High-voltage engineering

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 discharges. Their mechanism, detection and measurement

Macromolecular plasma-chemistry: an emerging field of polymer science

Experimental data are presented of the development of PD activity in artificial air-filled spherical voids in epoxy resin over a period of /spl sim/6 months. The data are presented in the form of phase averaged plots of the charge distribution over the time (aging plots) and phase resolved histograms (PRPD patterns) at various aging states. They are interpreted by comparison to numerical simulations which are based on a physical discharge model. This provides insight into the physical changes in the void during aging. The simulation is the basis for a physically meaningful interpretation of the PD data. It provides rules for the identification of the defect type, the defect quantification, and an assessment of the aging stage. >

Measurement and simulation of PD in epoxy voids

Partial discharge (PD) measurement has long been used as a test to evaluate different insulation system designs, and as a quality control test for new equipment. However, in the past 20 years, PD measurement has been widely applied to diagnose the condition of the electrical insulation in operating apparatus such as switchgear, transformers, cables, as well as motor and generator stator windings. Improvements in the capabilities as well the lower cost of sensors, electronics and memory is partly the reason for the increased popularity of PD diagnostics. Another reason has been the development of methods-including the use of ultrawide band detection-to improve the reliability of the PD measurement in the presence of noise. In addition, rapid progress is being made in automated pattern recognition techniques that also helps to suppress noise. This paper reviews the various PD measurement technologies that have been specifically developed to improve PD diagnostic methods, and outlines how they have been implemented for stators, cables, transformers and switchgear. Areas for further research are also presented.

Partial discharge diagnostics and electrical equipment insulation condition assessment

For a long time, classification of partial discharges was performed by eye, by studying discharge patterns at the ellipse of an oscilloscope screen. The introduction of digital processing techniques allowed automation of the recognition procedure. These procedures are reported and applied to a number of actual HV constructions which suffer from partial discharges. The results of these tests show that a quite satisfactory recognition of discharges takes place. >

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Classification of partial discharges

Making use of a computer-aided discharge analyzer, a combination of statistical and discharge parameters was studied to discriminate between different discharge sources. Tests on samples with different discharge sources revealed that several parameters are characteristic for different types of discharges and offer good discrimination between different defects. >

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Computer-aided recognition of discharge sources

Discharge detection in high voltage equipment

Industrial high voltage

This book is based on the lectures of Prof.dr.ir. F.H. Kreuger at the Delft University of Technology.

F.H. Kreuger

Papers

Classification of partial discharges

Computer-aided recognition of discharge sources

Discharge detection in high voltage equipment

Industrial high voltage

Industrial High DC Voltage: 1. Fields, 2. Breakdowns, 3. Tests