Design of Improved Linear Active Disturbance Rejection Control for Non-Minimum Phase Systems

Non-minimum phase systems, which are common in power generation due to their inherent instability, pose significant control challenges. To address this, an Improved Linear Active Disturbance Rejection Control (ILADRC) is proposed. This method involves decomposing the system model into minimum phase and non-minimum phase components, designing a feedforward compensator based on the minimum phase component, and developing a non-minimum phase Smith predictor compensator for the non-minimum phase part. Additionally, a rule for simplified parameter tuning of the ILADRC is introduced. The effectiveness of the proposed ILADRC was demonstrated through experiments using steam valve regulation in a turbine as a case study, compared with PID and LADRC. The results show that the proposed ILADRC outperforms existing methods in set-point tracking and disturbance rejection. Monte Carlo robustness tests further confirm the robustness advantage of the ILADRC, highlighting its significant potential for practical engineering applications.