• Journal of Institute of Control, Robotics and Systems
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• v.22 no.11
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• pp.925-931
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• 2016

The BLDC motor is used widely in industry due to its controllability and freedom from maintenance because there is no mechanical brush in the BLDC motor. Furthermore, it is suitable for high-speed applications, such as compressors and air blowers. For instance, for a compressor with a small impeller due to miniaturizing, the BLDC motor has to rotate at a very high speed to maintain the compression ratio of the compressor. Typically, to reach an ultra-high speed, airfoil bearings must be used in place of ball bearings because of their friction. Unfortunately, the characteristics of airfoil bearings change drastically depending on the revolution speed. In this paper, a BLDC motor with airfoil bearings is controlled with a PID controller. To analyze and determine the PID coefficients, the relay-feedback method is used. Additionally, for adaptive control, a fuzzy logic controller is used. Furthermore, the auto-tuning and self-tuning techniques are combined to control the BLDC motor. The proposed method is able to control the airfoil-bearing BLDC motor efficiently.

• The Transactions of the Korean Institute of Power Electronics
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• v.21 no.2
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• pp.144-149
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• 2016

This paper presents a power control method of high-speed single-phase BLDC motor. Most electric appliances require a power factor corrector (PFC) to mitigate grid current harmonics. However, the reactive components and power semiconductors in the PFC increase system cost and dimension. In this paper, a new motor drive system for a high-speed single-phase BLDC motor is proposed, which can decrease grid current harmonics without PFC by directly manipulating motor power and eliminating bulky electrolytic dc-link capacitor. Given that the proposed motor power control method does not require motor current controller, no current sensor is necessary. Moreover, the proposed algorithms can be easily implemented using a low-cost micro-controller. The effectiveness of the proposed power control method is verified by experiments.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.1
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• pp.1-8
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• 2006

Now a day, owing to high efficiency and easy speed control of brushless DC(BLDC) motor, the demand of BLDC motor that has high power and low noises are increasing. Especially demand of interior permanent magnet(IPM) BLOC with high efficiency and high power in electric motion vehicle is increasing. IPM BLDC motor has permanent magnets in the rotor. Because it has two different flux paths, magnetic reluctance differences are generated in d-axis and q-axis. As the result of the inductance differences that are generated by the saliency(magnetic reluctance differences) in the rotor, the motor has structure advantage that has the additional reluctance torque except a magnet torque and because magnet is situated inside the rotor, the mechanical structure is strong. Therefore IPM BLDC motor makes possible to have high speed and high power. This paper presents a design and characteristics analysis of IPM BLDC motor for electric vehicle. To design IPM BLDC motor, surface mounted permanent magnet(SPM) BLDC motor is used as the initial design model. According to the shape-ratio() of permanent magnet, the characteristic of IPM BLDC motor is analyzed by Finite element method (FEM). Characteristics analysis results of the designed motor are compared with the experimental results.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.429-433
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• 2000

Recently the demand of motor for industrial household machinery is increasing. As Switching devices and control technology are progressing so the use of BLDC Motor is increasing But 3-Phase BLDC Motor generally used has pulsating torque and speed variation in commutation so the range of it's application is limited high speed application Especially to solve these problems it is necessary to increase phase to Motor so study of Poly-Phase BLDC Motor is progressing. In this paper we designed 7-Phase BLDC Motor drive system and MSTC(Minimum Switching Time Controller)

• Journal of the Semiconductor & Display Technology
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• v.23 no.1
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• pp.48-51
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• 2024

Recently, high-performance BLDC(Brushless DC) motors are being applied to various fields such as industrial and personal mobility devices and drones. To achieve the best performance of BLDC, sensors such as hall sensors, encoders, and resolvers are used to determine the position of the rotor, and various speed control technologies are being developed. However, due to problems with high-speed control due to external environmental factors and frequency bandwidth of semiconductor sensing devices, research on BLDC motors without semiconductor sensing devices is in progress. Therefore, in this study, a signal brush was added to the end of the rotor of a BLDC motor and the rotor position of the BLDC motor was detected by analyzing the signal output through the signal brush.

