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Insulator aging tests with HVAC and HVDC excitation using the tracking wheel tester

Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2009.

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Main Author: Limbo, Beulah Sepo
Other Authors: Vermeulen, H. J.
Format: Thesis
Language:English
Published: Stellenbosch : University of Stellenbosch 2009
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access_status_str Open Access
author Limbo, Beulah Sepo
author2 Vermeulen, H. J.
author_browse Limbo, Beulah Sepo
Vermeulen, H. J.
author_facet Vermeulen, H. J.
Limbo, Beulah Sepo
author_sort Limbo, Beulah Sepo
collection Thesis
dc_rights_str_mv University of Stellenbosch
description Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2009.
format Thesis
id oai:scholar.sun.ac.za:10019.1/2529
institution Stellenbosch University (South Africa)
language English
last_indexed 2026-06-10T12:41:32.562Z
license_str Other — see source repository
provenance_str_mv Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository
publishDate 2009
publishDateRange 2009
publishDateSort 2009
publisher Stellenbosch : University of Stellenbosch
publisherStr Stellenbosch : University of Stellenbosch
record_format dspace
source_str SUNScholar — Stellenbosch University Repository
spelling oai:scholar.sun.ac.za:10019.1/2529 Insulator aging tests with HVAC and HVDC excitation using the tracking wheel tester Limbo, Beulah Sepo Vermeulen, H. J. Vosloo, W. L. University of Stellenbosch. Faculty of Engineering. Dept. of Electrical and Electronic Engineering. Insulator testing Aging Rotating wheel test Pollution Dissertations -- Electrical and electronic engineering Theses -- Electrical and electronic engineering Electric insulators and insulation -- Testing Surface discharges (Electricity) Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2009. ENGLISH ABSTRACT: Limited research results are available on the aging impacts of surface discharges for High Voltage Direct Current (HVDC) excitation on practical insulators using the Tracking Wheel Tester (TWT) methodology. This thesis gives details of an experimental investigation to compare the aging performance of insulator samples using the TWT for High Voltage Alternating Current (HVAC) and positive and negative polarity HVDC excitation. Two series of tests were performed. The first series of tests evaluated the aging of six insulator rods, namely three Room Temperature Vulcanized Silicone Rubber (RTV SR) coated glass samples and three uncoated glass samples. Three creepage distances were used for each of the test materials, namely 277 mm, 346 mm and 433 mm. The tests were conducted with HVAC excitation and the test methodology described in the IEC 61302 standard. The second series of tests involved the testing of actual insulator samples. The test voltage and conductivity of the salt water solution were also adapted. Six insulators from different manufacturers, representing different materials and specific creepage distances, were tested with HVAC and positive and negative polarity HVDC excitation. The test samples consisted of Ethylene Propylene Diene Monomer (EPDM), High Temperature Vulcanized Silicone Rubber (HTV SR), porcelain and SR coated porcelain insulators. The aging performance of the different test samples for the three types of excitation are compared in terms of peak leakage current, visual observations of surface degradation and hydrophobicity properties. The leakage current data for HVAC excitation shows that the insulators from the different manufacturers perform differently, even for the same type of material. The results also indicate differences in the way the surfaces degrade, as well as the rate of degradation. For insulators representing the same specific creepage distance, but different materials, it has been shown that the material does influence the aging performance. Comparison of the leakage current data for the HTV SR insulators from the same manufacturer, but with different specific creepage distances, shows that the specific creepage distance affect the aging performance significantly. In general, the test insulators showed higher peak leakage currents with HVDC excitation compared to HVAC excitation. The results for positive polarity HVDC excitation show that the dry band arcing, as well as the discharges, has the same form for all six insulators. The colour of the dry band discharges ranged from a blue-ish orange to a dark yellow, depending on the intensity of the leakage currents. The hydrophobic insulators, namely the HTV SR, EPDM and RTV SR coated porcelain insulators, had lost hydrophobicity within the first week of testing. The results for negative polarity HVDC excitation show severe surface degradation compared to the results for HVAC excitation. The effect of positive polarity HVDC excitation, however, seems to be more severe in terms of leakage currents and aging compared to negative polarity HVDC excitation. 2009-11-25T14:04:03Z 2010-06-01T08:51:24Z 2009-11-25T14:04:03Z 2010-06-01T08:51:24Z 2009-12 Thesis http://hdl.handle.net/10019.1/2529 en University of Stellenbosch application/pdf Stellenbosch : University of Stellenbosch
spellingShingle Insulator testing
Aging
Rotating wheel test
Pollution
Dissertations -- Electrical and electronic engineering
Theses -- Electrical and electronic engineering
Electric insulators and insulation -- Testing
Surface discharges (Electricity)
Limbo, Beulah Sepo
Insulator aging tests with HVAC and HVDC excitation using the tracking wheel tester
title Insulator aging tests with HVAC and HVDC excitation using the tracking wheel tester
title_full Insulator aging tests with HVAC and HVDC excitation using the tracking wheel tester
title_fullStr Insulator aging tests with HVAC and HVDC excitation using the tracking wheel tester
title_full_unstemmed Insulator aging tests with HVAC and HVDC excitation using the tracking wheel tester
title_short Insulator aging tests with HVAC and HVDC excitation using the tracking wheel tester
title_sort insulator aging tests with hvac and hvdc excitation using the tracking wheel tester
topic Insulator testing
Aging
Rotating wheel test
Pollution
Dissertations -- Electrical and electronic engineering
Theses -- Electrical and electronic engineering
Electric insulators and insulation -- Testing
Surface discharges (Electricity)
url http://hdl.handle.net/10019.1/2529
work_keys_str_mv AT limbobeulahsepo insulatoragingtestswithhvacandhvdcexcitationusingthetrackingwheeltester