• Proceedings of the KIEE Conference
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• 2000.11b
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• pp.330-332
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• 2000

To analyze the transient state of an induction motor, there have been studies for using the magnetic equivalent circuit method(MECD) instead of the time differential finite-element method. MECD which analyzes magnetic equivalent circuits after converting each part of an electric machine into the magnetic circuit elements, has the merits of short calculation-time and comparatively accurate results. To analyze an electric machine with MECM, we have to replace stator and rotor with the magnetic elements and express the air gap, where electromechanical energy conversion takes place, with the permeance. So in this study, to analyze an Induction Motor with HECM, we express the magnetic equivalent circuit as algebraic equations and then as the matrix for solving easily them. In particular, all relations are formed with matrixes to solve Mathematically them in the programming process later. As a result, this theory will be the basis on the static and dynamic analysis of an Induction Motor.

• Proceedings of the KSR Conference
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• 2000.11a
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• pp.674-679
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• 2000

Designing of the squirrel cage AC Traction Motor has many difficulties which has to be small size in order to be suitable into bogie frame, high efficiency and light weight. It means that induction motor for tractive purpose has to be different magnetic and electric loading ratio from industrial induction motor. This paper is devoted to an examination of how this ratio affects overall design concept and hence the main design points for traction motor. Also studied is tile changed coefficients of the magnetic and electric loading ratio squirrel cage induction motor for the traction purpose which has been already identified from tile reference book for industrial purpose induction motor.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.702-704
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• 2000

Designing of the squirrel cage AC Traction Motor has many difficulties which has to be small shape in order to be suitable into bogie frame, high efficiency and light weight. It means that induction motor for tractive efforts has to be different magnetic and electric loading ratio from industrial induction motor. This paper is devoted to an examination of how this ratio affects overall design concept and. hence the main design points for traction motor. Also studied is the changed coefficients of the magnetic and electric loading ratio squirrel cage induction motor for the traction purpose, which has been already identified from the referance book for industrial purpose induction motor.

• Journal of Electrical Engineering and Technology
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• v.9 no.4
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• pp.1309-1314
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• 2014

The measurement of stator core loss for an induction motor at each manufacturing process is carried out in this paper. Iron loss in the stator core of induction motor changes after each manufacturing process due to the mechanical stress, which can cause the deterioration of the magnetic performances. This paper proposes a new iron loss measuring system of the stator core in an induction motor, which can be applied to the case when the distribution of magnetic flux density is not uniform along the magnetic flux path. In the system, the iron loss is calculated based on the induced voltage of the B-search coil and exciting current.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.3
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• pp.509-515
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• 2009

When a squirrel cage induction motor is loaded, the magnetic noise can increase depending on the load current. It is due to the variation of air gap harmonic fluxes from the rotor current induced by loading. This unfavorable noise can be anticipated by analysing the radial force waves in the air gap, the mode shapes of them, and stator core natural frequencies at each mode. With the experimental tests with the different rotor slot numbers, the variation of magnetic noise depending on the load current is studied and the method to reduce the magnetic noise is suggested with the newly developed magnetic noise analysis program.

• The Journal of the Acoustical Society of Korea
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• v.10 no.3
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• pp.72-82
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• 1991

The Magnetic noise generated in three phase induction motor are investigated. Total noises measured by using JEM-1313 code and sound length method and the experimental formulae are derived of magnetic fk={K+$\frac{Z_s}{P}$(1-S)}f[Hz] noise is measured in the stator of induction motor except rotor supplied from power source and their datum are analyzed and compared with one another. The experimental value of magnetic noises are equal to the theoretical value at 1440[Hz] and 1560[Hz]. The biggest magnetic harmonic is generated at 1560[Hz].

