• 전력전자학회:학술대회논문집
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• 전력전자학회 2019년도 추계학술대회
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• pp.96-97
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• 2019

Pulse Width Modulation (PWM) is a widely adopted technique to drive the motor using the voltage source inverters. Since they generate high frequency Common Mode (CM) Voltage, a high shaft voltage in induction motor is induced which leads to parasitic capacitive currents causing adverse effects such as premature deterioration of ball bearings and high levels of electromagnetic emissions. This paper presents an Active Cancellation Circuit (ACC) which can significantly reduce the CM voltage hence the common mode current in the three phase induction motor drives. In the proposed method the CM voltage is detected by the capacitors and applied to the frame of the motor to cancel the CM voltage hence the CM current. Unlike the conventional methods the proposed method does not insert the transformer in between the inverter and motor, a high power rating three phase transformer is not required and no losses associated with it. In addition the proposed method is applicable to any kind of PWM motor drives regardless of their PWM methods. The effectiveness of the proposed method is proved by the experiments with a three phase induction motor (1.1kW 415V/60Hz) combined with a three phase voltage source inverter modulated by the Space Vector Modulation (SVM).

• Journal of Power Electronics
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• 제11권3호
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• pp.294-303
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• 2011

In this paper an effective five-phase induction motor (IM) and its drive methods are proposed. Due to the additional degrees of freedom, the five-phase IM drive presents unique characteristics for enhancing the torque producing capability of the motor. Also the five-phase motor drives possess many other advantages when compared to traditional three-phase motor drives. Some of these advantages include, reducing the amplitude and increasing the frequency of the torque pulsation, reducing the amplitude of the current without increasing the voltage per phase and increasing the reliability. In order to maximize the torque per ampere, the proposed motor has concentrated winding, the produced back electromotive force (EMF) is almost trapezoidal, and the motor is supplied with the combined sinusoidal plus the third harmonic of the currents. For demonstrating the superior performance of the proposed five-phase IM, the motors are also analyzed on the synchronously rotating reference frame. To supply trapezoidal current waveform and to exclude the effect of the $3^{rd}$ harmonic current, a new control stratagem is proposed. The proposed control method is based on direct torque control (DTC) and rotor flux oriented control (RFOC) of the five-phase IM drives. It is able to reduce the acoustical noise, the torque, the flux, the current, and the speed pulsations during the steady state. The DTC transient merits are preserved, while a better quality steady-state performance is produced in the five phase motor drive for a wide speed range. Experimental results clearly demonstrated a more dynamic steady state performance with the proposed control system.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2004년도 전력전자학술대회 논문집(1)
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• pp.274-278
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• 2004

This paper presents a strategy to drive built in-type spindle induction motor which is used as CNC (Computer Numerical Control) in the industrial world. The direct vector control which is robust to the changed machine parameters in the high speed range is used in this motor control method. And electrical model of induction motor presents the basic idea based on observer structure, which is composed of voltage model and current model. But the former has the defects in low speed range, the latter has the defects of sensitivity to motor parameter. Thus Gopinath model flux estimator which is the closed loop flux observer based on two models for the rotor flut estimation is used in this paper. Moreover this paper presents to drive the spindle motor in the high speed range by using the flux weakening control.

• 전자공학회논문지SC
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• 제42권6호
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• pp.77-82
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• 2005

본 논문은 FNN과 ANN 제어기를 이용한 유도전동기의 속도 제어 및 추정을 제시한다. 먼저, PI 제어기에서 나타나는 문제점을 해결하기 위하여 퍼지제어와 신경회로망을 혼합 적용한 FN 제어기를 설계한다. 퍼지제어기의 강인성 제어와 신경회로망의 고도의 적응제어의 장점들을 접목한다. 다음은 ANN을 이용하여 유도전동기 드라이브의 속도 추정기법을 제시한다. 2층 구조를 가진 신경회로망에 BPA(Back Propagation Algorithm)를 적용하여 유도전동기 드라이브의 속도를 추정한다. 추정속도의 타당성을 입증하기 위하여 시스템을 구성하여 제어특성을 분석한다. 그리고 추정된 속도를 지령속도와 비교하여 전류제어와 공간벡터 PWM을 통하여 유도전동기의 속도를 제어한다. 본 연구에서 제시한 FNN과 ANN의 제어특성 및 추정성능을 분석하고 그 결과를 제시한다.

