• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 A
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• pp.3-5
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• 1998

This paper presents a speed control method for the capacitor run single-phase induction motor. The equivalent circuit of a capacitor motor is analyzed using the forward and the backward components, and simple circuit equations are obtained. Simulations for the speed control are performed by adjusting the voltage magnitude of the auxiliary winding.

• 한국정보통신학회논문지
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• 제7권6호
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• pp.1291-1296
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• 2003

본 연구는 3상 소형 유도전동기의 고정자 권선 고장의 효과적인 진단을 위하여 고정자 전류에 대하여 Park's Vector 기법을 적용하였다. 본 기법은 고정자 3상 전류를 측정하여 Park's vector 변환을 통하여 직축, 횡축 전류로 변환하고, 이를 이용하여 고장 진단을 위한 Park's Vector Pattern을 얻어 정상 상태 패턴과 고장 권선 패턴을 비교하였다. 고정자 권선 한 상에 2턴, 10턴, 그리고 20 턴의 단락고장을 발생시켜 정격부하의 25%, 50%, 100% 부하변동에 따른 각각의 Park's Vector Pattern을 비교하여 얻은 실험 결과는 제안한 방법의 유용성을 보여준다.

• 전기의세계
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• 제18권5호
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• pp.20-25
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• 1969

The development of the frequency convertors using semiconductors devices makes it possible to control the speed of A.C. motors easily. It is now economically feasible to provide them with power at adjustable frequency using silicon-controlled rectifier (or thyristor) inverters. In such a case, in order to operate an induction motor efficiently over a wide speed range, it must be supplied from a variable frequency source of which frequency is adjustable over the speed range of the motor. It is desired to observe the changes in characteristics as primary current, torque-speed of induction motor etc. at any optional frequency. Although the characteristics can be obtained by means of the conventional methods, they require very complicated precedures of calculations. The Current Diagram Method in this paper suggests a new approach to simpler calculations of the characteristics, using the motor constants at reference frequency. The conclusions of this study are summarized as follows: 1) The equations of stator current at adjusted frequency were derived to construct graphical chart and the current circle required for the Current Diagram Method. 2) The radius, center of the current circle and the vector locus, the basis for calculating the characteristics, at any desired frequency could be easily determined with the aid of both the derived graphical chart and current circle at reference frequency. 3) The method was shown to be applicable to the various types of 3-phase induction motors and also dealt with its application to the split-phase, condenser motors.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 B
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• pp.531-533
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• 1998

This paper proposes the method that estimate optimally the parameters of Fuzzy-PID controller using genetic Algorithm. The controller is desined with the proposed method, and then is applied to 3-phase induction motor. Simulation results show that proposed method is more excellent then FPID and PID.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 B
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• pp.502-504
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• 1998

This paper proposes the method that estimate optimally the parameters of Fuzzy-PID controller using genetic Algorithm. The controller is designed with the proposed method, and then is applied to 3-phase induction motor. Simulation results show that proposed method is more excellent then FPID and PID.

• Journal of Electrical Engineering and Technology
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• 제12권3호
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• pp.1090-1100
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• 2017

This paper presents the comparison of starting current characteristics of a three-phase induction motor fed by two types of soft starters. The first soft starter under investigation is a conventional AC voltage controller on the basis of a phase-control technique. The other is the proposed asynchronous PWM AC chopper which is developed from the conventional synchronous PWM AC chopper. In this paper, the proposed asynchronous PWM AC chopper control scheme is developed by generating only two asynchronous PWM signals for a three-phase main power circuit (6 switching devices) from a single voltage control signal which is compared with a single sawtooth carrier signal. By this approach, the PWM signals are independent and easy to implement since the PWM signals do not need to be synchronized with a three-phase voltage source. Details of both soft starters are discussed. The experimental and simulation results of the starting currents are shown. It is found that the asynchronous PWM AC chopper efficiently works as a suitable soft starter for the three-phase induction motor due to that the starting currents are reduced and are sinusoidal with less harmonic contents, when being compared with the starting current waveforms using the conventional phase-control starting technique. Also the proposed soft starter offers low starting electromagnetic torque pulsation.

• 한국산학기술학회논문지
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• 제15권3호
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• pp.1685-1690
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• 2014

본 논문에서는 유도전동기 벡터제어 인버터에서 상전류를 검출할 때 발생하는 측정 오차를 실시간으로 보상하는 방법을 제안한다. 전류측정에 오프셋 오차와 변환이득 오차가 포함될 경우의 3상 유도전동기 토크 방정식을 유도하여 이러한 측정 오차들이 전동기의 토크 리플을 유발하는 것을 보였으며, 이러한 토크 리플을 제거할 수 있는 방법을 제시하였다. 특히, 본 논문에서는 전동기의 운전 상태에서 실시간으로 변환이득 오차에 의한 토크 리플을 제거하는 방법을 제안하였다. 이를 200[W]급 3상 유도전동기의 벡터제어 인버터에 적용하여 컴퓨터 시뮬레이션 및 실험을 수행함으로써 제안된 방법의 유효성을 검증하였으며, 그 결과 전류측정에서 변환이득 오차가 있더라도 전동기의 토크가 상당히 제거되는 것을 확인하였다.

• 전기의세계
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• 제19권3호
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• pp.1-9
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• 1970

In this paper, the equation for the generated force is introduced, on the basis of Maxwell's electromagnetic equation, by dividing the air-gap magnetic field into the region of the constant amplitude and the region of the pulsating field in the both ends of iron core, in the case that the typical 3 phase winding is employed in the double sided 3 phase linear induction motor with sheet rotor in accrodance with the winding method of rotary induction machine. With the effect of the overhang region being taken into account, the result, in which the equation is established, inducates that theoretical values nearly coincides with the measured values in the interval of slip s=0-0.8.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1989년도 추계학술대회 논문집 학회본부
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• pp.273-277
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• 1989

This paper concerns to drive Induction Motor with open delta winding, and improve general performance, speed response, operation region and flexibility of control, etc. And a control algorithm, which reduces large zero-phase current at this operation, is presented.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2008년도 하계학술대회 논문집
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• pp.216-218
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• 2008

This paper presents a space vector pulse width modulation (SVPWM) technique for four-switch three-phase (4S3P) inverter topology. The method aims to apply Field Oriented Control (FOC) of Induction motor using 4S3P. The simulations are carried out and the experimental results are given to verify the feasibility of this method.