• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1536-1540
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• 1996

The Design of are quenching parts of molded case circuit breakers depends on the utilization of strength and distribution of the magnetic field by which the arc is forced. The magnetic field causes the are to move into a set of V-slotted iron grids, where the are is extinguished rapidly. This paper present the effective method 10 design V-slotted iron plates of the are breaking chamber of molded case circuit breakers. This magnetic force was calculated by using the flux densities in the arc which are obtained by three dimensional finite element method, as a result of that this paper verified by testing that a grid model which has biggest magnetic force is excellent in the are quenching ability.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 B
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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.

• Journal of Power Electronics
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• 제13권2호
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• pp.275-286
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• 2013

An explicit frequency-domain circuit model for the conventional coupled magnetic resonance system (CMRS) is newly proposed in this paper. Detail circuit parameters such as the leakage inductances, magnetizing inductances, turn-ratios, internal coil resistances, and source/load resistances are explicitly included in the model. Accurate overall system efficiency, DC gain, and key design parameters are deduced from the model in closed form equations, which were not available in previous works. It has been found that the CMRS can be simply described by an equivalent voltage source, resistances, and ideal transformers when it is resonated to a specified frequency in the steady state. It has been identified that the voltage gain of the CMRS was saturated to a specific value although the source side or the load side coils were strongly coupled. The phase differences between adjacent coils were ${\pi}/2$, which should be considered for the EMF cancellations. The analysis results were verified by simulations and experiments. A detailed circuit-parameter-based model was verified by experiments for 500 kHz by using a new experimental kit with a class-E inverter. The experiments showed a transfer of 1.38 W and a 40 % coil to coil efficiency.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.36-38
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• 2002

Low voltage circuit breakers which interrupt rapidly and raise the reliability of power supply are widly used in power distribution systems. In the paper, it was investigated how much Interrupting capability was improved by correcting the shape of the contact system in molded case circuit breaker(below MCCB), Prior to the interrupting testing, it was necessary for the optimum design to analyze magnetic forces on the contact system, generated by current and flux density. This paper presents both our compuational analysis and test results contact system in MCCB.

• Tribology and Lubricants
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• 제27권3호
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• pp.167-173
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• 2011

In this paper, an actuator model of the thrust magnetic bearing for the flywheel energy storage is derived using magnetic circuit theory. And we compared this result with finite element magnetic field analysis result. Based on the actuator model, we made a simulation model of the thrust magnetic bearing system. We showed the closed loop transfer function and sensitivity function of the thrust magnetic bearing system using both the simulation model and the experiment. The experimental result at rotation velocity 18,000rpm of thrust magnetic bearing system is included.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 춘계학술대회 논문집 초전도 자성체
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• pp.83-87
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• 2002

In order to improve the capability of magnetic circuit, magnetic materials are used for all kinds of electromagnetic energy-conversion devices. This paper presents the analysis method considering magnetic properties of the magnetic material and analyzes that the effects of magnetic materials. In addition, it is described that the requirements of magnetic materials for the improvement of electric machines. Several application examples using a metal powder in electromagnetic energy conversion devices is introduced.

• Journal of Electrical Engineering and Technology
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• 제10권3호
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• pp.958-964
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• 2015

This paper implements a model of a double excited three-degree-of-freedom motor (3-DOF) coupled with a PI current controller for position control. The rotational trends of the rotor according to the applied steps are identified using a motion equation. The simulation model is a complete electrical and mechanical model of a 3-DOF motor, which mainly consists of mechanical torque equations, a nonlinear equivalent magnetic circuit, and a PI current controller. This machine is tested using the manufactured control board using the same conditions as in the simulation, where the experimental results also verify the accuracy of the simulation results.

• 조명전기설비학회논문지
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• 제22권3호
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• pp.88-95
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• 2008

In the paper, the permanent magnet synchronous generator of 1.5[MW] output power which is driven directly without gear system is designed by conventional magnetic equivalent circuit method and analyzed by finite element method. We analyzed the characteristics of generator like no load, rated load, short circuit condition and demagnetization of permanent magnet in order to verify the design results by magnetic circuit method. The last, the analysis results of two kinds of rotor types are compared with each other. Especially the THD(total harmonic distortion) of output voltage is examined for the comparison.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제48권11호
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• pp.597-603
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• 1999

Due to its simple construction, operation steadiness and low cost, claw pole step motor is widely used for OA machine and automobile. This paper deals with analysis fo claw pole motor, especially eyeing to dynamic characteristics. To analyze dynamic characteristics of claw pole step motor, torque development in each angular step of rotor are surveyed and torque equation is drived using permeance method. To adopt the airgap MMF, the magnetic equivalent circuit of the motor is introduced. On the base of the magnetic equivalent circuit, the air gap flux equation is derived. To get a optimum design of the motor, the torque characteristic is studied in variation of coil data and remanence value of permanent magnetic material.

• Journal of Magnetics
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• 제16권4호
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• pp.386-390
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• 2011

This paper deals with the magnetic equivalent circuit modeling and permanent magnet (PM) performance evaluations of a pole changing memory motor (PCMM). We use a coupled transient finite element method (FEM) and Preisach modeling, which is presented to analyze the magnetic characteristics of the permanent magnets. The focus of this paper is on the evaluation of characteristics such as the magnetizing direction and the pole number of the machine under re- and de-magnetization conditions.