Unified active disturbance rejection control (UADRC) for electrical machines with uncertainties

Electrical machines often exhibit nonlinear dynamics, parameter uncertainties, and external disturbances that degrade the performance of conventional controllers. To address these challenges, this paper proposes a unified active disturbance rejection control (UADRC) framework that generalises traditional ADRC for a broad class of electromechanical systems. The main contribution is the formulation of a unified, machine-independent control architecture applicable to heterogeneous electrical machines. The approach employs an Extended High-Gain Observer (EHGO) to estimate error states and simultaneously compensate for internal and external disturbances. By systematically lumping nonlinearities and parametric uncertainties into a single extended state, the framework moves beyond system-specific configurations. Unlike existing approaches requiring restructuring, UADRC provides a model-agnostic design for first- and second-order systems, including DC, PMSM, and induction machines. Simulation results demonstrate superior tracking accuracy and faster disturbance rejection compared to classical methods, proving that the same tuning methodology applies across different machine models without structural reconfiguration.