• Proceedings of the KIPE Conference
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• 2007.07a
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• pp.325-327
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• 2007

This paper proposes a novel sensorless fault detection algorithm for a brushless DC(BLDC) motor drive system. This proposed method is configured without the additional sensor for fault detection and identification. The fault detection and identification are achieved by a simple algorithm using the operating characteristic of the BLDC motor. This proposed method can also be embedded into existing BLDC motor drive systems as a subroutine without excessive computational effort. The feasibility of a novel sensorless fault detection algorithm is validated in simulation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.1
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• pp.48-53
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• 2014

Generally, the usage motor in the vehicle is exposed to highly ambient temperature and large vibration according to repeatedly starting and stopping during very short time. So, in this paper, the rotor shape design was performed to improve demagnetization endurance by considering starting current of Brushless DC Motor (BLDCM) through Finite Element Method(FEM). As a result, the end of Permanent Magnet (PM) in the basic model was occurring a partial irreversible demagnetization by starting current. To solve this problem, the installing flux barrier was limited to flux line on the core. Accordingly, demagnetization endurance and operating characteristics were improved.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.5
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• pp.481-486
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• 2018

DC motors are classified as DC motors with brush structure and BLDC motors without brush structure. Representing the speed control of the BLDC motor is the PI control. The speed control using the PI controller has a disadvantage that the response characteristic to reach the steady state is slow. Therefore in this paper, a voltage controlled speed controller using a Fuzzy Logic Controller (FLC), which has a short steady response time and usefulness of nonlinear control. The validity and usefulness of the proposed fuzzy speed controller are verified by simulation through Simulink of MATLAB program. Experiments were performed on the PI controller and the proposed fuzzy speed controller in three cases with reference speeds of 500rpm, 800rpm, and 1500rpm. Experimental results show that the proposed fuzzy controller has more 30% improved steady state speed response than PI controller.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.53 no.12
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• pp.709-717
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• 2004

Flux-reversal machine (FRM) is a new brushless doubly salient permanent magnet machine. Its operation is similar to that of the brushless DC motor, so it can be driven by 120 degree square wave voltage and use PWM pulse patterns in two-phase feeding scheme to control the speed. In this driving method, the back electromotive force (BEMF) current in the open phase is generated by the BEMF. It can be appeared or disappeared according to the changes of the neutral voltage of the machine. In this paper, the time-stepped voltage source finite-element method taking BEMF current into account is proposed. Its influences on the performances of the FRM are also investigated. To prove the propriety of the proposed analysis method, a Digital Signal Processor (DSP) installed experimental devices are equipped and the experiment is performed.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.790-791
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• 2008

이 연구는 이동 매쉬기법이 고려된 유한요소 해석법을 이용한 영구자석 Brushless 직류모터(BLDCM)의 동적 특성해석을 다루었다. 이 논문의 초점은 BLDCM의 적합한 속도 제어를 위한 정현파 구동시스템의 적합성을 보여주고 있다. 각각의 구형파 시스템과 BLDC 구동시스템의 제안된 속도리플과 전류응답을 비교하였다. 실험결과들에 의해 속도제어 시스템은 해석되어졌고, 정현파 구동시스템의 유효성은 검증되었다.

• International Journal of Control, Automation, and Systems
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• v.6 no.4
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• pp.477-487
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• 2008

This paper proposes a new position sensorless drive for brushless DC (BLDC) motors. Typical sensorless control methods such as the scheme with the back-EMF detection method show high performance only at a high speed range because the magnitude of the back-EMF is dependent upon the rotor speed. This paper presents a new solution that estimates the rotor position by using an unknown input observer over a full speed range. In the proposed method, a trapezoidal back-EMF is modelled as an unknown input and the proposed unknown input observer estimating a line-to-line back-EMF in real time makes it possible to detect the rotor position. In particular, this observer has high performance at a low speed range in that the information of a rotor position is calculated independently of the rotor speed without an additional circuit or complicated operation process. Simulations and experiments have been carried out for the verification of the proposed control scheme.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.333-336
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• 1997

In this paper, we present a nonlinear dynamic controller for position tracking of brushless dc motors. In constructing the controller, a backstepping-type approach is used under the condition of full state information, while an adaptive controller is adopted for parameter uncertainty throughout the entire electromechanical system. The nonlinear dynamic controller using the adaptive learning technique approach is shown to drive the state variables of system to the desired ones asymptotically and whose effectiveness is also sown via computer simulation.

• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.477-480
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• 2003

Generally, 2 phase excited brushless DC motor(BLDCM) operates only in the region of constant trapezoidal back-EMF on each phase. Therefore the efficiency decreases in comparison with 3phase excited BLDCM. This paper proposes the relation between the usage ratio of voltage and the change of fewer delivery of BLDCM according to extension of conduction intervals.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.10-13
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• 1999

본 논문에서는 선단부 유니폴라 PWM 방식의 전압원 인버터에 의해 구형파 형태의 전류로 여자되는 브러시리스 직류전동기에서 토크맥동 발생의 주된 원인이 되는 상 전류 전환 및 비이상적인 역기전력 파형에 희한 토크맥동을 저감시킬 수 있는 방식을 제안한다. 또한 실험을 통하여 제안한 토크맥동 저감기법의 효용성을 살펴본다.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.382-385
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• 1999

In this paper, by means of Lyapunov second method, the stability of IPD control servo systems is analyzed in the time domain for the first time. Based on the results of the stability analysis, the design rule to select the gain of IPD control is suggested such that the maximum error of output to the nominal system is guaranteed for all uncertainty and load variations. An example of a position control of a brushless dc motor is given to prove the unusefulness of the gain design rule.