The Application Research Of Generalized Predictive Control In Thermal Power Unit Load Control System

The thermal power unit load control system for fossil-fired unit is an important partto ensure energy conversion between boiler and turbine, which is a typical, strongcoupling, multi-variable, nonlinear and large delay system. This paper makes a detailedanalysis of three different load operating modes in the perspective of the process ofthermal power plant turbine unit, including boiler following mode, turbine followingmode and coordination mode. Meanwhile, characteristics of the above modes areconsidered; Reference the related documents and the empirical data, principle of leastsquare method is used to fit the mathematical model of300MW power unit. Referring toon-site plant operation data of fuel disturbance experiment in300MW power unit, thepaper verify the correctness of the parameter mathematical model, then get the dynamiccharacteristics of power unit. Through the study of the generalized predictive controltheory, a multivariable generalized predictive controller is designed in Matlab simulationplatform, comparing with conventional PID controller, the simulation results show thatthe generalized predictive controller effectively overcome the coupling of variables.Meanwhile, when the load changes for a wide range of conditions, generalized predictivecontroller also shows good control effect, the robustness of the system has improvedsignificantly. In addition, the paper also analyzes the generalized predictive control ofideological constraints, constraints attached to the proposed generalized predictivecontrol performance to overcome the situation in which the value exceeds the boundaryconstraints, the ideas in the simulation phase also achieved good control effect.In order to make generalized predictive control has reference to the actual operationof the unit, the paper briefly describes the DCS control system, making LN2000DCSsystem as an example, proposes an idea which get generalized predictive control appliedto actual experimental plant, namely that building a establishment of an independentcontrol system loops which connecting with the DCS through the communication module,DCS system determines the input and removal of generalized predictive control moduleaccording to system operation, thereby greatly enhancing the security and reliability ofsystem operation.