• 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.

• Tribology and Lubricants
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• v.29 no.5
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• pp.318-323
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• 2013

Overheating in electrical motors results in detrimental effects such as degradation of the insulation materials, demagnetization of magnets, increases in Joule losses, and decreases in motor efficiency and lifetime. Thus, it is important to find ways to dissipate heat from the motor and to keep the motor operating at its most efficient temperature. In this study, a new design to guide air flow through a given brushless direct current (BLDC) motor is developed and the design is analyzed, specifically by using computational fluid dynamics (CFD) simulations. The results showed that the temperature distribution in the three proposed models is lower than that in the original model, although the speed of the cooling fan in the original model reaches a very high value of $15{\times}10^3$ rpm. The results also showed that CFD can be effectively used to simulate the heat transfer of BLDC motors.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.339-341
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• 2006

This paper presents a new method on controller design of brushless dc motors. In such drives the current ripples are generated by motor inductance in stator windings and the back EMF. To suppress the current ripples the current controller is generally used. To minimize the size and the cost of the drives it is desirable to control motors without the current controller and the current sensing circuits. To estimate the motor current it is modeled by a neural network that is configured as an output-error dynamic system. The identified model is essentially a one step ahead prediction structure in which fast inputs and outputs are used to calculate the current output. Using the model, effective estimator to compensate the effects of disturbance has been designed. The effectiveness of the proposed current estimator is verified through experiments.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.3
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• pp.74-78
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• 2008

Conventionally, when we need to know about the dynamic characteristics of motors, the moving band method has been the first considerable technique. In this paper, we have investigated the moving material method that moves the property of the material in moving area elements of BLDC motors, instead of moving mesh elements of the rotor. From this method, we can reduce the demanded HDD memory for FEM analysis and the calculation time with same results.

• The Transactions of the Korean Institute of Power Electronics
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• v.14 no.3
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• pp.197-203
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• 2009

This paper presents a novel method to diagnose magnetization faults produced during magnetization process using stator coils of a brushless dc motor with concentrated windings. It is demonstrated that the stator coil magnetization faults can cause a drop of energy efficiency of the brushless dc motor through computer simulations using a magnetization fault model and efficiency test using compressors. The proposed method diagnoses the stator coil magnetization faults by using an inverter during the brushless dc motor driving test after the magnetization process is completed. An experimental study on the brushless dc motor for compressor shows that the stator coil magnetization faults can be detected with high sensitivity.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.3 no.4
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• pp.3-9
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• 2010

Recently, Applications of BLDC motor have grown gradually in energy savings and controls of speed and torque. But most of BLDC motors need controller and driving circuits aside from motor, according to various situations. In this paper, it was designed for a embedded controller and motor including microprocessor that programmable intelligent control as various circumstances. And in order that the user conveniently use better than to use web browser using TCP/IP module in controller.

• Proceedings of the KIEE Conference
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• 1995.07a
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• pp.83-85
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• 1995

In a permanent magnet motor, cogging torque arises from the intersection of the rotor magnets with the steel teeth on the stator. This paper describes design measures which can be taken to reduce the cogging torque. In this paper for the optimal shape design of brushless DC motor, evolution strategy is investigated to find the dimension of stator of BLDC motor that minimizes the cogging torque. The corresponding field analysis is performed by two-dimensional finite element method.

• Proceedings of the KIPE Conference
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• 2016.11a
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• pp.49-50
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• 2016

본 논문에서는 BLDC 모터의 홀 센서의 정렬 오차를 검출하고 보상하는 기법을 제안한다. 합성된 홀 센서 신호를 이용하여 고조파 분석을 수행하여 기본파 성분의 크기를 획득한다. 오차가 없는 경우의 기본파 성분의 크기와 비교하여 정렬 오차각을 검출하고 보상한다.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.60 no.2
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• pp.68-71
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• 2011

In the case of Seoul Metro, prior to installation of platform screen doors, had seen 4~6 cases a month of mortal injuries from accidents on the platforms, including suicide attempts towards the oncoming train. However, since the installation of platform screen doors, Seoul Metro has achieved a feat of '0 mortal injuries'. In the initial stages of introducing platform screen doors domestically, due to a lack of experience in controlling platform screen doors, the products were imported and installed through technical cooperations from Japan, France and the United States. Thereafter, following investments in technologies by domestic firms, domestic production of parts such as overall control mechanism, specific control mechanism, RF devices and others were achieved. However, having installed platform screen doors in a relatively short period of time, DCU(Door Control Unit), an integral part of the whole platform screen door system, is yet to be fully domestically produced. At this moment in time, installation is being done with imported products or DCUs developed with DC motors. In this research, advantages and disadvantages of DC and BLDC motors for use in DCU will be analyzed and will produce an own BLDC controlling unit in order to solve any problems arised. Furthermore, the BLDC controlling unit produced will be integrated with DCU to improve the performance of the product and its price competitiveness.

• Journal of Power Electronics
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• v.19 no.3
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• pp.761-770
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• 2019

This paper proposes a hybrid phase windings excitation method for improving the efficiency of a 7-phase brushless DC (BLDC) motor in the electric propulsion system of a ship. The electrical losses of a BLDC motor system depend on the operating region and the number of excited phase windings (2-phase, 4-phase or general 6-phase windings). In this paper the operating region and torque/speed characteristics according to the motor rotation speed and propeller load are analyzed for a number of excitation methods. In addition, it analyzes the electrical losses of the system under each of the excitation methods in the entire operating region of the motor. In every sampling time, the proposed control method calculates the electrical loss of the system for each of the excitation methods and operates a 7-phase BLDC motor by selecting the excitation method that results a decreased electrical loss at the operating speed. The usefulness of the proposed control algorithm is verified through experimental results.