The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
Dmitry Ishchenko - One of the best experts on this subject based on the ideXlab platform.
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Multi-phase Converters with Rotating Magnetic Field for Power System Protection
2020 IEEE PES Transmission and Distribution Conference and Exposition (T&D), 2020Co-Authors: Boris A. Korobeynikov, Dmitry Ishchenko, Alexey I. IshchenkoAbstract:This paper derives theoretical foundations for novel protective relaying system based on electroMagnetic multi-phase converters with Rotating Magnetic Field. The measurement circuit designed based on this principle can connect to the conventional voltage and current instrument transformers and utilize the fundamental laws of electromagnetism to generate output signals proportional to the magnitude of the voltage and current, as well as their combination, e.g. distance relay and symmetrical component filters. This is done without using digital signal processing, a microprocessor of any kind, or Rotating parts, as in the case of electromechanical relays. The Rotating Magnetic Field is obtained by using four windings in the primary circuit and performing the corresponding vector summation of the magnetomotive forces. A basic methodology to estimate the parameters for the Rotating Magnetic Field converter is also presented in the paper.
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Symmetrical Components Filters for Power System Protection Based on Converters with Rotating Magnetic Field
2018 IEEE PES Transmission and Distribution Conference and Exposition (T&D), 2018Co-Authors: Boris A. Korobeynikov, R. Shestack, Alexey I. Ishchenko, Dmitry IshchenkoAbstract:This paper presents a new method to implement positive, negative and zero sequence components filters based on converters with Rotating Magnetic Field. The filters are directly connected to the traditional instrument transformers, provide galvanic isolation and generate symmetrical components signals that can be used for power system protection purpose. Filter output is the voltage proportional to symmetrical components current magnitudes. The paper provides schematic diagrams of the sequence components filters and outlines the basic theoretical principles for their design. The methodology to create various sequence components filters by simple rewiring of the secondary Rotating Magnetic Field converter windings is also presented.
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Hybrid distance protection relay with Rotating Magnetic Field
2016 IEEE PES Transmission and Distribution Conference and Exposition (T&D), 2016Co-Authors: Boris A. Korobeynikov, Alexey I. Ishchenko, Gennadiy A. Zakharov, Dmitry IshchenkoAbstract:The paper presents a new hybrid distance protective relay based on single-phase transformers with Rotating Magnetic Field for distribution system applications. Both theoretical aspects and a method for the practical implementation of the distance protection element with predetermined impedance operating characteristic is shown. The paper also provides recommendations for the choice of its parameters to obtain the desired characteristics for the distance relay operation implemented as a circle in the complex plane. An experimental prototype distance relay based on converters with Rotating Magnetic Field has been created and the laboratory tests confirmed adequate performance compared to commercial state-of-the-art technology.
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Hybrid overcurrent protection relay based on Rotating Magnetic Field principle
Proceedings of the IEEE Power Engineering Society Transmission and Distribution Conference, 2014Co-Authors: Boris A. Korobeynikov, Alexey I. Ishchenko, Dmitry IshchenkoAbstract:This paper presents a novel hybrid power system overcurrent protection relay based on Rotating Magnetic Field principle. The device is directly connected into the regular current transformer (CT) secondary circuit and consists of an electroMagnetic component with Rotating Magnetic Field and an electronics circuit employed to generate a low-level analog output, which is directly proportional to the magnitude of the input current signal. The relay output is produced without using numerical signal algorithms by the hybrid physical system. Moreover, the relay provides galvanic isolation from the secondary CT circuit and is capable of auto-correcting the input current waveform distortions introduced by CT saturation.
Konstantin Mazuruk - One of the best experts on this subject based on the ideXlab platform.
