• 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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• 2006.07b
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• pp.781-782
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• 2006

This paper presents a drive strategy to reduce torque ripple of a permanent magnet Brushless DC Motor(BLDCM) with short $120^{\circ}$ flat top Back Electromotive Force(Back-EMF). In this strategy, the phase Back-EMF is divided into four sections. Then, in each section the phase current is regulated by corresponding PWM duty ratio to compensatethe torque ripple caused by imperfect Back-EMF. A program based on this strategy has been implemented in MATLAB@Simulink. The validity of the presented method is verified by simulation results.

• Journal of Magnetics
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• v.21 no.1
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• pp.78-82
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• 2016

Cogging torque will affect the performance of a permanent magnet Brushless DC Motor (BLDCM), thus the reduction of cogging torque is key for BLDCM optimization. In this paper, the phase shifting of cogging torque for a fractional-slot concentrated winding BLDCM is analyzed using the Maxwell tensor method. Moreover, a 9-slot 10-pole concentrated winding BLDCM driven by ideal square waveform is studied with the finite element method (FEM). An effective method to reduce the cogging torque is obtained by adjusting the slot opening. In addition, the influences of different slot openings on back electromotive force (back-EMF), air gap flux density and flux linkage are investigated and experimentally validated using the prototype BLDCM.

• Journal of international Conference on Electrical Machines and Systems
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• v.3 no.1
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• pp.1-6
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• 2014

A new sensorless control strategy for brushless DC (BLDC) motors is proposed in this paper. This technique builds a rotor position-related flux function, which is independent of the speed. By observing the flux function, the information of rotor position and commutation can be obtained. As the function is not speed-related, this control process can be used in a wider range of speed and improves the motor's performance during startup. An experimental test bad based on TMS320F2812 has been built, and the experimental result indicates that the motor achieves a smooth starting-up and stable phase commutation with the proposed control strategy.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.220-223
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• 2005

In this paper, a novel sensorless brushless DC (BLDC) motor drive method using the fuzzy back-EMF observer is proposed to improve the performance of conventional sensorless drive methods. Most existing back-EMF sensing methods need additional circuit and have a low performance intransient state or low speed range. Therefore, this paper proposes the fuzzy back-EMF observer and an algorithm using this observer to estimate a speed and a position of the rotor. The robustness of the proposed algorithm is proved through the simulation compared with other sensorless drive methods.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2753-2755
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• 2000

In this paper, the robust position tracking cotroller for a brushless DC motor driving a one-link robot manipulator is proposed. By using the backstepping approach, the adaptive and robust controller is appropriately designed to ensure global stability. The proposed robust backstepping controller can compensate for estimation errors in system parameters in the system with no structural changes in the controller and without destruction of the stability. The closed-loop stability of the system is shown using Lyapunov techniques. The tracking errors are shown to be globally uniformly bounded.

• Journal of Magnetics
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• v.20 no.2
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• pp.161-165
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• 2015

The Permanent Magnet Brushless DC (PMBLDC) motors have been used in modern industrial factories, hazardous chemical process, modern medical devices, and especially in advanced military devices such as army drones. By considering their sensitive role in the industrial and military applications, their optimal design has a real concern. This paper proposes a method for optimal eco-design of a PMBLDC motor using improved tabu search optimization. The objective function is based on losses, volume and cost. Electrical and mechanical requirements and other limitations are combined into constraints of problem. Also, finite element analysis has been used for verifications in magnetic mode.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.1087-1089
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• 2003

This paper presents a method to reduce commutation torque ripple in a sensorless brushless DC motor drive without current sensors. To compensate the commutation torque ripple completely, the duration of commutation must be known. The proposed method measures the duration of commutation from terminal voltage waveforms, calculates a PWM duty ratio to suppress the commutation torque ripple from the output of speed controller, and applies the calculated PWM duty ratio only during the commutation. Experimental results show that vibrations are considerably reduced when the proposed method is applied to the sensorless brushless DC moter drive for air-conditioner compressor.

• Journal of Power Electronics
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• v.10 no.6
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• pp.702-708
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• 2010

In this paper, a fault diagnosis algorithm for brushless DC (BLDC) motor drives is proposed to maintain control performance under switch open-damage. The proposed fault diagnosis algorithm consists of a simple algorithm using measured phase current information and it detects open-circuit faults based on the operating characteristic of BLDC motors. The proposed algorithm quickly recovers control performance due to its short detection time and its reconfiguration of the system topology. It can be embedded into existing BLDC drive software as a subroutine without additional sensors. The feasibility of the proposed fault diagnosis algorithm is proven by simulation and experimental results.

• Journal of Electrical Engineering and Technology
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• v.11 no.4
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• pp.889-897
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• 2016

This paper presents an improved approach for compensating rotor position signal displacement in brushless DC (BLDC) motors with misaligned hall-effect sensors. Typically, the hall-effect sensors in BLDC motors are located in each phase and positioned exactly 120 electrical degrees apart. However, limitations in mechanical tolerances make it difficult to place hall-effect sensors at the correct location. In this paper, a position error compensator to counteract the hall-effect sensor positioning error is proposed. The proposed position error compensator uses least squares error analysis to adjust the relative position error and back-EMF information to reduce the absolute offset error. The effectiveness of the proposed approach is verified through several experiments.