• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 B
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• pp.744-746
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• 2003

This paper presents characteristics analysis of brushless DC motor(BLDCM) which is driven by four types of PWM mode. The Phase current, radial forte and torque ripples are generated differently at each PWM mode. So they have different influences on motor characteristics. In this paper, we analyzed characteristics of BLDCM using time-stepped voltage source finite element method. The effect of four types of PWM mode had been confirmed by comparing each phase current and torque ripple waveform. The compared simulation result is useful to select a better PWM mode.

• Journal of Electrical Engineering and Technology
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• 제10권1호
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• pp.251-260
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• 2015

The main purpose of this paper is to describe a DTC (direct torque control) method for four-switch brushless dc motor (BLDCM) drive. In the method, a novel voltage space vector modulation scheme, an optimal switching table, and a flux observation method are proposed. Eight voltage vectors are summarized, which are selected to control BLDCM in SVPWM pattern, and an optimal switching table is proposed to improve the torque distortion caused by midpoint current of the split capacitors. Unlike conventional flux observers, this observer does not require speed adaptation and is not susceptible to speed estimation errors, especially, at low speed. Global asymptotic stability of the flux observer is guaranteed by the Lyapunov stability analysis. DC-offset effects are mitigated by introducing a PI component in the observer gains. This method alleviates the undesired current and torque distortion which is caused by uncontrollable phase. The correctness and feasibility of the method are proved by simulation and experimental results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.1108-1110
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• 2000

The BLDCM(Brushless DC motor) has been the Trapezoidal Back Electromotive Force(EMF) due to a surface magnet rotor with nonlinear distribution and full-pitch windings. Theoretically, it should be fed with rectangular phase current in order to minimize torque ripple. But, because voltage source inverter drives BLDCM, perfectly rectangular phase currents are not available. Now in this paper, using fourier series coefficients, calculating the coefficients of harmonic current within available orders and each harmonic component are controlled on stationary frame. Only using four switches, low cost and small size drive can be made and proposed method will be more useful in industrial. Simulation and experimental results prove the validity of the proposed method.

• 한국철도학회논문집
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• 제11권2호
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• pp.203-210
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• 2008

바퀴와 BLDC전동기 일체형으로 구성되는 Hub Wheel 전동기는 감속기가 없는 직접 구동방식으로서 저소음 고효율의 운전이 가능하여 경전철의 구동부로 활용이 가능하다. 하지만 Hub Wheel 전동기는 속도계측을 위한 센서의 장착이 용이하지 않다. 전동기의 원활한 속도 제어를 위해서는 별도의 속도 계측을 위한 방법이 요구된다. 본 논문에서 입력이 적극 반영된 간단한 수학적 시스템 모델을 가지고 이산 칼만 필터를 사용하여 전동기 속도를 추정하고 이를 이용하여 속도제어를 하는 방법을 제시한다.

• Journal of Advanced Marine Engineering and Technology
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• 제40권9호
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• pp.805-811
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• 2016

본 논문은 플래너 버스바가 적용된 BLDC 전동기 드라이브 시스템에서, 직류단 캐패시터 전단 전류를 이용한 BLDC 전동기의 상전류 추정 알고리즘을 제안한다. 플래너 버스바는 기생 인덕턴스의 크기를 최소화하여 스위칭 시 스파크에 의한 소자 파손을 방지하고, EMC (ElectroMagnetic Compatibility) 특성을 향상시킨다. 하지만 플래너 버스바의 장점을 극대화하기 위해서는 직류단 캐패시터의 전단에 전류 센서를 설치할 수밖에 없는 구조적 제약이 따른다. 직류단 캐패시터 전단에 설치된 전류 센서는 캐패시터에 흐르는 전류와 인버터 입력전류의 합을 측정하게 된다. 따라서 직류단 캐패시터 전단 전류로부터 인버터의 입력전류를 정확하게 추출하는 것이 BLDC 전동기의 전류 제어를 위해서는 필수적이다. 본 논문에서는 BLDC 전동기의 온/오프 구간 동안의 등가 회로를 분석하여 캐패시터 전단 전류로부터 인버터 입력전류를 추정하는 알고리즘을 제안하였다. 제안된 알고리즘은 실험을 통해 그 타당성을 검증하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2016년도 전력전자학술대회 논문집
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• pp.189-190
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• 2016

본 논문은 휠체어의 탑승자의 구동력과 BLDCM(Brushless DC Motor) 에서 출력되는 보조력인 전기적인 구동력을 동시에 사용하는 탈부착형 수전동 휠체어의 제어기를 제안한다. 제안된 방식에서는 탈부착형 수전동 휠체어 제어기는 휠체어의 기울기와 휠체어의 상관관계를 바탕으로, 탑승자의 휠체어 림 구동 상태를 추정하여 휠체어의 전동력을 전달하는 BLDCM에서 구동력을 사용자의 지령에 따라 보조하도록 제어한다. 사용자의 요구 상태는 림의 구동에 따른 휠체어의 상태를 가속도, 자이로 센서를 이용해 측정을 하게 되고, 이를 상보필터를 사용해 각도를 보정하여, 지령치를 계산하고, 구동부는 지령치에 따라 휠체어에 필요한 전동력을 발생하게 된다. 탈부착형 수전동 휠체어의 제어방식은 시뮬레이션을 통해 가능성을 검증하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2004년도 전력전자학술대회 논문집(2)
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• pp.660-664
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• 2004

The indirect rotor position detection method using terminal voltage of brushless DC motor (BLDCM) requires simple control circuit, and has wide speed range of sensorless operation. However, because the substantial phase difference exists between real back emf and terminal voltage, the existing indirect detection method using analog filter which is affected by frequency, speed, and load sensitively cannot be synchronized with current, in the end, it advances or delays. This paper presents new analog filter circuit design for rotor position estimation in order to solve the problem, and proposes novel sensorless operation method which is stable even in high speed range and not influenced by parameters with analysis on phase difference by load and speed. Moreover, the appropriateness of the proposed sensorless drive in this paper is verified and analyzed by experimentation.

• 대한전기학회논문지
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• 제44권4호
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• pp.447-452
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• 1995

In this paper a simple method of a position control for brushless DC motor is presented. For precise position control, a high performance torque controller is needed and a novel current control method is proposed. The current controller detects the uncommutating mode current for every 60.deg. (elec. angle) and controls it with PI controller. The current control loop includes the feedforward of back EMF and the feedforward of the neutral voltage between the neutral point of the inverter and the neutral point of the machine. In the position control, the acceleration pattern is calculated from the position reference. Then the speed trajectory is calculated from the acceleration pattern. The experimental results are presented to verify the proposed methods.

• 전기학회논문지
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• 제63권1호
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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.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2002년도 전력전자학술대회 논문집
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• pp.435-438
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• 2002

The Objects of this paper are developing and also improving a high-speed driving system of bushless DC motor(BLDCM) with economical and practical performance. Because BLDC motors are manufactured that each motor can create proper torque for their individual purpose, it is difficult to increase over the rated speed when a motor speed (with it's rated road) is reaching to a maximum speed so the motor torque cannot be increased. This paper verifies the effects of Leading Angle Algorithm, that is proposed on this paper, with examining existing methods to maximize the torque of a motor in high-speed driving area. The arithmetic processor for this experiment is TMS320C240 DSP controller that is designed for a special purpose of motor control in Texis Instrument Inc., and the used Inverter is PM10CSJ060, a Intelligent Power Module of Mitsubishi Corporation.