Analysis of flux distribution and core losses in interior permanent magnetmotor

The interior permanent magnet (IPM) motor with its robust rotor constructio n, hybrid torque production nature and flux-weakening capability is suitabl e for electric vehicle applications where wide speed and torque range is re quired. At high-speed operations, core losses become an important issue bec ause they affect efficiency and raise operating temperatures. This paper di scusses the results of two-dimensional finite element analysis into the rel ationship between flux distribution and core losses in the IPM motor. The a nalysis is further supported by flux measurements using search coils instal led in an experimental motor. Three methods of predicting the core losses i n IPM motor are also investigated. These methods are the empirical formula method, finite element computed waveform method and the search coil induced voltage method.