• Proceedings of the KIEE Conference
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• 1998.11a
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• pp.168-170
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• 1998

In this paper a driving method using the microcomputer in safe driving the axial type double rotor brushless DC motor without shaft position sensor is studied. The rotor position is determined from the back-EMF passed though special filter. Starting technique which uses the motor as a synchronous motor at standstill are explained. The motor speed is controlled by changing the duty cycle of PWM. The test motor has Y-connected three-phase stator and 8-pole axial type double rotor. From the experiments, we got good performences of the proposed control system.

• IEMEK Journal of Embedded Systems and Applications
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• v.18 no.5
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• pp.209-215
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• 2023

This study proposes an AC servo motor control program structure and its implementation method to efficiently integrate 13 types of additional compensation algorithms into the basic FOC (field-oriented control) algorithm program. Various compensation algorithms are necessary to enhance the stability and performance of machine tools by compensating for interference from disturbances and vibrations. Each compensation algorithm is implemented as a separate, independent function and called from a switch-case statement in the ISR (interrupt service routine) of the PWM (pulse-width modulation) device. The advantages of this approach include facilitating not only debugging and testing but also reducing the possibility of errors during the program development phase. Thus, it is easy to add and activate each specific compensation algorithm for the program update during the program operation phase. The implemented motor control program was experimented with a single-axis feed shaft testbed driven by a commercial AC servo motor control drive board and a 750 Watts SPMSM (surface-mounted permanent magnet synchronous motor), and the results verified its normal operation and performance improvement.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.986-989
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• 2008

Recently the agitator are being widely used in the machine plan in order to increase the petrochemical industry. The agitator normally consist of impeller, shaft, hub, reduction gear and the driving motor. It is one of the key design issue to confirm that the vibration caused by the rotation of the shaft should not coincide with the natural frequency of the shaft itself. And petrochemical industry as well as plants have been in operation for long period beyond their original design lives. In this paper the vibration of Ox-Reactor Agitator is measured for check machine condition. The result of diagnosis and solution is discussed in this paper.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.6
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• pp.36-45
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• 2005

This paper addresses the application of motor current spectral analysis for the detection of rolling-element bearing damage in induction machines. We set the experimental test bed. They is composed of the normal condition bearing system, the abnormal rolling-element bearing system of 2 type induction motors with shaft deflection system by external force and a hole drilled through the outer race of the shaft end bearing of the four pole test motor. We have developed the embedded distributed fault tolerant and fault diagnosis system for industrial motor. These mechanisms are based on two 32-bit DSPs and each TMS320F2407 DSP module is checking stator current The effects on the stator current spectrum are described and related frequencies are also determined. This is an important result in the formulation of a fault detection scheme that monitors the stator currents. We utilized the FFT(Fast Fourier Transform), Wavelet analysis and averaging signal pattern by inner product tool to analyze stator current components. Especially, the analyzed results by inner product clearly illustrate that the stator signature analysis can be used to identify the presence of a bearing fault.

• Journal of Magnetics
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• v.15 no.2
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• pp.78-84
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• 2010

A 3-D.O.F. spherical PM motor has 3 degrees of freedom in its motion by tilting and rotating of a shaft, which can be applied in a range of fields. The back-EMF is proportional to the field flux and angular velocity. The back-EMF constant in conventional rotating machine has a uniform value. However, in a spherical PM motor, the back-EMF constant of the coils varies according to the tilting conditions regardless of whether the angular speed is constant. Consideration of the back-EMF constant is useful for designing 3-D.O.F. spherical PM motors. In this study, the back-EMF constant of the spherical PM motor was considered carefully.

• Journal of Advanced Marine Engineering and Technology
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• v.27 no.4
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• pp.503-510
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• 2003

A new method of induction motor drive, which requires neither shaft encoder nor speed estimator, is presented. The proposed scheme is based on decreasing current gap between a numerical model and an actual motor. By supplying the identical instantaneous voltage to both model and motor in the direction of reducing the current difference. the rotor approaches to the model speed. that is. reference value. The indirect field orientation algorithm is employed for tracking the model currents. The performance of induction motor drives without speed sensor is generally characteristic of poorness at very low speed. However, in this system, it is possible to obtain good speed response in the extreme low speed range.

• Journal of Advanced Marine Engineering and Technology
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• v.27 no.7
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• pp.930-936
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• 2003

A new method of direct current motor drive, which requires neither shaft encoder nor speed estimator, is presented. The proposed scheme is based on decreasing current gap between a numerical model and an actual motor. By supplying the identical instantaneous voltage to both model and motor in the direction of reducing the current difference, the rotor approaches to the model speed, that is, reference value. The performance of direct current motor drives without speed sensor is generally poor at very low speed. However, in this system, it is possible to obtain good speed performance in the low speed range.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1667-1672
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• 2009

The spherical motor is an electric machine which is able to tilt its shaft on 3-dimensional space as using electromagnetic force. Recently a permanent magnet is remarkable material for applying electric machinery, because of high magnetic flux density. In this paper, a spherical motor, which has permanent magnet on its rotor, is researched. As known, the spherical motor has a special feature as 3 degrees of freedom (D.O.F) operation. This performance can be realized by using electromagnetic torque between coils and magnets. Therefore, in this paper, a permanent magnet spherical wheel motor is introduced and performance characteristics are analyzed for improving of operation stability.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.50 no.3
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• pp.117-124
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• 2001

The aim of this paper is to develop a controller of multi-phase bipolar brushless DC (MPB BLDC) motors for an electric bicycle. A MPB BLDC motor has a Permanent magnet rotor in which the magnetic arrangement is radial to the shaft and integral to the rotor laminations. This technique concentrates flux, giving a higher flux density than a surface-mounted PM motor and increases reluctance torque. The stator of MPB BLBC motor has parallel winding, allowing multi-phase separate independent controllability. It gets much more high power than wye-connection at same low voltage. The conventional techniques of exited with modulation(EWM), bidirection control, and partial square wale control are Proposed with one H-bridge and two photo sensors per phase. The Proposed controller is satisfied for the limited speed control and designed for system stability Experimental results show the performance of the proposed controller of MPB BLDC motors for an electric bicycle.

• Proceedings of the KSME Conference
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• 2001.06b
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• pp.416-421
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• 2001

It was firstly issued that frequently broken of Encoder installed at travelling motor during RTGC operation. Estimated as broken due to excessive vibration of traveling and motor manufacturer claimed it as resonance of motor base. The principal vibration of Encoder was caused by the rotating vibration component of motor and by traveling wheel. The component transmitted from the wheel didn't have great vibration by the resonance with motor and other parts. Therefore, the plans was tried to add the support point to prevent the Encoder shaft vibrated greatly and inhibit the vibration. These showed good results.