• Journal of the Korean Institute of Telematics and Electronics T
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• v.36T no.3
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• pp.50-55
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• 1999

Brushless DC Motor(BLDCM) has high efficiency. But this type of motor needs a rotor sensor which complicates the motor configuration. Rotor position sensor degrades system reliability in the severe environmental condition. In this paper, we study a controller which permits the determination of the rotor position by the back EMF to eliminate the rotor position sensor Also, since the back EMF is zero at standstill, a starting technique which permits the starting of an asynchronous motor without a sensor is described. The controller is implemented using microcontroller for minimal external component.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.53 no.5
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• pp.325-331
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• 2004

The multiobjective optimization (MO) problem usually includes the conflicting objectives and the use of conventional optimization algorithms for MO problem does not so good approach to obtain an effective optimal solution. In this paper, genetic algorithm (GA) as an effective method is used to solve such MO problem of brushless DC motor (BLDCM). 3D equivalent magnetic circuit network (EMCN) method which enables us to reduce the computational burden is also used to consider the 3D structure of BLDCM. In order to effectively obtain a set of Pareto optimal solutions in MO problem, ranking method proposed by Fonseca is applied. The objective functions are decrease of cogging torque and increase of torque respectively. The airgap length, teeth width and magnetization angle of PM are selected for the design variables. The experimental results are also shown to confirm the validity of the optimization results.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.7 no.2
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• pp.7-12
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• 2013

In this paper, we propose a brushless DC motor drive system for active knee prosthesis and low-cost estimation method for phase current from DC-link current. To control motor torque directly, current sensing is very important and current sensing point should be synchronized with voltage switching command to minimize the effect of switching noise in current measurement, For maintaining small form factor, simplifying control schemes and achieving low-cost system, control schemes using DC-link current are used. Moreover, we incorporated phase current estimation method using analog MUX for minimizing current estimation error between DC-link current and phase current. The validity of the proposed system is verified through experimental works.

• Proceedings of the KIEE Conference
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• 2007.10c
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• pp.25-27
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• 2007

Brushless DC Motor (BLDCM) is DC motor and Interior PM Synchronous Motor (IPMSM) is AC motor. Besides their way of control is different. But it is similar that both motors rotate synchronous velocity and use the permanent magnet. So, it is an objective to grasp a tendency of motor design and efficiency of motor through a characteristic comparison of BLDCM and IPMSM with the same power, rotation velocity, torque and input voltage.

• Proceedings of the KIEE Conference
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• 2007.04c
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• pp.183-186
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• 2007

This Paper presents a solution to control the Brushless DC Motor(BLDCM) in Hard Disk Drive(HDD) using the Linear Quadratic Regulator(LQR). Generally, The speed of BLDCM in HDD is controlled by the lead angle control or the input voltage control using PAM(Pulse Amplitude Modulation) etc. These control methods have speed overshoot in speed control and need the long time until BLDCM reaches at the steady state. In order to improve the performance, this paper present the PI speed controller using the LQR based on vector control and the rotor position detection methods at the space vector PWM inverter. The proposed methods are proved by the simulation and experimental results.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.443-446
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• 2002

Brushless DC motor(BLDCM) are suitable to operate in a wide speed range, easy to control and since there are no mechanical brushes and commutators, require low maintenance costs and are free from restrictions of application environment. And since the ratio of instantaneous torque and rated torque is high, BLDCM are appropriate for variable speed operation. This paper proposes the optimal model by using Matlab/simulink based on modelling and characteristic analysis of trapezoidal back EMF type BLDCM and verifies the validity of the proposed model by applying control systems.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1102-1103
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• 2007

This Paper presents a solution to control the Brushless DC Motor(BLDCM) in Digital Lightening Processor(DLP) using the Linear Quadratic Regulator(LQR). Generally, The speed of BLDCM in DLP is controlled by the lead angle control or the input voltage control using PAM(Pulse Amplitude Modulation) etc. These control methods have speed overshoot in speed control and need the long time until BLDCM reaches at the steady state. In order to improve the performance, this paper present the PI speed controller using the LQR based on vector control and the rotor position detection methods at the space vector PWM inverter. The proposed methods are proved by the experimental results

• Proceedings of the KIEE Conference
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• 1999.07a
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• pp.49-51
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• 1999

This paper presents an efficient 2D finite element analysis(FEA) for brushless DC motor (BLDCM) taking into account the eddy current and lamination effect of stator. In BLDCM, the dynamic characteristic analysis considering the eddy current and driving circuit is applied for the accurate prediction of motor performance in high speed because the eddy current loss is proportional of square of the driving frequency. According to the variation of lamination number, the characteristics of electro magnetic force, torque, and eddy current loss are analyzed. From the results, it is known that the effect of the lamination of stator on the eddy current loss is verified.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.4B no.1
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• pp.20-23
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• 2004

BLDCMs are widely used in many industries. In certain specialized areas, they need to have high efficiency, high power rate and produce a low volume of noise, etc. In this study, a new type of slotless BLDCM is proposed that has no cogging torque, low iron loss and low volume as compared to commonly used BLDCMs. With a high performance magnet and coreless compact winding structure similar to those employed in linear synchronous motors, motor volume is reduced. The proposed motor has been put been through various experiments arid has demonstrated acceptable results for industry applications.

• Journal of Electrical Engineering and Technology
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• v.11 no.3
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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.