Design studies of hybrid excitation motor for main spindle drive using 3D-FEA applying manufacturing constraints

This paper presents detailed design studies of the proposed permanent magnet hybrid excitation motor (HEM) for high-speed main spindle drive in machine tools based on results obtained from experiment using prototype motor. The proposed HEM has been intentionally designed using 3D-FEA for the target application. Although the basic working principle of HEM has been proven by the experimental results, the induced voltage waveforms measured have shown a large deviation from those computed by 3D-FEA due to 5th harmonics. This has been a primary factor which has degraded the drive performances of test machine. After checking the differences between the designed drawing and real prototype motor, design studies are conducted to the tested HEM using 3D-FEA. As a result, the stator parameters such as, the stator pole shoe arc angle, the stator teeth, are studied for relatively good agreement with the tested results.