• Title/Summary/Keyword: Model predictive controller

Search Result 169, Processing Time 0.022 seconds

Neural model predictive control for nonlinear chemical processes (비선형 화학공정의 신경망 모델예측제어)

  • 송정준;박선원
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1992.10a
    • /
    • pp.490-495
    • /
    • 1992
  • A neural model predictive control strategy combining a neural network for plant identification and a nonlinear programming algorithm for solving nonlinear control problems is proposed. A constrained nonlinear optimization approach using successive quadratic programming cooperates with neural identification network is used to generate the optimum control law for the complicate continuous/batch chemical reactor systems that have inherent nonlinear dynamics. Based on our approach, we developed a neural model predictive controller(NMPC) which shows excellent performances on nonlinear, model-plant mismatch cases of chemical reactor systems.

  • PDF

Improved Deadbeat Current Controller with a Repetitive-Control-Based Observer for PWM Rectifiers

  • Gao, Jilei;Zheng, Trillion Q.;Lin, Fei
    • Journal of Power Electronics
    • /
    • v.11 no.1
    • /
    • pp.64-73
    • /
    • 2011
  • The stability of PWM rectifiers with a deadbeat current controller is seriously influenced by computation time delays and low-pass filters inserted into the current-sampling circuit. Predictive current control is often adopted to solve this problem. However, grid current predictive precision is affected by many factors such as grid voltage estimated errors, plant model mismatches, dead time and so on. In addition, the predictive current error aggravates the grid current distortion. To improve the grid current predictive precision, an improved deadbeat current controller with a repetitive-control-based observer to predict the grid current is proposed in this paper. The design principle of the proposed observer is given and its stability is discussed. The predictive performance of the observer is also analyzed in the frequency domain. It is shown that the grid predictive error can be decreased with the proposed method in the related bode diagrams. Experimental results show that the proposed method can minimize the current predictive error, improve the current loop robustness and reduce the grid current THD of PWM rectifiers.

High Performance Current Controller for Sparse Matrix Converter Based on Model Predictive Control

  • Lee, Eunsil;Lee, Kyo-Beum;Lee, Young Il;Song, Joong-Ho
    • Journal of Electrical Engineering and Technology
    • /
    • v.8 no.5
    • /
    • pp.1138-1145
    • /
    • 2013
  • A novel predictive current control strategy for a sparse matrix converter is presented. The sparse matrix converter is functionally-equivalent to the direct matrix converter but has a reduced number of switches. The predictive current control uses a model of the system to predict the future value of the load current and generates the reference voltage vector that minimizes a given cost function so that space vector modulation is achieved. The results show that the proposed controller for sparse matrix converters controls the load current very effectively and performs very well through simulation and experimental results.

Fuzzy Neural Network Based Generalized Predictive Control of Chaotic Nonlinear Systems (혼돈 비선형 시스템의 퍼지 신경 회로망 기반 일반형 예측 제어)

  • Park, Jong-Tae;Park, Yoon-Ho
    • The Transactions of the Korean Institute of Electrical Engineers D
    • /
    • v.53 no.2
    • /
    • pp.65-75
    • /
    • 2004
  • This paper presents a generalized predictive control method based on a fuzzy neural network(FNN) model, which uses the on-line multi-step prediction, fur the intelligent control of chaotic nonlinear systems whose mathematical models are unknown. In our design method, the parameters of both predictor and controller are tuned by a simple gradient descent scheme, and the weight parameters of FNN are determined adaptively during the operation of the system. In order to design a generalized predictive controller effectively, this paper describes computing procedure for each of the two important parameters. Also, we introduce a projection matrix to determine the control input, which deceases the control performance function very rapidly. Finally, in order to evaluate the performance of our controller, the proposed method is applied to the Doffing and Henon systems, which are two representative continuous-time and discrete-time chaotic nonlinear systems, res reactively.

Intelligent Predictive Control of Time-Varying Dynamic Systems with Unknown Structures Using Neural Networks (신경회로망에 의한 미지의 구조를 가진 시변동적시스템의 지능적 예측제어)

  • Oh, S.J
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.20 no.3
    • /
    • pp.286-286
    • /
    • 1996
  • A neural predictive tracking system for the control of structure-unknown dynamic system is presented. The control system comprises a neural network modelling mechanism for the the forward and inverse dynamics of a plant to be controlled, a feedforward controller, feedback controller, and an error prediction mechanism. The feedforward controller, a neural network model of the inverse dynamics, generates feedforward control signal to the plant. The feedback control signal is produced by the error prediction mechanism. The error predictor adopts the neural network models of the forward and inverse dynamics. Simulation results are presented to demonstrate the applicability of the proposed scheme to predictive tracking control problems.

