• 한국산학기술학회논문지
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• 제15권10호
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• pp.6270-6275
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• 2014

본 논문에서는 전기자동차용 견인전동기로서의 다극 매입형 영구자석 동기전동기의 회전자 돌극 설계에 의한 토크리플 개선 방안을 연구하였다. 다극 매입형 영구자석 동기전동기의 경우 영구자석에서 발생되는 자속이 고정자에 쇄교되지 않고 회전자 브릿지를 통해 누설되는 자속이 크다. 이러한 누설자속을 줄여 출력밀도를 향상시키고 토크리플을 저감하기 위해 영구자석 사이의 회전자 표면에 슬릿을 적용하였다. 슬릿에 적용되는 두 설계 파라미터를 제안하고 반응표면법을 이용하여 토크리플 감소와 출력 향상 최대화 설계를 수행하였다. 자속의 포화를 고려하기 위해 본 논문에서는 2차원 유한요소법을 이용하여 특성해석을 수행하고 이를 분석하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 하계학술대회 논문집 B
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• pp.977-980
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• 1993

The technique to design high performance small motors has been based on experimental data, which results from lots of cost, experience and time in manufacturing. Recently, as high-performance computer appears, many engineers use numerical methods to design and analyze electric machine. Since, the step motor which has very small air gap(0.02-0.05mm) is different from other electric machine in its structure. The shape of rotor teeth and stator teeth influence seriously on the torque characteristics. And it is operated over magnetic saturation point. Therefore, the design of step motor needs to solve nonlinear problem and to calculate magnetic field precisely. In this paper, we solve nonlinear problem by employing Finite Element Method and obtain torque-displacement characteristics for the design of step motor. We also manufacture VR step motor according to the obtained results, and measure some torque characteristics. Through comparing calculated results with experimental results, it is verified that FEM is very useful to design step motor, and the motor designed by our technique is improved in its step accuracy.

• 한국자기학회지
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• 제5권5호
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• pp.900-904
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• 1995

돌림힘 자력계를 이용하여 일축 이방성 자성체의 M-H 이력 곡선을 측정하는 새방법을 개발하였다. 본 방법에 의한 M-H 이력 곡선으로부터 포화 및 잔류 자기화량과 보자력을 얻을 수 있었다. 본 방법의 정확도는 자기회사 비균질한 보자력 근처의 인가 자기 마당에서도 영향받지 않았다. $2{\times}10^{-3}$ dyn cm의 측정 감도를 갖는 돌림힘 자력계를 이용한 자기화량 측정에서 $10^{-6}$ emu 이상의 고감도를 얻었다.

• Journal of Power Electronics
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• 제13권3호
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• pp.369-380
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• 2013

Direct torque control based on space vector modulation (SVM-DTC) protects the DTC transient merits. Furthermore, it creates better quality steady-state performance in a wide speed range. The modified method of DTC using SVM improves the electrical magnitudes of asynchronous machines, such as minimizing the stator current distortions, the stator flux with electromagnetic torque without ripple, the fast response of the rotor speed, and the constant switching frequency. In this paper, the proposed method is based on two new control strategies for direct torque control with space vector modulation. First, fuzzy logic control is used instead of the PI torque and a PI flux controller to minimizing the torque error and to achieve a constant switching frequency. The voltages in the direct and quadratic reference frame ($V_d$, $V_q$) are achieved by fuzzy logic control. In this scheme, the switching capability of the inverter is fully utilized, which improves the system performance. Second, the close loop of stator flux estimation based on the voltage model and a low pass filter is used to counteract the drawbacks in the open loop of the stator flux such as the problems saturation and dc drift. The response of this new control strategy is compared with DTC-SVM. The experimental and simulation results demonstrate that the proposed control topology outperforms the conventional DTC-SVM in terms of system robustness and eliminating the bad outcome of dc-offset.