• 전자공학회논문지SC
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• 제40권1호
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• pp.45-54
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• 2003

종래의 터보기기는 회전자의 높은 회전속도를 얻기 위하여 증속기어를 사용하였으나 근래에는 초고속 전동기를 적용하여 기계적인 효율 및 시스템의 소형차에 관한 연구가 활발히 진행중이다. 본 논문은 직접구동방식의 터보 압축기를 위한 초고속 영구자석 동기전동기 구동시스템에 관한 논문으로서 150마력 70,000rpm 영구자석 동기전동기 구동시스템을 개발하여 상품에 적용하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(5)
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• pp.219-222
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• 2002

There are screw, reciprocating type turbo compressor by structure in an air compressor which is essential equipment on the industrial spot. Recently, the application range of a turbo compressor tend to be wide gradually. And this type of compressor needs high speed rotation of impeller in structure so high ratio gearbox and conventional induction motor driving required. This mechanical system have results of increased moment of inertia and mechanical friction loss. Recent studies of modern turbo compressor have been applied to developing super high speed BLDC motor and driver which remove gearbox that make its size small and mechanical friction loss minimum. To accomodate this tendency, we tried to develope a super high speed motor drive system for 150Hp, 70,000rpm direct drive Turbo compressor using DSP(Digital Signal Processor) and SVPWM(Space Vector Modulation PWM) technique. The results of this specific application show that super high speed driver and controller could be implemented well with digital electronics.

• Journal of Power Electronics
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• 제11권6호
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• pp.824-836
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• 2011

A new fault-tolerant control topology for open-loop motor-drive systems with Delta-connected stator windings is introduced in this paper. This new control topology enables the operation of a three-phase induction machine as a two-phase machine fed by a three-phase inverter upon a failure in one of the motor phases. This topology utilizes the "open-Delta" configuration to independently control the current in each of the two remaining healthy phases. This new control technique leads to the alleviation of any torque pulsations resulting from the consequences of the asymmetrical conditions associated with this class of faults.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 F
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• pp.2143-2145
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• 1997

SV_PWM inverter for Induction motor drive system was designed at SIMULINK environment in MATLAB. This paper was performed the analysis of output current harmonics using DSP blockset. It was roved in this paper that SV_PWM method has been ore effective than triangle comparison PWM method on harmonic reduction at steady state.

• 대한전자공학회논문지TE
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• 제42권1호
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• pp.29-34
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• 2005

권선형 유도전동기는 기동시에 충분히 큰 저항을 외부에서 삽입하여 기동전류를 작게하는 동시에 기동토크를 크게 할 수 있다. 또한, 유도전동기의 각 기동방식중에서 가장 우수한 시동특성을 가지고 있으며 크레인, 시멘트공장 등 중부하 시동이 요구되는 경우 널리 사용되고 있다. 권선형 유도전동기 드라이브 시스템의 전류, 토크, 위치 및 속도 등의 제어를 위하여 일반적으로 산업현장에서는 PI 제어기가 많이 적용되고 있다. 그러나 이러한 시스템은 센서 부착시 여러가지 환경적 제약으로 인한 전체시스템의 성능 저하를 가져올 수 있어 이를 개선하기 위한 센서리스 벡터제어가 활발히 연구되고 있다. 본 논문은 권선형 유도전동기의 센서리스 벡터제어를 위해 MRAS 기법을 적용하였고, 기존 MRAS에 의한 유도전동기 속도 센서리스 제어시 발생하는 저항 값의 변화에 따른 저속 영역에서의 속도 특성 악영향을 개선키 위해 권선형 유도전동기의 고정자 저항과 회전자 저항 값을 추정하는 제어 알고리즘을 추가하여 시스템의 동특성 개선을 시도하였다. 제안된 기법의 타당성 및 유효성을 컴퓨터 시뮬레이션으로 확인하였다.

• 전력전자학회논문지
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• 제18권3호
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• pp.279-288
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• 2013

This paper proposes a improved speed control system for five-phase squirrel-cage induction motor(IM) injecting 3rd. current harmonic components with field oriented control (FOC) A five-phase IM drives present unique characteristics due to the additional degrees of freedom and also drives possess many others advantage compared with the traditional three-phase motor drive system, such as reducing a amplitude of torque pulsation at low frequency and increasing the reliability. In order to maximize the torque per ampere, the proposed motor has concentrated windings. The produced back-electromotive force is almost trapezoidal, and the motor is supplied with the combined sinusoidal plus third harmonic of currents. There is necessary to controlled 3rd harmonic current in order to high response characteristics. For presenting the superior performance of the proposed the speed control system, experimental results are presented using a 32-bit fixed point TMS320F2812 DSP with 1.5[kW] induction motor.