According to such characteristics of the controlled object as large inertia

large delay and nonlinearity

a model free adaptive control and PED(MFAC-PID)cascade control system with dead zone was designed

on the basis of anti interference of PID control and strong adaptability of model free adaptive control(MFAC)to inertia and delay system.Moreover

taking the selective non-catalytic reduction(SNCR)flue gas denitration system in Midong Thermal Power Plant as the object

the system simulation model was established

and the MATLAB software was applied to compare the two control methods.The results show that

under conditions with step disturbance and model mismatch

the MFAC-PID cascade control system with dead zone has smaller overshoot and shorter settling time than the conventional PID cascade control system.Under unit load disturbance condition

the MFAC-PID cascade control system with dead zone has very small fluctuation.Therefore

the MFAC-PID cascade control system with dead zone can better adapt to the changes of object parameters

and has strong robustness and adaptability.