• Proceedings of the KAIS Fall Conference
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• 2006.05a
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• pp.298-301
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• 2006

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($Al_2O_3$) 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($Al_2O_3$) growth and we will design about realtime monitoring systems of the automatic gas contol DC- Motor for single crystal($Al_2O_3$) growth

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.1126-1129
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• 2000

The equivalent transformation of a brushless DC motor into an separately exited DC motor has been possible with the vector control technique. Vector control is an effective technique for controlling variable speed drives of brushless DC motors. Conventional vector controllers, however, suffer from electrical machine parameter variations because these controllers depend on the parameters. This paper presents the vector control of brushless DC motor using a neural network. In the proposed method, a neural network is employed as on-line estimator of the nonlinear dynamic equations of brushless DC motor. The neural network based vector controller has the advantage of robustness against machine parameter variations as compared with conventional vector controller The simulation results using Matlab/Simulink verify the useful of the proposed method.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.714-716
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• 2003

This paper deals with the characteristic analysis of a brushless DC motor (BLDC) and taking into consideration the freewheeling diodes and DC link voltage ripple using a time-stepped voltage source finite element method. By comparing with the experimental results, we show that the proposed computational method is useful for the analysis and design of a BLDC motor. We also examine the influence of freewheeling diodes and DC link voltage ripples on the performance of a BLDC motor such as torque ripples and radial force on the surface of the teeth.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.954-958
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• 2003

새로운 에너지원인 풍력 발전에 대한 연구가 세계적으로 활발히 진행되고 있는 가운데 본 논문에서는 풍력 발전의 핵심 부분인 풍력 터빈에 관한 모의실험을 다루고자 한다. 실제 기상조건과 유사한 바람데이터를 실시간으로 생성, 이를 이용하여 풍력터빈 시뮬레이터용 DC motor의 토크제어 시스뎀을 설계 구현하였다. 본 연구는 기존의 단순 토크제어 시스템과는 달리 실시간으로 생성되는 데이터를 이용하여 보다 실제 풍력발전에 가까운 모의실험을 가능하게 한다. M/G Set를 기반으로한 DC motor 토크 제어 시스템은 바람데이터의 변화에 따른 풍력터빈의 토크와 발전단의 부하의 상관관계를 명확히 하는데 크게 이바지 할 것이며 더 나아가 발전기로의 정확한 토크 전달로써 계통 연계 연구에 많은 기여를 하고자 한다.

• Proceedings of the KIPE Conference
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• 2004.07a
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• pp.325-329
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• 2004

본 논문은 하이브리드 전기자동차의 12V보조배터리 충전용 DC-DC 컨버터의 최적설계에 관한 것으로 하이브리드 전기자동차의 특성상 DC-DC 컨버터는 최대부하의 $30\%\~70\%$ 정도의 비교적 낮은 부하영역에서 주로 동작하므로 이에 따른 적절한 설계가 요구된다. 따라서 DC-DC 컨버터의 주 동작영역에서 효율이 높도록 주요 설계요소인 스위칭 주파수와 고주파 변압기의 누설인덕턴스를 적절히 선정하고 코아의 윈도우 면적을 최소화하는 최적설계에 관한 연구이다.

• Proceedings of the KIEE Conference
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• 2005.05a
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• pp.66-68
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• 2005

DC motor is easy to control and can make torque easily. DC motor uses wide range. But DCmotor have limited by using a brush and structural complexity. But, BLDC doesn't have brush so that is more simple than DC motor, and the rotor of BLDC motor is made by permanent magnet that dose not need to make a fixed flux speed for flux current. BLDC motor is very efficiency, controllable, and reliable. This paper presents an error detection with a BLDC motor current. Generally, BLDC motor current is used to current feedback, so that can make a critical fault in the system. this paper suggests to detect error by inspection of threshold current value both positive and negative.

• Journal of Electrical Engineering and Technology
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• v.12 no.2
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• pp.665-673
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• 2017

This paper proposes a field weakening control method for operating an induction motor with a variable DC input voltage condition. In the variable DC voltage condition such as a battery, the field weakening method are required for the maximum output power. The conventional field weakening control methods can be used for operating the induction motor over the rated speed in a constant DC-link voltage condition. However, the conventional methods for operating the motor with the variable DC voltage is not suitable for the maximum output power. To overcome this problem, this paper proposes the optimized field weakening control method to extend the operating range of the induction motor with a rated power in a limited thermal and a wide DC input voltage conditions. The optimized d-axis and q-axis current equations are derived according to the field weakening region I and II to extend the operating region. The experimental results are presented to verify the effectiveness of the proposed method.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2203-2205
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• 2003

In this thesis, it is a purpose to carry out speed control of DC servo motor without using encoder and the resolver which are speed sensor of DC servo motor and it should use estimate algorithm or observer and must assume a speed in order to control speed sensorless. Therefore, high gain observer was designed to estimate rotor speed of DC servo motor and it carries out speed control from the feedback of the speed that assumed done in the thesis. Also, implementation used easy PI controller in speed-controller of DC motor though it was simple. It is compared estimate performance of Luenberger and high gain observer in a way of computer simulation in order to verify performance of the high gain observer which proposed in this thesis, and proved excellency of the high gain observer. And the thesis proved that smooth speed sensorless control of DC servo motor was implemented in invariable driving.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.437-440
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• 2003

Recently, the study on the design of NCS(Network Control System) using Ethernet is being rapidly progressed. NCS can be extensively applied in manufacturing automation, office automation, home automation, remote control and ect. A merit of NCS on based Ethernet is to make good use of advanced Internet environment and to apply a application of abundant TCP/IP upper layer to NCS. The purpose of this paper is to control a speed of DC-motor using NCS on based Ethernet. The control system is divided into a server part and a client part. A server transfers a value of reference speed of a DC-motor. A client receives a output signal of DC-motor and a reference input obtained from the server. A client computes a error of two signals and then makes a control input. The control input is transferred to a actuator In this pater, A controller uses a classical control using a general feedback. In this paper, a viewpoint is to compare performance of NCS with performance of a classical control and to analyze the cause of that.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.13 no.2
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• pp.88-93
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• 2004

The main objective of the research is to Propose an algorithm that to estimate the screwing torque from parameters of DC motor current without using any stain gage and torque cell. The auto screw drive system is divided into two parts, one is the DC motor ind the other is mechanical part in which the friction torque and damping ratio are a function of rotational of spindle electro motive force constant. The torque is estimated from the friction torque. The research is concerned with applying the method to an auto screw drive and the advantages and limitations are also discussed in this paper.