• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.723-724
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• 2008

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.666-669
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• 2005

As computer power increased, the system with complex phenomenon has been analyzed with the help of CAE software which can handle the coupled physics, such as electromagnetic, structure, thermal and fluid physics. To predict the electromagnetic repulsion force and the temperature distribution of an air circuit breaker with electric contact mechanism, ANSYS/EMAG, FLOTRAN can be used. Although some assumptions and simplifications were introduced to simulate the model, results from the computational model were in good agreement with actual measurements obtained from experiments.

• Proceedings of the KIEE Conference
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• 1999.11b
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• pp.95-97
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• 1999

This paper describes electromagnetic repulsion force of multipolar axial magnetic field type electrodes for vacuum interrupter used in vacuum circuit breaker. It was distinguished that repulsion force of multipolar axial magnetic field type electrode in consideration of eddy current effect between upper electrode and lower electrode by finite element method. And it was found out that suitable contact weight of multipolar axial magnetic field type electrode for vacuum circuit breaker from repulsion force analysis results by finite element method.

• Proceedings of the KIEE Conference
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• 2001.11b
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• pp.364-367
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• 2001

In this paper, an analysis of electromagnetic repulsion force is presented using 3D FEM considering eddy current. It is important for the optimum design of switching device to analysis electromagnetic repulsion forces generated by the interaction of the electric current and its own magnetic field on the closed electric contacts flowing over current. The validity of our analysis is confirmed by comparing analytic and experimental results.

• Journal of Electrical Engineering and Technology
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• v.8 no.3
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• pp.595-602
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• 2013

An air circuit breaker (ACB) with novel double-breaker contact and permanent magnet actuator (PMA) is presented. Three-dimensional (3-D) finite element method (FEM) is employed to compute the electro-dynamic repulsion forces, including the Holm force and Lorentz force, which are acting on the static and movable contacts. The electro-dynamic repulsion forces of different contact pieces are computed, illustrating there is an optimal number of contact pieces for the ACB being studied. The electro-dynamic repulsion force of each contact, which varies from the outer position to the inner position, is also computed. Finally, the contacts of the double-breaker are manufactured according to the analyzed results to validate the simulations.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.786-789
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• 2002

The behaviour of contactors protected by arcs under short-circuit currents is analysed using a simple model to represent the electric circuit and the contactor. In most cases, the protection of contactors against short-circuit currents is entrusted to fuses. Fuses are suitable for preventing excessive damage to the contactor, or parts of the contactor, under short-circuit conditions. In particular, they are capable of limiting the thermal and electrodynamic stresses which can lead to arcing or welding together of the contacts of a contactor. This paper is the Dynamic Motion Analysis of a Moving Contact by Electromagnetic Repulsion Force in Molded Case Circuit Breaker(MCCB)

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.264-268
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• 2005

Most of the train brakes depends on friction between wheels and tracks. This requires braking force reduced in order not to cause wheel slides since the friction decreases as the train speed increases and consequently results in extension of braking distance. The braking system called 'Linear eddy current brake' or simply' Eddy current brake' is a braking system for making a brake independent from friction, which consists in creating electromagnet by coiling around shoes attached. to bogies; having the shoes above the tracks approached to the tracks upon acknowledgement of a braking command; and authorizing braking force that is irrelevant to friction through magnetic repulsion between electromagnet attached to the tracks and train set by the use of the electromagnet's magnet field characteristics. An electromagnetic attraction braking system that consists in pressing pole shoes attached to bogies against the tracks by using electromagnet's attraction force is called 'Electromagnetic track brake' or simply 'Track brake'. This paper has been prepared in purpose of studying technological tendencies of the eddy current brake and the track brake so that it can be utilized as fundamental data for commissioning Korean high-speed trains with the eddy current brake hereafter.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.51 no.12
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• pp.562-570
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• 2002

The Purpose of this paper is to design and manufacture an educational system in order to demonstrate the causes and effects of electromagnetic induction.'rho educational system described in this study is a "jumping ring apparatus". This system demonstrates the principle of electromagnetic induction, a force from AC sources, Lenz's law of repulsion and transformer. The educational system is composed of a jumping ring apparatus, a sensor array, encoder, A/D converter, D/A converter and nonlinear controller. The educational system is controlled by 586 PC using Turbo C program. The sensor array is composed of 20 optical sensors. The nonlinear controller consists of nonlinear control algorithm and control board included SCR, FET and phase controller. The A/D converter is used to show the height of ring position to analog for an education purpose. The control signal calculated from the nonlinear control of algorithm send control board through 8 bit D/A convertor. Experiment results are given to verify that Proposed nonlinear controller is useful in on line control of the educational system.al system.