Simulation Study Of Advanced Control In Thermal System

Energy-saving and emission reduction in thermal power plant was the core of energy-saving and emission reduction in industry of electricity-generating.Coal consumption and electricity consumption rate in power plant was the focal point of energy-saving and emission reduction in industry of electricity-generating.From the reality of energy-saving, the two principal aspects of research in this article were the control parameters tuning and control strategy optimazation in coal-fire power plant.Firstly, this article introduced the self-tuning algorithm of PID parameters. Aiming at gaining the best effect on self-tuning, a new program was proposed. This program did a research on the optimization of the PID parameters. It is applied in the research that the Hooke-Jeeves algorithm which performance objectives could be specified as the function of error items. The result of simulation indicated that using different performance objectives would make diverse influence on the control quality. This program could get the most suitable formula for the specific system.Secondly, compositing the advantages of single-variable generalized predictive control and cascade control, the GPC-PID cascade control was discussed in detail, and a simulation study of the main steam temperature in power plant was carried out. A good control performance was achieved. In order to reduce the amount of calculation, a design in which the control increment gradually decreased in certain time-domain was introduced. In this design, a new algorithm of control increment attenuation was proposed. Next, because most of industrial process was multi-input and multi-output system, the centralized algorithm and distributed algorithm of MGPC (multivariable generalized predictive control) were introduced. In order to reduce the calculation in practical application, the simplify strategy which avoided calculating the inverse matrix was proposed in centralized MGPC and distributed MGPC. Moreover, it showed that the distributed MGPC algorithm had the feature of coupling in the result of simulation.Finally, the centralized and constrained distributed MGPC algorithm were both introduced in unit coordinated control system considering the the good coordination properties of MGPC algorithm. And the simulation results verified the feasibility of technologies and ideas. Meanwhile, in this advanced control, the set point depended on the reference curve of the change of load. Then a design that the set point that was set according to the actual reference curve of the load was proposed to meet the requirements of the load following to the order of electric network.