• Proceedings of the KSME Conference
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• 2000.11a
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• pp.829-836
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• 2000

High performance laser printer requires high speed scanning motor, which can operate up to 40,000 rpm. However, development of high speed scanning motor has been restricted due to the practical problems such as use of high speed bearing, compact circuit design and high cost. In this study, we designed a high speed scanner motor for use on laser scanning unit and discussed some design principles including the reduction method of cogging torque of the motor, development of hemispherical aerodynamic bearing, windage loss estimation, and operating circuit design to reduce noise.

• Journal of Korean Society of Forest Science
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• v.89 no.3
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• pp.405-413
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• 2000

This study was conducted to develop an on-line monitoring system for a forest hydrological environment and its meteorological condition, such as temperature, wind direction and speed, rainfall and water level on V-notch, electrical conductivity(EC), potential of hydrogen(PH) by the motor drive sensor unit and measurement with a single-chip microprocessor as controller. These results are summarized as follows ; 1. The monitoring system consists of a signal process unit, motor drive sensor unit, radio modem unit and power supply. 2. The motor drive sensor unit protects the sensor from swift current or freezing and can constantly maintain fixed water level during measurements. 3. This monitoring system can transfer the data by radio modem. Additionally, this system can monitor hydrological conditions in real time. 4. The hardware was made of several modules with an independent CPU. They can be mounted, removed, repaired and added to. Their function can be changed and expanded. 5. These are the result of an accuracy test, the values of temperature, EC and pH measured within an error range of ${\pm}0.2^{\circ}C$, ${\pm}1{\mu}S$ and ${\pm}0.1pH$ respectively. 6. This monitoring system proved to be able to measure various factors for a forest hydrological environment in various experimental stations.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.33 no.9
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• pp.327-339
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• 1984

In this paper we present how to design the software-based speed and position controller of a DC servo drive system for an educational robot. The controller designed by fully digital scheme consists of a CPU, drive unit, encoder pulse coding unit, speed and position detector. The control algirithm of the controller is a hybrid one such that speed control and position control are switched at some instant to get more accuracy. The experimental resusts of the proposed DC servo-controller show good performances for the position and speed control of the proposed educational robot system.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.390-394
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• 2001

A dynamic simulation model for the brush less dc (BLDC) motor drives using Matlab is presented. In this model, an entire BLDC motor drive, including power conversion unit, BLDC motor, and speed/torque control system, is investigated. Especially, the PWM inverter is modeled using switching function concept, so that the detailed voltage and current waveforms, such as line-to-line voltages, inverter input current, ac line current, and switch/diode currents, can be obtained and average/rms ratings of the components can be easily calculated. Also, the proposed model is made into modular blocks and it can be easily extended to other ac motor applications with a little modification. The detailed modeling method is explained and its actual implementation is described. The validity of the proposed model is verified by various simulation results.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.3
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• pp.562-568
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• 2010

In this paper, a low cost magnetic position sensor for linear position detection is proposed. The proposed magnetic sensor can be applied to the linear motor which has stator with periodical teeth, such as transverse flux linear motor(TFLM). Sine and cosine waves can be generated from the unit sensor module as the linear motor moves, and the outputs can be converted to the position data by interpolation IC. To reduce the speed ripple caused by the position error, the Luenberg observer is introduced. The validity of the proposed magnetic position sensor is verified by experiment with a 750N three-phase TFLM.

• Proceedings of the KIEE Conference
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• 2007.10c
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• pp.175-177
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• 2007

This paper presents for the torque characteristics and improving the efficiency of driving system of electric bicycle which applied IEWPM(Independently Excited Winding Permanent Magnet) motor. IEWPM motor can expand the number of phase from 3 phases to multiphase like SRM motor because stator windings are unconnected directly. BLDC motor raise rotor'-s electromagnetic torque per unit volume by using Spoke type permanent magnet. By using two photo sensor per phase and applying excited width, advance angle and bipolar control, we confirmed higher torque at a low speed, higher out-put at a high speed, and efficiency improvement at a wide speed control area.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1092-1096
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• 2011

The "standard regulation" of the vehicles from "urban transit law" are being adopted to electric multiple unit in domestic. In the standard regulation, there are two types for EMU. One is heavy EMU for Seoul. The other is large EMU for Pusan, Daegu, Gwangju, Daejeon, Incheon. Korea Railroad Research Institute, with the assistance of the Ministry of Land, Transport and Maritime Affairs, "advanced EMU development project" are progressed, and 6th year started at September, one unit to six cars is completed. Now "urban transit vehicle performance tests are on the current progress. The main characteristics of AUTS(Advanced Urban Transit System) are as follows. One inverter control one motor, DDM(Dircet Drive Motor), no driving gear, plug door and steps, mounting and maintenance costs down, passenger convenience improvement. This paper describes the key features the next generation EMU, and performance test results, and the commercial success method of national R&D business.

• Journal of the Korean Society of Safety
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• v.29 no.1
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• pp.7-14
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• 2014

Inverter module, which feeds the converted power to the traction motor for EMU. Consists of the power semiconductors with their gate drive unit(GDU)s and the control computer for driving, voltage, current and speed controls. Electrolytic condenser, connected to the gate drive unit and a core component to drive the power semiconductor, has problems such as reduction in lifetime and malfunction caused by electrical and mechanical characteristic changes from heat generation during high speed switching for generation of stable power. In this study, To check the service life of electrolytic condenser, the test was carried out in two ways. First, In the case of accelerated life testing of condenser, the Arrhenius model is a way of life testing. Another way is to analyze the reliability of the failure data by the method of parametric data analysis. Eventually, life time by accelerated life test than a method of failure data analysis(Weibull distribution) was found to be slightly larger output.

• Proceedings of the KIEE Conference
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• 2007.10c
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• pp.65-67
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• 2007

In this paper describes the design and characteristic analysis of a novel 2-DOF(Degree of Freedom) motor. For multi DOF actuating, several numbers of motors have been used. But the using of normal motors they connected each other in single joint, have necessary to a several type of complex power transmission devices. The 2-DOF motor can drive pan, tilt motion in only one unit and it is not necessary to use additional gears and links parts. Therefore by the using of 2-DOF spherical motor ran eliminate; combined effects of inertia, backlash, non-linear friction, and elastic deformation of gears. The validity of the analysis is confirmed by 3D finite element method.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.8
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• pp.1362-1370
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• 2008

This paper describes the design and characteristic analysis of a novel 3-DOF(Degree of Freedom) spherical motor. For multi DOF actuating, several numbers of motors have been used. By the using of normal motors they connected each other in single joint, is necessary to a several type of complex power transmission devices. The 3-DOF spherical motor can drive roll, pitch, and yaw motion in only one unit and it is not necessary to use additional gears and links parts. Therefore the using of 3-DOF spherical motor can eliminate; combined effects of inertia, backlash, non-linear friction, and elastic deformation of gears. In this paper, we propose the novel structured 3-DOF spherical motor and derive its principles of operation. Firstly, we designed concept model of novel structured 3-DOF spherical motor. Next, we derive the control method by calculating the currents. Also, to have intuitive driving control, we express the rotor position in equivalent angle-axis system and determine the exciting period of currents from the calculation result of the currents. To verify the control method, we calculated the currents by the position of rotor. and then we analyzed the characteristics by 3D Finite Element Method when the calculated currents are excited.