A Comparative Study on Drive Cycles Performance of Laboratory PMSMs Using Efficiency Maps and Time-Stepping Approaches

Numerous studies have explored the performance of electric motors under various drive cycles, with many initially concentrating on steady-state analysis to generate efficiency maps mainly due to their simplicity and computational efficiency. However, this approach does not necessarily provide accurate insights and quantification of transient drive cycle performance, where the focus extends beyond a single steady-state operating point (OP) to the dynamic sequence of torque-speed points and the factors influencing this transient behavior. Indeed, there is only fragmented knowledge on how such transient cycles can be evaluated in smaller scale laboratory settings. To address these gaps, this study evaluates grid-based efficiency maps against time-stepping measurements for a permanent magnet synchronous motor (PMSM) across diverse drive cycles, examining both total drive cycle energies and localized performance deviations. A laboratory-based PMSM is used as the reference system, with standardized drive cycles appropriately scaled for experimental validation. Steady-state efficiency maps are constructed using a combination of finite element analysis (FEA), analytical methods, and laboratory measurements, evaluated across multiple torque-speed grid resolutions. The motor’s performance over different drive cycles, as estimated using these efficiency maps, is then evaluated and validated against direct time-stepping measurements obtained from experimental testing. A detailed quantification of the results from both study approaches is also presented.