Robust optimal tuning of reduced active disturbance rejection controller with limiting real minimum and application for steam temperature control in power plant

In this paper, a robust optimal tuning method of a reduced active disturbance rejection controller (RADRC) is proposed for conventional industrial processes. Robust optimal tuning was performed for high-order processes and first-order plus delay time (FOPDT) approximation models. The tuning rule is analytically derived to get the minimum integral error (IE) value under the real minimum (RM) limit to ensure the robust performance and the control performance of the system. The RM is considered as one of the robust measures that simultaneously limits the amplitude and phase margins since it coincides with the vertical asymptote of the Nyquist diagram in the high-order process and the vertical tangent in the FOPDT approximation model. This paper applies the proposed tuning method to more complex benchmark plants and analyzes its effectiveness through the results of comprehensive simulation based on it. The simulation was carried out through comparison with several previous methods, including the parameter tuning method of PID controller. The proposed method is also applied to the steam temperature control of the power plant, which shows its practical effectiveness.