On the basis of analyzing the features of boiler drum water level variation and the internal model control(IMC)

an IMC-based three-impulse cascade control system for water level in boiler drum was proposed.This system regards steam flow rate as the feed-forward signal.In order to overcome the interference of water pressure and flow

the PID controller was adopted in the inner loop.The IMC was adopted in the outer loop to overcome the interference of steam flow rate and keep the water level constant.Results simulated by the IMC-based boiler drum water level control system were compared with that by the PID-PID boiler drum water level control system.The results indicated that

the IMC control system can response more rapidly

and had better steady state performance

stronger robustness and higher anti-interference ability.Furthermore

the effectiveness of the IMC-based three-impulse cascade control system for boiler drum water level control was verified.