• Proceedings of the KIEE Conference
• /
• 1999.07a
• /
• pp.203-205
• /
• 1999

In this paper, voltage source FEA considering magnetic hysteresis characteristics is presented. Magnetization dependent model is used as a hysteresis model. The unknowns in finite element equation are the magnetic vector potential and current. Core model is analyzed and current waveform is compared with the experimental one. It is found that current can be accurately predicted with the voltage variation.

• Journal of Magnetics
• /
• v.20 no.2
• /
• pp.155-160
• /
• 2015

Recently, $CO_2$ emission standards and fuel efficiency legislation has been tightened globally. Therefore automotive alternator performance becomes increasingly important to meet the requirements. Many proposed methods have suggested adding magnets or regulation control to increase alternator efficiency and output. However, this creates a significant additional cost. During the stator lamination process, the magnetic property of the stator deteriorates mainly due to stamping and slinky process for an alternator. To maximize the alternator performance, heat treatment of the stator core was performed and magnetic properties were compared to find the optimal condition. Finally, alternator output and efficiency test were performed resulting in significant output and efficiency improvement up to 6.8% and 0.6% respectively.

• Smart Structures and Systems
• /
• v.18 no.2
• /
• pp.233-247
• /
• 2016

The vibration characteristic analysis of sandwich cylindrical shells subjected with magnetorheological (MR) elastomer and constraining layer are considered in this study. And, the discrete finite element method is adopted to calculate the vibration and damping characteristics of the sandwich cylindrical shell system. The effects of thickness of the MR elastomer, constraining layer, applied magnetic fields on the vibration characteristics of the sandwich shell system are also studied in this paper. Additionally, the rheological properties of the MR elastomer can be changed by applying various magnetic fields and the properties of the MR elastomer are described by complex quantities. The natural frequencies and modal loss factor of the sandwich cylindrical shells are calculated for many designed parameters. The core layer of MR elastomer is found to have significant effects on the damping behavior of the sandwich cylindrical shells.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.49 no.3
• /
• pp.138-144
• /
• 2000

The detent force caused by the interaction of magnets with the teeth of a armature core deteriorates the driving performance of a permanent magnet linear synchronous motor. In this paper, we analyze the fields and forces of a linear synchronous motor with segmented or skewed magnet arrangement according to lateral overhang length of permanent magnets. For the analysis, the 3-dimensional equivalent magnetic circuit network method is used. The detent force and the static thrust are analyzed according to the segmented or skewed angle and the overhang length of permanent magnets, and the optimal angles that the detent force is minimized are found out in each case. The analysis results are compared with the experimental ones and shown a reasonable agreement.

• Proceedings of the KIEE Conference
• /
• summer
• /
• pp.1046-1048
• /
• 2004

Inductance is an important parameter determining the characteristics of current waveform in electric motors. There are many kinds of inductances, however, self and mutual inductances are the major components. These inductances are changed under the variation of the magnetic circuit, current, frequency etc., even in the same winding distribution. Therefore this paper deals with the characteristics of inductance according to the shape of stator tooth. The analysis model is newly developed motor made of SMC(Soft Magnetic Composite) to reduce the core loss in high speed. the result of this paper gives the basic understandings of inductance to extend the applications of the motors.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.43 no.5
• /
• pp.753-760
• /
• 1994

This paper proposes a new method to compute the static thrust of a hybrid-type LPM by the coenergy method, which can be applied to a nonlinear programming of the optimization techniques for the optimal design. In the process of the computation, the magnetic nonlinearities of the permanent magnet, the primary and the secondary core are interpolated by the cubic spline method. And then, the equivalent magnetic circuit including the airgap reluctance which is a function of the displacement is modelled by the permeance method. The static thrust which is a derivative of the coenergy is computed by the Newton Raphson method at each displacement. To verify this proposed method, the results of the compjutation are compaction with those of the experiment obtained from the DLPM with 2 phase and 4 poles.

• Proceedings of the KIEE Conference
• /
• 1999.07g
• /
• pp.3328-3330
• /
• 1999

In this paper, the fabrication of a micro actuator with a micro electromagnet and an actuator diaphragm is presented. The micro electromagnet consists of a magnetic core and a micro inductive planar coil. The actuator diaphragm is the p+ silicon diaphragm on both sides of which magnetostrictive materials are deposited by sputtering. The micro electromagnet is fabricated by sputtering, evaporating, etching and electroplating. The magnetic flux density of the micro electromagnet is measured by using the gauss meter. The deflection of the actuator diaphragm is measured by using the laser vibrometer and optic microscope.

• Journal of Sensor Science and Technology
• /
• v.19 no.6
• /
• pp.475-482
• /
• 2010

Rogowski coil which detects magnetic flux on current changes. It is used for digital integration with watt-hour meter's current sensor, because, Rogowski coil has non-cored or non-magnetic core structure, so that, it cannot be saturated magnetically. This is a study for inventing accurate electric current sensors that have been applied on multi-layer ceramic substrate. We have confirmed its properties from each different layer's materials and pattern sizes by MWS 3D Electromagnetic field analysis program. And, after sensor manufacturing on multi-layer ceramic substrate, we confirmed its sensing quality is reliable as accurate electric current sensor for watt-hour meter.

• Proceedings of the KIPE Conference
• /
• 2012.07a
• /
• pp.534-535
• /
• 2012

The characteristics of wireless power transfer is achieved at high frequencies in short range magnetic resonant wireless power transfer system. Use PFC pre-regulator for power supply of high frequency inverter. Supplied power to high power factor and high efficiency. Accordingly, the input voltage is 110V-220V. The designed of 175W Class with the output voltage of 385V. As a experiment result, maximum power factor and maximum efficiency measured 99% and 97% respectively. Therefore, in this paper, the design of a inductor which is the most important element in PFC converter for short range magnetic resonance wireless power transfer system was studied. Used an CS330125 core through the designed of 175W class. Examination results power loss was 0.2%.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.60 no.4
• /
• pp.759-765
• /
• 2011

This paper proposes an effective assistant model for considering the stator slot-opening effect on air gap flux density distribution in conventional interior-type permanent magnet (IPM) motor. Different from the conventional slot-opening effect analysis in surface-type PM (SPM) motor, a composite effect of slot-opening uniquely existing in IPM motor, which additionally causes enhancement of air gap flux density due to magnet flux path distortion in iron core between the buried PM and rotor surface. This phenomenon is represented by a proposed assistant model, which simply deals with this additional effect by modifying magnetic pole-arc using an effective method. The validity of this proposed analytical model is applied to predict the air gap flux density distribution in an IPM motor model and confirmed by finite element method (FEM).