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Rayleigh–Bénard instability in a vertical cylinder with a Rotating Magnetic Field
International Journal of Heat and Mass Transfer, 2003Co-Authors: John S. Walker, Martin P. Volz, Konstantin MazurukAbstract:Abstract This paper presents a linear stability analysis for the Rayleigh–Benard convection in a finite-length, vertical cylinder with a Rotating Magnetic Field. The vertical wall of the cylinder is adiabatic, and the planar top and bottom walls are isothermal with a higher temperature at the bottom. The stabilizing effects of the Rotating Magnetic Field are studied for four values of the Prandtl number. Results for one Prandtl number are compared to previously published experimental results.
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An experimental study of the influence of a Rotating Magnetic Field on Rayleigh Bénard convection
Journal of Fluid Mechanics, 2001Co-Authors: Martin P. Volz, Konstantin MazurukAbstract:A destabilizing vertical temperature gradient and a Rotating Magnetic Field have been applied to a cylindrical column of liquid gallium. The convective flows which arise as a function of these parameters are identified. For small Magnetic Field strengths, a regime of stationary flow is observed. This regime is bounded by critical values of the Rayleigh and Magnetic Taylor numbers. As the Rotating Magnetic Field is increased, the critical Rayleigh number can increase by more than a factor of 10. The Rotating Magnetic Field itself induces an instability at a critical value of the Magnetic Taylor number independent of the Rayleigh number. The nature of the bifurcations (whether subcritical or supercritical) and the convective flows occurring at the critical Rayleigh numbers are dependent upon the Magnetic Taylor number
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The Effect of a Rotating Magnetic Field on Flow Stability During Crystal Growth
2000Co-Authors: Martin P. Volz, Konstantin MazurukAbstract:The effect of a Rotating Magnetic Field on the stability of flow in crystal growth configurations has been experimentally modeled using liquid gallium contained in a finite cylinder and heated from below. Several distinct flow regions were determined as a function of the Rayleigh and Hartmann numbers. At low values of the Rayleigh and Hartmann numbers, a region of stationary flow exists. As the Rotating Magnetic Field is increased, the critical Rayleigh number bounding the stationary flow region can increase by a factor of 10. However, the Rotating Magnetic Field itself induces an instability at a critical value of the Hartmann number independent of the Rayleigh number. In the stationary flow region, the Rotating Magnetic Field can induce fluid motion with velocities several orders of magnitude larger than typical semiconductor crystal growth velocities. Thus, a Rotating Magnetic Field can be used to achieve the benefits of forced convection without triggering deleterious instabilities.
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Solidification of II-VI Compounds in a Rotating Magnetic Field
1999Co-Authors: D. C. Gillies, Martin P. Volz, Konstantin Mazuruk, S. Motakef, Michael Dudley, R. MatyiAbstract:This project is aimed at using a Rotating Magnetic Field (RMF) to control fluid flow and transport during directional solidification of elemental and compound melts. Microgravity experiments have demonstrated that small amounts of residual acceleration of less than a micro-g can initiate and prolong fluid flow, particularly when there is a static component of the Field perpendicular to the liquid solid interface. Thus a true diffusion boundary layer is not formed, and it becomes difficult to verify theories of solidification or to achieve diffusion controlled solidification. The RMF superimposes a stirring effect on an electrically conducting liquid, and with appropriate Field strengths and frequencies, controlled transport of material through a liquid column can be obtained. As diffusion conditions are precluded and complete mixing conditions prevail, the technique is appropriate for traveling solvent zone or float zone growth methods in which the overall composition of the liquid can be maintained throughout the growth experiment. Crystals grown by RMF techniques in microgravity in previous, unrelated missions have shown exceptional properties. The objective of the project is two-fold, namely (1) using numerical modeling to simulate the behavior of a solvent zone with applied thermal boundary conditions and demonstrate the effects of decreasing gravity levels, or an increasing applied RMF, or both, and (2) to grow elements and II-VI compounds from traveling solvent zones both with and without applied RMFs, and to determine objectively how well the modeling predicts solidification parameters. Numerical modeling has demonstrated that, in the growth of CdTe from a tellurium solution, a Rotating Magnetic Field can advantageously modify the shape of the liquid solid interface such that the interface is convex as seen from the liquid. Under such circumstances, the defect structure is reduced as any defects which are formed tend to grow out and not propagate. The flow of liquid, however, is complex due to the competing flow induced by the Rotating Magnetic Field and the buoyancy driven convection. When the acceleration forces are reduced to one thousandth of gravity, the flow pattern is much simplified and well controlled material transport through the solvent zone can be readily achieved. Triple axis diffractometry and x-ray synchrotron topography have demonstrated that there is no significant improvement in crystal quality for HgCdTe grown on earth from a tellurium solution when a Rotating Magnetic Field is applied. However, modeling shows that the flow in microgravity with a Rotating Magnetic Field would produce a superior product.
