• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.12
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• pp.1986-1991
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• 2016

The vibration soucre of motor has a electromagnetic and mechanical causes. The most widely known, electromagnetic reasons are cogging torque and RMF(Radial magnetic force). Recently, analysis of the cogging torque has been made actively. but analysis of the RMF was not filled. So, in this paper, analyzed RMF. the vibration test were performed for the basic and reduced model of cogging torque and RMF. And it analyzed for the effect of each factor on the vibration. Finally, the vibration was formulated for stator's weight and RMF. To this end, natural, cogging torque and RMF of frequency were analyzed and these relationships were considered.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.2
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• pp.298-303
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• 2016

In this paper, the vibration source of IPM type BLDC motor was analyzed by finite element method. The main causes of the electrical vibration were RMF(Radial magnetic force) and cogging torque. It was designed model of minimized cogging torque and RMF equilibrium. Design models were selected the optimum model using the design of experiment method. And, the vibration experiment was carried out through prototype machine of each model. Finally, the experimental results were compared with the analysis ones.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.9
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• pp.882-887
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• 2011

A spiral electrodynamic wheel is proposed as an actuator for the contactless conveyance of a conductive rod. When rotating the wheel around the rod, a radial force, a tangential force, and an axial force are generated on the rod and cause a screw motion of the rod. The rotation of the rod is the inevitable result due to traction torque of the wheel and the unintended motion to be excluded. However, the rotating speed of the rod should be measured without mechanical contact to be cancelled out through the controller, so the electrodynamic wheel is used as a sensor measuring the rotating speed of the rod indirectly as well as an actuator. In this paper, we model the magnetic forces by the proposed wheel theoretically and compare the derived model with simulation result by Maxwell, and analyze influences on the magnetic forces by key parameters constituting the wheel. The feasibility of the conveyance system is verified experimentally.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1197-1198
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• 2008

There have been few papers using finite element method(FEM) to analyze arc driving force for spiral type vacuum interrupter electrode up to date while there have been many papers dealing with AMF type electrode by means of FEM. AMF analysis is very important in AMF type electrode because it has proportional relation with effective area which means the area of magnetic flux density above critical magnetic flux density to diffuse arc. In the same manner, arc driving force is an important factor to drive arc by Lorentz force. In this paper two models were calculated and compared by using commercial FEM software Maxwell 3D.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.10
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• pp.6453-6457
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• 2015

In this paper, the theoretical analysis for a solenoid with a finite length was verified by the finite element simulation. The solenoids are widely being used in the field of mechanical, industrial, medical industry due to their simple structure and fast responses. Solenoid actuators use an electromagnetic force. A magnetic field is formed around the solenoid coil when a current is applied. The magnetic force generated by the magnetic field enables an inside plunger to move linearly. The axial and radial magnetic fields (magnetic flux density, B) at a certain point were calculated from the Biot-Savart's law and compared with the simulation analysis from the ANSYS-Magnetostatic S/W. Comparison result, an error exists in the error range, and could therefore verify the accuracy.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.7
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• pp.8-13
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• 2019

As increasing demand for precise machining in advanced disciplines, especially in semi-conductor, aeronautical and automotive industries, the magnetic abrasive deburring(MAD) which is able to eliminate micro-sized burr on complex surface in less time has drawn the attention in the last decades. However, the performance of MAD is subject to shape and size of a tool. Therefore, this study aim to identify deburring behavior of MAD in U-type flow channel by measuring the length rate of burr removal in radial distance of the cylindrical tool under four process factors. In order to evaluate the deburring effect of MAD on the surface, finishing regions are divided based on center of the circular cutting tool. As a results, it was defined that the amount of burr removal in a downward direction moving toward flow channel from the top surface was higher than upward direction. This is because the magnetic abrasives were detached from magnetic lines of force due to geometrical shape.

• Journal of Electrical Engineering and Technology
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• v.6 no.3
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• pp.356-363
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• 2011

Vibrations and noise in electrical machines are directly related to the characteristics of the radial forces on one hand, and mechanical behavior on the other [1, 4]. The characteristics of these forces depend on the air gap flux density, which is also influenced by other factors, such as stator slots and poles, saturation level, winding type, and certain faults. The aim of this work is to investigate the effect of eccentricity and demagnetization faults on electromagnetic noise generated by the external surface of Permanent Magnet Synchronous Machine [PMSM]. For this purpose, an analytical electromagnetic vibroacoustic model is developed. The results confirm the effect of eccentricity and demagnetization fault in generating some low modes radial forces.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.48 no.11
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• pp.604-610
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• 1999

Vibration of a rotor-bearing system driven by an electric motor is a coupled phenomenon between mechanical characteristics and magnetic origins through the air-gap. With the advent of new high-energy magnets together with high precision motor applications, magnetic sources of vibration are becoming more serious. This paper investigates the transient whirl responses of a rotor system with purely mechanical origins and compares it with that of magnetically coupled origins. A perturbation method is applied to model the magnetic field associated with rotor eccentricity. Electromagnetic forces are obtained by the Maxwell stress method, which utilizes the analytical expression of radial flux density distribution. The FEM was applied to a rotor-motor system to illustrate magnetically coupled effects in rotor dynamics. Results show that magnetically coupled sources significantly affect the vibration of the rotor-motor system.

• Proceedings of the KIEE Conference
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• 2007.10c
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• pp.118-120
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• 2007

This paper deals with the vibration analysis of characteristics for BLDC motor by electromagnetic exciting force. Vibration analysis of electric machine is mainly divided into mechanical and electrical approach. However, it need to execute coupling analysis of mechanical and electrical computation because the vibration sources have relation to each other. Magnetic fields is calculated from Maxwell stress method with electromagnetic finite element method. And magnetic radial force is calculated from previous magnetic fields. With coupled electromagnetic and structure finite element, the vibratory behavior between the phase commutation advancing technique and pulse-width control is investigated in single phase brushless dc motor.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.879_880
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• 2009

this paper studies the influence of permanent magnet on the vibration of synchronous motor two PM motors with NdFeB and Ferrite magents which have same Back-EMF and output power have been desined. First, the dynamic simulation is performed with these two motors' parameters. The current waveforms can be evaluated. And then based on the equivalent magnetization current principle, the magnetic force density and force including the tangential and radial direction components can be calculated. According to the relationship between the vibration and radial force, the vibration of these two motors can be predicted. This result will give meaningful advice to the motor design.