Two-degree-of-freedom PID boiler steam temperature control method based on the internal model principle

Due to the high inertia and large time-delay characteristics of the process in controlling the boiler steam temperature, it is very challenging to design the boiler steam temperature control system. This paper proposes a two-degree-of-freedom analytical PID controller based on the internal model principle(IM-TDF-PID), to solve the problems of improving the stability, reducing overshoot and shortening the response time of boiler steam systems. The adjustment of two controller parameters provides the system with good tracking performance and interference rejection characteristics simultaneously. PD feedback is also used in the controller to improve the characteristics of large inertia of the steam. Finally, simulation results and robustness analysis of the IM-TDF-PID controller illustrate the effectiveness of reducing the time delay process when compared with conventional cascade PID controllers. The results show that the method presented in this paper can improve system control performance.