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.77-79
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• 1988

There are various causes for noise production in induction motors, and among them, the noise generated by magnetic vibrating distribution forces have an important meanings. In this paper, the magnetic vibrating distribution forces in squirrelcage induction motors were arranged systematically in the consideration of stator harmonics and it's forces were not considered the effection of airgap eccentricity and deformation. With the application of the finite element method in order to find magnetic flux density and with the calculation of the permeance of rotor node, the magnetic vibrating distribution forces were analyzed.

• 전기의세계
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• v.19 no.1
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• pp.1-10
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• 1970

The foundation for the theoretical establishment of the linear motor lies in the investigation of the magnetic flux distribution in its airgaps. Generally speaking, the linear motor is similar, in the principle of its operation, to the general induction motor. However, there are great differences in the aspects of its structure and characteristics, especially, in the fact that the formation of its travelling magnetic field depends on the method of its winding. This paper is written in order to introduce the method of calculating the air gap magnetic flux distribution on the basis of its ampere-conductor in the case that 2 phase winding is applied on its open magnetic circuit iron core, and to present the results of investigation of the pulsation in its travelling fields. the first and second example of winding show the case of travelling magnetic field with the constant amplitude except the end region. The third example deals with the configuration of coil-side displaced outside the core and which produce the increased flux density at the ends, but, on the contrary, forms the pulsated travelling field.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.9 no.2
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• pp.58-67
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• 1995

The paper describes the variation of magnetic fields caused by the operation of induction motors. The measuring system consists of the self-integrating magnetic field sensor, amplifier, and active integrator. From the calibration experiments, the frequency bandwidth of the magnetic field measuring system ranges from 20[Hz] to 300[kHz] and sensitivity is 0.234(mV/$\mu\textrm{T}$]. The magnetic fields generated under steady state and starting operations of duction motor are recorded by the proposed measuring system, and the fast Fourier transformation(FFT) of the measured data is performed to analyze the harmonic components. A single pulsed magnetic field is strongly caused by direct starting the induction motor, and its peak value is greater than 5 times as compared with the steady state value. The long transient duration and high intensity originates from the large inductance and dynamic characteristic of the induction motor, During the steady state operation of induction motor, subharmonics of magnetic field components, which depend on the pole number of induction motor, are observed. The lower order power-line harmonics can be inferred from the voltage flicker and current ripple which are derived from the torque fluctuation of induction motor. In the case of the induction motor drived by inverter, the harmonics of magnetic field are much more than those caused by direct starting method and are found generally to increase with decreasing the driving frequency.

• Nuclear Engineering and Technology
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• v.40 no.3
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• pp.213-224
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• 2008

The pumping of coolant in a liquid metal fast reactor may be performed with an annular linear induction electro-magnetic (EM) pump. Linear induction pumps use a traveling magnetic field wave created by poly-phase currents, and the induced currents and their associated magnetic field generate a Lorentz force, whose effect can be the pumping of the liquid metal. The flow behaviors in the pump are very complex, including a time-varying Lorentz force and pressure pulsation, because an induction EM pump has time-varying magnetic fields and the induced convective currents that originate from the flow of the liquid metal. These phenomena lead to an instability problem in the pump arising from the changes of the generated Lorentz forces along the pump's geometry. Therefore, a magneto-hydro-dynamics (MHD) analysis is required for the design and operation of a linear induction EM pump. We have developed a time-harmonic 2-dimensional axisymmetry MHD analysis method based on the Maxwell equations. This paper describes the analysis and numerical method for obtaining solutions for some MHD parameters in an induction EM pump. Experimental test results obtained from an induction EM pump of CLIP-150 at the STC "Sintez," D.V. Efremov Institute of Electro-physical Apparatus in St. Petersburg were used to validate the method. In addition, we investigated some characteristics of a linear induction EM pump, such as the effect of the convective current and the double supply frequency (DSF) pressure pulsation. This simple model overestimated the convective eddy current generated from the sodium flow in the pump channel; however, it had a similar tendency for the measured data of the pump performance through a comparison with the experimental data. Considering its simplicity, it could be a base model for designing an EM pump and for evaluating the MHD flow in an EM pump.