Diagnostic of nonceramic insulators aged in a salt fog chamber by using electric field sensor

Abstract

Abshocr: The objective of this paper is to validate the electric field measurement technique for the diagnosis of uon-ceramic insulators (NCI). To validate this technique, fifteen NCI were aged in a salt fog chamber by applying uon-staudard methods. Before ageing the NCI, the electric field distribution aloug each insulator was measured (sound field curve). When an insulator flashed over during the ageing test, the insulator was removed from the salt fog chamber and its electric field distribution was again measured (aged field curve). AU the insulators that flashed over had visible defects and showed an electric field distribution different to that initially Obtained. The comparison between the sound field and aged field curves for these insulators validated the location of the defects along the insulator. On the other hand, the electric field distribution measured on insulators which had no visible defects was similar to that initially obtained. This means that for these cases the flashover was only caused by the pollution phenomenon, and not by any defect Furthermore, the electric field distribution measurements on all the insulators at the middle and at the end of the ageing test were performed, in order to mainly determine if some internal defect in the insulators, without visible defects, had occurred. According to the results, uo-defects were found in the insulators without visible defects, being as their aged fieid curves equaled their sound field curves. It is concluded that this diagnostic technique may be used io service to evaluate the performance of non-ceramic insulators if the measurement methodology is systematically applied and the electric field detector is used in a proper way. The insulators that did not suffer damage during the ageing test show a good correspondence between the electric field curves measured before and aner ageing.

Experiences on pollution level measurement in Mexico

“…This means that is necessary to modify the standard continuous 5000 h salt fog test to determine the long-term performance of polymeric insulators. In 2003, the IIE applied visual corona and electrical field techniques to check out the operational state of the polymeric insulators installed on 230 and 400 kV Mexican transmission lines [15][16][17][18]. These techniques were applied live using the following equipment: DayCor II Corona Camera for visual corona and Polymeric Insulator Tester for electrical field [18].…”

“…In 2003, the IIE applied visual corona and electrical field techniques to check out the operational state of the polymeric insulators installed on 230 and 400 kV Mexican transmission lines [15][16][17][18]. These techniques were applied live using the following equipment: DayCor II Corona Camera for visual corona and Polymeric Insulator Tester for electrical field [18]. The camera DayCor II shows the position, type and magnitude of corona activity, which may mean degradation or damage on the insulator.…”

Spatial distribution of electric field measurement system: straight characterization of one or more original electric field sources in association with a new triaxial sensor

“…have been used in atmospheric science to study and predict meteorological phenomena such as lightning storms [4][5][6][7] or sand storms [8] and are now part of payloads for solar system exploration missions [9]. In industrial applications, EF sensors can be used to prevent electrostatic discharge during electronic manufacturing processes [10] or as online diagnostics for non-contact detection of internal defects in non-ceramic insulators [11,12]. EF under power lines have also been investigated to understand potential health effects from exposure to electromagnetic fields [13][14][15] or to detect ice accretion on high power electric cables [16].…”

Measurement of electric field distribution along composite insulators by integrated optical electric field sensor

“…The electric field of 735 kV and 315 kV insulators were measured online by this tester [9]. And power corporations of America and Mexico diagnosed the nonceramic insulators aged in a salt fog chamber by field sensor [10].…”