According to the characteristic of main steam controlled object such as large inertia and delay

an improved model free adaptive predictive control(MFAPC) scheme is designed by using the pseudo-partial-derivative dynamically to linearize a controlled system and build a predictive model.The new control method is applied to the main steam pressure cascade control system which is a typical controlled process with large time constant and large time-delay parameters in a thermal power plant.The main control loop is implemented by the MFAPC algorithm

and the inner control loop by a conventional PI controller.Simulation results convince that

compared to the traditional PID-PI cascade control system

the MFAPC-PI system has higher response speed

stronger anti-jamming performance

and better robustness for time-variable of system parameters.