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The effect of a Rotating Magnetic Field on Rayleigh-Benard convection
1999Co-Authors: Martin P. Volz, Konstantin MazurukAbstract:A destabilizing vertical temperature gradient and a Rotating Magnetic Field have been applied to a cylindrical column of liquid gallium. The convective flows which arise as a function of these driving parameters are identified. For small Magnetic Field strengths, a region of stationary flow is observed. This region is bounded by critical values of the Rayleigh and Hartmann numbers. As the Rotating Magnetic Field is increased, the critical Rayleigh number can increase by more than a factor of 10. The Rotating Magnetic Field itself induces an instability at a critical value of the Hartmann number independent of the Rayleigh number. The nature of the bifurcations (whether subcritical or supercritical) and the convective flows occurring at the critical Rayleigh numbers are dependent upon the Hartmann number. In the stationary flow region, the Rotating Magnetic Field can induce fluid motion with velocities on the order of cm/s. Thus, a Rotating Magnetic Field can be used to achieve the benefits of forced convection during crystal growth processes without triggering deleterious instabilities.
Boris A. Korobeynikov - One of the best experts on this subject based on the ideXlab platform.
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Multi-phase Converters with Rotating Magnetic Field for Power System Protection
2020 IEEE PES Transmission and Distribution Conference and Exposition (T&D), 2020Co-Authors: Boris A. Korobeynikov, Dmitry Ishchenko, Alexey I. IshchenkoAbstract:This paper derives theoretical foundations for novel protective relaying system based on electroMagnetic multi-phase converters with Rotating Magnetic Field. The measurement circuit designed based on this principle can connect to the conventional voltage and current instrument transformers and utilize the fundamental laws of electromagnetism to generate output signals proportional to the magnitude of the voltage and current, as well as their combination, e.g. distance relay and symmetrical component filters. This is done without using digital signal processing, a microprocessor of any kind, or Rotating parts, as in the case of electromechanical relays. The Rotating Magnetic Field is obtained by using four windings in the primary circuit and performing the corresponding vector summation of the magnetomotive forces. A basic methodology to estimate the parameters for the Rotating Magnetic Field converter is also presented in the paper.
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Symmetrical Components Filters for Power System Protection Based on Converters with Rotating Magnetic Field
2018 IEEE PES Transmission and Distribution Conference and Exposition (T&D), 2018Co-Authors: Boris A. Korobeynikov, R. Shestack, Alexey I. Ishchenko, Dmitry IshchenkoAbstract:This paper presents a new method to implement positive, negative and zero sequence components filters based on converters with Rotating Magnetic Field. The filters are directly connected to the traditional instrument transformers, provide galvanic isolation and generate symmetrical components signals that can be used for power system protection purpose. Filter output is the voltage proportional to symmetrical components current magnitudes. The paper provides schematic diagrams of the sequence components filters and outlines the basic theoretical principles for their design. The methodology to create various sequence components filters by simple rewiring of the secondary Rotating Magnetic Field converter windings is also presented.
