• 한국자동차공학회논문집
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• 제6권3호
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• pp.106-114
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• 1998

Cogging torque is often a principal source of vibration and control difficulty in permanent magnet motors, especially at low speeds and loads. For example, reduction of cogging torque is an important specification for DC motors used for electric power stee- ring. This paper examines two motor design techniques, stator tooth notching and rotor pole skewing with magnet pole shaping, for reduction of cogging torque, and the effect of each method on the airgap flux, and the use of the Maxwell stress method and Fourier decomposition to calculate the periodic cogging torque. The analyses show that the cogging torque can be nearly eliminated by the suggested designs, with minimal scacrifice of output torque.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.77-79
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• 2006

본 논문에서는 Brushless DC Motors(이하 BLDC Motor이라 함)의 비대칭 영구자석 오버행 구조에 의한 Z축 방향 추력, 진동 특성을 연구하였다 무부하인 경우에는 Z축방향 추력이 일정하므로 베어링에 하중으로만 작용하여 진동은 발생하지 않는다. 그러나 코일전류가 증가할수록 코일전류에 의한 증자, 감자작용으로 인하여 자속에 리플이 발생하며 Z축 방향 추력도 리플은 물론 진동이 발생한다. 따라서, 븐 연구에서는 전기자 전류 변화에 따른 자속밀도 및 Z축 방향 추력 특성을 해석하였으며 이를 실험치와 비교하였다.

• Journal of Electrical Engineering and Technology
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• 제9권6호
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• pp.2181-2186
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• 2014

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

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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• pp.339-341
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• 2006

This paper presents a new method on controller design of brushless dc motors. In such drives the current ripples are generated by motor inductance in stator windings and the back EMF. To suppress the current ripples the current controller is generally used. To minimize the size and the cost of the drives it is desirable to control motors without the current controller and the current sensing circuits. To estimate the motor current it is modeled by a neural network that is configured as an output-error dynamic system. The identified model is essentially a one step ahead prediction structure in which fast inputs and outputs are used to calculate the current output. Using the model, effective estimator to compensate the effects of disturbance has been designed. The effectiveness of the proposed current estimator is verified through experiments.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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• pp.342-344
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• 2006

This paper present a method of current control for torque ripple reduction in brushless dc motor which have a trapezoid back EMF. In such drives the current ripples are generated by motor inductance in stator windings and the back EMF. The ripples suppression techniques that are practically effective in high speed as well as in low speed regions are rarely found. The proposed method here is based on a strategy that the commutation intervals of the incoming ang the outgoing phases can be equalized by a proper PWM control.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.697-698
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• 2008

This paper deals with finite element characteristic analysis of brushless DC motor according to magnetic property measurement methods. Magnetic property data for non-oriented (NO) electrical steel for electric motors are measured by the Epstein test which is considered as the international standards. Data from Epstein test may result in discrepancy from motor characteristic tests due to innate anisotropic property of NO electrical steel. Finite element analysis were performed for a BLDC motor by various measurement methods such as Epstein test, Ring test and single sheet test (SST), and calculated results were compared with considering anisotropic property conditions.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.991-993
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• 2000

The paper presents the software control of a brush-less do motor with parameter identification. Not only speed and current controls but also a real-time identification of the motor parameters can be implemented by software using the digital signal processor TMS320F240. The DSP Controller TMS320F240 from Texas Instruments is suitable for a wide range of motor drives TMS320F240 provides a single chip solution by integrating on-chip not only a high computational power but also all the peripherals necessary for electric motor control. This new family of DSPs enables single chip, cost effective, modular and increased performance solutions for BLDC drives. The present paper describes how a speed controlled brushless DC drive can be implemented using TMS320F240 and what kind of results can be achieved.

• 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.

• 전기학회논문지
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• 제56권6호
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• pp.1039-1046
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• 2007

This paper presents the analysis for power consumption, mechanical vibration and acoustic noise characteristics of the Coreless and Slotless Brushless DC motor in Digital Lightening Processor(DLP) Motor with the Air-Dynamic Bearing. The Coreless BLDC motor has not the stator yoke as well as the stator slot to remove the unbalance force by the interaction between the stator yoke and Air-Dynamic Bearing clearance. The assembling tolerance and the processing error make the air-gap difference between the magnet and the stator yoke .which occurs the unbalanced electro-magnetic force in the Slotless BLDC motor. It imposes the air-dynamic bearing on the disturbance force and makes the Air-Dynamic Bearing vibrated and noised. Also, The attractive force between the magnet and the silicon steel stator yoke increases the power consumption. In this paper, the power consumption, mechanical vibration and acoustic noise of the Coreless BLDC motor and the Slotless BLDC motor with the silicon steel stator yoke are simulated, analyzed, and tested using the manufactured proto-type motors with Air-Dynamic bearing. The simulated and tested results present that the Coreless BLDC motor without the silicon steel stator yoke has the lower mechanical vibration and noise ,and lower power consumption than the Slotless BLDC motor with the silicon steel stator yoke in Digital Lightening Processor Motor with Air-Dynamic Bearing.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.627-630
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• 2004

The PID type controller has been widely used in industrial application due to its simply control structure, ease of design, and inexpensive cost. However, control performance of the PID type controller suffers greatly from high uncertainty and nonlinearity of the system, large disturbances and so on. This paper presents a hybrid fuzzy logic proportional plus conventional integral derivative controller (fuzzy P+ID). In comparison with a conventional PID controller, only one additional parameter has to be adjusted to tune the fuzzy P+ID controller. In this case, the stability of a system remains unchanged after the PID controller is replaced by the fuzzy P+ID controller without modifying the original controller parameters. Finally, the proposed hybrid fuzzy P+ID controller is applied to BLDC motor drive. Simulation results demonstrated that the control performance of the proposed controller is better than that of the conventional controller.