• 전력전자학회논문지
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• 제7권5호
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• pp.427-436
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• 2002

본 논문은 직접토크제어(Direct torque control, DTC)를 사용한 릴럭턴스 동기전동기(Reluctance synchronous motor, RSM)의 위치센서 없는 모션제어 시스템을 제안한다. 고성능 효율제어를 수행하는데 있어서 DTC를 이용한 릴럭턴스 전동기 드라이브는 고정자 쇄교자속의 포화와 부하전류에 따라 비선형적으로 변하는 인덕턴스로 인해 여러 가지 문제점들이 발생한다. 이러한 이유로 본 논문에서는 정확한 고정자 쇄교자속과 토크를 계산하기 위해서 자속관측기의 $L_d\;와\; L_q$값을 회전자 위치와 고정자 전류에 대해 보상하였으며, 빠른 토크 응답특성과 최적 효율특성을 얻기 위해서 기준자속을 부하에 따라 계산하였다. 제안된 알고리즘의 정당성을 확인하기 위해서 1.0[kW] 릴럭턴스 동기 전동기를 사용하여 $\pm$20[rpm]과 $\pm$1500[rpm]에서 실험을 수행하였고, 실험을 수행한 결과 저속영역과 고속영역 모두 우수한 동특성과 향상된 효율을 얻을 수 있었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.869_870
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• 2009

This paper presents optimal design of tooth and yoke width for increasing torque density when designing concentrated winding Interior Permanent Magnet Synchronous Motor(IPMSM) which is used currently. In case of IPM, characteristic of motor chages according to saturation, thus design consib dering saturation should be done. This paper proposed method to decide tooth and yoke width using magnetic equivalent circuit with calculated magnetic resistance. This method provide less effort and time than FEM using optimal design when deciding tooth and yoke width. Proposed method and FEM are compared and verified.

• 조명전기설비학회논문지
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• 제26권8호
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• pp.65-70
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• 2012

Induction motor is the most widely used to obtain the driving force in the industrial site. Induction motor generates a high current at startup. Most of starting currents are often more than five times of rated current. This high starting current can cause problems such as the voltage drop in the system. In order to solve these problems, if the motor capacity is large, generally we use reactor starting method rather than direct on line starting method. When a high startup current passes through reactor, reactor can serve as a nonlinear elements. In this study, we analyzed that the current, torque and power of the induction motor are different from the change of linear and nonlinear components of the reactor magnetic field.

• 대한전기학회논문지:시스템및제어부문D
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• 제53권10호
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• pp.697-702
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• 2004

In this paper, we proposed that the problem of controlling induction motor with magnetic saturation, is studied from an input-output feedback linearization with adaptive algorithm. is considered. An adaptive input-output feedback linearizing controller is considered under the assumption of known motor parameters and unknown load torque. In order to achieve the speed regulation with the consideration of improving power efficiency, rotor angular speed and flux amplitude tracking objectives are formulated. Simulation results are provided for illustration.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 합동 추계학술대회 논문집 정보 및 제어부문
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• pp.325-328
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• 2002

In this paper, we proposed that the problem of controlling induction motor with magnetic saturation is studied from an input-output feedback linearization with adaptive algorithm. The $\pi$-model of induction motor is considered. An adaptive input-output feedback linearizing controller is considered under the assumption of known motor parameters and unknown load torque. Simulation results are provided for illustration.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 학술대회 논문집 전문대학교육위원
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• pp.108-112
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• 2001

Vector control schemes are used in inverter-fed induction motor drives to obtain high performance. Crucial to the success of the vector control scheme is the knowledge of the instantaneous position of the rotor flux. However, the position of the rotor flux change with temperature and magnetic saturation of the motor. This variation cause deterioration of both steady state and dynamic operation of the motor drives. Performance degradation is in the form of input-output torque nonlinearity and saturation of the motor. Analytic expressions are derived to evaluate the effects due to parameter sensitivity.