The Experts below are selected from a list of 18 Experts worldwide ranked by ideXlab platform
René Smeets - One of the best experts on this subject based on the ideXlab platform.
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Complete analysis of very fast transients in layer-type Transformer Windings
2020Co-Authors: Marjan Popov, L. Van Der Sluis, René SmeetsAbstract:This paper deals with the measurement, modelling and simulation of very fast transient overvoltages in layer-type distribution Transformer Windings. Measurements were performed by applying a step impulse with 50 ns rise time on a single-phase test Transformer equipped with measuring points along the Winding. Voltages along the Transformer Windings were computed by applying multi-conductor transmission line theory for Transformer layers. The Secondary voltage of the Transformer was simulated with another model implemented in ATP-EMTP which takes into account the surge capacitance between the primary and Secondary Transformer Winding. It was found that, when an impulse with a short rise time is applied, internal resonance occurs, which results in a very high Secondary voltage. The computations were verified by measurements.
Marjan Popov - One of the best experts on this subject based on the ideXlab platform.
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Complete analysis of very fast transients in layer-type Transformer Windings
2020Co-Authors: Marjan Popov, L. Van Der Sluis, René SmeetsAbstract:This paper deals with the measurement, modelling and simulation of very fast transient overvoltages in layer-type distribution Transformer Windings. Measurements were performed by applying a step impulse with 50 ns rise time on a single-phase test Transformer equipped with measuring points along the Winding. Voltages along the Transformer Windings were computed by applying multi-conductor transmission line theory for Transformer layers. The Secondary voltage of the Transformer was simulated with another model implemented in ATP-EMTP which takes into account the surge capacitance between the primary and Secondary Transformer Winding. It was found that, when an impulse with a short rise time is applied, internal resonance occurs, which results in a very high Secondary voltage. The computations were verified by measurements.
L.s. Shirshov - One of the best experts on this subject based on the ideXlab platform.
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Apparatus for the inductive measurement of critical current of multistrand superconducting cables above 10 kA as a function of the temperature and magnetic field
IEEE Transactions on Magnetics, 1992Co-Authors: L.s. ShirshovAbstract:An apparatus for the critical current measurements of high-current cables was designed to test short samples in magnetic fields up to 6 T and at temperatures from 2 K to 9 K. The sample is energized by an inductive method using a superconducting (SC) Transformer. The hair-pin sample and Secondary Transformer Winding are fixed inside the inner Dewar and cooled by helium gas at the specified temperature. The inner Dewar can be placed into the cryostat with liquid helium, where the SC solenoid and primary Transformer Winding are fixed stationary, thus making it possible to make a fast replacement of the sample. The author presents the parameters of the apparatus and results on measuring the critical currents of SC cable versus the magnetic field and temperature for an E=1 mu V/cm electric field. >
L. Van Der Sluis - One of the best experts on this subject based on the ideXlab platform.
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Complete analysis of very fast transients in layer-type Transformer Windings
2020Co-Authors: Marjan Popov, L. Van Der Sluis, René SmeetsAbstract:This paper deals with the measurement, modelling and simulation of very fast transient overvoltages in layer-type distribution Transformer Windings. Measurements were performed by applying a step impulse with 50 ns rise time on a single-phase test Transformer equipped with measuring points along the Winding. Voltages along the Transformer Windings were computed by applying multi-conductor transmission line theory for Transformer layers. The Secondary voltage of the Transformer was simulated with another model implemented in ATP-EMTP which takes into account the surge capacitance between the primary and Secondary Transformer Winding. It was found that, when an impulse with a short rise time is applied, internal resonance occurs, which results in a very high Secondary voltage. The computations were verified by measurements.
J.j. Walker - One of the best experts on this subject based on the ideXlab platform.
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Optimizing the properties of the optical current Transformer with special reference to faster transient response
2014 ICHVE International Conference on High Voltage Engineering and Application, 2014Co-Authors: N.j. Oosthuysen, J.j. WalkerAbstract:A current Transformer, in general, is a means of measuring a very large electrical current, converting it to a much smaller current, requiring low power equipment as simple as a multimeter to display it. The traditional method is based on the electromagnetic principle of an iron ring around the current conductor, supplied with a Secondary Transformer Winding. The latter will deliver a small current directly proportional to the large current, to be displayed by a small current measuring device. An optical current Transformer (OCT) is constructed by Winding an optical fibre cable around the current conductor. The phenomenon where the angle of a polarized light beam propagating through the optical cable, is deflected when the magnetic flux lines generated by the large current, are appearing longitudinal in the said cable, are utilized to determine the main current. OCT's are already well developed, but lack to respond to very fast changing transient impulses. This paper describes a research and developing process to address this problem.