systems. The generalized model allows us to derive approximate relations between defect characteristics, insulation design parameters and test conditions on one side, and measurable PD characteristics on the other. The inversion of these relations yields rules for extracting defect information from the PD data. The application of the generalized model is illustrated by two simple examples, namely, spherical voids in an insulator and electrode protrusions in SF/sub 6/. >

Partial discharges. Their mechanism, detection and measurement

Abstract: Different partial discharge (PD) detection and measurement procedures suitable for use on cables, capacitors, transformers and rotating machines are examined and compared. Both narrow and wide bandwidth PD detectors are considered; particular attention is given in regard to their suitability to different types of electrical apparatus and cable specimens under test as well as their applicability to discharge site location and their capability to detect different forms of PD. A rather substantial portion of the discussion is devoted to the use of intelligent machines as applied to PD pattern recognition in terms of either PD pulse-height/discharge epoch (phase) distributions or discharge pulse shape attributes.

Partial Discharge Detection in High Voltage Equipment

Abstract: Electrical discharges that do not completely bridge the electrodes are called partial discharges Although small, these discharges have been known for more than fifty years to cause progressive deterioration Since 1945 the use of new high voltage dielectrics has required the use of sophisticated detection techniques Discharge detection has grown into an indispensible tool for the evaluation of modern insulation The subject has received little attention in books on high voltage techniques although a good deal is scattered in various papers and reports The object of this book is to collect this knowledge and present it as a coherent study Topics covered include the behaviour detection and measurement of discharges, the choice of detection method and procedure, the location of discharges and discharge detection in practice

Partial discharge monitoring of power transformers using UHF sensors. Part I: sensors and signal interpretation

Abstract: Determining whether power transformers are suffering from internal arcing or dangerous levels of partial discharge (PD) is important because failure without warning can result in damage to neighboring equipment, customer dissatisfaction, disruption to economic activity, and the imposition of regulatory fines. This paper provides an overview of the excitation of UHF signals by PD inside transformers. The use of externally mounted sensors has been outlined, and the structure of a dielectric window that can be constructed on an inspection hatch has been outlined. Attenuation of UHF signals propagating inside a transformer tank has been shown to be relatively low. A new approach to locating PD sources in three dimensions has been presented, based on using a numerical model of the transformer materials, which defines electromagnetic propagation velocities on a mesh of 5-cm sub-cells. The concepts of the propagation-velocity matrix (PVM) and the propagation-time matrix (PTM) were thereby introduced. Once the PD source has been located to a specific region of the transformer, the PVM might be used to index a database of physical descriptions of the transformer that could provide additional information to assist with diagnosis.