Boiler Drum Water Level Fuzzy Adaptive Control And Simulation

Boiler is an important power in industrial production process, boiler drum water level automatic control is the important factors affecting the safe and economic operation of unit. However, because of the boiler drum water level is nonlinear, uncertainty, and the existence of false water level and other characteristics, designing the boiler drum water level control system has brought difficulties. In order to make the boiler drum water level control system can realize the small overshoot, good tracking performance, strong anti-interference ability, quick response. This paper has mainly done the following work:(1) Through the object model and the real object in parallel, let the dynamic inversion controller close to the model to desig internal model PID control system. Compared with the cascade PID control of boiler drum water level system, the simulation results show that the internal model control method in the ability to suppress interference, maintaining the stability of the system are better than that of PID cascade control method.(2) Using fuzzy mathematics and fuzzy logic reasoning theory to design fuzzy PID controller, the controller is compared with the cascade PID control of boiler drum water level system. The simulation results show that the fuzzy control method of rapid response, smaller overshoot, stronger anti-interference ability, higher tracking accuracy.(3) Combination of the fuzzy and IM controlling theory, it uses the relative arithmetic to design the IM controller and the PID parameters can be tuned though calculating the error-e between the reference model output and the test output as well as the changing rate. The simulation results are compared with the internal model PID controller and fuzzy PID controller of boiler steam drum water level system. The simulation results show that the model reference adaptive internal model based on fuzzy PID control is faster responsed, small overshoot, strong robustness, higher accuracy and the boiler steam drum water level under the condition of model parameter mismatch, this method is better than internal model control and fuzzy PID control to maintain the stability of the system.(4) The hardware scheme is designed based on DSP boiler drum water level control system. Collecting the steam flow rate, feed flow rate and differential pressure signal, they are transmitted to the DSP executing algorithm. Then the output control valve opening to maintain the stability of the drum water level.