• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.99-101
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• 2005

This paper deals with drive characteristics of LSRM according to position detection angle. Position of LSRM detected approximation sensor. Position choose mover of LSRM and inductance. When approved current in each phase by decided position, we made sure current and voltage according to turn-on, turn-off.

• 전기학회논문지
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• 제59권2호
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• pp.471-475
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• 2010

This paper presents a frequency synthesizer using low voltage active inductor VCO(Voltage Controlled Oscillator). The low voltage active inductor VCO with feedback resistor increases its equivalent inductance and the quality-factor(Q). Under certain conditions, the low voltage active inductor with feedback resistor generates a negative resistance at the input. In this paper, the conditions for negative resistance are obtained by small signal analysis. The designed low voltage active inductor VCO covers a frequency band between 1059MHz and 1223MHz. The measured phase noise at 1.178GHz is -81.8dBc/Hz at 1MHz offset.

• 전기학회논문지
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• 제59권2호
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• pp.318-327
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• 2010

This paper deals with analysis on dynamic characteristic and circuit parameter of linear switched reluctance motor by electromagnetic analytical method. Above all, using space harmonic method, which is electromagnetic method, the air-gap flux density is analyzed in the both align and unaign positions, and the inductance profile, force characteristic and resistance per phase are calculated by means of the process. The validity of the analyzed results are demonstrated by the finite element method(FEM) and manufacture of the prototype machine. Second, the dynamic simulation is analyzed by the use of circuit parameters derived from analytical method, and the operating system of the prototype machine is manufactured to demonstrated the validity of simulation analysis. As a result, it is considered that the characteristic equation suggested in this paper will contribute to the design, analysis and application of LSRM.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 A
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• pp.176-178
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• 1999

The Synchronous Reluctance Motor(SynRM) was made and experimented. Salient type SynRM was manufactured by cutting two sides of the three phase squirrel case rotor. So this prototype motor has same stator and capability with the counterparts of the induction motor. The airgap flux density, inductance and torque characteristics was inspected by Finite Element Analysis (FEA). The static torque experiments was accomplished. The paper proposed the effect of rotor bar by comparing two models.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 A
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• pp.394-396
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• 1999

ADD has developed a special BLDCM(brushless d.c. motor) that has small size and high power density. The model of BLDCM is like that of advanced nation. Design, production and test carried out by ADD and HYOSUNG Corp.. We simulated back EMF of phase, inductance of line and eddy current loss of rotor after we tested the motor at 80 Kw. According to analysis we have established the performance of 100Kw power recently. There are the same results that we designed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 A
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• pp.91-93
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• 1998

In this paper 30 kVA superconducting generator's transient-state electromagnetic analysis by FEM is described. The transient-state analysis by moving air gap technique was performed to analyze its 3 phase sudden short circuit characteristics. External circuit components were connected to generator model with end-winding resistance and inductance.

• Journal of Korean Vacuum Science & Technology
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• 제2권1호
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• pp.43-48
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• 1998

The effect of mcirostructure on the electrical properties of yttria stabilized zirconia (YSZ) was analyzed by modeling layer arrangements and mixed phase structure. The YSZ thin films were deposited by RF magnetron sputtering using 30mol% YSZ and 8 mol% YSZ targets with yttrium pellets on porous alumina substrates. The structure, composition and electricla properties of the YSZ films were investigated as functions of sputtering conditons and layer arrangements by XRD, TEM, XPS and acimpedance spectroscopy. The results showed that the triple palyered YSZ films had highermicrohardness, lower compressive stress state and higher ionic conductivity by one order than single and double layered YSZ films. However, sputtered YSZ films have low conductivity compared to YSZ pellets or doctor bladed YSZ thin plates. These results were probably due to the influence of insulating alumina substrates, impractical for most stacking geometries and inductance induced by relatively long platinum, lead wire on YSZ conductivity.

• Journal of Electrical Engineering and Technology
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• 제9권4호
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• pp.1315-1323
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• 2014

Although the power density in Double Stator Switched Reluctance Motor (DSSRM) has been improved, the torque ripple is still very high. So, it is important to reduce the torque ripple for specific applications such as Electric Vehicles (EVs). In This paper, an effective rotor shaping optimization technique for torque ripple reduction of DSSRM is presented. This method leads to the lower torque pulsation without significant reduction in the average torque. The method is based on shape optimization of the rotor using Finite Element Method and Taguchi's optimization method for rotor reshaping for redistribution of the flux so that the phase inductance profile has smoother variation as the rotor poles move into alignment with excited stator poles. To check on new design robustness, mechanical analysis was used to evaluate structural conformity against local electromagnetic forces which cause vibration and deformation. The results show that this shape optimization technique has profound effect on the torque ripple reduction.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 B
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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.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 전력전자학술대회 논문집
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• pp.25-29
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• 2001

The BLDCM (Brushless DC Motor) characterized by linear torque to current, and speed to voltage has low acoustic noise, and fast dynamic response. Moreover, it has high power density with high proportion of torque to inertia in spite of small size drive. But, it produce torque ripple due to the motor inductance components in stator windings and back-EMF, when armature current is commutated. Therefore, it is difficult to apply the BLDCM to a precision servo drive system. In this paper is proposed to a new current control algorithm with using fourier series coefficients can minimize torque ripple due to the phase current commutation of BLDCM. Simulation and Experimental results prove the effectiveness the proposed algorithm through comparison with the conventional used unipolar PWM method.