48V MHSG용 클로우폴 코아의 표면 홈 가공에 따른 특성 연구

To meet the increasing market need for passenger comfort, safety and global environment protection, mild hybrid vehicles with 48V power system have been studied. The claw-pole alternator is almost universally used for power generation in modern vehicles. A main advantage of claw-pole alternator can control field flux of rotor and produce higher torque density values than conventional machines. Currently when permanent magnet is embedded in the rotor of claw pole machine, the magnetic saturation of rotor core is largely reduced. As a result of the reduction of magnetic saturation, reluctance is reduced. Thus, larger Back-EMF is attributed to the increase of flux linkage. However, the claw-pole rotor has larger temperature rising than conventional rotor because of copper loss and larger core loss than laminated cores. The increase in temperature of the rotor causes not only to reduce the efficiency of the machine from the risen copper loss, but also damage the bearings from the thermal expansion of shaft and bearings. Therefore, it is necessary to reduce loss of claw-pole rotor and improve radiation performance of heat.