Intelligent Predictive Control of Time-Varying Dynamic Systems with Unknown Structures Using Neural Networks (신경회로망에 의한 미지의 구조를 가진 시변동적시스템의 지능적 예측제어)

  • Oh, Se-Joon
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.20 no.3
    • /
    • pp.154-161
    • /
    • 1996
  • A neural predictive tracking system for the control of structure-unknown dynamic system is presented. The control system comprises a neural network modelling mechanism for the the forward and inverse dynamics of a plant to be controlled, a feedforward controller, feedback controller, and an error prediction mechanism. The feedforward controller, a neural network model of the inverse dynamics, generates feedforward control signal to the plant. The feedback control signal is produced by the error prediction mechanism. The error predictor adopts the neural network models of the forward and inverse dynamics. Simulation results are presented to demonstrate the applicability of the proposed scheme to predictive tracking control problems.

  • PDF

Neural Model Predictive Control for Nonlinear Chemical Processes

  • Song, Jeong-Jun;Park, Sunwon
    • Proceedings of the Korean Institute of Intelligent Systems Conference
    • /
    • 1993.06a
    • /
    • pp.899-902
    • /
    • 1993
  • A neural model predictive control strategy combining a neural network for plant identification and a nonlinear programming algorithm for solving nonlinear control problems is proposed. A constrained nonlinear optimization approach using successive quadratic programming combined with neural identification network is used to generate the optimum control law for complex continuous chemical reactor systems that have inherent nonlinear dynamics. The neural model predictive controller (MNPC) shows good performances and robustness. To whom all correspondence should be addressed.

  • PDF

Damping of Inter-Area Low Frequency Oscillation Using an Adaptive Wide-Area Damping Controller

  • Yao, Wei;Jiang, L.;Fang, Jiakun;Wen, Jinyu;Wang, Shaorong
    • Journal of Electrical Engineering and Technology
    • /
    • v.9 no.1
    • /
    • pp.27-36
    • /
    • 2014
  • This paper presents an adaptive wide-area damping controller (WADC) based on generalized predictive control (GPC) and model identification for damping the inter-area low frequency oscillations in large-scale inter-connected power system. A recursive least-squares algorithm (RLSA) with a varying forgetting factor is applied to identify online the reduced-order linearlized model which contains dominant inter-area low frequency oscillations. Based on this linearlized model, the generalized predictive control scheme considering control output constraints is employed to obtain the optimal control signal in each sampling interval. Case studies are undertaken on a two-area four-machine power system and the New England 10-machine 39-bus power system, respectively. Simulation results show that the proposed adaptive WADC not only can damp the inter-area oscillations effectively under a wide range of operation conditions and different disturbances, but also has better robustness against to the time delay existing in the remote signals. The comparison studies with the conventional lead-lag WADC are also provided.

A Study on the Level Control in the Steam Generator of a Nuclear Power Plant by using Model Predictive Controller (MPC를 이용한 원전 증기발생기의 수위제어에 관한 기초연구)

  • Son, Duk-Hyun;Lee, Chang-Goo;Han, Jin-Wook;Han, Hu-Suk
    • Proceedings of the KIEE Conference
    • /
    • 2000.07d
    • /
    • pp.2495-2497
    • /
    • 2000
  • Level control in the steam generator of a nuclear power plant is important process. But, the low power operation of nuclear power plant causes nonlinear characteristics and non minimum phase characteristics (swell and shrink), change of delay. So, we can't lead good results with conventional PID controller. Particularly, the design of controller with constraints is necessary. This paper introduces MPC(Model Predictive Control) with constraints and designs a good performance MPC controller in spite of the input constraints and nonlinear characteristics, non-minimum phase characteristics

  • PDF

Novel Predictive Current Control Pulse Width Modulation Method for Matrix Convertors (매트릭스 컨버커를 위한 새로운 예측 전류제어 펄폭 변조 방법)

  • Li, Yulong;Choi, Nam-Sup;Han, Byung-Moon;Yang, Seung-Chul
    • Proceedings of the KIEE Conference
    • /
    • 2008.11a
    • /
    • pp.65-67
    • /
    • 2008
  • A new pulse width modulation method based on predictive current control strategy is proposed to modulate matrix converters. The predictive current controller utilizes a discrete-time model to predict the future values of output currents and generates proper duty-ratios ta minimize the output current errors. The proposed method uses continuous carrier and establishes a predictive current controller to predetermine duty ratio signal for directly generating gating signals an thus is named "predictive current control PWM(PCCPWM)". The modulation algorithm nd the required equations are derived by using average concept over one switching period. Thus it can be easily extended to other matrix converter topologies, especially with neutral connections, such as sing le-phase ad two-phase matrix converters. The feasibility and validity of the proposed strategy are verified by computer simulation and experimental results.

  • PDF