• 동력기계공학회지
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• 제3권2호
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• pp.70-78
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• 1999

The vector controlled induction motor(I.M) with speed sensor has been widely used for variable speed drive systems. In these application fileds, speed sensorless control are expected strongly to progress reliability, simplicity and cost performance of I.M and to expand its application part. This paper describes a novel speed sensorless control method of I.M based on feedforward quick torque response control technique. Especially, this paper aimed at the realization of sensorless control in the very low speed region, The proposed method can be formulated simply from a motor circuit equation and conducted easily by detecting primary motor currents and a voltage command at every sampling time. Throughout some results of numerical simulations with the assumption of using a pulse width modulation(PWM) voltage source inverter, the validity of the method was successfully confirmed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 A
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• pp.267-269
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• 1996

Servo systems became indispensable to applications such as industrial robots and numerically controlled machinery. Especially, induction motor drives are widely used as ac-servo system owing to the fact that it is maintenance-free. At the present time, Quick torque control methods such as vector control have been employed that enables an induction motor to attain as quick torque response as a dc motor. However, these methods can not be realized without knowing several motor parameters accurately, because the methods need them to calculate flux or voltage command. Most of all, secondary resistance has to be identified accurately, because it's value varies greatly for operation of induction motors. In this paper, a new identification method of secondary resistance based on quick torque control system of induction motors is proposed. The proposed method is derived theoretically from motor circuit equation and can be realized very simply by detecting primary current and voltage command of the motor. Through the numerical simulation considered using PWM inverter, the validity of the proposed method was successfully confirmed.

• 수산해양기술연구
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• 제31권4호
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• pp.393-401
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• 1995

본 논문에서는 전압형제어에 의한 유도전동기의 토크 속응제어법의 메카니즘이 기술되어 졌다. 특히 본 논문에서는 펄스전압 인가에 의한 과도토크 소거원리를 전류레벨에서 해석함과 동시에 직관적 이해를 돕기 위해 벡터표현을 이용하여 제안 방식의 이론적 타당성을 입증하였다. 이상의 검토에서 얻어진 결과를 요약하면 다음과 같다. (1) 전압형제어에 있어서는 임펄스를 인가함으로써 스텝응답을 실현할 수 있다. (2) 유한 미소정정시간 $\Delta$를 매개로 정식화를 행함으로써, 토크의 스텝응답을 실현할 수 있는 이론적인 전압해 및 현실적으로 실현 가능한 전압해를 동시에 구할 수 있다. (3) 토크 속응제어를 $\Delta$이후의 과도전류가 0으로 되는 전압지령에 의해 실현하므로 펄스전압인가에 의한 스파이크 전류는 발생하지 않는다. (4) 전동기 정수가 불변 또는 실시간으로 동정된다면, 제안방식은 제어지령을 결정함에 있어서 전류정보에 직접 의존하지 않고도 피드포워드적으로 전압지령의 연산이 가능하다. 따라서 제어 시스템 구성의 간략화와 동시에 제어정도가 전류정보에 전적으로 의존하지 않는 제어계의 구축이 가능하다

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 전력전자학술대회 논문집
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• pp.276-279
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• 2001

Direct torque control(DTC) is known to produce quick response in ac drives. Some drawbacks of the classical DTC are the relatively large torque ripple in a low speed range and notable current pulsation during steady state. They are reflected speed response and increased acoustical noise. In this paper, The DTC quick response are preserved at transient state, while better qualify steady state performance is produced by Space Vector Modulation(SVM). It is able to reduce the acoustical noise, torque ripple and current pulsation during steady state. The system presented are closed loop stator flux and torque observer for wide speed range that inputs are currents and voltages sensing of motor terminal. Simulation results for the 2.2kw general purposed induction motor are presented and discussed.

• Smart Structures and Systems
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• 제3권1호
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• pp.115-131
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• 2007

The electromechanical integrated toroidal drive is a new drive system. For the control of the drive, the torque fluctuation and the steady-state errors should be removed and the fast response to the input change should be achieved. In this paper, the torque fluctuation of the drive system is analyzed and expressed as Fourier series forms. The transfer function of the torque control for the drive system is derived from its electromechanical coupled dynamic equations. A 2-DOF control method is used to control the drive system. Using definite parameter relationship of the 2-DOF control system, the steady errors of the torque control for the drive system is removed. Influences of the drive parameters on the control system are investigated. Using proper drive parameters, the response time of the control system is reduced and the quick torque response of the drive system is realized. Using a compensated input voltage, the torque fluctuation of the drive system is removed as well. The compensated input voltage can be obtained from the torque fluctuation equation and the transfer function. These research results are useful for designing control system of the new drive.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1999년도 전력전자학술대회 논문집
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• pp.394-398
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• 1999

Direct Torque Control method for an Induction Motor is presented which is quite different from field-oriented control. It carries out a precise and quick control of the stator flux and electromagnetic torque of an IM without calling for coordinate transformation, speed measurement, and stator current control. In principle, moreover, DTC operation requires only the knowledge of the stator resistance.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 F
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• pp.2172-2174
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• 1998

In this paper, a speed estimation based on the quick torque control is proposed to realize speed sensorless control in a full range of induction motors. The proposed method can be formulated simply from a motor circuit equation and conducted easily by detecting primary motor currents and a voltage command at every sampling time. Since the method need not the differential values of primary currents in an arithmetic of a speed, it can be expected to improve the precision of speed estimation in a very low speed area, especially. Some numerical simulations were conducted with the assumption of using a Pulse Width Modulation voltage source inverter.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 A
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• pp.255-257
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• 1995

In this paper, a new speed estimation method of induction motors based on the very quick torque control is proposed to realize speed sensorless control. The proposed method can be realized very simply by detecting primary motor current and voltage command at every sampling time. As the method need not the differential value of primary current in a arithmetic of voltage command, it can be expected to promote the precision of speed estimation in low speed area, especially. Through the numerical simulation, the validity of the proposed method was successfully confirmed.

• 전력전자학회논문지
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• 제7권3호
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• pp.297-302
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• 2002

유도전동기의 직접 토크 제어방식은 구조가 간단하여 구현이 용이하고, 빠른 토크 응답성을 갖는 것을 특징으로 견인용 유도전동기의 추동시스템 등에 그 응용분야를 넓혀가고 있다. 그러나 히스테리시스 제어기를 사용하여 출력전압을 결정하는 기존의 직접 토크 제어방식에서는 인버터의 스위칭 주파수가 히스테리시스 밴드 폭과 운전조건에 따라 가변하고 토크맥동이 발생하는 문제점이 있다. 따라서 본 논문에서는 인버터의 스위칭 주파수를 일정하게 유지하고 저속 및 고속 운전영역에서 전동기의 토크 및 고정자 전류 맥등을 저감하기 위한 목적으로 고정자 자속 제어개념과 공간전압벡터 P%에 의한 새로운 직접 토크 제어방식을 제안하였다. 시뮬레이션과 실험을 통해 제안한 알고리즘의 타당성을 입증하였다.

• 수산해양교육연구
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• 제7권1호
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• pp.127-132
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• 1995

In this paper, a new speed estimation method of induction motors based on the very quick torque control is proposed to realize speed sensorless control. The proposed method can be realized very simply by detecting primary motor current and voltage command at every sampling time. As the method need not the differential value of primary current in a arithmetic of voltage command, it can be expected to promote the precision of speed estimation in low speed area, especially. Through the numerical simulation, the validity of the proposed method was successfully confirmed.