A Novel, Self-Adaptive, Reticular Loss Model Algorithm for Efficiency Enhancement in Induction Motor Drives

This work presents a novel and simple loss-model based control strategy for three-phase induction motor drives that accounts for copper losses, core losses, and magnetic saturation while also considering the variability of the machine parameters. The proposed loss model algorithm determines the optimal values of the direct-axis and quadrature-axis current components by exploiting the capability curves of the motor and building a reticular loss pattern in the dq plane by combining iso-current, iso-torque, and iso-speed trajectories, and uses a fast bisection routine to compute, for each operating condition of the motor, the optimal magnetization level that minimizes total losses with self-refinement depending on the thermal conditions of the drive. The algorithm is integrated in a standard field-oriented control scheme and implemented on a low-cost ATSAM3X8E micro controller. Validation combines simulations and an extensive experimental campaign on a 5.5 kW machine. Significant results in terms of efficiency enhancement are presented and discussed, demonstrating that the proposed control strategy considerably reduces drive power losses. The method yields a practical, computationally light pathway to efficiency-oriented operation suitable for embedded drives.