• Journal of Industrial Technology
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• v.18
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• pp.149-155
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• 1998

This paper describes a reference flux angle selection for a vector control in the parallel operation system that consists of a inverter and several induction motors. In particular, this paper suggests which flux angle of motors prefers for the vector control in the train drive system that diameters of wheels are different. Through simulation for a 210[kW] induction motor drive system, it is clear that the vector control by using of the flux angle of a motor having a minimum wheel diameter leads to a minimum torque difference. However, it requires too many current sensors. So, it is shown that the vector control by a average flux angle of motors is preferable.

• Journal of Industrial Technology
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• v.30 no.A
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• pp.31-35
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• 2010

In this paper, a speed estimation method at coasting operation in an induction motor speed sensorless control for railway vehicle traction systems is presented. At coasting operation, there is no information obtaining rotor speed since all switches of an inverter are turned off. The inverter frequency should be synchronized with the rotor frequency for repowering at coasting condition. The proposed method injects DC current to the induction motor during a short time, then the flux angle and rotor speed needed for control can be estimated rapidly.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.3 no.1
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• pp.38-43
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• 2002

In this study, we deal with the system design and development of the automatic page passing machine. In order to turn pages without injury of a book or a musical note, we used an inhalation motor. Also, when we turn over pages. the successive actions of fixation and inhalation are embodied by motors which are operated by a microprocessor. In traditional products. some limited pages must be fixed into the Turning Bar in advance. On the contrary, proposed equipment is able to turn over the pages of a book without laying the groundwork. Experimental results using produced facilities are presented to demonstrate the efficacy of the proposed equipment.

• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.3073-3076
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• 1999

In this paper, $H_{\infty}$ two-degree-of freedom(2-DOF) model following control method is applied for the control of a brushless servo motor to achieve high robust performance. The proposed robust control algorithm designed to meet the robust stability and performances present that the robust control method is superior to conventional control methods in controlling the speed and position of a servo motor. The designed controller is implemented as an outer loop controller to a factory designed motor-servopack system. It is illustrated by simulations that the proposed method is effective to control servo systems.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2006.05a
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• pp.302-308
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• 2006

We introduce the concept of a remote distributed embedded system to integrated fieldbus based control systems in internet/Intranet. As a result fieldbus systems are opened up for remote monitoring, remote maintenance, and remote control applications using state of the art Web-technology. This paper addresses the design of a remote distributed embedded system using Internet and CAN for multi-Induction motor of Building and Industrial field. The fieldbus used the CAN based networked intelligent multi-motor control system using DSP2812 microprocessor. To build such a system, the TCP/IP-CAN Gateway which convert a CAN protocol to TCP/IP protocol and vice verse, was designed. A experimental simulation system consists of a TCP/IP-CAN Gateway in remote place and a command PC ti be connected ti Ethernet.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1694-1695
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• 2007

DC-Motor is needed more and more sophisticated control to follow the highest precision of industrial automation and used in a number of control equipment or industrial fields. It is also useful to control single crystal(Al2O3) growth. It is possible to procure a quality crystal utilizing a DC-Motor, if you mix Hydrogen and Oxygen gas properly and keep proper temperature in accordance with time process. In this paper, we will study about electrical valve positioning system for the gas mixture to improve the quality of single crystal($Al_{2}O_{3}$) growth and we will design about realtime monitoring systems of the automatic gas contol DC- Motor for single crystal($Al_{2}O_{3}$) growth

• Proceedings of the KIEE Conference
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• 2004.05a
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• pp.19-21
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• 2004

This paper considers pulse width modulation (PWM) methods which are used in 3-phase brushless DC motor controller. Due to many disadvantages of bipolar PWM method, unipolar PWM method is mostly used in industrial field. In constant speed control application, the unipolar PWM method shows a good performance of speed control. But in the wide range of speed control application, it shows a poor performance especially when deceleration is needed. So we propose hybrid PWM method that utilizes two PWM methods according to the sign of speed controller output. The simulation and experimental result shows that the proposed method improves a speed control performance of the brushless DC motor which is applied to industrial sewing machines.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.1
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• pp.634-638
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• 2015

Phase currents should be measured in real time for vector control of a 2-phase induction motor. Generally, the phase currents of the motor are measured using two Hall current sensors installed at the output terminal of an inverter. Unfortunately, Hall current sensors are expensive and uneconomical because a vector-controlled inverter for 2-phase induction motor is mainly used in low-power and low-price applications. This paper proposes a low-cost current measurement method using two shunt resistors instead of expensive Hall current sensors. The proposed method can measure the phase currents under all operating conditions of the motor. This method was applied to an experimental vector-controlled inverter for 2-phase induction motor of 220[V]/360[W] and was verified through computer simulations and experimentation.

• Journal of Korea Society of Industrial Information Systems
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• v.17 no.7
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• pp.35-41
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• 2012

To control screen door installed in the subway platform, geared BLDC motors have been being used. However, because of the geared mechanisms, the control profile of the screen door in slow speed is very poor. Moreover, geared mechanism tends to leads system malfunctions and low efficiency. To overcome those problems, in this paper, the techniques of developing hi-efficiency direct drive gearless PMAC motor controller and application example to control the screen door of subway platforms are proposed. The developed system has advantages that; the energy efficiency has been increased by adopting gearless PMAC motor; the system break-down factor has been decreased due to the actuator mechanism has been simplified. In this paper, the screen door control system structure, PMAC motor drive circuit design, implementations of vector control algorithm, and test results are shown.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.492-498
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• 2016

It is well known that since abrupt faults in induction motors tend to lead to subsequent faults and deterioration of the drive apparatus, motor faults may lead to several operating restrictions, such as security problems and economic loss. A lot of research has been done in the area of diagnosis to detect machine faults and to prevent catastrophic hazards in the motor drive system. This paper presents a new method of motor current signature analysis in which the DC-link current of the inverter-driven induction motor system, where a single current sensor is employed instead of three AC current sensors, is measured, and fast Fourier transform analysis is performed. This proposed method makes it possible to easily discern and clearly separate the motor fault current signature from the normal operation current flowing through the stator and rotor windings.