Method of Mitigating Heat generated by rotor of a 45kW-Class Magnetic Geared-Permanent Magnet Synchronous Motor

Subways are the most common transportation in South Korea, but they are very expensive to build and maintain and lack door-to-door connectivity, so trams are being proposed to compensate. Problems with the tram's drive system are more likely to lead to operation impediments, which can have a significant impact on traffic flow on existing roads. Therefore, it is proposed a new drive system, Magnetic Geared Permanent Magnet Synchronous Motor(MG-PMSM), magnetic gears and electric motors form a single system which don't have a direct contact with each other so wouldn't cause operation impediments. However, after manufacturing a 45kW-class MG-PMSM, it was found that a large amount of heat was generated during the no-load test from outer rotor(Pole-pieces). It has been concluded that the heat was caused by poor insulation of the bolts inserted to join the pole-pieces during the stacking process. Therefore, this paper aims to explain the discrepancy between the analytical and experimental values and suggests where and how to improve the insulation to prevent such occurrences