Study of Efficiency Characteristics of Interior Permanent Magnet Synchronous Motors

This paper presents an effective method for calculating the current excitations for optimal operating condition of interior permanent magnet (IPM) synchronous machines for traction application. The relationships between torque, current amplitude, and current angle during optimal operation are studied. For a given torque and speed command, the steps of searching for the ideal current excitations can be simplified using a script developed in ANSYS Maxwell, which significantly accelerates the process of evaluating performance and creating efficiency map of an IPM machine.