• 한국정밀공학회지
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• 제19권10호
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• pp.107-113
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• 2002

To monitor the torque of an induction motor using current, rotating speed has been measured and used to calculate the slip angular velocity. Additional sensor, however, can cause extra expense and trouble. In this paper, a new algorithm is proposed to monitor the torque of vector controlled induction motor without any speed measuring sensor. Only stator current is measured to estimate the magnetizing current which is used to calculate flux linkage, rotor velocity and motor torque. Graphical programming is used to implement the suggested algorithm and to monitor the torque of an induction motor in real time. To solve the fluctuation problem of estimated torque caused from instantly varying rotating speed of an induction motor, the rotating speed is reconstructed based on the measured current signals. From several experiments, the proposed method shows a good estimation of the motor torque under the normal rotational speed.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2002년도 전력전자학술대회 논문집
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• pp.192-195
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• 2002

The thesis proposes the sensorless vector control method that estimates the rotor speed and rotor time constant at the same time using stator current. In the proposed method, stator current error in the stationary reference frame is proportional to estimated speed error, and stator current error in the synchronous reference frame is proportional to estimated rotor time constant error. The proposed method can simultaneously produce a fast speed estimation and rotor time constant estimation. Therefore, this new method offers an improvement in the performance of a sensorless vector controller. And, the superiority of the proposed method is verified by simulation.

• 한국조명전기설비학회지:조명전기설비
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• 제9권4호
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• pp.62-70
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• 1995

Brushless DC Motor (BDCM) is widely used in the industry such as a variable speed motor in a compressor for room air conditioners, because the motor can be easily controlled and operated over a wide speed range. The system to drive BDCM needs encoder that senses rotor position. Gut in a certain application, the position sensor has to be avoided. In the paper, various position sensorless drive systems for BDCM are investigated and critically evaluated, so that the effective method of sensorless control can be selected. Out of these methods, the freewheeling diode current sensing has many advantages. For example, the simple starting procedure makes it possible to perform sensorless control even in low speed. So the hardware design for this method has been carried out and the system has been implemented using DSP. The experimental results verified that the freewheeling diode current sensing approach has advantages in starting procedure and low speed sensing.

• 전기학회논문지P
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• 제53권4호
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• pp.195-200
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• 2004

Many kinds of speed sensorless control system of induction motor had been developed. But it is difficult to implement at the real system because of complex algorithm and equations. This paper investigates a novel speed sensorless control of induction motor using neural networks. The proposed control strategy is based on neural networks using stator current and output of neural model based on state observer. The errors between the stator current and the output of neural model are back-propagated to adjust the rotor speed, so that adaptive state variable will coincide with the desired state variable. This algorithm may overcome several shortages of conventional model, such as integrator problems, small EMF at low speed and relatively large sensitivity of stator resistance variation. Also, this paper presents a newly developed optimal equation about the momentum constant and the learning rate. The proposed algorithms are verified through simulation.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2004년도 전력전자학술대회 논문집(2)
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• pp.976-980
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• 2004

This paper presents a position sensorless control system of Switched Reluctance Motor (SRM) using neural network. The control of SRM depends on the commutation of the stator phases in synchronism with the rotor position. The position sensing requirement increases the overall cost and complexity. In this paper, the current-flux-rotor position lookup table based position sensorless operation of SRM is presented. Neural network is used to construct the current-flux-rotor position lookup table, and is trained by sufficient experimental data. Experimental results for a 1-hp SRM is presented for the verification of the proposed sensorless algorithm.

