Prediction of surface degradation of composite insulators using PD measurement in cold fog

Hussain, Muhammad Majid; Farokhi, S.; McMeekin, Scott G.; Farzaneh, M.

doi:10.1109/icd.2016.7547711

Cited by 8 publications

(13 citation statements)

References 11 publications

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“…Obviously, the LC pulses were obtained at a location between 0°–90° for the positive cycle and 180°–270° for the negative cycle. This result corroborates the findings of [21, 24–26] who classified the discharge pattern distributed within the first and third quadrants of phase window as surface discharge. The non‐uniform contamination layer along the surface of glass insulators applied during the experiment could lead to the formation of a high tangential field and could enable the occurrence of this surface discharge.…”

Section: Resultssupporting

confidence: 91%

Space charge distribution and leakage current pulses for contaminated glass insulator strings in power transmission lines

Othman

Piah

Adzis

2017

IET Generation, Transmission & Distribution

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Section: Resultssupporting

confidence: 91%

Space charge distribution and leakage current pulses for contaminated glass insulator strings in power transmission lines

Othman

Piah

Adzis

2017

IET Generation, Transmission & Distribution

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“…As mentioned above, the existence of these water-droplets is due to the good hydrophobicity of the materials. Previous studies have shown that the maximum electric field strength of the water-droplets on the upper shed appears at the interface between the liquid and the shed surface, where air is ionized [3][4][5][6][7][8][9][10][11][12][13][14]. These corona discharges did not further develop into an arc, because the shape of the water-droplets on the upper shed did not change significantly, resulting in no further distortion of the electric field intensity around the water-droplets.…”

Section: Discharge Characteristics and Flashover Processmentioning

confidence: 91%

“…In real applications, the whole post insulator is composed of several sections. It has been found that when the insulation height is less than 10m, the pollution flashover voltage of the post insulator increases linearly with the increase of insulation height [5][6][7][8][9][10][11][12][13][14][15]. Therefore, only one section of the entire insulator was used in this test to reduce the test voltage.…”

Section: Artificial Contamination Rain Flashover Testmentioning

confidence: 99%

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Discharge Behavior and Morphological Characteristics of Suspended Water-Drop on Shed Edge during Rain Flashover of Polluted Large-Diameter Post Insulator

et al. 2021

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Rain is one of the dominant meteorological factors threatening the outdoor insulation performance of ultra-high voltage (UHV) power stations. Discharge occurring on the polluted surface of post insulators in rain has always been a major concern of power stations. Previous studies have shown that suspended water droplets on the shed edge play an important role in the rain flashover process. In this work, artificial contamination rain flashover tests were carried out in a laboratory on a UHV DC (Ultra-High Voltage Direct Current) large-diameter composite post insulator, which had a rod diameter of 625 mm and alternating sheds (105 mm and 75 mm for larger and smaller shed overhang, respectively). The discharge mechanism was analyzed base on the observation of discharge phenomenon of suspended water-drops on the shed edge. Moreover, simulation models by COMSOL Multiphysics were established to investigate the electric field around sheds and suspended water-drops, as well as the shape change of water droplets on the insulation surface, especially at the edge of the shed. Results show that the shape parameters of water-droplets changed continuously under the combined action of gravity, surface tension, and capillary tension. Suspended water-droplets on the shed edge showed a great influence on the electric field distribution, and the resulting discharge lead to the bridging between sheds. This work paves a new way to revealing the contamination rain flashover mechanism on post insulators and provides critical knowledge for power stations on preventing flashover accidents.

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“…8 During this, the pertinent focus is to understand the physical, chemical, and structural changes on the insulator caused by the industrial, saline, and acidic contamination and influence of environmental and climatic conditions such as cold, ice, fog, and so forth. [24][25][26][27][28][29] During this, effect of surface leakage current, field distribution, surface roughness, electrical discharges, tracking, and so forth, are intensively studied and the factors that aggravates aging phenomena are investigated. [24][25][26][27] On contrary, extrapolating the same to tar depositions on the porcelain insulator may not be feasible.…”

Section: Introductionmentioning

confidence: 99%

Quasi‐phase resolved partial discharge pattern analysis of surface discharges arising on the tar polluted porcelain bushing of an electrostatic precipitator unit under high voltage DC

Schröder¹,

Neubauer²,

Schoenemann

et al. 2021

Engineering Reports

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This paper investigates on understanding the DC electrical discharges arising on the surface of feed-through type indoor bushing with tar depositions. Such information not only provides diagnostic status but also characterizes the multitude of species forming tar depositions which is currently unavailable in literatures. The current practice on analyzing surface discharges initiated under DC voltage employs primitive methods that accounts for the individual discharge events over a larger span rendering it less sensitive and time consuming.The usual practice is to count the discharge events initiated under DC voltage as PD pulses and count the events, repetition rates, time of occurrence, and so forth, to estimate the severity of the fault condition. On contrary, synchronizing these discharge pulses to the phase of the AC voltage, input to the rectifier unit, manifests a pattern, which is time independent and is sensitive in revealing diagnostic status of the bushing. These objectives are initially verified on a sample extracted from a tar polluted bushing. A half-wave bridge rectifier that produces an uncontrolled positive and negative DC voltage is selected to initiate surface discharges. Pertinent pulses are then correlated to the phase of the AC voltage input to the rectifier and a quasi-phase resolved partial discharge pattern (QPRPD) is developed. Using this QPRPD pattern, the significance of positive and negative DC voltages applied on the surface of the polluted sample is studied and the inception of discharges events and their correlation to the defect conditions are evaluated. Following this, the pertinent findings are validated on an ‡ Dipl.-Ing. (FH) Philipp Schröder and Dr. Ing. York Neubauer worked at the Institute of Energy Engineering at TU Berlin on the topic presented in this paper within the "EMF project". Both continued their work on high voltage applications in gas cleaning and gas conditioning in the junior research group NWG-TCKON at the same institute.

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Prediction of surface degradation of composite insulators using PD measurement in cold fog

Cited by 8 publications

References 11 publications

Space charge distribution and leakage current pulses for contaminated glass insulator strings in power transmission lines

Space charge distribution and leakage current pulses for contaminated glass insulator strings in power transmission lines

Discharge Behavior and Morphological Characteristics of Suspended Water-Drop on Shed Edge during Rain Flashover of Polluted Large-Diameter Post Insulator

Quasi‐phase resolved partial discharge pattern analysis of surface discharges arising on the tar polluted porcelain bushing of an electrostatic precipitator unit under high voltage DC

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