• Journal of KSNVE
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• v.10 no.6
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• pp.977-984
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• 2000

Vibration of disk drive spindle is one of the major limiting factors in achieving higher track densities in hard disk drives. Vibration of a BLDC motor is a coupled phenomenon between mechanical characteristics and magnetic origins through the motor air-gap. In this paper, radial magnetic forces for symmetric and asymmetric BLDC motor are calculated with respect to the various rotor eccentricity using analytic method. Based on the results of the radial magnetic forces, transient whirl responses of the spindle motor are analyzed using finite element and transfer matrices. Results show that an asymmetric motor has a worse effects on unbalanced magnetic forces and vibration when mechanical and magnetic coupling exists.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.3
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• pp.295-300
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• 2018

Conventionally, a PI control algorithm has been widely used as a speed control algorithm for BLDC motor. The PI control algorithm has a disadvantage in that is slow to reach the steady state due to the slow speed and torque response with various speed changes. Therefore, in this paper, PWM fuzzy logic control algorithm which can reach the steady state quickly by improving the response speed although there is a little overshoot is proposed. PWM reduces response speed and fuzzy logic control algorithm minimizes overshoot. The proposed PWM fuzzy logic control algorithm consists of DC chopper, PWM duty cycle regulator, and fuzzy logic controller. The performance and validity of the proposed algorithm is verified by simulation with Simulink of Matlab 2018a.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.11
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• pp.1528-1534
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• 2013

This paper proposes the optimal design of stator shape for cogging torque reduction of single-phase brushless DC (BLDC) motor with asymmetric notch. This method applied size and position of asymmetric notches to tapered teeth of stator for single-phase BLDC motor. Which affects the variation of the residual flux density of the permanent magnet. The process of optimal design included the extraction of the sampling point by using Latin Hypercube Sampling(LHS), and involved the creation of an approximation model by using kriging method. Also, the optimum point of the design variables were discovered by using the Genetic Algorithm(GA). Finite element analysis was used to calculate the characteristics analysis and cogging torque. As a result of finite element analysis, cogging torque were reduced approximately 39.2% lower than initial model. Also experimental result were approximately 38.5% lower than initial model. The period and magnitude of the cogging torque were similar to the results of FEA.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.988-990
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• 2000

This paper presents the software control of a brush-less DC motor. 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 (DSP) 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. The main benefits are increased system reliability and cost reduction of the overall system. The present paper describes how a speed controlled brushless DC drive can be implemented using TMS320F240.

• 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 KIEE Conference
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• 2008.10c
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• pp.237-239
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• 2008

본 논문에서는 Matlab Simulink을 사용하여 고성능 BLDC(Brushless DC) 전동기 드라이브를 위한 DC Link 가변 전압 인버터 모델링을 제안한다. 다른 프로그램을 이용한 BLDC 전동기 시뮬레이션은 하드웨어적인 구현에는 유리하지만 처리속도가 늦고, 계산상의 오차가 크게 발생하는 단점이 있다. 이러한 단점을 보완하기 위해 수식기반인 Matlab Simulink를 활용하여 보다 정확하고 연산 속도가 빠른 시뮬레이션을 수행하였다. 제안된 모델은 승압 및 강압모드가 가능한 2-스위치 buck-boost 컨버터와 6-스위치 인버터 및 BLDC 전동기로 구성되고, 시뮬레이션을 통하여 전동기의 속도에 따른 DC Link 전압의 가변을 확인하였다.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.1
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• pp.36-48
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• 1990

A new control method for robust position control of brushless dc motor is presented. The model of brushless dc motor is approximately linearized by field-orentation method, and it is shown that augmented state variable feedback can be applied to this system. In addition, robustness is obtained without any change of overall system response. Load disturbance is detected by 0-observer of unknown and inaccessible input, and is compensated by feedforward which has fast response. Overall system is controlled by using the MC68000 microprocessor, and the performance of the proposed control algorithm is verified by the results of simulation and experiment.

• Transactions of the Korean Society of Automotive Engineers
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• v.23 no.2
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• pp.153-160
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• 2015

Hybrid Electric Vehicles(HEVs) have seriously come into prevalence recently as car manufacturers and consumers have become more aware of the environmental and economic problems of conventional vehicles. For the alternative power-train and battery cooling systems in HEVs, an effective thermal management system is required, and many automakers are interested in using Brushless DC(BLDC) motors for cooling fans for the overall traction unit's performance and energy saving capability. This paper presents the development status of BLDC motors as major parts of the power-train, i.e. the engine cooling and battery cooling fans of HEVs. A design that uses BLDC motors for the power-train and each battery cooling fan, is successfully implemented through using electro-magnetic analysis, and prototype BLDC motors are examined. As experimental results, the BLDC motors achieved an efficiency of 85% as engine cooling fans and 72% as a battery thermal management fan motor. The electric cogging noise is significantly reduced by changing the skew of the slot pitch angle and optimizing the magnetic shape.

• Journal of international Conference on Electrical Machines and Systems
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• v.1 no.1
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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.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.406-408
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• 1996

This paper describes the BLDC motor which is applicated for a top front loading domestic washing machine. This motor is adopted direct drive washing machine without gear-belt-pulley system. Because gear box is removed, machine volume and noise are reduced. Moreover mechanical troubles in gear box are removed. Realization of variable speed region through of PWM control and high speed is able to efficient washing and spinning.