Theory and implementation of a MTPA tracking controller for anisotropic PM motor drives

Energy saving will be the key-factor of the next-generation electrical drives. Extremum-seeking techniques, and the derived injection-based Maximum Torque per Ampere (MTPA) strategies, are a step towards the optimal drive efficiency, combining implementation easiness and robustness against parameter variations. Nevertheless, due to both the heavy motor non-linearity and the presence of mixed frequency signal dynamic, not all the implementation issues have been successfully addressed yet. Along this path, the paper offers a comprehensive theoretical and experimental validation of the MTPA tracking algorithm based on high frequency signal injection, including the stability numerical proof and an extended batch of commented experimental results.