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Sulphur hexafluoride as a high-voltage insulation - selected problems

Opydo W., Juszczyk Z., Stawicki J., Opydo-Szymaczek J.

Computer Applications in Electrical Engineering

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2014

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Vol. 12

206--216

EN

The paper presents some selected properties of sulphur hexafluoride (SF6) a medium used for high-voltage insulation and electric arc suppression purposes. The results are presented of the studies aimed at determining the effect of the electrode material type, temperature, gas density and interelectrode gap on the SF6 electric strength. The considered systems had both flat electrodes or one flat and the other (cathode) having the form of a rod of 3 mm or 30 mm diameter, ended with a hemisphere. The electrodes have been made of stainless steel or aluminum. The results were mathematically processed with the use of the Statistica [11] computer software. It was found that SF6 temperature changes in the range from 243 K to 293 K with constant SF6 density did not cause variation of electric strength of the gas. Moreover, the effect of the electrode material type on electric strength of SF6 was observed only in the systems distinguished by macroscopic uniformity of the electric field and in case of the gas density exceeding 15 kg/m3, corresponding to SF6 pressure amounting about to 2.5-105 Pa in the temperature 293 K. Physical interpretation of the study results is proposed and formulated. Additionally, the paper discusses the hazards arising from the use of SF6 for the health of the persons operating the equipment and for the environment.

2

Review and comparison of electro-insulation properties of vacuum and sulphur hexafluoride

Opydo W., Stawicki J., Opydo-Szymaczek J.

Computer Applications in Electrical Engineering

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2013

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Vol. 11

222--229

EN

The paper specifies the results of the tests on electric strength of vacuum, sulphur hexafluoride (SF6) and the insulation mineral oil under alternate voltage. The tests have been carried out for planar electrodes made of stainless steel or aluminum. It was found that 10-3 Pa vacuum, 3 105 Pa SF6, and insulation mineral oil situated with equal inter-electrode gap equal to several millimeters, have approximately equal electric strength. The degrees of influence of basic parameters of the insulation system on electric strength of SF6 and vacuum are presented. Advantages and faults of vacuum, SF6, and insulation mineral oil are mentioned, taking into account possible use of these media as a high-voltage insulation in various electric equipment. Mathematical processing of the test results was carried out with the use of the Statistica software [5].

3

Current pulses caused by microparticle motion in vacuum and gas high- voltage insulation systems

Zakrzewski S., Bieliński W., Opydo W.

Poznan University of Technology Academic Journals. Electrical Engineering

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2009

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No 60

97-102

EN

The paper presents a computer program allowing for determining a time pattern of the current flowing through a vacuum or gas high-voltage insulation system, in result of the motion of a microparticle (being a small charged metallic particle) occurring in the inter-electrode gap. Moreover, the program calculates the velocity of the microparticle impact against the opposite electrode surface and the critical velocity of inelastic collision with the surface.

4

Application of many neural networks paradigms for the high voltage insulation

Mokhnache Leila, Boubakeur Ahmed

Archives of Electrical Engineering

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2003

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Vol. 52, nr 3

243--253

EN

An application of some artificial neural networks algorithms to the diagnosis of transformer oil and high voltage insulation thermal ageing prediction has been presented. An RBFG neural network trained by Random Optimisation Method has been applied for prediction and a Back-Propagation network trained by Levenberg-Marquardt technique has been used for diagnosis. The simulation had been validated by experimental results carried out in the National Algerian Company of Electricity and Gas, the national company of cable and the high voltage laboratories of the Warsaw University of Technology.

PL

W artykule przedstawiono zastosowanie algorytmów sieci neuronowych w diagnostyce oleju transformatorowego oraz prognozowaniu starzenia termicznego izolacji wysokonapięciowej. Do celów prognozowania zastosowano sieć neuronową podstawowej funkcji radialnej Gaussa trenowaną metodą optymalizacji stochastycznej a dla celów diagnostyki sieć neuronowa propagacji zwrotnej trenowaną techniką Lavenberga-Morquardta. Symulacje potwierdzone zostały wynikami eksperymentów przeprowadzonych w Algierskim Narodowym Przedsiębiorstwie Elektryczności i Gazu, Narodowym Przedsiębiorstwie Kablowym oraz w laboratorium WN Politechniki Warszawskiej.