• The Transactions of the Korean Institute of Power Electronics
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• v.5 no.4
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• pp.352-357
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• 2000

The vector control scheme is usually applied to the high performance induction motor drives. The PI controller is adopted traditionally to control the motor speed and currents in the vector control scheme. In this case, the dynamic performance of the induction motor is dependent on the PI gains and the gain optimization is necessary in order to get a good dynamic performance. But, it is very hard to optimize the PI gains uniquely within the speed control range because the equivalent model of the motor control system should be known exactly. In this paper, we propose the hybrid control scheme to remove the defects of PI controller. The hybrid control scheme includes the simplified fuzzy controller which operates in the transient state and the PI controller which operates in the steady state. The proposed scheme is applied to the vector control for induction motor, and the digital simulation and the experimental results are given to verify the proposed scheme.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.17-19
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• 1997

원자력 발전소용 증기발생기의 수위제어에 기존의 경우 주로 PI제어기를 이용하는데 반해 본 논문에서는 기타의 주급수유량에 대한 주증기 유량의 변화를 2-자유도 PID제어기를 이용해 제어하는 문제를 연구하였다. 2-자유도 PID제어기의 파라메터 .alpha..betha..gamma.를 외란에 대해 가인하도록 하고 설정치변화에 대해서는 기존의 PID 파라메터가 부담하도록 함으로서 외란 및 설정치 모두에 대해 고찰한 결과 기존의 PI제어기에 비해 성능이 우수함을 나타내었다.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1995.10b
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• pp.243-248
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• 1995

본 논문에서는 신경회로망의 학습능력을 이용하여 AC 모터의 속도제어에 이용된 기 존의 PI제어기의 문제점을 보완하고자 한다. 기존의 아날로그 PI제어기에서는 각 비례, 적분 파라메타를 개발자가 조정하여 고정하면 부하가 변동될 경우 적응성이 떨어지는 문제점을 안고 있었다. 본 논문에서 제시된 디지털 신경망제어기는 학습을 통해 새로운 환경에 적응 가능하다는 점에 가정하여 설계하고 성능을 비교 평가하였다. 본 논문에서 사용된 신경회로 망의 구조는 신경망중에서 가장 범용적으로 사용되는 다층 퍼셉트론 모델구조를 선택하였 다. 신경망 제어기장치로는 인텔 8097 마이크로 콘트롤러를 이용하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.3
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• pp.1255-1262
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• 2012

Look into the nuclear power plant of Wolsong currently, it is controlled in order to required operating pressure with PI controller. PI controller has a simple structure and satisfy design requirements to gain setting. However, It is difficult to control without changing the gain from produce changes in parameters such as loss of the valves and the pipes. To solve these problems, the dynamic change of the PI controller gain, or to compensate for the PI controller output is desirable to configure the controller. The aim of this research and development in the parameter variations can be controlled to a stable controller design which is reduced an error and a vibration. Proposed PI/NN control techniques is the PI controller and the neural network controller that combines a parallel and the neural network controller part is compensated output of the controller for changes in the parameters were designed to be robust. To directly evaluate the controller performance can be difficult to test in real processes to reflect the characteristics of the process. Therefore, we develope the simulator model using the real process data and simulation results when compared with the simulated process characteristics that showed changes in the parameters. As a result the PI/NN controller error and was confirmed to reduce vibrations.

• Journal of the Korean Institute of Intelligent Systems
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• v.5 no.3
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• pp.64-72
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• 1995

This paper proposes how to tune the gains of PI controllers in case of gain change in a process control system. Controllers of PI type have been used in industry and the gains of the controllers have been tuned by expert engineers. It, therefore, takes much time and efforts to tune the controllers. It is more difficult to find gains of multi-loop processes. The tuning method of a fuzzy tuner in this paper is developed based on the assumptions that the PI controllers are of analog type and are tuned off-line, and that the characteristic values must be supplied for the tuner. A Tuner using Fuzzy Logic(FLT1 is capable of showing presentlpast states of a process control system and finding gains of PI controllers. The verfication of the FLT is shown by various experiments.

• The Transactions of the Korean Institute of Power Electronics
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• v.8 no.6
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• pp.561-568
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• 2003

There arc two ways in the output voltage control method in PWM inverters. One Is double loop voltage control composed of inner current control loop and outer voltage control loop.'rho other is single loop voltage control method composed of voltage control loop only. It's characteristics shows lower performance in case of high output impedance than double loop voltage control. However, in case of low output impedance, it shows good control performance in all load ranges than double loop voltage control. In this paper, the rule and the gain of single loop voltage control have been developed analytically and these were verified through computer simulation and experiment.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2008.04a
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• pp.259-263
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• 2008

The dynamics of mobile robot is nonlinear. To cope with this nonlinearity, many advanced control schemes have been proposed recently. Generally, the advanced control schemes are complicated and not good for the practical real-time control when they are implemented as control programs. So, in this paper, a relatively simple PI controller is proposed and applied to the position control of mobile robot with the adoption of reference trajectory calculation method used for the AUV(Autonomous Underwater Vehicle) control. The proposed PI controller is programmed using LabVIEW which is popular for its graphical programming characteristics. The simulation and experimental results show the feasibility and effectiveness of the proposed PI controller.

• The Transactions of the Korean Institute of Power Electronics
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• v.10 no.6
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• pp.534-542
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• 2005

This paper proposes the fuzzy logic based vector control method for a Surface Mounted Permanent Magnet Synchronous Motor(SMPMSM) used in the elevators. The gain of a conventional PI speed controller in the elevator drive system can not be usually set high due to mechanical resonances, therefore its performance becomes deteriorated. There have been many methods to solve above problems such as an acceleration feedback in the speed controller. However, the above methods have defects that parameter information is demanded. In this paper', a Fuzzy controller(FC) is adopted in the elevator drive system. The performance of a fuzzy controller is compared with a PI controller in the no load and load conditions by simulation and experiments.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.12 no.4
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• pp.6-13
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• 1998

It is difficult to control for the level of the steam generator in the nuclear power plant because there is swell and shrink, and many disturbance such as, feed water rate, feedwater temperature, main steam flow rte, coolant temperature effect steam generator level. If the conventional PI controller use in this system, we cannot have a stability in the control of the lower power, the rejection function of disturbance, and the load following effectively. In this paper, e study the application of the of neural network based Kp, Ti for Pi controller to the level control of the steam generator of nuclear power plant through the simulation and experimental on the steam generator. We are satisfied with the resulting against the inturrupt of the disturbance, the change of setpoint through the simulation and the swell and shrink, the response of controller on the experimental steam generator.

• Proceedings of the KIEE Conference
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• 1997.07b
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• pp.654-656
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• 1997

본 논문에서는 직접신경회로망제어기(DNNC)를 사용하여 결합된 PI제어기의 이득을 구하여 보일러 터빈시스템을 제어하고자 한다. 직접신경회로망제어기는 플랜트의 동특성을 학습시키는 에뮬레이터 없이 제어입력에 대한 플랜트의 동작방향에 대한 정보만을 사용하여 신경회로망을 학습시키고, 이 신경회로망을 사용하여 제어대상 플랜트인 다중입출력플랜트를 제어하기 위하여 결합된 PI 제어기의 이득을 구한다. 컴퓨터 시뮬레이션을 통하여 제안한 알고리즘의 타당성을 입증하고자 한다.