An on-line loss minimization controller for interior permanent magnet motor drives

In this paper, an on-line adaptive loss minimization controller (ALMC) for interior permanent magnet motor drives is introduced after the minimum loss operation of these motors is analyzed. The ALMC provides a novel pattern of change in d-axis stator current to achieve a minimum drive input power at any operating condition. The operation of the ALMC results in a smooth and fast loss minimization, thus overcoming the major drawbacks of existing on-line loss minimization control approaches. The proposed ALMC provides more energy savings in comparison with other methods and extends the application of loss minimization control to a class of motor drives requiring efficient and smooth operation in the face of frequent changes in the operating point. The design and DSP implementation of the ALMC applied to an experimental 1 hp rare-earth IPM motor drive are presented. Several experimental results are given to prove the validity of the ALMC.