For enhancing the accuracy of fault diagnosis for power transformers, a multiple SVMs scheme is proposed in this paper. In this scheme, SVM is used to establish the base classifier for its good performance and fast learning speed. Secondly, the several base classifiers based on single SVM will be combined by consulting ensemble techniques. And then a multiple SVM s method is obtained. The real ...

Power transformers can be sources of disturbing and annoying acoustic noise. This paper is a first phase report of a wider framework of study that investigates the noise radiation characteristics of air-cooled power transformers. The dynamics of the transformer core structure plays a significant role in the noise generation process. The reported work focuses on the influence of lamination of th...

The reliability of electrical energy networks depends on both the quality and the reliability of its electrical equipment, e.g. power transformers. Local failures inside their insulation can lead to breakdowns and hence to high outage and penalty costs. Usually, power transformers are tested on partial discharge (PD) activity before commissioning. UHF PD monitoring can be used to prevent these ...

This paper presents the results of a comprehensive investigation of five blackouts that occurred on 28 August to 8 September 2011 due to bushing failures of the 132/33 kV, 125 MVA transformers at JBB Ali Grid station. The investigation aims to explore the root causes of the bushing failures and come up with recommendations that help in rectifying the problem and avoiding the reoccurrence of sim...

Oil-impregnated paper is widely used in power transmission equipment as a reliable insulation. However, copper sulphide deposition on oil-paper insulation can lead to insulation failures in power transformers. This paper presents the influences of copper sulfur corrosion and copper sulphide deposition on copper wires and oil-paper insulation in power transformers. Thermal aging tests of paper-w...

The reliability of electrical energy networks depends on both, the quality and the reliability of its electrical equipment, e.g. power transformers. Local failures inside their insulation can lead to breakdowns and hence to high outage and penalty costs. Usually, power transformers are tested on partial discharge (PD) activity before commissioning. UHF PD monitoring can be used to prevent these...

The infrastructure of the electricity grid and super grid system in the hitherto industrialized world was to a large extent built up in the decades following World War II with a peak in investments around 1960-1980. This means that the flotilla of power transformers is now starting to reach projected lifetime of around 40 years. During the last couple of decades there has also been an ongoin...