• Journal of Electrical Engineering and Technology
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• v.7 no.2
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• pp.184-192
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• 2012

The torque and unbalanced magnetic forces in permanent magnet machines are resultants of the tangential, axial and normal magnetic forces, respectively. Those are in general influenced by pole-teeth-winding configuration. A study of the torque and unbalanced magnetic forces of a small flux concentrating permanent magnet transverse flux machine (FCPM-TFM) in segmented compact structure is presented in this paper. By using FLUX3D software from Cedrat, Maxwell stress tensor has been solved. Finite element (FE-) magneto static study followed by transient analysis has been conducted to investigate the influence of unsymmetrical winding pattern, in respect to the rotor, on the performance of the FCPM-TFM. Calculating the magnetic field components in the air gap has required an introduction of a 2D grid in the middle of the air gap, whereby good estimations of the forces are obtained. In this machine, the axial magnetic forces reveal relatively higher amplitudes compared to the normal forces. Practical results of a prototype motor are demonstrated through the analysis.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.9
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• pp.85-91
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• 2022

The demand for electric vehicles has increased because of environmental regulations. The lithium-ion battery, the most widely used type of battery in electric vehicles, is composed of a cathode, an anode, and an electrolyte. It is manufactured according to the pole plate, assembly, and formation processes. To improve battery performance and increase manufacturing efficiency, the manufacturing process must be optimized. To do so, simulation can be used to reduce wasted resources and time, and a finite-element method can be utilized. For high simulation quality, it is essential to reflect the material properties of the electrode by considering the pores. However, the material properties of electrodes are difficult to derive through measurement. In this study, the representative volume element method, which is a homogenization method, was applied to estimate the representative material properties of the electrode considering the pores. The representative volume element method assumes that the strain energy before and after the conversion into a representative volume is conserved. The method can be converted into one representative property, even when nonhomogeneous materials are mixed in a unit volume. In this study, the material properties of the electrode considering the pores were derived. The results should be helpful in optimizing the electrode manufacturing process and related element technologies.

• Proceedings of the KIPE Conference
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• 2013.11a
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• pp.23-24
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• 2013

In recent years, ISG (Integrated Starter and Generator) system receives a great attention for electric electrification of normal gasoline vehicle. As a cost-effect machine design, an ISG without a permanent magnet is considered. A 12slot-10pole field-excitation flux-switching synchronous machine (FEFSSM) is designed and analyzed via JMAG. The active parts such as the field excitation coil and armature coil are located on the stator. The rotor part consisting of single piece iron makes it more robust and suitable to apply for high speed motor drive system application coupled with reduction belt. The design target is the motor with a maximum torque of 40Nm, a maximum power of 10kW and a maximum speed of 14000 rpm. In this paper, design optimization method is proposed for high torque capability.

• Journal of Chest Surgery
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• v.6 no.2
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• pp.237-242
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• 1973

Two cases of traumatic diaphragmatic hernia are reported, who were operated on in this department during the last 12 months` period. The first case, a 34 year old male, fell from 6 meters` height while he was working on electric pole. He sustained rib fractures, left 8th, 9th and 10th rib, left diaphragmatic rupture and ileal perforation. In the pleural cavity, there were stomach, omentum, left lobe of liver, transverse colon and ileum, which were reduced into the peritoneal cavity, and the diaphragmatic aperture was closed through anterolateral thoracotomy. After closure of the thoracic incision, median abdominal incision was made and closed the ileal perforation by primary suture. The second case was a 19 year old tyre repairman, who felt abrupt severe abdominal pain during lifting a heavy lyre. A barium study revealed a marked displacement of the stomach into the left pleural cavity. Immediately, thoracotomy was performed and closed the ruptured diaphragm after reduction of the herniated stomach, omentum, transverse colon, spleen and small intestine. The size of the diaphragmatic aperture were measured 17cm. in first case and 12cm. in the other respectively. Both cases discharged after uneventful recovery.

• Proceedings of the KIEE Conference
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• 2003.04a
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• pp.110-112
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• 2003

Electric control of eddy coupling offers many new possibilities in process control and other industrial control applications. And a form of speed control for the load is affected for a system driven by costant frequency induction motor. This paper analysis speed-torque characteristic of the eddy-current coupling by using the 3-dimensional analytical method. Characteristic experiment is put into operation for the claw pole type eddy current coupling. Design procedure is presented based on the analysis.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.10
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• pp.1038-1044
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• 2009

In this study, vibrations of an electric motor are analyzed when the motor has the interaction between mechanical and electromagnetic behaviors. For this vibration analysis a 3-phase 8-pole brushless DC motor is selected. Vibrations of the motor are influenced by coupled electromechanical characteristics. The variation of air-gap induced by vibration has an influence on the inductance of the motor coil. To analyze dynamic characteristics of the rotor, we studied inductance by the variation of an air-gap. After obtaining the kinetic, potential and magnetic energies for the motor, the equations of motion are derived by using Lagrange's equation. By applying the Newmark time integration method to the equations, the dynamic responses for the displacements and currents are computed.

• Proceedings of the KIEE Conference
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• 2007.11c
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• pp.165-169
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• 2007

Organic EL has been expected to adopt to a new styles of technology that make flat display after Tang & Vanslyke made food electric luminescence device in late 1980s. Their studies based on multi layer structure that consists of emitting layer and carrier transporting layer using proper organic material. In this study we made multi layer device using $Eu(TTA)_3(phen)$ as a luminescence material by PVD and investigate luminous properties of each device. But oxidization of organic layer by ITO, energy walls in both pole interface, contaminations of ITO surface, importance of protecting membrane, diffusive dimming of light to cathode organic layer, these causes of degradations are common facts of a macromolecule and micromolecule. We think these degradation caused by the impact of heat and electro-chemical factor, bulk effect and interface phenomenon, and raise a question.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.895-897
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• 2001

It must be able to calculate thrust to design and manufacture linear BLDC motor by required specification. If magnetic energy with respect to displacement of mover of linear BLDC electric motor be obtained, thrust can be calculated. It can decide optimal design factor of linear BLDC motor through change of thrust by design variable using magnetic energy method. It can predict variation of thrust by pitch of pole and design optimally using coenergy that is attained from FEM.

• Proceedings of the KIEE Conference
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• 1993.11a
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• pp.56-58
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• 1993

This report describes the high speed DC motor (8,000 rpm) that we have designed, manufactured and tested. DC motor is the best drive system in electric-mechanical energy conversion. The design concept for high speed and high energy density to DC motor is to maximize Ampere-conductor in armature and to maximize flux density in armature teeth, armature core, pole, yoke using flux path.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.115.1-115
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• 2002

This study proposes a new conceptual Hybrid Electric Brake System (HEBS) which overcomes the problems of the conventional hydraulic brake system. The HEBS uses the contactless brake system when vehicle speed is high to obtain superior braking force by eddy current, which is induced in pole area by magnetic flux through a rotating conductive disk. On the contrary, when a vehicle speed is low, contact type brake system such as conventional hydraulic brake system makes higher braking force. HEBS transfers faster a braking intention of drivers and guarantees a safety of drivers because of vehicle dynamic superior controllability. Braking torque analysis is peformed based upon Lee. Barn\ulcornermath...