• 전력전자학회논문지
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• 제8권5호
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• pp.427-434
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• 2003

본 논문은 스위치드 릴럭턴스 전동기(SRM)에서 회전자위치검출의 새로운 방법을 다루었다. 전동기에 대한 센서리스방식의 제어기법들은 상전류의 측정과 비여자 구간에서의 펄스전압인가를 포함하고 있다. 회전자의 위치를 추정 할 수 있는 윈리는 펄스 전류를 통한 인턱턴스의 검출을 기포로 한다. 이 센서리스 제어법은 회전자의 위치검출 연산이 매우 간단하여 전속도구간에서 운전이 가능하여 드라이브 시스템을 효율적으로 구성할 수 있다. 제안한 방식을 이용하여 구동시스템을 구성하고 실험을 통하여 검증하였다.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제55권2호
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• pp.107-115
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• 2006

In this paper, a new speed sensorless control based on an instantaneous reactive power is proposed for the interior permanent magnet synchronous motor(IPMSM) drives. In proposed algorithm, the current observer estimates the line currents and the estimated speed can be yielded from the voltage equation because the information of speed is included in back EMF. To implement speed sensorless control, the current observer is composed by using the voltage equation of the IPMSM in the stationary reference frame fixed to the stator. The estimated speed of the rotor is composed by using the voltage equation of the IPMSM in the rotating reference frame fixed to the rotor The estimated speeds to minimize the speed error compensated by using the instantaneous reactive power. The instantaneous reactive power is calculated on the rotating reference frame fixed to the rotor. The effectiveness of the preposed algorithm is confirmed by the experiments.

• 전기학회논문지
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• 제62권7호
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• pp.956-962
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• 2013

Recently, sensorless controls, which eliminate position and speed sensor in a permanent magnet synchronous motor drive, have been much studied. Most sensorless control algorithms are based on the back-EMF and speed estimations which are obtained from the voltage equations. Therefore, the sensorless control performance is largely affected by the parameter errors of a motor. This paper investigates a novel adaptive control with the parameter error compensation for the speed sensorless control of a permanent magnet synchronous motor. The proposed parameter estimation is obtained from the d-axis current error between the real and estimated currents. The proposed algorithm is verified through the simulation and experimentation.

• Journal of international Conference on Electrical Machines and Systems
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• 제1권4호
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• pp.477-482
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• 2012

This paper describes a new rotor position sensorless control method for SRM drives based on an improved simplified flux linkage method. In the traditional simplified flux linkage method, every phases take turns conduction and current chopping control method is used. Every phases take turns conduction means turning on the incoming working phase while turning off the working phase. This conduction mode causes coupling between turn-on and turn-off angles, which goes against optimal efficiency or torque ripple minimization with sensorless speed control. In the improved simplified flux linkage method, turn-off angle is calculated by flux loop, the turn-on angle can be given arbitrarily and has no relations with the turn-off angle, and the current chopping control method is used. The speed and rotor position can be estimated then. Finally, a sensorless SRM speed control system and an experiment platform with DSP are built and validity of this method is confirmed.

• 전력전자학회논문지
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• 제9권3호
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• pp.246-252
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• 2004

본 논문에서는 신경회로망을 이용한 위치센서 없는 스위치드 릴럭턴스 전동기의 제어시스템에 관해 연구하였다. 스위치드 릴럭턴스 전동기는 회전자 위치에 따라 적정 고정자 권선을 여자시킴으로써 회전력을 발생하기 때문에 회전자 위치정보가 필수적이다. 회전자 위치추정을 위한 위치 검출기는 전반적인 시스템 비용을 증가시키고, 시스템이 복잡해지는 요인이 된다. 본 논문에서는 전류와 자속에 대한 회전자 위치정보의 룩업 테이블을 바탕으로 위치센서 없는 스위치드 릴럭턴스 전동기의 제어에 관해 연구하였다. 신경회로망은 실험을 통해 구해진 데이터를 바탕으로 회전자 위치추정을 위한 근사함수의 유도를 위해 활용되었으며, 학습된 신경회로망을 이용하여 룩업 테이블을 구성하였다. 제안된 센서리스 알고리즘은 1마력 SRM에 적용되었으며, 실험 및 시뮬레이션을 통해 실현 가능성이 확인되었다.