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Hybrid distance protection relay with Rotating Magnetic Field
2016 IEEE PES Transmission and Distribution Conference and Exposition (T&D), 2016Co-Authors: Boris A. Korobeynikov, Alexey I. Ishchenko, Gennadiy A. Zakharov, Dmitry IshchenkoAbstract:The paper presents a new hybrid distance protective relay based on single-phase transformers with Rotating Magnetic Field for distribution system applications. Both theoretical aspects and a method for the practical implementation of the distance protection element with predetermined impedance operating characteristic is shown. The paper also provides recommendations for the choice of its parameters to obtain the desired characteristics for the distance relay operation implemented as a circle in the complex plane. An experimental prototype distance relay based on converters with Rotating Magnetic Field has been created and the laboratory tests confirmed adequate performance compared to commercial state-of-the-art technology.
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Hybrid overcurrent protection relay based on Rotating Magnetic Field principle
Proceedings of the IEEE Power Engineering Society Transmission and Distribution Conference, 2014Co-Authors: Boris A. Korobeynikov, Alexey I. Ishchenko, Dmitry IshchenkoAbstract:This paper presents a novel hybrid power system overcurrent protection relay based on Rotating Magnetic Field principle. The device is directly connected into the regular current transformer (CT) secondary circuit and consists of an electroMagnetic component with Rotating Magnetic Field and an electronics circuit employed to generate a low-level analog output, which is directly proportional to the magnitude of the input current signal. The relay output is produced without using numerical signal algorithms by the hybrid physical system. Moreover, the relay provides galvanic isolation from the secondary CT circuit and is capable of auto-correcting the input current waveform distortions introduced by CT saturation.
Andrejs Cēbers - One of the best experts on this subject based on the ideXlab platform.
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Swarming of micron-sized hematite cubes in a Rotating Magnetic Field – Experiments
Journal of Magnetism and Magnetic Materials, 2020Co-Authors: Oksana Petrichenko, Guntars Kitenbergs, Martins Brics, Emmanuelle Dubois, Régine Perzynski, Andrejs CēbersAbstract:Energy input by under-Field rotation of particles drives the systems to emergent non-equilibrium states. Here we investigate the suspension of Rotating Magnetic cubes. Micron-sized hematite cubes are synthesized and observed microscopically. When exposed to a Rotating Magnetic Field, they form Rotating swarms that interact with each other like liquid droplets. We describe the swarming behaviour and its limits and characterize the swarm size and angular velocity dependence on the Magnetic Field strength and frequency. A quantitative agreement with a theoretical model is found for the angular velocity of swarms as a function of the Field frequency.
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Diffusion of magnetotactic bacterium in Rotating Magnetic Field
Journal of Magnetism and Magnetic Materials, 2010Co-Authors: Andrejs CēbersAbstract:Swimming trajectory of a magnetotactic bacterium in a Rotating Magnetic Field is a circle. Random reversals of the direction of the bacterium motion induces a random walk of the curvature center of the trajectory. In assumption of the distribution of the switching events according to the Poisson process the diffusion coefficient is calculated in dependence on the frequency of the Rotating Field and the characteristic time between the switching events. It is confirmed by the numerical simulation of the random walk of the bacterium in the Rotating Magnetic Field.
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dynamics of magnetotactic bacteria in a Rotating Magnetic Field
Biophysical Journal, 2007Co-Authors: Kaspars ērglis, Andrejs Cēbers, Qi Wen, Velta Ose, Andris Zeltins, Anatolijs Sharipo, Paul A JanmeyAbstract:The dynamics of the motile magnetotactic bacterium Magnetospirillum gryphiswaldense in a Rotating Magnetic Field is investigated experimentally and analyzed by a theoretical model. These elongated bacteria are propelled by single flagella at each bacterial end and contain a Magnetic filament formed by a linear assembly of ∼40 ferroMagnetic nanoparticles. The movements of the bacteria in suspension are analyzed by consideration of the orientation of their Magnetic dipoles in the Field, the hydrodynamic resistance of the bacteria, and the propulsive force of the flagella. Several novel features found in experiments include a velocity reversal during motion in the Rotating Field and an interesting diffusive wandering of the trajectory curvature centers. A new method to measure the Magnetic moment of an individual bacterium is proposed based on the theory developed.