• Proceedings of the KIPE Conference
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• 2003.07b
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• pp.663-666
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• 2003

This paper presents a speed controller method based on the disturbance torque observer of high performance brushless DC (BLDC) motor drives. In case of the speed control of robot arms and tracking applications with lower stiffness, we cannot design the speed controller gain to be very large from tile viewpoint of the system stability. Thus, the feedforward compensator using disturbance torque observer was proposed. This method can improve the speed characteristic without increasing the speed controller gain. The enhanced speed control performance can be achieved and the speed response against the disturbance torque can be Improved for high-performance BLDC motor drive systems in which the bandwidth of tile speed controller cannot be made large enough. Consequently, speed control for high-performance BLDC motor drives become improved. The simulation results for BLDC motor drive systems confirm the validity of the proposed method.

• Proceedings of the KIEE Conference
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• 1998.07a
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• pp.116-118
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• 1998

This paper describes a basic structure, analysis of characteristics and test method for high speed axial-gap BLDC motor. The newly designed axial-gap BLDC motor has 2-stator disks with 3-rotor disks and is easy to increase power capacity by increasing the numbers of stator/rotor disks. For high speed operating, the rotor is composed of light and strong strength material and has several separated magnets to reduce stress concentraction by centrifugal force.

• Journal of Advanced Marine Engineering and Technology
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• v.20 no.1
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• pp.24-30
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• 1996

BLDC motor is widely used as a servo motor, because it has high efficiency, high power ratio, low inertia, and easy maintenance. However, position and speed sensors generally attached in BLDC motor increase motor cost, and limit environments of application. This study describes a sensorless speed control of sinusoidal BLDC motor using the d-q transformed instantaneous voltage equation, and presents the result of computer simulation. The sensorless algorithm is applied to the casse of a voltage controlled PWM inverter. The result indicates good dynamics and a robust control in cases of a load change and a system parameter variation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.11
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• pp.1663-1668
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• 2017

A BLDC motor with higher number of phases has several advantages, compared to the conventional three-phase BLDC motors. It can reduce the commutation torque ripple and the iron loss without increasing the voltage per phase and increase the reliability and power density. Higher number of phases increase the torque-per-ampere ratio for the same machine volume and output power by widening the electrical conduction period. In this paper, the proposed seven-phase BLDC motor drive system is made into several functional modular blocks, so that it can be easily extended to other ac motor applications: back-EMF block, hysteresis current control block, pwm inverter block, phase current block, and speed/torque control block. Also in a system of BLDC motor drive, the PI controller has been widely used in the speed controller because of the simple implementation. To obtain a good speed response in a general drive system using the PI controller, the high bandwidth of a controller is established. therefore, in this paper, a Fuzzy controller is applied to the 7-phase BLDC motor drive system in order to improve the speed control performance. The Fuzzy controller is compared with a conventional PI controller through the experiment with respect to speed dynamic responses. These experimental results show that the Fuzzy controller of the 7-phase BLDC motor drive system is superior over the conventional PI controller. The algorithm using the Fuzzy controller can improve a comfortable ride in the field of high performance 7-phase BLDC motor drive applications.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1138-1142
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• 2007

As a brush DC motor, the brushless DC motor is also operated by DC power supply but has no mechanical contacts occurred by a brush or a commutator. Though the performance of BLDC motor is almost similar with that of DC motor, the BLDC motor has the advantage of the high speed responsibility, the high controllability, and the high effectiveness. The control valve using the BLDC motor, which excludes the burnout effect provoked possibly by the vacuum condition during the flight, is employed for the upper stage of a launch vehicle. For the component level analysis, the dynamic response characteristics of BLDC and DC motors to the same design input sources have been studied in using AMEsim.