The Design of the Proportional/Proportional-Integral H∞ Performance Observer for the Boiler Steam Temperature Control

The boiler steam temperature is a multi-order-inertia plant with big parameter disturbances. So the two state observers with H-infinite performance are designed. By regulating the coefficient factors beta and gamma, and solving a LMI problem, the observers can be obtained without the knowledge of the disturbance limit, which can constrain the observing error within an optimal or suboptimal range. Based on either of the observers, the compound control systems of state-feedback-and-PI are constructed. To simulate with the steam temperature models of a 300MW plant, the results show that the compound control systems have better control qualities than the traditional cascade-PID control system on the aspects of the accurateness and the quickness of the regulating process