Multiphysics thermal analysis of a high speed permanent magnet brushless DC motor

High speed permanent magnet motor is widely used and has gained more and more attention due to high power density and efficiency. However, its high speed brought up large losses and high temperature rise in the motor. In order to avoid the demagnetization of permanent magnet and damage of winding insulation caused by temperature, multiphysics thermal analysis is applied on the high speed brushless dc motor in this paper. Based on various losses calculation, finite element software Fluent is employed to analyze fluid and thermal field. From the agreement between experimental and simulation results of a 2.2kW prototype motor, the proposed method can effectively predict motor temperature, which largely reduce research cost in the design stage.