• 한국인터넷방송통신학회논문지
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• 제23권5호
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• pp.139-144
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• 2023

토크, 효율 등 전동기의 최대특성을 얻기 위해 모든 전동기는 각 전동기 특성에 맞게 설계된 범용인버터를 기본적으로 사용한다. 그러나 최근 연구 결과들을 살펴보면 BLDC 범용인버터인 6-스위치 인버터를 이용한 SRM 구동 연구, 3상 BLDC 전동기를 4-스위치 인버터를 이용한 구동 연구사례들을 살펴볼 수 있다. 따라서 기존 범용인버터에서 벗어나 각 전동기를 구동할 시킬 수 있는 구동 및 제어에 대한 여러 방법에 대해 접근하여 연구 방법들을 모색할 수 있다. 이러한 연구 경향에 맞춰 본 논문에서는 SRM 구동용 컨버터인 C- dump 형태의 컨버터를 BLDC 전동기의 구동 드라이버로 적용하여 이에 대한 특성과 가능성에 관해 연구하였다.

• Journal of Power Electronics
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• 제18권3호
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• pp.714-722
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• 2018

This paper presents a wide-range speed control scheme of brushless DC (BLDC) motors based on a hall sensor with separated low- and normal-speed controllers. However, the use of the hall sensor signal is insufficient to detect motor speed in the low-speed region because of low sensor resolution and time delay. In the proposed method, a micro-stepping current control method according to the torque angle variation is presented. In this mode, the motor current frequency and rotating angle are determined by the reference speed without the actual speed fed by the hall sensor. The detected torque angle is used to adjust the current value in a limited band to control the current value in accordance with the load. The torque angle is detected exactly at the changing point of the hall sensor signal. The rotor can follow the rotating flux with the variable torque angle. In a normal speed range, the conventional vector control scheme is used to control the motor current with a PI speed controller using the hall sensor. The torque characteristics are analyzed on the basis of the back EMF and current shape. To adopt the vector control scheme, the continuous rotor position is estimated by the measured speed and hall sensor position. At the mode changing point between low and normal speed range, the proper initial current command and reference rotor position are calculated. The calculated current command can reduce the torque ripple during transient mode. The proposed method is simple but effective in extending the speed control range of a conventional BLDC motor with hall sensor without the need for a high-resolution encoder. The effectiveness of the proposed method is verified by various experiments on a practical BLDC motor.

• 예술인문사회 융합 멀티미디어 논문지
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• 제9권5호
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• pp.865-872
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• 2019

본 논문은 한국교통대학교 태양광 자작 자동차 동아리 늘해랑에서 WSC(World Solar Challenge)에 참가하기 위해 제작한 Solar Car 구동시스템에 대하여 서술한다. WSC는 세계 최대의 태양광 자동차 경주 대회로 별도의 자동차 규정을 가지고 있어 태양전지 면적이나 배터리 용량등에 제약을 두기 때문에, 제한된 규정내에서 최대 에너지 효율을 가지도록 구동시스템을 설계하는 것이 가장 중요한 기술적인 팩터이다. Solar car의 구동시스템은 태양광 에너지를 전기 에너지로 변환해주기 위한 solar array, 변환된 전기에너지를 최대 출력으로 추적하기 위한 MPPT(Maximum Power Point Tracker) controller, 생산된 전기에너지를 저장하기 위한 battery, 전기에너지를 역학에너지로 변환하여 차량 구동을 위한 BLDC(Brushless DC) motor, BLDC motor를 제어하기 위한 motor controller 등으로 구성되어 있다. 본 연구에서는 최적 구동 시스템을 위해 태양전지 에너지 변환 시스템과 배터리, 모터로 구성된 전기 구동시스템 설계에 대한 내용을 포함하고 있다.

