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 review of partial discharge detection, diagnosis techniques in high voltage power cables

Abstract: Partial discharges (PDs) are the first indication of insulation materials degradation. This paper provides a general review on partial discharge in power cables. It starts with discussing the importance of PD detection and its effect on the continuity of operation and reliability of power systems. It then provides a description of the insulation explaining the process that leads to its breakdown. The stresses on the voids inside the power cable are explained and the equivalent circuit is discussed. The paper then discusses the most common methods to detect the partial discharge off-line and on-line, specifically in power cables. Methods of location of partial discharge inside the power cable are discussed as well. The most common signal de-nosing techniques are also briefly explained. Lastly, a deep insight of the current challenges and difficulties in PD detection and monitoring are provided.

High voltage insulation monitoring sensor

Abstract: A sensor for condition monitoring the high voltage insulation of an electrical, generation, transmission or distribution system and/or an item of plant is described. The sensor comprises an impedance measurement unit that connects directly, via a single point of connection, to the electrical system to be tested. The electrical components of the impedance measurement unit are arranged so that high frequency partial discharge signals and low frequency power cycle information signal are preferentially transmitted through separate branches. Analysis of these separated signals thus enables extraction of information about the insulation of the electrical system being monitored. Safe operation of the sensor for users is also achieved through an opto-electronic circuit being employed to control the impedance measuring unit.

Influence of impulse voltage repetition frequency on RPDIV in partial vacuum

Abstract: The reliability of low-voltage inverter-fed motors is highly dependent on the inception of partial discharges. The effect of impulsive waveform parameters must be investigated to predict the repetitive partial discharge inception voltage (RPDIV) and define test procedures that can indicate properly the behavior in service of the insulation system. This paper focuses on the RPDIV of magnet wires using twisted pairs subjected to repetitive unipolar impulsive voltage waveforms. The effects of supply frequency (5 to 200 kHz) at pressure levels that are typical for aircraft (20 to 100 kPa) is examined. Results show that RPDIV steadily decreases with frequency up to 100 kHz where it reaches a plateau. This behavior is explained as an effect of the oscillations that inevitably exist in the applied voltage waveform. Therefore, a conservative estimate of the RPDIV could be achieved by raising the supply frequency well above the operation frequency. In the experiments, the RPDIV is decreasing linearly with pressure. If this behavior could be confirmed for other insulation systems, the design of systems working at pressures typical of aircraft would result relatively easy.

Partial discharge characteristics of polymer nanocomposite materials in electrical insulation: a review of sample preparation techniques, analysis methods, potential applications, and future trends.

Abstract: Polymer nanocomposites have recently been attracting attention among researchers in electrical insulating applications from energy storage to power delivery. However, partial discharge has always been a predecessor to major faults and problems in this field. In addition, there is a lot more to explore, as neither the partial discharge characteristic in nanocomposites nor their electrical properties are clearly understood. By adding a small amount of weight percentage (wt%) of nanofillers, the physical, mechanical, and electrical properties of polymers can be greatly enhanced. For instance, nanofillers in nanocomposites such as silica (SiO2), alumina (Al2O3) and titania (TiO2) play a big role in providing a good approach to increasing the dielectric breakdown strength and partial discharge resistance of nanocomposites. Such polymer nanocomposites will be reviewed thoroughly in this paper, with the different experimental and analytical techniques used in previous studies. This paper also provides an academic review about partial discharge in polymer nanocomposites used as electrical insulating material from previous research, covering aspects of preparation, characteristics of the nanocomposite based on experimental works, application in power systems, methods and techniques of experiment and analysis, and future trends.