Control of an Ultra-supercritical Boiler System Using Affine Nonlinear Control Methods

Ultra-supercritical units are complicated nonlinear systems, which have the characteristics of strong coupling, multi disturbance, large time delay and multi variable. In order to ensure the safe operation of the systems, we study the control of ultra-supercritical boiler units. First of all, ultra-supercritical units are used as the research object, and a high accuracy model is selected. Then the linear model of the system is obtained by the method of deviation. After the linear model is decoupled, linear control is carried out under different loads. Meantime, based on the theory of affine nonlinear system, the model is solved by the method of coordinate mapping and state feedback. In the end, the simulation experiments are conducted to verify the feasibility and effectiveness of the two control strategies based on the linear control and nonlinear control law. Results illustrate that compared with the linear control strategy, the performance index of the nonlinear control strategy is better, and it is more advantageous.