Alexey I. Ishchenko - One of the best experts on this subject based on the ideXlab platform.
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Multi-phase Converters with Rotating Magnetic Field for Power System Protection
2020 IEEE PES Transmission and Distribution Conference and Exposition (T&D), 2020Co-Authors: Boris A. Korobeynikov, Dmitry Ishchenko, Alexey I. IshchenkoAbstract:This paper derives theoretical foundations for novel protective relaying system based on electroMagnetic multi-phase converters with Rotating Magnetic Field. The measurement circuit designed based on this principle can connect to the conventional voltage and current instrument transformers and utilize the fundamental laws of electromagnetism to generate output signals proportional to the magnitude of the voltage and current, as well as their combination, e.g. distance relay and symmetrical component filters. This is done without using digital signal processing, a microprocessor of any kind, or Rotating parts, as in the case of electromechanical relays. The Rotating Magnetic Field is obtained by using four windings in the primary circuit and performing the corresponding vector summation of the magnetomotive forces. A basic methodology to estimate the parameters for the Rotating Magnetic Field converter is also presented in the paper.
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Symmetrical Components Filters for Power System Protection Based on Converters with Rotating Magnetic Field
2018 IEEE PES Transmission and Distribution Conference and Exposition (T&D), 2018Co-Authors: Boris A. Korobeynikov, R. Shestack, Alexey I. Ishchenko, Dmitry IshchenkoAbstract:This paper presents a new method to implement positive, negative and zero sequence components filters based on converters with Rotating Magnetic Field. The filters are directly connected to the traditional instrument transformers, provide galvanic isolation and generate symmetrical components signals that can be used for power system protection purpose. Filter output is the voltage proportional to symmetrical components current magnitudes. The paper provides schematic diagrams of the sequence components filters and outlines the basic theoretical principles for their design. The methodology to create various sequence components filters by simple rewiring of the secondary Rotating Magnetic Field converter windings is also presented.
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Hybrid distance protection relay with Rotating Magnetic Field
2016 IEEE PES Transmission and Distribution Conference and Exposition (T&D), 2016Co-Authors: Boris A. Korobeynikov, Alexey I. Ishchenko, Gennadiy A. Zakharov, Dmitry IshchenkoAbstract:The paper presents a new hybrid distance protective relay based on single-phase transformers with Rotating Magnetic Field for distribution system applications. Both theoretical aspects and a method for the practical implementation of the distance protection element with predetermined impedance operating characteristic is shown. The paper also provides recommendations for the choice of its parameters to obtain the desired characteristics for the distance relay operation implemented as a circle in the complex plane. An experimental prototype distance relay based on converters with Rotating Magnetic Field has been created and the laboratory tests confirmed adequate performance compared to commercial state-of-the-art technology.
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Hybrid overcurrent protection relay based on Rotating Magnetic Field principle
Proceedings of the IEEE Power Engineering Society Transmission and Distribution Conference, 2014Co-Authors: Boris A. Korobeynikov, Alexey I. Ishchenko, Dmitry IshchenkoAbstract:This paper presents a novel hybrid power system overcurrent protection relay based on Rotating Magnetic Field principle. The device is directly connected into the regular current transformer (CT) secondary circuit and consists of an electroMagnetic component with Rotating Magnetic Field and an electronics circuit employed to generate a low-level analog output, which is directly proportional to the magnitude of the input current signal. The relay output is produced without using numerical signal algorithms by the hybrid physical system. Moreover, the relay provides galvanic isolation from the secondary CT circuit and is capable of auto-correcting the input current waveform distortions introduced by CT saturation.
