Application Of Active Disturbance Rejection Control In Boiler System

Boiler is an very important energy conversion equipment in the process of petroleum, chemical industry, power plants and others. But at the same time, it is a typical multi-input and multi-output industrial process control system with time delay, uncertainty, nonlinearity and so on. With the progress and development of the society, the requirement of boiler control gradually to reduce energy consumption, production efficiency and clean production. However, the automation level of the boiler in our country has no way to fully meet the high requirements, so it is necessary to design a boiler control system which can not only make the boiler system operate safely and stably, but also give attention to the energy saving and emission reduction.The study object of this article is the boiler system in the whole process of water vapor thermal energy, which is simulated by SMPT-1000. Based on the process flow and the characteristics of the controlled object, the boiler control system is divided into two parts, namely, water vapor system and combustion system. According to the design principle of control system, the PID control scheme of boiler is designed, the positive and negative effects and control rules of PID controller are given. The boiler control scheme is carried out by using PCS7 to complete CFC configuration, SFC configuration and HMI, and also complete the implementation of boiler PID control system.Due to the limitation of PID control, the effective control of the boiler system is not well realized. In view of the uncertainty, nonlinear, time delay and other characteristics of the boiler system, this paper adopts the active disturbance rejection control method to control the boiler system. The superheated steam pressure is a typical uncertainty object in the boiler system. The method of least square identification is used to identify and verify the steam pressure model. The mathematical model is used to control the steam pressure by active disturbance rejection control, and the other control loop is still controlled by PID. Using MATLAB to simulate the PID control system and active disturbance rejection control system of superheated steam pressure. The control effect is compared and analyzed, and then the control scheme is implemented in the PCS7 control system. Experimental results show that the control effect of using active disturbance control is better than that of PID control. Active disturbance rejection control has very good adaptability to the uncertainty object, and it can also improve the robustness of the system parameters.