• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.4
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• pp.98-107
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• 2005

Brushless DC motor(BLDCM) can be driven by 120[^{\circ}]$ square wave voltage and use PWM pulse patterns in two-phase feeding scheme to control the speed of the motor. This Paper introduces four PWM modes used BLDCM control system, and analyzes their different influences on the motor performances using a time-stepped voltage source finite element method. To verify the proposed computational method, we built the prototype motor for electrical power steering(EPS) and compared the predicted and the measured back EMF and phase current.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.49 no.6
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• pp.395-402
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• 2000

This paper presents the improvement for speed characteristics of a Brushless DC Motor (BLDCM), it was applied to digital PI control for this. The practical PID control has been widely used to velocity control of DC motors. In this paper, a digital PI controller is used in order to decrease the speed error in constant velocity control of BLDCM. A TMS320C31 DSP is used for the microprocessor of digital PI control. The method using the DSP carry out the real-time control. The DSP has the rapid calculation ability and sampling time used lms. Driving BLDCM used 50W, motor input DC 150V and rotation speed 3000rpm. When BLDCM is to approval for discretion velocity at the acceleration and deceleration driving with any load, it was a feasible for stabilization control. Therefore, the experimental results indicate the superiority and validity of the velocity control by digital PI control.

• The Transactions of the Korean Institute of Power Electronics
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• v.21 no.5
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• pp.449-452
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• 2016

This paper presents a simplified analysis on the rotor position detection error in sensorless interior permanent magnet brushless DC motor (BLDCM) drives, wherein terminal voltage sensing based on the back-electromotive force (back-EMF) zero-crossing point detecting circuitry is employed. The effect of a rotor saliency on the back-EMF's zero-crossing point detection is analyzed using the extended EMF-based voltage equation of the interior permanent BLDCM in a stationary reference frame, and thus the overall analysis is considerably simplified compared to the conventional one. Simulation results are provided to verify the effectiveness of the proposed method.

• The Transactions of the Korean Institute of Power Electronics
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• v.6 no.2
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• pp.180-190
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• 2001

In this paper, a method of reducing torque ripples caused by phase winding inductances in BLDCM(Brushless DC Motor) drives is presented. In order to compensate the inductive current delays, commutation angle is controlled by the value compensating angle varied in accordance with rotational speed. Using the microprocessor AVR 8515, the proposed compensator is implemented and experiments are done with a 4-pole 3-phase BLDCM. The results show the remarkable reduction of torque ripple at whole speed ranges.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.4
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• pp.582-588
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• 2002

This paper presents a efficient sensorless driving strategy for brushless dc motor(BLDCM). By varying PWM switching frequency(4KHz, 6KHz, 8KHz) properly according to the rotating speed, the improvement of the efficiency and the operating characteristics through the wide speed are obtained.. The experimental results show that the proposed method can efficiently improve the sensorless driving performance for BLDCM with trapezoidal back emf.

• 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.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2000.11a
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• pp.99-104
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• 2000

This paper present the design, produce, circuit design and practical measurement for a Brushless DC Motor(BLDCM) with Ferrit-Magnet. It was used PI controller. The practical PI control has bin widely used for DC-Motor.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.5
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• pp.54-59
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• 2005

Brushless DC motor is a motor which is modified form DC brush motor and it does not have brushes. BLDCM is easy to centre, has wide speed range, high efficiency. However it needs speed sensor like encoder which increases the motor price and cause some faults in poor surroundings.. In this paper, for the sensorless control, the driving techniques for the initial stable start and the steady state are studied For the steady state the rotor position is determined using the measured back-EMF. To enhance the initial stating performance, the current signal from the free-wheeling diode is used. The results are conformed through the experiments.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1294-1296
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• 2005

Because of its cost effectiveness, the Brushless DC Motor(BLDCM) is focused by the industry these days. Considering the constant back-EMF region of the BLDCM, only a simple position information should be provided for constant torque control. From this point of view, using expensive position sensors, such as encoder, resolver, etc, decreases the cost effectiveness of the BLDCM. The Proposed detecting circuit detects position of zero crossing point(ZCP) then relative position could be calculated from ZCP. This circuit is robust to noise because of working in the current level. BLDCM is driven from the position information by the ZCP The reliability on BLDCM sensorless control using the voltage detecting circuit is shown through simulation using Matlab.

• Journal of Power Electronics
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• v.15 no.6
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• pp.1559-1566
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• 2015

The brushless DC motor (BLDCM) has many advantages. As a result, it is widely used in electric vehicle (EV) drive systems. To improve the reliability of the motor control system, a position sensorless control strategy based on a sliding mode observer (SMO) is proposed. The global fast terminal sliding mode observer (GFTSMO) is proposed to enhance the control performance of the SMO control system. The advantages of the linear sliding mode and the nonsingular terminal sliding mode (NTSM) are combined in the control strategy. The convergence speed of the system state is enhanced. The motor commutation point is obtained with the observation of the back EMF, and the instantaneous torque value of the motor is calculated. Therefore, the position sensorless control of the BLDCM is realized. Experimental results show that the proposed control strategy can improve the convergence speed, dynamic characteristics and robustness of the system.