Katsumi Yamazaki, Chiba Institute of Technology.
Novel designs of interior permanent magnet motors with distributed and concentratedv windings are developed by the electromagnetic field analysis in order to reduce the core and magnet eddy current losses. First, the losses in the motors are investigated by the 3-D nonlinear time-stepping finite element method that considers the rotor movement and carrier of the inverters. From the results, the main loss factors and the loss generation mechanisms are clarified. Next, automatic shape optimizations of the motor cores and magnets are carried out in order to reduce the losses. Finally, the validity of the optimizations is confirmed by the experiments with the prototype motors. The losses are effectively investigated by using the numerical techniques of the electromagnetic field decompositions into harmonic components and their origins. The automatic optimizations are stably carried out by using the adaptive finite element method. As a consequence, high-performance and practical motors have been created.