Predictive Control And Its Application Of Superheated Steam Temperature In Power Plant

The superheated steam temperature of boiler superheated system in fired power station is the typical object, which has nonlinear, uncertain, large delay and inertial characteristics. At present, general PID cascade control system is mainly adopted, but it cannot work well when more disturbance varieties come or work condition is changed. Predictive control will be more suitable for this uncertain boiler superheated system control ,for it takes full advantage of the rolling optimizing and feedback adjusting effectiveness.To avoid large amounts of computation of the traditional generalized predictive control algorithm, a fast algorithm of GPC based on implicit generalized predictive control and the soft coefficient matrix is presented by exactly computing the current control action and approximately computing the future control sequence off line. The algorithm is simpler and doses not need solving the Diophantine equation and the inverse matrix so that the on-line computation burden is strongly reduced and responding speed of the system is increased, it can limit the inputs within the range of constraints required. The simulation results show that the proposed algorithm is practicable and effective. Meanwhile, implicit generalized predictive control has the characteristic of robustness when the order and parameter of the model have changed, so it can be suitable for the superheated steam temperature of boiler superheated system.Finally the simulation experiments are done for superheated steam temperature system control of sub-critical 600MW boiler, the simulation results have shown this method's validity and superior control performance index and applied foreground.