• The Transactions of the Korean Institute of Power Electronics
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• v.11 no.5
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• pp.440-446
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• 2006

The magnitude of output torque in a BLDC Motor depends on torque angle so that the exact initial position of rotor is essentially required for good starting. This paper presents a novel starting control method for smooth starting in a position-sensorless controlled BLDC motor drive for reciprocating compressor of refrigerator. The proposed method starts a BLDC motor using information on the initial position of rotor, determined from current response characteristics, and shows robust starting capability to starting load variations. The effectiveness of the proposed method is verified through experimental results.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.4
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• pp.495-501
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• 2013

In the present study, a BLDC motor for a pump in which a neodymium PM is replaced with a Ferrite PM has been developed in preparation for the cost increase and to ensure the stability of the resource supply. One of the currently used motors for pumps is a BLDC motor having an interior PM wherein a rare-earth PM is adopted. However, a BLDC motor for a pump is designed to have large airgap because of the use of a waterproof insulator according to its structural characteristics, and therefore, a SPM structure is suitable. Hence, an SPM BLDC motor in which a Ferrite PM is used is designed. Nevertheless, the use of Ferrite instead of rare-earth materials causes a deterioration in the performance of the electric motor, such as a decrease in the BEMF and the maximum power of the motor and the irreversible demagnetization of the PM. In order to mitigate such disadvantages, an optimized design of the BLDC motor is developed by changing each design parameter and by improving the electromagnetism structure.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.4
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• pp.757-764
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• 2018

This paper describes the design and implementation of a 1hp class two-phase type BLDC fan motor used in an air conditioning system. The BLDC motor, which is implemented in this study, is not a commutator motor type with excellent lifetime and durability and is driven by two phase power source. The most important target specification of a motor used in an air conditioning system is that it has a high efficiency at the rated operating point. For this purpose, we designed the stator shape of the BLDC motor, the design of the rotor magnet, and the control circuit for driving. The BLDC motor has a structure where the motor part, the control part, and the power part are integrated. The finite element analysis was used to calculate the characteristics of the BLDC motors, and the conformity of the design results was confirmed by fabricating and testing the prototype model.

• Proceedings of the KIPE Conference
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• 1997.07a
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• pp.79-83
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• 1997

The inverter fed BLDC(Brushless DC) motor has been increasingly applied to industry and home appliances due to the advance of power electronics and permanent magnet technology, and its high efficiency and good acoustic noise characteristics. The BLDC motor and drives, however, require the rotor position sensors that may cause some problems such as the high cost and space. In this paper, sensorless algorithm for an interior permanent magnet BLDC motor is proposed. The maximum torque per ampere operation with advance angle considering load torque and speed was simulated and verified through the experiment.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11a
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• pp.512-516
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• 2001

It is recent trend that the manufactures of refrigerator use BLDC motor which RPM is changed by voltage of DC power, instead of induction motor in order to reduce energy consumption and noise radiation. It can be controlled two or more RPM suitable to environmental condition. For example it is operate much lower RPM than normal(usual) in the night. This paper introduce the method of noise control in the case of using BLDC Fan motor for refrigerator.

• Journal of the Korea Safety Management & Science
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• v.17 no.4
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• pp.403-410
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• 2015

This study documents the 3-phase BLDC(Brushless DC) motor to improve conventional exhaust fan motor. Energy efficiency, noise, and air pollution reduction for the high-performance vibration of the BLDC motor has been used in many fields. It is necessary to achieve the information of rotor position for driving 3-phase type brushless DC motor. It is also necessary that the PWM control algorithm design for a MOSFET driver to control the motor speed control for each of three phases. BLDC motors for exhaust fan, we studied the controller and software. The control circuit and motor control program through which Exhaust fan up close and person can be used safely and protect the environment.

• Proceedings of the KIEE Conference
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• 2001.10a
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• pp.104-106
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• 2001

In this paper, it is object of design of high efficiency slotless BLDC motor using film coil. Slotless BLDC motor is able to have high efficiency property and low cogging torque, due to magnetization of stator core have constant contribution by slotless core. But it is difficult to make coil winding of slotless BLDC motor. So we make amateur of slotless BLDC motor using film coil. Film coil is fabricated by drilling, electro-plating and etching of copper/insulator/copper plate. In this paper, after design of slotless BLDC motor for moving axial blower, it is fabricated by NdFeB permanent magnet type rotor and film coil.

• Journal of Applied Reliability
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• v.15 no.4
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• pp.241-247
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• 2015

Purpose : The demand for higher fuel economy vehicles has helped develop fuel-efficient vehicles such as a CVVL called continuous variable valve lift. Existing CVVL has been applying DC type motor to control intake valve, but recently some car parts manufacturers have been developing a BLDC type CVVL motor for improvements of endurance performance. The purpose of this study is to find the potential failure mechanism of the CVVL BLDC moto in early stage of development based on the design properties and design the accelerated life test model. Methods : CVVL BLDC is consist of brushs, coil, magnetic, PCB, bearing and so on. Each component has a latent failure mechanism caused by temperature, humidity, vibration. By analysis result of the failure mechanism, thermal fatigue is the most important factor of a durability of CVVL BLDC motor. So, we designed a new accelerated life test model for guarantee of the CVVL BLDC motor. Results : A crack occurred on via hole in test using the conditions we designed, so we did change the design to avoid this failure. The via hole dimension is changed a little larger, as a result we achieve improvements in reliability of the CVVL BLDC motor. By applying various kinds and extreme level of stresses, we can find the operating limits of products. Conclusion : In thesis, We analyzed the failure mechanism of CVVL BLDC and designed an accelerated life test method to give a guarantee for reliability. Based on the test results, we could improve the reliability of developments by change of design.

• 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.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.22-25
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• 1999

A brushless DC motor has the high quality of torque output and silence, has been more widely used in industrial area. As the driver and controller of BLDC motor have been more complicated and precise, simulation method has been much used in motor design. And the output characteristics of BLDC motor is determined by the waveform of BACK-KMF in instinct. But because the conventional model of BLDC motor is obtained by approximation of real nonlinear waveform to ideal trapezoidal waveform, the error is occurred in simulation result. Thus in this paper, for the correction of this error in simulation, the model of real nonlinear waveform considered is proposed, and the simulation result is obtained in case of three-phase, four-poles Y-connected, surface mounted permanent magnet BLDC motor.