Test of iron losses due to armature field for permanent magnet brushless DC motor

This paper presents an experiment method designed to separate the iron losses due to armature magnetic field from other losses for permanent magnet brushless DC (PMBLDC) motor. The iron losses due to armature magnetic field for the prototype PMBLDC motor with carbon fiber retaining sleeve of 30kW are tested. The temperature rise tests have been done for the prototypes with carbon fiber retaining sleeve and stainless steel sleeve. The test results show that iron losses due to armature magnetic field attribute about 45 percent of the total losses while the prototype output power is about 27kW, those in rotor is more than those in stator, and those in stainless sleeve is more than those in carbon fiber sleeve.