• 한국안전학회지
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• 제14권2호
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• pp.52-61
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• 1999

This paper proposes the application of fuzzy control for high performance control of induction motor using electric vehicles. A fuzzy controller converts a set of liguistic rules based on expert knowledge into a automatic control strategy. Such controllers have often been found superior to conventional controllers especially when information being processed is inexact and uncertain. A system with fast torque response is very beneficial in applications where direct self control (DSC) is highly desirable. The response of DSC is slower during startup and during change in command torque. Fuzzy control is used for implementation of DSC to improve its slow response. Simulation implementation of the fuzzy logic controller was carried out to verify the behavior of the controller. The simulation results with fuzzy control are compared with those of the conventional DSC. The starting flux and torque response and the responses to the step changes in command torque with fuzzy implementation show a considerable improvement over the conventional control. The steady state responses in both the cases are the same.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 A
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• pp.219-223
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• 1995

This paper deals with the robust control system for parameter variations, fast responses and load torque variations. Frist, fuzzy-sliding adaptive control be used to. Fuzzy-sliding adaptive control is good at fast response. Second, there are many requests for selecting freely the moment of inertia, even though moment of inertia is determined with the materials, structure, shape, and size of the motors. Therefore we developed an inertia-lowering control system that uses torque observer to reduce the moment of inertia. Finally, using torque observer, torque control is done so as to compensate load torque. Consequently, the proposed system verified the superiority through the simulations using MATLAB.

• 전력전자학회논문지
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• 제7권5호
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• pp.427-436
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• 2002

본 논문은 직접토크제어(Direct torque control, DTC)를 사용한 릴럭턴스 동기전동기(Reluctance synchronous motor, RSM)의 위치센서 없는 모션제어 시스템을 제안한다. 고성능 효율제어를 수행하는데 있어서 DTC를 이용한 릴럭턴스 전동기 드라이브는 고정자 쇄교자속의 포화와 부하전류에 따라 비선형적으로 변하는 인덕턴스로 인해 여러 가지 문제점들이 발생한다. 이러한 이유로 본 논문에서는 정확한 고정자 쇄교자속과 토크를 계산하기 위해서 자속관측기의 $L_d\;와\; L_q$값을 회전자 위치와 고정자 전류에 대해 보상하였으며, 빠른 토크 응답특성과 최적 효율특성을 얻기 위해서 기준자속을 부하에 따라 계산하였다. 제안된 알고리즘의 정당성을 확인하기 위해서 1.0[kW] 릴럭턴스 동기 전동기를 사용하여 $\pm$20[rpm]과 $\pm$1500[rpm]에서 실험을 수행하였고, 실험을 수행한 결과 저속영역과 고속영역 모두 우수한 동특성과 향상된 효율을 얻을 수 있었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 B
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• pp.666-668
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• 2002

Reluctance torque is generated by the rotor of the rugged construction in Synchronous Reluctance Motor. Its construction is simple, and it is very economic because a rotor in existed AC motor can be used. As the Synchronous inductance in Synchronous Reluctance Motor is an element that is proportional to torque, the exact value must be experimentally or analytically found for controlling and the performance development of motors. In this paper, direct torque control simulation to maximize the torque of the Synchronous Reluctance Motor and fast response characteristics was carried out with the inductance value by the Finite Element Method. For the simulation results, there are torques and fluxs response characteristics when controlling speed.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제55권1호
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• pp.9-15
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• 2006

The conventional hysterysis band DTC(Direct Torque Control) strategy have relatively high torque ripple at low speed and variable switching frequency according to motor speed even though it provides a fast torque response with very simple scheme consisted with only two hysteresis band comparators and a switching table for torque and flux control. In this paper, author proposed a new DTC scheme based on the torque slope and reference voltage control. The new scheme can maintain the minimized torque ripple and constant switching frequency. Experimental tests carried out with an 1.5kW induction motor drive system show improved dynamic characteristics and prove the feasibility of proposed strategy.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2007년도 하계학술대회 논문집
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• pp.208-210
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• 2007

This paper proposes a novel direct instantaneous pressure control(DIPC) of hydraulic pump system with SR drive. And it has very simple control structure, because it doesn’t use any speed and torque control for adjusting pump pressure. The hysteresis band of pressure and proper switching rules can make the actual pump pressure to be constant with fast dynamic response. Therefore, the proposed DIPC method can control of hydraulic pump pressure steadily with fast dynamic response.

• 대한전기학회논문지:시스템및제어부문D
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• 제49권3호
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• pp.117-123
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• 2000

A new control method for precision robust position control of a PMSM (Permanent Magnet Synchronous Motor) using asymptotically stable adaptive load torque observer is presented in the paper. Precision position control is obtained for the PMSM system approximately linearized using the field-orientation method. Recently, many of these drive systems use the PMSM to avoid backlashes. However, the disadvantages of the motor are high cost and complex control because of nonlinear characteristics. Also, the load torque disturbance directly affects the motor shaft. The application of the load torque observer is published in [1] using fixed gain. However, the motor flux linkage is not exactly known for a load torque observer. There is the problem of uncertainty to obtain very high precision position control. Therefore, a model reference adaptive observer is considered to overcome the problem of unknown parameter and torque disturbance in this paper. The system stability analysis is carried out using Lyapunov stability theorem. As a result, asymptotically stable observer gain can be obtained without affecting the overall system response. The load disturbance detected by the asymptotically stable adaptive observer is compensated by feedforwarding the equivalent current which gives fast response. The experimental results are presented in the paper using DSP TMS320c31.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1997년도 전력전자학술대회 논문집
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• pp.97-100
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• 1997

A new control method for the robust position control of a brushless DC(BLDC) motor using the asymptotically stable adaptive load torque observer is presented. A precision position control is obtained for the BLDC motor system approximately linearized using the field-orientation method. And the application of the load torque observer is published in [1] using fixed gain. However, the flux linkage is not exactly known for a load torque observer. Therefore, a model reference adaptive observer is considered to overcome the problem of the unknown parameter in this paper. And stability analysis is carried out using Liapunov stability theorem. As a result, asymptotically stable observer gain can be obtained without affecting the overall system response. The load disturbance detected by the asymptotically stable adaptive observer is compensated by feedforwarding the equivalent current having the fast response.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.296-299
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• 2003

The conventional DTC strategy provides a fast torque response even though it has very simple scheme consisted with only two hysteresis band comparators and a switching table for torque and flux control. Drawbacks of the conventional DTC are relatively high torque ripple at low speed and variation of the switching frequency according to motor speed. In this paper, the new direct torque control(DTC) schemes are proposed. Those schemes are based on the torque slope and enable to reduce the torque ripple and maintain the switching frequency constantly.

• 전력전자학회논문지
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• 제19권3호
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• pp.249-256
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• 2014

This paper proposes a torque control method of permanent magnet synchronous motor, which has small torque ripple. The proposed control method is using the finite control set-model predictive control(FCS-MPC) strategy. An optimal input voltage vector minimizing a cost function is chosen among 6 passible active input voltage vectors following the FCS-MPC strategy. Then, a modulation factor for the optimal input voltage vector is computed to minimize the torque ripple. Thus, the proposed control method yields fast torque response and small torque ripple. The efficacy of the proposed method was verified through simulation and experiment.