Modeling Power Losses in Electric Vehicle BLDC Motor

Abstract

In order to design an efficient motor cooling system, it is important to accurately predict the power losses which are normally dissipated in form of heat. This study presents an analytical method for estimating bearing frictional losses and numerical method for estimating electromagnetic losses for an electric vehicle BLDC motor. The power losses obtained are used as heat sources when evaluating the thermal performance of the motor. The results showed that electromagnetic losses are dominant and contribute over 80% of all losses, while bearing losses contribute about 12% of the total electric motor. The results also showed that bearing losses increase significantly with increasing speed or load.

Keywords: BLDC motor, bearing frictional losses, electromagnetic losses, joules losses, eddy current losses