• The Transactions of the Korean Institute of Electrical Engineers
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• v.36 no.10
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• pp.703-712
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• 1987

A position detection method for 2 phase bifilar permanent magnet step motors is proposed. The back emfgenerated on 2 phase windings by rotor permanent magnet is calculated using motor terminal voltage and current by analog circuit, and the rotor position output is obtained from tese back emf signals through some logical manipulation circuit. This position detector functionally acts like a 2 channel optical incremental encoder, and it is also shown by experimental results that it works well over wide range of speed or under resonant condition where the rotor rings around the detent position. Its resolution is twice of the number of steps per revolution. Bu software implemented on micro-processor, the reliability of position output is enhanced, detecting and correcting error dut to external and/ or internal noise.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.12
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• pp.1123-1127
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• 2006

There are various elements that have influence on safety and reliability of high speed railway. Among them, mechanical characteristics of traction motors are very important. Therefore, we verified that temperature characteristics have influence on damage and durability of these parts. We designed a measurement system for temperature test, and could measure the temperature of each device by the system. As the result of temperature test, we could confirm that the traction motors on Korean High-Speed Train satisfy the criteria. From this test, we get information of the traction motor about the temperature characteristic during running speed and running time.

• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.190-192
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• 2002

The industrial power distribution system is a radial system and therefore usually protected with time delayed over current relays (OCR's). Proper time dial settings are provided at the OCR's. Meanwhile, the systems, where synchronous generator, or synchronous motors, or large induction motors are operating, can not be protected with only OCR's with time grading. This paper presents a technical limit and a suitable range of time delay in applying OCR's to clearing faults in the industrial power systems for maintaining stability. Dynamic simulations are made to show them employing a real power systems of a large petro-chemical complex.

• Proceedings of the KIEE Conference
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• 1999.07f
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• pp.2761-2763
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• 1999

In this paper, we analyzed the characteristics of the detected EMF signals used to detect the rotor position in the IPM(Interior Permanent Magnet) BLDC motor and SPM (Surface Permanent Magnet) BLDC motor. The position sensing signal, in the IPM BLDC motors, advances the real rotor position due to the variation of the rotor inductances. This fact was verified by the simulation and experiment.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.1154-1157
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• 2004

During normal machine operation, partial discharge(PD) measurements were performed with turbine generator analyzer(TGA) in imitation stator winding of high voltage motors. The motor was energized to 4.47kV, 6.67, respectively. Applied voltage to Imitation winding was used two voltage level, 4.47[KV]and 6.67[KV]. Motors having imitation stator winding were installed with 80pF capacitive couplers at the terminal box Case of PD Pattern regarding applied voltage phase angel, the PD patterns were displayed two dimensional and three dimensional. TGA summarizes each plot with two quantities such as the normalized quantity number(NQN) and the peak PD magnitude(Qm). As the result, we could discrimidate using TGA the difference of internal and surface discharge for imitation stator winding. We have used the other technique, in order to feature extraction of faulty signals on stator winding, Daubechies Discrete wavelet transform and Harmonics analysis(FFT) about faulty signals.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.05b
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• pp.61-64
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• 2000

An ultrasonic linear motor was composed of a slider and a stator vibrator including piezoelectric material and elastic material. The ultrasonic linear motors mainly consist of an ultrasonic oscillator which generates elliptical oscillations. Elliptical oscillations are generated by synthesizing two degenerated modes. The design of a stator for an ultrasonic linear motor was optimized with respect to vibration mode and direction of vibratory displacement by employing the finite element method. Applying multilayer piezoelectric ceramics. we found larger elliptical oscillations. The motors were designed by varying the width of stator vibrator and the thickness. the length and the position of multilayer piezoelectric ceramics.

• Proceedings of the KIEE Conference
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• 2004.07e
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• pp.17-20
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• 2004

This paper is presented for the development of the brushless DC(BLDC) motor for the spindle motor of hard disk drives. To design the spindle motors for HDD, it is very important to consider the reduction of vibration and noises. To design the each parts and investigate the assemble of a motor, we need to calculate the press force and size variation according to the press force. If we design the each parts without the consideration of the size variation, we can not get good result of assemble and performance with exact size of parts. In this paper, we get the computer simulation results to verify optimal size and assemble.

• Proceedings of the KIEE Conference
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• 2004.07d
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• pp.2281-2283
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• 2004

In this paper, we show the vector control performances for the parallel-connected motor drive system using the indirect vector control and the proposed vector control. The suggested estimation scheme of the rotor flux position is presented to reduce the sensitivity due to the load difference between the motors. To confirm the validity of the proposed control method, we compare the simulation results of the proposed control method with those of the conventional indirect vector control method. The simulation results show that the proposed control method is more effective for a change in the load torque.

• Proceedings of the KIEE Conference
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• 1993.11a
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• pp.59-62
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• 1993

The evaluation of the temperature of the motor in operation is necessary for smaller and lighter design of motors and for the determination of insulation class. And the evaluation of the temperature in thermal transient state is necessary for the determination of the intermittent rating and the protection from the thermal overload. The temperature can be calculated exactly by considering the loss distribution, the thermal resistances and the thermal capacities dependent on temperature. Using the detailed thermal equivalent circuit, the temperature of any local part of the motor can be evaluated. The comparison between the calculated results and the experiments is performed to verify the validity of the analysis.

• Proceedings of the KIEE Conference
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• 2009.04a
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• pp.77-79
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• 2009

Nonlinear system fault detection and isolation of this paper is about the failure of unknown function approximation using neural network for fault detection and isolation techniques of induction motors were applied. observer-based fault signal residual value was used. Induction motor using the speed controller of the backstepping controller. Proposed fault detection and isolation to prove the performance of the simulation was applied to and the actual system.