• Journal of Industrial Technology
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• v.30 no.A
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• pp.31-35
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• 2010

In this paper, a speed estimation method at coasting operation in an induction motor speed sensorless control for railway vehicle traction systems is presented. At coasting operation, there is no information obtaining rotor speed since all switches of an inverter are turned off. The inverter frequency should be synchronized with the rotor frequency for repowering at coasting condition. The proposed method injects DC current to the induction motor during a short time, then the flux angle and rotor speed needed for control can be estimated rapidly.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2255-2257
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• 2001

This paper introduces a indirect rotor position and speed estimation algorithm for the SRM(switched reluctance motor) sensorless control, based on the sliding mode observer. The information of position and speed is generally provided by encoder or resolver. However, the position sensor not only adds complexity, cost, and size to the whole drive system, but also causes limitation for industrial applications. In this paper, in order to eliminate the position sensor, indirect position sensing method using sliding mode observer is used for SRM drives. And this observer parameters are optimized by evolutionary algorithm. PI controller is also optimized for the SRM to track precisely using evolutionary algorithm.

• Proceedings of the KIPE Conference
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• 2017.07a
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• pp.395-396
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• 2017

차세대 고속 이동수단에 필요한 고전력 전동기에 대한 관심이 꾸준히 증가하는 추세이다. 본 논문에서는 고전력 동기전동기(PMSM) 구동에 필요한 전력 인버터의 제어 및 센서리스 제어기법을 적용한 자속 기준 제어(Field-oriented control)를 시뮬레이션을 통해 입증하였다. 고전력에서 인버터 스위치의 전력부담을 줄이기 위해 3-레벨 인버터를 설계하고, 벡터 제어 SVPWM 방식을 적용하였으며 고전력 및 고속 PMSM의 파라미터에 맞추어 센서리스(sensorless) 제어기를 설계하였다. 센서리스 제어에는 모델 기준 적응 시스템(MRAS)을 통해 속도 및 위치를 예측하여 모터를 제어하는 방식을 적용하였다. 가속시 5초간 가가속도 값을 적용하여 필요 토크 및 속도제어를 Matlab/Simulink에서 설계 및 구현하고, 예측속도와 실제 모터속도는 최대 0.01 rad의 오차를 나타났고, 67초 동안 목표 속도 500 rad/s까지 가속함을 확인하였다.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.1138-1141
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• 2003

This paper proposes a new speed and flux estimation method which has the robustness against the variation of the electrical parameters of the motor and the superiority in the dynamic characteristics compared with the conventional sensorless schemes. In the proposed method, the stator currents and the rotor fluxes are observed on the stationary reference frame using the sliding mode concept. And the rotor speed is estimated using the current estimation errors and the observed rotor fluxes based on the Lyapunov stability theory. Also a design method of the observer gain is proposed to minimize the effect of the speed estimation error on the rotor flux observation. The experimental results verified that the proposed method shows more robust and improved performances than the previous estimation method under the variations of motor resistance and inductance.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.600-603
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• 2012

본 논문은 최근 친환경 차량인 EV & HEV의 전장품에 운전 효율 및 연비를 극대화하기 위해 브러시리스 직류 (Brushless DC) 전동기 및 Sensorless Drive를 적용시키는 사례가 증가하고 있다. 특히 전 세계적으로 환경오염의 주범이 되고 있는 차량의 이산화 탄소 배출량 규제, 계속된 유가상승 등에 따라 가장 밀접하게 연관되어 있는 자동차 전장품에 전동화를 통한 연비향상을 적극적으로 추진하고 있다. 본 논문에서는 차량의 전장 제품으로 다양하게 적용되고 있는 에어컨 압축기로 냉방용 컴프레서에 브러시리스 직류전동기 및 Sensorless 제어기를 적용 에어컨 컴프레서를 개발 하여 20CC 전동식 스크롤 컴프레서에 적용하여 실험하였다. 이러한 실험으로 제품의 운전 효율 증대시킴은 물론 우월한 압축 성능을 가져 옴으로써 차량용 에어컨 컴프레서의 고효율 전동화를 유도 시킬 수 있음을 확인 할 수 있었다.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1294-1296
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• 2005