• Journal of international Conference on Electrical Machines and Systems
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• 제1권1호
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• pp.91-98
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• 2012

Climate change and other pollutions make a huge demand of environment friendly and high efficient motors especially Brushless DC (BLDC) motors. Generally, bidirectional energized BLDC motors are used widely; however, inverter devices used in the driver put fear of being effected by noise. This paper proposes unidirectional energized BLDC motor which utilizes asymmetrical H-bridge circuit as the driver circuit. The Minato motor is one of the pioneers in unidirectional energized system. The use of bar magnets in the rotor is one of the biggest disadvantages of the motor. We proposed using tabular magnets. The paper compares the power consumption and efficiency of the Minato motor and the proposed motor. During high speed rotation, undesirable armature current is generated that has a deceleration characteristic. This current lowers the motor's efficiency. In this paper, we propose the solutions and show comparison through equations of the copper loss ratio for the Minato and our proposed motors. The third motor, which has the highest efficiency, was discovered during examination of the equations.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.119-121
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• 2007

The increment of electric power demand causes interest on new higher power system such as 42V Power Net, and furthermore necessity for development of energy storage device is highlighted recently. 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) type BLDC with high efficiency and high power in electric motion vehicle is increasing. This paper presents the design of the BLBC motor for EHPS(Electro-Hydraulic Power Steering) in 42V system and verified the characteristics by simulation and test results.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2007년도 하계학술대회 논문집
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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.

• 한국자동차공학회논문집
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• 제22권1호
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• pp.95-102
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• 2014

This paper presents zero crossing point(ZCP) estimation methods considering discretization error for a high speed brushless DC(BLDC) motor drive. The ZCP is estimated by detecting the change of back-EMF polarity for the BLDC sensorless drive, and the discretization error exist on the estimated ZCP. The discretization error of the ZCP is a cause of the delay of a commutation timing of current and increment of a current ripple factor. Besides a delay of a ZCP estimation brings on the limitation of a speed range for the BLDC sensorless drive. The compensation method based on the error analysis with probability theory for reducing the effects of the discretization error of the ZCP is proposed. Also a ZCP estimation method according to the Back-EMF patterns is proposed to widen the speed range for the BLDC sensorless drive. The proposed methods are verified by the experiment.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2004년도 전력전자학술대회 논문집(2)
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• pp.646-650
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• 2004

This paper presents a novel method to detect the rotor position of the BrushLess DC(BLDC) motor at standstill and a start-up method to accelerate the rotor up to a certain speed where the conventional position sensorless control methods based on the back EMF could work reasonably The proposed initial rotor position estimation method is suitable to avoid the temporary reverse rotation or the starting failure. This method can be implemented using only one current sensor at DC link of the inverter. It does not depend on the model of the motor , and it is robust to motor parameter variations. By the proposed method, it is demonstrated experimentally that a stable starting can be achieved even with severe mechanical disturbance.

• Journal of Power Electronics
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• 제16권2호
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• pp.798-804
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• 2016

This paper proposes a new operation and control strategy for Power-Assisted Wheelchairs (PAW) using one brushless DC (BLDC) motor. The conventional electrical wheelchairs are too heavy and large for one person to move because they have two electric motor wheels. On the other hand, the proposed PAW system has a small volume and is easy to move due to the presence of a single wheel motor. Unlike the conventional electric wheelchairs, this structure for a PAW does not have a control joystick to reduce its weight and volume. To control the wheelchair without a joystick, a special control system and algorithm are needed for proper operation of the wheelchair. In the proposed PAW system uses only one sensor to detect the acceleration and direction of PAW's movement. By using this sensor, speed control can be achieved. With a speed control system, there are three kinds of operations that can be done on the speed of a PAW: the increment of PAW speed by summing external force, the decrement of PAW speed by subtracting external force, and emergency breaking by evaluating the time duration of external force. The validity of the proposed algorithm is verified through experimental results.

• 한국자동차공학회논문집
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• 제6권2호
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• pp.235-243
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• 1998

For motor operation at low speeds and loads, torque pulsation by the cogging torque is often a source of vibration and control difficulty. In this paper, the magnetic field of a motor is calculated by finite element method. The periodic cogging torque is determined using Maxwell stress method and time stepping method, and then decomposed using fourier series expansion, The purpose of this paper is to characterize design parameters on the cogging torque and to design a permanent magnet motor with a cogging torque less vulnerable to vibration, without sacrificing the motor performance. The design parameters include stator slot width, permanent magnet slot width, airgap length and magnetization direction. A new design with a less populated frequency spectrum of the cogging torque is proposed after characterizing individual effect of design parameters. Magnet pole edge shaping, by gradually increasing the cogging torque with reduced higher harmonics.