Journal ArticleDOI
Corrosive Sulfur Induced Failures in Oil-Filled Electrical Power Transformers and Shunt Reactors
TLDR
In this paper, the nature and causes of corrosive sulfur induced failures in oil-filled transformers and shunt reactors are examined in the presence of paper tapes insulating the conductors.Abstract:
The nature and causes of corrosive sulfur induced failures are examined in oil-filled transformers and shunt reactors. Copper sulfide, which is formed when the corrosive sulfur in a mineral oil reacts with the copper conductors, is likely to diffuse into the paper tapes insulating the conductors. Since copper sulfide is partially conducting, the dielectric losses of the contaminated oil-impregnated-paper tapes are markedly increased; paper tapes in close proximity to the copper conductors are found to attain tan delta values > 1.0 even at room temperature. It is highly likely that thermal instabilities develop at those sites at operating temperatures, leading to increased loss currents and, ultimately, short circuits between the turns. This sequence of events is substantiated by evidence from the field, which indicates large areas of thermally degraded insulations and charred breakdown regions along the coils, the extent of which becomes more pronounced at higher operating temperatures (toward the top of the windings).read more
Citations
More filters
Journal ArticleDOI
Condition Monitoring of Power Transformers - Bibliography Survey
TL;DR: In this article, the authors proposed a preventive maintenance technique for power transformers, such as DGA, thermal monitoring, partial discharge measurement, capacitance and tan delta measurements, frequency response analysis, etc., to identify problems at an early stage before a catastrophic failure occurs.
Journal ArticleDOI
Corrosive sulfur effects in transformer oils and remedial procedures
TL;DR: In this paper, the behavior of corrosive sulfur in mineral oils is examined in terms of the failures observed in transformers, the surfaces of the copper sulfide covered conductors and degraded paper insulating tapes.
Journal ArticleDOI
An expert system approach for transformer insulation diagnosis combining conventional diagnostic tests and PDC, RVM data
TL;DR: In this paper, an expert system is proposed to perform insulation diagnosis using both traditional and newer techniques in order to come to a definitive conclusion, where the expert system extracts insulation condition sensitive information from data obtained using different techniques and then uses these to devise an optimized insulation model.
Journal ArticleDOI
Condition assessment of cellulosic part in power transformer insulation using transfer function zero of modified debye model
Arijit Baral,Sivaji Chakravorti +1 more
TL;DR: In this article, a performance parameter, which is less sensitive to insulation geometry, can be evaluated from Transfer Function, TFM(s) of Modified Debye Model (MDM), which is located farthest away from the origin in the Left Half Plane of s-plane.
Journal ArticleDOI
Suppressive mechanism of the passivator irgamet 39 on the corrosion of copper conductors in transformers
TL;DR: In this article, the presence or absence of Irgamet 39, a metal passivator, was found to improve the oxidation stability and dielectric loss tangent of transformer oil.
References
More filters
Book
Atmospheric Oxidation and Antioxidants
TL;DR: In this paper, Al-Malaika et al. discuss the effect of the reaction environment upon Oxidation and Antioxidant Mechanisms and the present position of Biological Oxidation.
Journal ArticleDOI
Corrosive Sulfur in Insulating Oils: Its Detection and Correlated Power Apparatus Failures
TL;DR: In this paper, high amounts of dibenzyl-disulfide (DBDS) were found in many of the tested oils, which may cause shorting faults between turns.
Journal ArticleDOI
Thermal decomposition of dibenzyl disulphide and its load-carrying mechanism
TL;DR: In this article, the homogeneous and heterogeneous thermal decomposition of dibenzyl disulphide in hexadecane solution over the temperature range 170-250 °C was investigated.