• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.629-630
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• 2006

This paper describes a novel sensorless excitation position detecting method of Switched Reluctance Motor(SRM) drive. A suitable excitation pattern of each phases is determined by comparison of detecting current without an inductance estimation. The principle of the rotor position estimation is based on the detection of phase current according to rotor position. This sensorless method is very simple and gives efficient control of drive system. The suggested method is verified by experiments.

• Proceedings of the KIEE Conference
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• 2003.04a
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• pp.91-93
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• 2003

Disk type Single Phase SRM(Switched Reluctance Motor) can be used axial direction magnetic flux and radial direction magnetic flux. In this paper, the flux linkage was measured according as rotor positions of disk-tyre single phase SRM, which is designed and manufactured in previous research. From the measured data, we got the magnetization curves, inductance profile and Co-energy.

• Proceedings of the KIEE Conference
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• 1997.07a
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• pp.297-299
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• 1997

The switched reluctance motor is an electric machine in which torque is produced by the tendency of its movable part to move to a position where the inductance of the excited winding is maxmized. It is as well as PM brushless do systems. It's many advantages-a wide speed range, and inherently simplicity and ruggedness, low manufacturing cost, make it a vigorous challenger to these drives. It is a fascinating machine with all kinds of interesting application possibilities. In this paper, the design and evaluate the performance is treated.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.3
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• pp.66-73
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• 2008

This paper presents a position sensorless control system of SRM over wide speed range. Due to the doubly salient structure of the SRM, the phase inductance varies along with the rotor position. Most of the sensorless control techniques are based on the fact that the magnetic status of the SRM is a function of the angular rotor position. The rotor position estimation of the SRM is somewhat difficult because of its highly nonlinear magnetizing characteristics. In order to estimate more accurate rotor position over wide speed range, Neural Network is used for this highly nonlinear function approximation. Magnetizing data patterns of the prototype 1-hp SRM are obtained from locked rotor test, and used for the Neural Network training data set. Through measurement of the flux-linkage and phase currents, rotor position is able to estimate from current-flux-rotor position lookup table which is constructed from trained Neural Network. Experimental results for a 1-hp SRM over 16:1 speed range are presented for the verification of the proposed sensorless control algorithm.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.8
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• pp.1217-1223
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• 2015

In this paper, we study the problem of torque ripple minimization in Brushless DC Motors (BLDC) and proposes a disturbance observer (DOB) based controller in order to efficiently reduce the torque ripple. In the DOB based control system, an equivalent disturbance (plant disturbance and effect of modelling error) is cancelled by its estimate. When the DOB controller is applied to BLDC motors, the effect of inverter switching is considered as an equivalent disturbance and to be cancelled by the DOB controller. Through computer simulations, it is shown that the performance of the proposed DOB controller is superior to that of the conventional PI controller. In the case where the numerical values of resistance and inductance are not known exactly, it is shown that the proposed DOB controller achieves better performance than the PI controller.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.840-842
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• 2000

DC모터의 T-N(토크-회전수)특성이 선형성을 갖는다는 사실은 널리 알려져 있다. 더욱이 인덕턴스가 작은 소형 모터의 경우에는 T-N특성이 거의 직선에 가깝게 된다. 그러나 대형모터일수록 인덕턴스가 커지므로 이 인덕턴스의 영향으로 T-N특성은 비선형의 곡선으로 변하게 된다. 이렇게 되면 모터의 출력은 직선으로 예측하였을 때 보다 실제적으로 작은 출력이 발생하게 된다. 따라서 일반적으로 DC모터를 설계할 때 T-N특성의 비선형화로 인한 출력의 감소현상을 고려하여 임의의 여유를 주고 설계하여 왔다. 그러나 효율적인 모터설계를 위하여서는 임의의 여유가 아닌, 이론적 계산에 의한 정확한 T-N특성의 곡선을 필요로 하게 된다. 하지만 아직까지 이를 위한 용이한 계산법은 마련되어 있지 않다. 따라서 본 논문에서는 matlab을 이용하여 DC모터의 비선형 T-N곡선의 계산법을 도출하여 그 방법을 제시하고자 한다.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.48 no.10
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• pp.530-536
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• 1999

This paper investigates effects of segmented poles on exciting forces such as cogging torque, BEMF, phase current, torque ripple and local forces. Cogging torque, BEMF and local force are determined by FEM analysis and phase current is calculated using voltage equations after determining BEMF and phase inductance. Effective dead zones at pole separations result in wider than the physical dead zones due to leakage field during magnetization. Due to the existence of dead zones, there exist additional exciting harmonics of the cogging torque which play adverse effect on vibration and noise performance. The magnitude of BEMF is decreased and the waveforms are also distorted depending on dead zone positions. Segmented poles inevitably cause uneven magnetic field distribution at pole separations which introduces additional harmonics of exciting forces which are detrimental to structural to structural resonances. They also decrease motor efficiency by reducing effective phase BEMF.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.7
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• pp.1047-1052
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• 2017

In this paper, the calculation torque using the d-q axis has advantage like faster execution time. However, the torque ripple can't be considered in the torque calculation using d-q axis equivalent circuit because the time-dependent component is removed. When d-q transformation was performed, it was founded that some parameters has some characteristics. These characteristics were considered for representing torque ripple. The calculation with d-q axis transformation and Finite Element Analysis(FEA) were performed, and the results were compared. As a result, it was validated that the calculated torque can be expressed with ripple.

• Proceedings of the KIEE Conference
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• summer
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• pp.977-979
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• 2004

전기기기가 빠르게 발전함에 따라 전기기기의 핵심부분인 전동기의 활용도가 매우 넓어지고 있다. 따라서 전동기의 효율향상은 전기기기의 정확한 작동 및 비용절약에 있어 중요한 부분이 되고 있다. 따라서 전동기에서 발생하는 손실의 정확한 원인과 해결방법을 제시하여야 한다. 이에 지금까지의 연구들은 대부분 제어회로를 이용한 고주파성분 제거나 자기손실이 적은 재질개발에 의존하고 있다. 그러나 이들 방법들은 기존의 기동제어회로에 새로운 소자나 제어회로를 부착하거나 고가의 소재를 사용하여야 하는 단점이 있다. 이에 본 연구에서는 정자계 유한요소법과 손실곡선을 이용한 단상유도전동기 코어의 손실해석 및 손실저감을 위한 설계기법을 제시하였다.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.1
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• pp.21-26
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• 2006

This paper deals with the dynamic analysis and experiments of moving-magnet linear actuator with/without spring. On the basis of two dimensional (2-D) analytical solutions and experiments, control parameters such as thrust constant, back-emf constant, inductance and resistance are obtained. And then, dynamic simulation algorithm is established from the voltage and motion equation. Finally, for various values of frequency, dynamic simulation results for characteristics of current and displacement of moving-magnet linear actuator with and without spring are presented and confirmed through the experiments. In particular, This paper applies the PWM voltage waveform obtained from a DSP for bidirectional voltage drive to the actuator.