Drive motors are required to have high efficiency in a wide operating range from low speed to low load operation to high speed rotation, and their characteristics are evaluated on an efficiency map. The maximum efficiency of the drive motor is 95% or more, and improvement studies on the order of 1% are being conducted. Therefore, in order to evaluate the performance of the machine on a model basis, it requires an accuracy error within 1% of the measurements.
In this paper, we compare the simulation-based efficiency map and the actually-measured efficiency map, and analyze the difference between the two efficiency maps and the factors that cause the difference. As a result, it was found that the influence of harmonic iron loss and alternating current copper loss due to the PWM carrier is relatively large.