Active disturbance rejection controller design for circulating fluidized bed boiler´ combustion system

The circulating fluidized bed boiler´ combustion system, is a multivariable thermal system, characterized by large time lag, long time-delay and strong coupling, thus it is not conducive to improve the control performance. In view of this, this paper firstly adopts the invariance principle to design a dynamic decoupling compensator in order to partly decouple the cross-coupling of the circulating fluidized bed and then simplify the model of decoupling compensator. Thirdly on the basis of dynamic decoupling, the linear active disturbance rejection controllers (LADRC) are designed separately to further reduce the coupling, for the extended state observer (ESO) estimates the coupling among variables and external disturbances in real time by taking them as a total disturbance, and the linear state error feedback (LSEF) control law is designed to compensate their combined effect. Finally the simulation is designed to compare the control effect between LADRC and PID control for the circulating fluidized bed boiler´ combustion system, then the results show that LADRC can provide better decoupling, stronger robust ability and disturbance rejection than PID.