1,354,180 research outputs found
Comparison of partial discharge inception voltages for ester and mineral oils under divergent fields
No full textEster oils are making their way into the transformer market, but still some doubts exist about their ability to be successful fluids for high and extra-high voltage transformers. In this paper, we compare the PDIV of two commercially available fluids: a natural ester and mineral oil. Two different setups were considered: Point to plane in oil and point to plane on a pressboard sheet immersed in oil. Fluids and pressboard sheets were fully conditioned prior testing. Results suggest that ester oils perform slightly better with simple point-to-plane electrodes, independently of the gap length. When testing oil/plane electrode configurations with pressboard, ester oils perform much better at short gaps. This behavior has been explained considering the hydrophilicity of ester oils, which helps in further drying the pressboard prior testing. Therefore, ester oils could prove superior to mineral oils in suppressing creeping discharges
A comparison of the voltage withstand properties of ester and mineral oils
No full textEO has proved to be a viable substitute for MO. Its dielectric performance is always comparable with, if not superior to that of MO, at least when new, dried, and highly purified. The smaller permittivity mismatch between pressboard and EO, compared to that between pressboard and MO, leads to a more uniform field distribution at the oil/pressboard interface. We have observed that EO has higher PDIVs than MO for corona and creepage discharges. However, our understanding of the oil/pressboard interface is incomplete. There is a lack of standardization in PDIV measurements, particularly in the case of creepage discharges. Because industry is striving to provide new insulating oils for use at increased transmission voltages, improving electrical testing techniques and the understanding of the oil/pressboard interface is important
Investigations on the effect of nanoparticles in mineral oil
No full textPower transformers are one of the critical components in power system; traditionally mineral oil is used in transformers for the purpose of dielectrics as well as cooling. In this work, an investigation has been carried out to analyze the performance of Ferrofluids (nano fluids) along with mineral oil for various concentrations. Ferrofluids concentration of 0.1g/liter, 0.2g/liter and 0.5g/liter has been prepared with moisture content less than 5 ppm. Partial Discharge Inception Voltage (PDIV), discharge characteristics of test samples for AC, DC positive and negative voltage is analyzed. Moreover charges produced for each Partial Discharge (PD) have been evaluated. The results illustrate that Ferrofluids with lower concentration shows enhanced PDIV and charge accumulation characteristics than other concentrations as well as mineral oil
Knowledge Acquisition And Revision Using Neural Networks: An Application To A Cross-National Study Of Brand Image Perception
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Improved SOM Labeling Methodology for Data Mining Applications, In Soft Computing for Knowledge Discovery and Data Mining (O. Maimon and L. Rokach, Eds.)"
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