Results 291 to 300 of about 262,039 (330)
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A current transformer modeling
COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, 2002This paper presents the modeling of a current transformer by various methods with the FLUX3D software. The technique used is based on the finite element method coupled with electric circuits. A magnetic scalar potential reduced versus T0 formulation (T0ϕ−ϕ) taking into account the electric circuits with an air‐gap is used for this purpose.
Le Floch, Yann +4 more
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Clamp current transformers for noninvasive calibration of current transformers
2016 IEEE International Instrumentation and Measurement Technology Conference Proceedings, 2016This paper deals with a noninvasive calibration system of current transformers in electrical power systems. The proposed system requires precise current sensors located on the primary and the secondary side of the transformer. Current sensors were designed as current transformers with a nanocrystalline magnetic core.
Karel Draxler +4 more
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Current transformer performance for inrush current in power transformers
Electric Power Systems Research, 1988Abstract A mathematical model has been developed for a current transformer to predict the transient performance during switch-in of a power transformer with residual flux. Typical 50 - 100 - 200/1 and 300/1 current transformers have been simulated and the secondary current response has been computed for different values of the current transformer ...
B.T. Desai, H.O. Gupta, M.K. Vasantha
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1982 IEEE Power Electronics Specialists conference, 1982
A general purpose, magnetically isolated current sensor is described. Based upon the flux nulling technique, this sensor uses a novel flux detector, instead of a Hall effect device, to achieve improved performance at lower cost.
Jonathan R. Leehey +2 more
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A general purpose, magnetically isolated current sensor is described. Based upon the flux nulling technique, this sensor uses a novel flux detector, instead of a Hall effect device, to achieve improved performance at lower cost.
Jonathan R. Leehey +2 more
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American Journal of Physics, 1986
Current transformers are used primarily to measure time varying currents under conditions where some degree of isolation from the primary circuit is desired. In this paper, the basic physics of current transformers is considered and several useful techniques for extending their performance are described.
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Current transformers are used primarily to measure time varying currents under conditions where some degree of isolation from the primary circuit is desired. In this paper, the basic physics of current transformers is considered and several useful techniques for extending their performance are described.
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Current-transformer summations
Journal of the Institution of Electrical Engineers, 1931The paper deals with the summation metering of multifeeder supplies by paralleled current transformers, with special reference to the errors likely to result and to suggested means of obviating such errors. The theoretical aspect of the effect of an idle transformer in a pair which is laralleled is discussed in section(2).
E.W. Hill, G.F. Shotter
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Transformer magnetizing inrush currents
Electrical Engineering, 1951THERE ARE formulas available by which it is possible to calculate the peak of the first cycle of magnetizing inrush current for a transformer. There have been no convenient formulas available for determining the maximum values of successive cycles of current.
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A Milliampere Current Transformer
Transactions of the American Institute of Electrical Engineers, 1914(1) It is pointed out that by the use of a current transformer having a primary to secondary current ratio of the order of 1 to 100, oscillograms can be obtained of the charging current of a single high-tension insulator or of a few feet of high-tension transmission line; that is, oscillograms of currents of the order of 0.1 to 0.5 milliampere may be ...
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IEEE Transactions on Power Delivery, 2007
This paper presents a current-transformer (CT) model that is useful for low-frequency applications. To describe the iron-core magnetic behavior, a hysteresis model is proposed, which is able to generate minor asymmetric loops and remanent flux. The effects of classic eddy current losses and anomalous losses are represented by linear and nonlinear ...
Francisco das Chagas Fernandes Guerra +1 more
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This paper presents a current-transformer (CT) model that is useful for low-frequency applications. To describe the iron-core magnetic behavior, a hysteresis model is proposed, which is able to generate minor asymmetric loops and remanent flux. The effects of classic eddy current losses and anomalous losses are represented by linear and nonlinear ...
Francisco das Chagas Fernandes Guerra +1 more
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Current summations with current transformers
Journal of the Institution of Electrical Engineers, 1955The behaviour of current transformers in parallel, and of similar circuits employing summation transformers, is studied for different conditions of load distribution.After the existing theory concerning idle currents has been rejected it is demonstrated that the overall error is very nearly constant for a given total load, no matter how the current may
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