Department of Electrical Engineering, Nanjing University of Aeronautics and Astronautics
Comprehensive optimization of an electrical machine design requires that its electromagnetic (EM) and thermal performance must be analyzed and optimized simultaneously since electric machines are heavily constrained by thermal limits. This research presents the integration of a coupled EM/thermal model that can efficiently identify the maximum current density for a given machine during static operation, into the iterative machine design optimization program. For demanding applications such as traction motors, the electric machine is frequently required to run at peak power conditions for short periods of time, causing large thermal swings. In addition to steady-state operating conditions, a transient version of the coupled EM/thermal model has been developed. This makes it significantly easier for machine designers to maximize the winding current density to achieve the highest possible torque/power ratings within thermal limits set by the winding insulation or demagnetization threshold requirements. Further, this transient model has been integrated into the optimization program to give it the capability of optimizing the machine designs for both steady-state and short-duration transient operating conditions. Although finite element (FE) analysis is a powerful analytical tool for electric machines, it is rarely used in iterative machine design optimization programs since it is computationally intensive, requiring excessive calculation times. This research introduces an approach for overcoming this obstacle using a high-throughput computing (HTC) environment that harnesses the parallel processing capabilities of large numbers of computers to evaluate many candidate designs simultaneously.