PMSM Design for Achieving a Target Torque-Speed-Efficiency Map

During the last years, the requirements for a fast and reliable design of electrical machines by applying optimization methods using finite element analysis (FEA), has become a subject of study. Due to their capabilities, permanent magnet synchronous machines (PMSMs) have become the preference choice for many applications, including electric vehicles (EVs) propulsion, water-pumping, robotics, or renewable power generation among others. This paper presents a novel methodology for designing and optimizing PMSMs using the torque-speed-efficiency map. The design-optimization algorithm requires as input, the torque-speed-efficiency map of the target motor, to define the required performance for the given application. The objective is to find the motor geometry which better approximates the target torque-speed-efficiency map. The PMSM is evaluated by using magneto-static FEA combined with direct-quadrature (d-q) electrical modeling, thus greatly reducing the computational burden when compared to conventional time-dependent FEA methods. The magneto-static FEA method calculates iron losses taking into account the magnetic flux density harmonic content by applying a time-space conversion approach. The design-optimization process takes into account the control strategy as well as losses separation, which is validated by using the public experimental data of the Toyota Prius and Camry PMSMs.