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.

Modelling of partial discharge characteristics in electrical tree channels: Estimating the PD inception and extinction voltages

Abstract: Partial discharge (PD) characteristics are inherently linked to associated electrical tree growth characteristics. This paper employs both phase-resolved patterns and pulse-sequence analysis (PSA) to study PDs in a short branch-tree grown from a metallic needle tip. It is found that the shape of PSA dV-dV patterns vary with applied voltage; in particular the values of characteristic voltage difference increase with applied voltage. At 10 kV the value of characteristic voltage difference decreases with tree growth, the average number of PDs per cycle increases, the PD magnitudes decrease, and the characteristic wing-like phase-resolved pattern evolves into a turtle-like pattern. This paper proposes a physical model relating PD activity to tree development, considering space charge accumulation inside the tree channel. All key features of experimental results are explained by the model. It is shown that the characteristic voltage differences are determined by the local PD inception and extinction electric fields. These key parameters determining the PD events can be calculated giving a clear physical interpretation of PD measurements, which is invaluable to those using PD as a condition monitoring or asset management tool.

A physical model, describing the nature of partial discharge pulse sequences

Abstract: A description is given of a straightforward physical model, which is based on only a few physically meaningful parameters and that allows to describe the PD behaviour resulting from specific insulation defects. It is demonstrated that computer simulations of PD pulse sequences on the basis of this model correspond closely to experimental results. The comparison of simulated sequences and experimental results suggests that the discharge activity is not mainly a stochastic process but consists of periods, with different prevailing processes, each showing a nearly deterministic behaviour.

Locating defects in high voltage transmission lines

Abstract: Methods of locating defects in overhead high voltage and extra-high voltage transmission lines are described and evaluated. Included is a technology which utilizes corona partial discharge detection to find faulty conditions while simultaneously performing routine visual inspections from a helicopter. The corona inspection system proved to be very useful in locating broken strands, loose spacers, insulators with internal or external discharges, and other faulty line conditions.

On-line monitoring of partial discharges in a HVDC station environment

Abstract: This paper deals with the on-line measurement of partial discharges (PD) in a high voltage direct current (HVDC) converter station. The HVDC station is a particularly challenging environment for measurement due to elevated interference levels caused from the switching of thyristor-controlled converters. In this work, online PD measurements were performed on two specimens; one is an HVDC converter transformer and the other an HVDC converter wall bushing. The measurements were performed in the high-frequency range from 400 kHz to 30 MHz with modern wideband PD measurement instrumentation. Results demonstrate that on-line measurement of PD in an HVDC station environment is possible and that a combination of input filtering and modern signal processing methods for feature extraction can be used to mitigate the converter interference. The feature extraction method used plots partial discharge data on a time-frequency classification map. The map enabled isolation of individual PD phenomena, and demonstrated that trending to monitor insulation degradation is possible with online partial discharge measurement. Furthermore, specific strategies for PD measurement and analysis are developed for each of the transformer and bushing specimens.

An UWB Printed Antenna for Partial Discharge UHF Detection in High Voltage Switchgears

Abstract: As important fundamental equipment, high voltage switchgears are widely used in electric power systems and directly relative to the power reliability and quality. Partial discharge (PD) online monitoring is one of the most effective methods used for insulation testing and diagnosis in high voltage switchgears and power systems. This paper proposes a unique ultra-wide-band (UWB) antenna with high performance for PD ultra-high-frequency (UHF) detection in high voltage switchgears. Actual PD experiments were carried out, and the designed antenna was used for PD measurements. The measured results demonstrate that the proposed antenna has wide work frequency band, good omnidirectional radiation patterns and appreciable gain, which indicate that the proposed antenna is suitable for UHF online monitoring of PDs in high voltage switchgears.