Application Of Predictive Technology In Coordinated Control System Of Unit Plant

With the strengthening of national economic strength and advances in power related technologies.In order to operate more reliably and economically,large units with high parameters and large capacity(600 WM?1000 MW)gradually occupy the dominant position in the power industry.Therefore,it is required to improve the control level of the power plant in order to ensure the safe and economic operation of the unit.Local control of conventional steam turbine and boiler furnace can not reach satisfactory control effect.Under such background,coordinated control of steam turbine and boiler becomes more and more important.Therefore,coordination control has become the most central control method.With the rapid rise of intelligent control theory,some advanced control strategies are emerging and the control effect is better than that of PID.As an advanced control method,predictive control not only has low requirement on the accuracy of thermal object model,but also has simple algorithm,good robustness and easy to implement.In this paper,the generalized predictive control(GPC)is applied to the coordinated control system of 600 MW unit.Firstly,based on the understanding of the basic concept of the coordinated control system,the object characteristics of the coordination system are analyzed and the mathematical model of the research object is determined.Secondly,the principle of single variable GPC algorithm is deduced and improved,and the simulation application is realized with specific examples,which proves the superiority of the algorithm.Thirdly,the mathematical model of #3 unit coordination system of a power plant is used as the control object of the system when the load is 75%.The control of the coordination system is obtained by using the GPC algorithm of double entry single out system,and the control effect is better than that of the PID.The generalized predictive control(GPC)is used to achieve the furnace main control feedforward prediction of the system,and the range of pressure fluctuation is reduced.Based on the multi GPC furnace main control feedforward prediction,the ability to adapt to the variation of different load amplitude is improved.The feasibility of the algorithm is proved by the simulation experiment and the good control quality is obtained.In order to reduce the deviation between the set value and the output value,so as to reduce the overshoot and enhance the stability of the system,the concept of pressure fixed value planning is proposed.Finally,the multivariable generalized predictive centralized control algorithm is used to control the system.The simulation results show that the algorithm can achieve good control results.