• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.4
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• pp.39-46
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• 1998

For permanent magnet brushless DC motors used for high speed fuel pumps, torque ripple is an important origin of vibration, acoustic noise and speed fluctuation. In this paper, the output torque profile of a PM motor with one phase energized is decomposed into the commutation torque, the reluctance torque and the armature reaction torque according to their source origins. It verifies that the output torque profile is qualitatively equivalent to the BEMF profile for low reluctance motors. This paper discusses the effect of magnet pole shaping and magnet arc length on the output torque and torque ripple. A magnet edge shaping is proposed to design a trapezoidal BEMF motor without torque ripple, with minimal sacrifice of the maximum output torque.

• 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 Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.4
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• pp.98-107
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• 2005

Brushless DC motor(BLDCM) can be driven by 120[^{\circ}]$ square wave voltage and use PWM pulse patterns in two-phase feeding scheme to control the speed of the motor. This Paper introduces four PWM modes used BLDCM control system, and analyzes their different influences on the motor performances using a time-stepped voltage source finite element method. To verify the proposed computational method, we built the prototype motor for electrical power steering(EPS) and compared the predicted and the measured back EMF and phase current.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.1
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• pp.1-8
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• 2006

Now a day, owing to high efficiency and easy speed control of brushless DC(BLDC) motor, the demand of BLDC motor that has high power and low noises are increasing. Especially demand of interior permanent magnet(IPM) BLOC with high efficiency and high power in electric motion vehicle is increasing. IPM BLDC motor has permanent magnets in the rotor. Because it has two different flux paths, magnetic reluctance differences are generated in d-axis and q-axis. As the result of the inductance differences that are generated by the saliency(magnetic reluctance differences) in the rotor, the motor has structure advantage that has the additional reluctance torque except a magnet torque and because magnet is situated inside the rotor, the mechanical structure is strong. Therefore IPM BLDC motor makes possible to have high speed and high power. This paper presents a design and characteristics analysis of IPM BLDC motor for electric vehicle. To design IPM BLDC motor, surface mounted permanent magnet(SPM) BLDC motor is used as the initial design model. According to the shape-ratio() of permanent magnet, the characteristic of IPM BLDC motor is analyzed by Finite element method (FEM). Characteristics analysis results of the designed motor are compared with the experimental results.

• 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.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.6
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• pp.968-974
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• 2017

In this paper, modeling of brushless DC motor (BLDC) driving system for platform screen door control applied fuel cell power generation system has been proposed. At first the system configuration and operational principle of the developed fuel cell simulator has been investigated and the design of BLDC motor driving system is studied and the overall performance and dynamics of the proposed system could be effectively examined by simulation. PSIM simulation program is implemented to verify the performance and compatibility of the fuel cell power generation system and BLDC motor control system modeling.

• Proceedings of the KIPE Conference
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• 2007.07a
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• pp.220-222
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• 2007

본 논문에서는 하나의 DC-Link 전류센서를 사용하여 BLDC 모터의 상 저항을 고려한 상 전환 토크리플 저감 방법을 제안하고자 한다. 지금까지 하나의 DC-Link 전류센서를 사용하여 BLDC 모터의 상 전환 토크리플 저감에 대한 연구는 많이 진행 되어 왔다. 기존의 방법들은 상 저항 값을 무시하여 상 인덕턴스 성분만을 가지고 제어한 방법이 주류를 이루어 왔다. 하지만 상 저항 값이 크면, 저속 영역과 고속 영역 구간에 변화를 가져와 기존의 방법을 사용할 시 토크리플이 발생한다. 또한 상 전환 시 전류 기울기와 상 전환 시간에 대해 영향을 미치게 되어 기존의 방법을 사용할 경우 토크리플이 발생하게 된다. 본 논문에서는 시뮬레이션을 통하여 상 저항을 고려한 BLDC 모터의 상 전환 토크리플 저감 방법에 대해 효용성을 입증하고자 한다.

• 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 Power Electronics
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• v.12 no.4
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• pp.318-323
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• 2007

This paper investigates the field weakening operation of a five-phase permanent magnet motor. The proposed motor has concentrated windings such that the produced back-EMF is almost trapezoidal and is supplied with the combined sinusoidal plus third harmonic of currents to produce trapezoidal current. Therefore this motor, while generating the same average torque as an equivalent permanent magnet brushless dc motor, overcomes its disadvantages. It is shown that torque producing and flux producing components of current for this motor can be decoupled by using multiple reference frame transformation. Therefore, Vector control is easily applicable to the motor. This motor has benefits such as high torque density of a BLDC motor below the rated speed and controllability of PMSM above the rated speed and during the field weakening region and simulation and experimental results are provided to prove the validity of the superior performance of this drive.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1500-1505
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• 2004

This paper presents the design and control of a small Brushless DC (BLDC) Motor for entertainment robots. In order to control the developed BLDC motor, Adaptive Fuzzy Control (AFC) scheme via Parallel distributed Compensation(PDC) is developed for the multi- input/multi-output plant model represented by the Takagi-Sugeno(TS) model. The alternative AFC scheme is proposed to provide asymptotic tracking of a reference signal for the systems with uncertain or slowly time-varying parameters. The developed control law and adaptive law guarantee the boundedness of all signals in the closed-loop system. In addition, the plant state tracks the state of the reference model asymptotically with time for any bounded reference input signal. The suggested design technique is applied to the velocity control of a developed small BLDC motor for entertainment robots.