A Novel magnetic-thermal bidirectional coupled model of permanent magnet motors based on subdomain methods and 3D thermal network

A computational model is proposed to consider the magnetic-thermal bidirectional coupled (MTBC) phenomenon in permanent magnet motors, based on the electromagnetic subdomain method and three dimensional (3D) thermal network. Compared with the traditional finite element (FE) and analytical methods, this model has the advantage of fast calculation speed and high precision. Firstly, independent models are established for the motor electromagnetic and thermal fields based on the subdomain method and 3D thermal network, respectively. Then, the remanent flux density of the permanent magnet (PM) is changed from an invariant value in the traditional electromagnetic subdomain model to a variable determined by the thermal network temperature in the coupled model. In this way, the interaction between the motor electromagnetic field and node temperatures of 3D thermal network can be realized. The steady-state temperature rises of the arc linear flux switching permanent magnet motor (AL FSPM) is calculated to verify the effectiveness of the MTBC model.