• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.1813-1814
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• 2006

BLDC 전동기는 AC서보 일종으로 스위칭 소자를 이용한 인버터 회로를 통해 정류하므로 정류 시 회전자의 위치 정보를 회전자에 홀 센서나 레졸버와 같은 위치 센서를 부착하여 위치 정보를 얻는다. 위치 센서는 전동기 가격 및 크기를 증가시키고 구조를 복잡하게 만들기에 위치 검출 센서 없이 구동하는 센서리스 구동 방법이 최근 많이 연구되고 있다. 센서리스 구동 방법에 가장 많이 쓰는 방법이 역기전력을 이용하는 것이다. 역기전력을 이용하는 경우 전동기가 고속으로 회전 시 비교적 잘 적용되지만 정지 상태에 있거나 저속에서 운전 시, 역기전력이 충분히 크지 않을 경우 적용이 어려운 단점이 있다. 본 논문에서는 BLDC 전동기의 3상 중 2상의 단자전압을 이용하여 센서리스 구동 방법을 제안한다. 정지 상태에서의 회전자 위치 파악은 DC링크 단에 전류 센서를 사용하여 초기 위치를 파악하고 한상의 단자전압을 검출하여 각 상의 여자 시점을 결정하여 초기 구동함으로써 기존의 다른 센서리스 회로의 간략화와 효율적이고 구현이 간단하며 무엇보다 가격전인 측면에서 여타의 방법에 비해 유리하다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.869-873
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• 2008

Optimization method for the open loop commutation time intervals in HDD spindle start-up control is presented in this paper. A hard disk drive(HDD) uses a sensorless brushless DC motor(BLDC) for the platter rotation. Because there is no direct sensor for the rotor position, open loop commutations after sensing the rotor position at a standstill using inductive sensing method are performed to speed up the rotor up to a certain speed where the zero crossings of the back electromotive force(EMF) are measurable. Therefore successful open loop commutations are necessary for the stable start-up control of the spindle motors. Random neighborhood search(RNS) algorithm is introduced as a optimization technic in this paper. Rotor speed and its standard deviation are used as a cost function and commutation intervals obtained from the spindle motion equation are used as initial parameter values for the RNS. With the help of the proposed method optimized open loop commutation time intervals for the very low start-up current are acquired and tested. The experimental results shows that the proposed method can decrease the start-up failure rate of a HDD spindle motor.

• 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.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.9
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• pp.1-7
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• 2014

Brushless Direct Current(BLDC) Motor is essential to measure a rotor position because of that this motor type needs to synchronize the rotor's position and changeover phase current instead of a brush and commutator used on the existing dc motor. Recently, many researches have studied on sensorless control drive for BLDC motor. The conventional control methods are a compensation value dq, Kalman filter, Fuzzy logic, Neurons neural network, and the like. These methods has difficulties of detecting BEMF accurately at low speed because of low BEMF voltage and switching noise. And also, the operation is long and complex. So, it is required a high-performance microprocessor. Therefore, it is not suitable for a small BLDC motor sensorless drive. This paper presents control methods suitable for economic small BLDC motor sensorless drive which are an improved design of the BEMF detection circuit, simplifying a complex algorithm and computation time reduction. The improved motor sensorless drive is verified stability and validity through being designed, manufactured and analyzed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.5
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• pp.620-625
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• 2013

This paper presents the design of a switched reluctance motor (SRM) for electric air conditioning compressors which are applied to hybrid electric vehicles (EVs). The motor for driving air conditioning compressor which is recently used on EV(electric vehicle) / HEV (hybrid electric vehicle) is PMSM(permanent magnet synchronous motor) or BLDCM(brushless DC motor). However disadvantage of motors that uses permanent magnets are vulnerable to high temperatures because of the demagnetization by the high temperature and the permanent magnet is expensive because of the high price of rare earth materials from China's monopoly. Therefore, in the automotive insustry is interested in the non-rare-earth motors. SRM has many advantages. it's resistant to high temperatures, price is cheaper, because there are no permanent magnets and winding in the rotor. Also it's high relability and efficiency, suitable for high-speed operation because of structure is simple. In this paper, the SRM, non-rare-earth motor, are designed, analyzed and experimented drive to replace an existing electric compressor drive motor.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.6
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• pp.89-95
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• 2009

A new class of electronically commutated brushless motor, the flux-switching motor(FSM) is gradually emerging in power tools and household appliances especially fan and pump application because of green policy. This motor offers advantages of high-power density and relatively high efficiency compare with induction motor, low cost and simple motor structure compare with bldc motor. This paper presents the principle of the FSM and design of the 12/6 pole FSM drive system for fan application. Finally, test results of the prototype motor are provided to verify a validity of the fan application with TMS320F2812 DSP and inverter.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.9 no.4
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• pp.62-70
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• 1995

Brushless DC Motor (BDCM) is widely used in the industry such as a variable speed motor in a compressor for room air conditioners, because the motor can be easily controlled and operated over a wide speed range. The system to drive BDCM needs encoder that senses rotor position. Gut in a certain application, the position sensor has to be avoided. In the paper, various position sensorless drive systems for BDCM are investigated and critically evaluated, so that the effective method of sensorless control can be selected. Out of these methods, the freewheeling diode current sensing has many advantages. For example, the simple starting procedure makes it possible to perform sensorless control even in low speed. So the hardware design for this method has been carried out and the system has been implemented using DSP. The experimental results verified that the freewheeling diode current sensing approach has advantages in starting procedure and low speed sensing.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.4
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• pp.108-115
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• 2015

This paper proposed a optimal current control method to improve efficiency of BLDC motors. The aim of the proposed method is to use the maximum torque operating method by increasing the effective voltage at the maximum torque point unlike existing SPM operating method. The proposed method is based on existing IPM maximum torque operating method grafting onto a square wave operating of SPM motors. As the method of increasing the effective output voltage from inverter using the maximum torque point, the proposed method is to improve efficiency of BLDC motors using the same amount of the existing current effectively. For this method, the maximum torque point is carried out by FEA and analysis of magnetic flux vector. In this paper, the prototype of general-purpose BLDC drive is manufactured and the performance characteristic and validity are verified.

• Proceedings of the KIPE Conference
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• 1997.07a
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• pp.97-100
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• 1997

A new control method for the robust position control of a brushless DC(BLDC) motor using the asymptotically stable adaptive load torque observer is presented. A precision position control is obtained for the BLDC motor system approximately linearized using the field-orientation method. And the application of the load torque observer is published in [1] using fixed gain. However, the flux linkage is not exactly known for a load torque observer. Therefore, a model reference adaptive observer is considered to overcome the problem of the unknown parameter in this paper. And stability analysis is carried out using Liapunov stability theorem. As a result, asymptotically stable observer gain can be obtained without affecting the overall system response. The load disturbance detected by the asymptotically stable adaptive observer is compensated by feedforwarding the equivalent current having the fast response.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.1406-1409
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• 2004

The Resolver usually used in industry is the absolute angle analog sensor that must be in order to driving BLDC (brushless DC) motor, and it needs RDC(Resolver-to-Digital converter) for changing the output signal to digital to be applied to the SVPWM(Space Vector Pulse Width Modulation) algorithm. Commonly used S/W RDC needs trigonometric function. What it takes a lot of calculation time of processor is gotten at weak point. In this paper, S/W RDC is realized except trigonometric functions as a result of feedback resolver outputs after filtering using FIR filter. thus, processing time is reduced. So, One-chip DSP Controller operating the Vector Control, RDC, and SVPWM can be designed.