Performance Map Calculation of a Salient-Pole Synchronous Motor with Hairpin Winding

Leveraged by the increasing interest in electrical drives for automotive applications, variable speed drives for vehicle traction have gained more attention recently. However, this industry sector sets challenging demands on the manufacturing process of electric machines regarding scalability, repeatability and total manufacturing time. Hairpin windings are a promising option to meet these requirements. However, since hairpin windings are usually characterized by the use of large solid conductors and a low number of turns per coil, eddy-current effects should be considered. In automotive applications, the operating point an electric motor works on varies considerably. Thus, it is advisable to assess the machine's performance for a range of possible operating points. Performance maps give a clear overview of physical quantities of an electric drive for different steady-state torque-speed operating points. This work will give insight into a workflow developed to calculate performance maps for quantities such as ohmic losses and total efficiency as functions of the demanded operating point numerically. A salient-pole, wound-rotor synchronous machine is chosen as an example traction machine in the analyses. The workflow is used to evaluate the frequency-dependent losses for different points of operation.