3D Finite Element Thermal Analysis of a Small Power PM DC Motor

The paper presents a 3D numerical analysis of the thermal behavior of a small permanent magnet DC motor, performed by Finite Element Method (FEM). The accuracy of the computed temperatures was confirmed by comparison with experimental results; a prototype of the motor was tested in the steady-state in order to calibrate the numerical model. The motor was subsequently analyzed using a transient heat transfer numerical model, under various load conditions. Given the diverse applications and demanding operating conditions, small DC servo motors must be precisely designed and rated, especially with regard to the maximum heating of their windings and sometimes in connection with special thermal restrictions set on the mounting system. Numerical simulation of the heat transfer process proves to be a valuable tool that provides a great flexibility in studying the temperature distribution inside such motors, under various load conditions.