Design And Application Of Coordinated Control System Based On ADRC Tchnology And Incremental Function Observer

With the increasing of the unit capacity and ultra (ultra) critical technology application, Supercritical once-through boiler unit has obtained rapid development and promotion, but the supercritical unit object characteristics are complex, including nonlinear, coupling, time-varying parameters, resulting in the characteristic of supercritical unit is not easily controlled. At the same time, rapid response of power plant side to the needs of the grid is also increasing, AGC operation mode is to become more normal.Research work on the characteristics of controlled object becomes more urgent, thus improving the existing mathematical model is one of the main research work in this paper, it is also the basis of future research work. On the basis of the study of mathematical model of a coordinated control system, the key point of this paper is to improve the model and to carry out simulation test.In addition, in the condition of ensuring the stable operation of the unit, which improve the rapid response capability of control system to meet the requirements of stable operation of power grid increasing day by day, becomes another important research topic in the field of thermal control. Because of the complex object properties, the single of control theory and method has become very difficult for controlled object.This paper focuses on the study of the incremental function observer theory(IFO-KΔx) and the active disturbance rejection control technique(ADRC),which is suitable for the nonlinear system. ADRC is fused to the original incremental state observer and PID combinated control system, which formed a new type of coordinated control system, in order to further improve the performance of control system. The new system is divided into CCS loop and superheater spray water control loop. For CCS loop, based on the learning of the concept of Professor Han Zhongxu’s generalized intelligent control system, it mainly introduce the control algorithm of ADRC to offset the adverse effects of PID algorithm, but also simplifies the control system structure. But from the simulation result, the ADRC control performance of load parts is better than that of the main steam pressure parts, the author thinks that the reason is the larger delay of the boiler system. In the coal quality disturbance experiments, we saw that not only anti-interference ability has been improved, but also the robustness of the system has been increased for control system optimized.For superheater spray water control loop,it is still using the cascade structure.This paper analyse simulation experiment of control system applied combination of increment function observer and PID, as well as integrated control system simulation experiment for the application of the ADRC algorithm and the incremental function observer and PED binding.Through comparing these two kinds of scheme with the traditional cascade control scheme we can see, IFO+PED scheme is superior in speed and accuracy than the PID+PID cascade scheme and ADRC+PID+IFO scheme, ADRC+PID+IFO scheme is superior in stability than the cascade PID+PID scheme and IFO+PID scheme, at the same time, the change amplitude of control output is the most gentle. This paper argues that the ADRC+PID+IFO scheme can be used as an alternative control scheme of superheater spray water control.In this paper, the achievements have provided a new idea and method for the design of coordinated control system in thermal control field.