New robust adaptive control algorithm for high performance AC drives

The paper presents a new robust structure for a model reference adaptive control (MRAC) controller for field-oriented controlled (FOC) AC motor drives which requires no prior knowledge of the drive parameters and is guaranteed to provide global asymptotic stability of the closed-loop system. This structure simplifies the design and implementation of the adaptive controller requiring less effort to synthesise than a standard MRAC system. Discussion on theoretical aspects (such as selection of a reference model, stability analysis proof, gain adaptive process, steady-state error elimination and robustness to unmodelled dynamics) are included. The paper describes many practical aspects of the implementation, such as adaptive gain analysis, adaptive rate selection, the gain variation limits, gain wind-up prevention measure and initial values. The new robust adaptive controller has been successfully implemented on a FOC drive and experiment results for dynamic tracking, sudden loading and unloading, gains adaption under different operation conditions are presented to support the robustness of the proposed controller