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.

Development of a method of partial discharge detection in extra-high voltage cross-linked polyethylene insulated cable lines

Abstract: Deterioration in the insulation performance of extra-high voltage XLPE (cross-linked polyethylene) cables is believed to be attributable to the deterioration caused by partial discharges. After using an XLPE cable to investigate the behavior of partial discharges under various adverse conditions, the authors succeeded in developing a highly sensitive novel method of measuring partial discharge in XLPE cable lines. Partial discharges in a 275 kV XLPE cable live line have been measured using this method. As a result, a detection sensitivity of 1 pC has been achieved. >

Application of K-Means method to pattern recognition in on-line cable partial discharge monitoring

Abstract: On-line Partial Discharge (PD) monitoring is being increasingly adopted in an effort to improve asset management of the vast network of MV and HV power cables. This paper presents a novel method for autonomous recognition of PD patterns recorded under conditions in which a phase-reference voltage waveform from the HV conductors is not available, as is often the case in on-line PD based insulation condition monitoring. The paper begins with an analysis of two significant challenges for automatic PD pattern recognition. A methodology is then proposed for applying the K-Means method to the task of recognizing PD patterns without phase reference information. Results are presented to show that the proposed methodology is capable of recognising patterns of PD activity in on-line monitoring applications for both single-phase and three-phase cables and is also effective technique for rejecting interference signals.

Partial discharge characteristics over differently aged oil/pressboard interfaces

Abstract: The choice of the materials used as the dielectric media in large transformers continues to be a combination of pressboard and mineral oil. However, a number of failures in the field have been attributed to the surface discharge or creeping discharge over the oil/pressboard interface. This paper reports on an experiment to study surface discharge over oil/pressboard. The TJ (triple-junction) model was used to study the characteristic of partial discharge (PD) from inception to flashover. The max PD charge, pattern, frequency and current pulse were measured during the flashover process. Four oil/pressboard specimens with different aging degrees were used and their influence on the flashover process over oil/paper interface was studied in this experiment. The results indicate that the max PD charge and PD frequency increase with the increase of applied voltage. The oil aging has great influence while the pressboard aging has little influence on PD characteristic over oil/pressboard. The PD pattern and current pulse shape show great difference for various applied voltages. The results therefore suggest that the PD detection on the oil/pressboard can be used effectively to implement the early monitor of surface discharge thereby to avoid the formation of surface flashover.

Mandrel-Based Fiber-Optic Sensors for Acoustic Detection of Partial Discharges—a Proof of Concept

Abstract: Acoustic emission monitoring is often used in the diagnosis of electrical and mechanical incipient faults in high-voltage apparatus. Partial discharges are a source of failure in power transformers, and the differentiation from other sources of acoustic emissions is of the utmost importance. This paper reports the development of a new sensor concept-mandrel-based fiber-optic sensor-for the detection of incipient faults in oil-filled power transformers, taking direct measurements inside a transformer. These sensors can be placed in the inner surface of the transformer tank wall, not affecting the insulation integrity of the structure, and improving fault detection and location. The applicability of these acoustic sensors in air, water, and oil is investigated and the paper presents the promising results obtained, which will enable the industrial development of practical solutions.

Dynamic behavior of surface charge distribution during partial discharge sequences

Abstract: A surface charge measurement system based on Pockels effect was constructed to detect the variation of residual surface charge distribution in partial discharge (PD) sequences. The current form (ns level) of the PD sequence was measured simultaneously. By using this system, it is found that surface charge distribution caused by PDs appeared as several isolated charges spots similar to that in dielectric barrier discharges (DBD). The result also agrees with the previous models, suggesting that charge distribution is not uniform and that it plays an important role in the stochastic behavior of PDs. As the applied voltage increased, the number of charge spots increased and the hetero-discharge occurred. Besides, a charge ring along the void edge was observed after aging due to PD. An approximate linear relationship existed between PD magnitude and the corresponding accumulated surface charges. In the PD sequence, the discharges tended to take place at the sites having heterocharges at dielectric surface after voltage polarity reversed. Moreover, there were no homodischarges observed at the decreasing part of applied voltage even at the area without surface charges existing. This could not be explained by the accumulation of surface charges. It was also observed that more than one charge spot in one PD could occur. This was named simultaneous discharge in our paper, and may be attributed to the effects of photoionization and time lag.