Because of its cost effectiveness, the Brushless DC Motor(BLDCM) is focused by the industry these days. Considering the constant back-EMF region of the BLDCM, only a simple position information should be provided for constant torque control. From this point of view, using expensive position sensors, such as encoder, resolver, etc, decreases the cost effectiveness of the BLDCM. The Proposed detecting circuit detects position of zero crossing point(ZCP) then relative position could be calculated from ZCP. This circuit is robust to noise because of working in the current level. BLDCM is driven from the position information by the ZCP The reliability on BLDCM sensorless control using the voltage detecting circuit is shown through simulation using Matlab.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.6
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• pp.879-884
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• 2002

There are screw, reciprocating and turbo compressor by structure in an air compressor, essential equipment on he industrial spot. Resently it is wide that the range of turbo compressor's use in gradual, turbo compressor needs high speed rotation of impeller in structure, high rated gearbox and conventional induction motor. This mechanical system increased the moment of inertia and mechanical friction loss. Resently the study of turbo compressor applied super high speed motor and drive, removing gearbox made its size small and mechanical friction loss minimum. In this study we tried to develope variable super high speed motor drive systems for 150Hp, 70,000rpm drect drive Turbo compressor. The result of study is applied to a 150Hp direct turbo compressor and makes it goods.

• International Journal of Automotive Technology
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• v.7 no.6
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• pp.729-739
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• 2006

This paper describes an active fault-tolerant control system for an induction motor drive that propels an Electrical Vehicle(EV) or a Hybrid one(HEV). The proposed system adaptively reorganizes itself in the event of sensor loss or sensor recovery to sustain the best control performance given the complement of remaining sensors. Moreover, the developed system takes into account the controller transition smoothness in terms of speed and torque transients. In this paper which is the sequel of (Diallo et al., 2004), we propose to introduce more advanced and intelligent control techniques to improve the global performance of the fault-tolerant drive for automotive applications(e.g. EVs or HEVs). In fact, two control techniques are chosen to illustrate the consistency of the proposed approach: sliding mode for encoder-based control; and fuzzy logics for sensorless control. Moreover, the system control reorganization is now managed by a fuzzy decision system to improve the transitions smoothness. Simulations tests, in terms of speed and torque responses, have been carried out on a 4-kW induction motor drive to evaluate the consistency and the performance of the proposed fault-tolerant control approach.

• Journal of Drive and Control
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• v.16 no.3
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• pp.23-32
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• 2019

This study proposed a fault tolerant control algorithm for electro-hydraulic brake systems where permanent magnet synchronous motor (PMSM) drive is adopted to boost the braking pressure. To cope with motor position sensor faults in the PMSM drive, a braking pressure controller based on an open-loop speed control method for the PMSM was proposed. The magnitude of the current vector was determined from the target braking pressure, and motor rotational speed was derived from the pressure control error to build up the braking pressure. The position offset of the pump piston resulting from a leak in the hydraulic system is also compensated for using the open-loop speed control by moving the piston backward until it is blocked at the end of stroke position. The performance and stability of the proposed controller were experimentally verified. According to the results, the control algorithm can be utilized as an effective means of degraded control for electro-hydraulic brake systems in the case that a motor position sensor fault occurs.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.1
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• pp.48-56
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• 2006

This paper studies particularly applicable method for sensorless PM BLDC motor drive system. The waveform of the motor internal voltages(or back emf) contains a fundamental and higher order frequency harmonics. Therefore the third harmonic component is extracted from the stator phase voltage. The resulting third harmonic signal keeps a constant phase relationship with the rotor flux for any motor speed and load condition. Also because of low resolution of estimated signal obtained by the proposed sensorless algorithm, to improve the wide range of speed response characteristic more exactly, we propose the rotor position signal synthesizer using PLL circuit based on estimated signals. Some experimental results are provided to demonstrate the validity of the proposed control method.