Computer Based Motor Parameter Determination for High Speed Operation of Permanent Magnet Synchronous Machines

A method is presented which allows for the experimental determination of the characteristics of brushless PM synchronous machine parameters in the high speed operating range. The theory and real-time implementation is described for this computer based parameter identification method. Special computer assisted measuring techniques are conducted on a laboratory test setup, used to drive a commercially available 3 hp interior PM synchronous machine at up to 8000 rpm. Results are presented which show a significant variation in the machine parameters as a function of the torque angle. Magnetic non-linearities are accounted for by recomputation of the machine model over a wide range of operating points. Such model recomputation is shown to provide repeatable analysis of any brushless PM synchronous machine over its entire operating range. The authors have demonstrated that all tests can be performed with no previous knowledge of manufacturer proprietary information or results from finite element simulation.