• 전력전자학회논문지
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• 제5권6호
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• pp.523-529
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• 2000

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(1)
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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.

• 전력전자학회논문지
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• 제6권2호
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• pp.180-190
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• 2001

본 논문에서는 브러시리스 직류 전동기(BLDCM)의 정류과정에서 발생하는 유도성 상 전류의 위상각 제어에 의한 토크 리플의 감소 방법에 대하여 연구한다. 고정자 코일에서 발생하는 유도성 전이 전류에 대한 위상지연의 크기는 전동기의 회전속도에 따라 달라지므로, 속도에 대한 보상각을 결정하고 테이블 처리에 의하여 실시간 제어한다. 실험으로, AVR 8515 마이크로 프로세서를 이용하여 위상지연을 보상하는 회로를 설계하였으며 4극 3상의 브러시리스 직류 전동기에 대하여 전동기의 모든 운전영역에서 토크 리플이 현저하게 감소함을 확인하였다.

• Journal of Power Electronics
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• 제13권2호
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• pp.250-255
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• 2013

This paper proposes an optimal current distribution method of dual-rotor brushless DC machines (DR-BLDCMs) which have inner and outer surface-mounted permanent-magnet rotors. The DR-BLDCM has high power density and high torque density compare to the conventional single rotor BLDCM. To drive the DR-BLDCM, dual 3-phase PWM inverters are required to excite the currents of a dual stator of the DR-BLDCM and an optimal current distribution algorithm is also needed to enhance the system efficiency. In this paper, the copper loss and the switching loss of a DR-BLDCM drive system are analyzed according to the motor parameters and the switching frequency. Moreover, the optimal current distribution method is proposed to minimize the total electrical loss. The validity of the proposed method was verified through several experiments.

• Journal of Electrical Engineering and Technology
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• 제11권3호
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• pp.653-661
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• 2016

This paper proposes a capacitance estimation method of the dc-link capacitor for brushless DC motor (BLDCM) drive systems. In order to estimate the dc-link capacitance, the BLDCM is operated in quadrant-II or -IV among four-quadrant operation. Quadrant-II and -IV are called reverse braking and forward braking, respectively. During the braking operation of the BLDCM, the capacitor is charged by the phase current and then the voltage is increased during the braking operation time. The capacitor current and voltage can be obtained by using the phase current sensor of BLDCM and the dc-link voltage sensor. The capacitance and be easily obtained by the voltage equation of the capacitor. The proposed method guarantees the reliable and simple calculation of the dc-link capacitance without additional hardware system except several the sensors already installed for the motor control system. The effectiveness of the proposed method is verified through both the simulation and experimental results.

• 전기전자학회논문지
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• 제18권2호
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• pp.282-290
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• 2014

본 논문은 1인승 전기차량의 임베디드 전동 제어장치 설계를 제안하였다. 제안된 임베디드 장치는 PIC18F8720 프로세서, 16Mb flash ROM, 32Mb SDRAM과 신호처리회로로 설계되었다. 제안된 1인승 전기차량은 4KW 인휠 BLDCM, $180^{\circ}$ 도통 공간 벡터제어 3상 전압형 인버터, PID 속도제어기와 전동제어 장치와 임베디드 제어장치로 구성된다. 이 1인승 전기차량은 역 3륜 형태의 기계적인 구조를 가지고 있으며, 인휠 BLDCM과 틸팅 기능을 가지는 조향 메카니즘이 적용되었다. 또한 제안된 임베디드 전동제어장치의 성능은 PEV에 대한 Lab 실험과 도로 주행시험을 통하여 검증하였다.

• 전기학회논문지
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• 제56권12호
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• pp.2127-2134
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• 2007

The simulation model has been already developed not for 7 phase but for 3 phase BLDC motor. It is necessary to develop a new simulation model of multi-phase BLDC motor including the phase delay angle especially in the high speed region. In this paper, the suitability of the proposed model is verified through the several computer simulations, and experimented results.

• 전력전자학회논문지
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• 제17권3호
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• pp.246-251
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• 2012

This paper proposes a new position compensation method for misaligned Hall-effect sensors of BLDCM(Brushless DC Motor). If the Hall-effect sensors are installed at wrong position, the exact rotor position cannot be obtained. Therefore, when the BLDCM is controlled with this wrong position, the torque ripple can be increased and the average torque also decreases. The back-EMF of BLDCM can be obtained by using the voltage equation and by multiplying the back-EMF constant and rotor speed. At a constant speed, the estimated back-EMF by using the multiplication of the back-EMF constant and rotor speed is constant, but the estimated back-EMF from the voltage equation decreases at the commutation point because the line-to-line back-EMF of two conducting phases is start to decrease at this point. Therefore, by using the difference between these two estimated back-EMFs, the commutation point of the phase current can be determined and position compensation can be carried out. The proposed position correction method doesn't require additional hardware circuit and can be easily implemented. The validity of the proposed position compensation method is verified through several experiments.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.33-36
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• 2001

Torque ripple control of brush less DC motor has been the main issue of the servo drive systems in which the speed fluctuation, vibration and acoustic noise should be minimized. Most methods for suppressing the torque ripples require Fourier series analysis and either the iterative or least mean square minimization. In this paper, the novel approach to achieve the ripple-tree torque control with maximum efficiency based on the d-q-0 reference frame is presented. The proposed method optimize the reference phase current waveforms including even the case of 3 phase unbalanced condition, and the motor winding currents are controlled to follow up the optimized current waveforms by delta modulation technique. As a result, the proposed approach provides a simple and clear way to obtain the optimal motor excitation currents. The validity and practical applications of the proposed control scheme are verified through the simulations and experimental results.

• Journal of Power Electronics
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• 제10권6호
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• pp.717-723
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• 2010

This paper proposes a new torque control algorithm for BLDC motors to get the maximum torque in the high speed region. The delay of the phase currents is severe due to the stator reactance. The torque fluctuations of BLDC motors increase and the average torque is decreases due to a slow rise in the phase current when compared to the back EMF. In this paper, the phase current of BLDC motors under the high speed condition is analyzed and a torque maximization control is developed on the basis of using numerical analysis. Computer simulations and experimental results show the usefulness of the proposed control algorithm.