Thermal Modelling and Simulation of Brushless D.C. Motor for Electromechanical Actuation

Abstract

A lumped-parameter thermal model is described which provides both a steady-state and transient solution to the temperatures within an electrical machine. The model is sufficiently complex to identify the temperatures at most locations in the machine, including the peak temperatures in the end winding and the surface temperatures of the rotor. It is formulated out of purely dimensional information and constant thermal coefficients and is therefore easily adapted to a range of frame sizes. The thermal behaviour of the machine is accurately described by the solution of just eight linear differential equations. The model is therefore suitable for application to online temperature estimation for protection and duty-cycle evaluation. The model performance is confirmed by experimental temperature test result. The simulation has been carried out using Simpower toolbox in Simulink.

Keywords: Thermal coefficient, simulink, thermal modelling, online temperature estimation