标题：Experimental Investigations and Ageing Studies on Effects of Insulating Barriers in Transformer Oil during High Frequency High Voltage Transients in I
期刊名称：International Journal on Electrical Engineering and Informatics
印刷版ISSN：2085-6830
出版年度：2014
卷号：6
期号：1
DOI：10.15676/ijeei.2014.6.1.2
出版社：School of Electrical Engineering and Informatics
摘要：Insulating barriers utilized in complex high voltage insulation systems hasbeen exploited widely by manufacturers of power apparatus. Barriers have found utilityin a variety of power apparatus for protection against direct lightning strokes, as aninterface at the boundaries of composite insulation materials etc. Though investigationshave been carried out by researchers on the breakdown characteristics, barrier positionin the gap, influence of space charge etc these characteristics have been analyzed basedon aspects pertinent to classical testing procedures only. Advent of high speed switchingdevices in power systems provides avenues to investigate the effect of insulationperformance due to High Frequency High Voltage (HFHV) also. Further,uncharacteristic failures in oil filled distribution transformers have been reportedindicated fast transients as the major cause for failures which was not revealed duringclassical laboratory testing. This research focuses on the influence and effects of solidinsulating barriers placed in transformer oil due to HFHV in inhomogeneous fields. Testcell arrangement has been fabricated for carrying out experimental investigations toadhere international standards. Exhaustive experimentation has been performed to inferthe influence of the position of barrier, nature of field and breakdown voltage, erosioncharacteristics of the barrier at an appropriate range of frequencies. A detailedcomparison between HFHV and classical power frequency voltage has been carried out.The nature of ionization at the barrier interface and the subsequent increase in thebreakdown voltage as explained by Double Electric Layer (DEL) theory has been crossvalidated. In addition, a study has also been carried out to assess and characterize theageing of oil based on Dissolved Gas Analysis (DGA) analysis using Weibulldistribution.
关键词：High Frequency High Voltage- HFHV; Double Electric Layer- DEL;Barrier; Dissolved Gas Analysis – DGA
