This paper aims to propose a quantitative tuning method for active disturbance rejection control (ADRC) that controls the K/(Ts+1)n-type high-order processes. An asymptote in the Nyquist curve has been observed for the first time and its mathematical expression has been deduced. An asymptote condition is provided in order to derive a parameter tuning rule under the sensitivity constraint. Although this proposed tuning rule is originally designed for a certain type of high-order processes, it can be extended to other types processes that can be approximated into the form of K/(Ts+1)n. Comparisons with different PID control strategies have been conducted for a range of cases to demonstrate the efficiency of the proposed tuning method. Finally, the effectiveness of the proposed tuning rule is experimentally verified on water tank system that exhibits high-order dynamics. Field tests on the superheater steam temperature control of a circulating fluidized bed (CFB) power plant further demonstrate its potential for applications in complex industrial processes.

Photovoltaic (PV) power forecasting is challenged by its inherent variability. Pure data-driven models struggle with generalization under data scarcity and

In this paper, we uncover a new connection between standard PI/PID controllers and active disturbance rejection control (ADRC), from which we establish formal conditions of equivalence between the two control schemes. Using the equivalence, we devise a step-by-step procedure of transitioning from PI/PID to error-based ADRC. We also show how to go from 1DOF to 2DOF ADRC while retaining a standard 2DOF PI/PID structure. Both procedures facilitate expressing error-based ADRC schemes as standard industrial 1DOF and 2DOF controllers. This allows the designed controller to have the desired characteristic of ADRC (i.e. strong robustness against internal and external uncertainties) while still being expressed in a form that is familiar to industrial practitioners, where PI/PID structures are still the workhorse of modern control systems. The results of the paper ensure backward compatibility of future ADRC-based solutions and foster the adoption of active disturbance rejection-based methods in industrial practice as a viable alternative to standard controllers. To further support the findings, a set of tests is conducted in time and frequency domain, followed by a comparative analysis in FPGA-in-the-loop simulation utilizing a realistic plant model.