Torque Constant Density in Different Type of Double Stator Permanent Magnet Brushless Dc Motor

Abstract

This paper discusses the torque constant density in different types of Double Stator Permanent Magnet Brushless DC Motor (DSPM) which are designed for portable applications. It should have high torque constant density so that it will have higher torque as well as lightweight. Previously, there have been many DSPM motor designs that only focus on increasing the torque constant and torque density. However, it is unclear which DSPM motor is the best since the torque constant and torque density are different parameters. Torque constant density will include the torque, volume and current of the motor. The objective of this research is to analyze different types of DSPM motors including the proposed Slotted Rotor DSPM motor (DSPM-SR) which produces higher torque constant density. Besides that, this paper also describes in detail the torque constant density from an electromagnetic point of view. Finite Element Analysis (FEA) and analytical calculation are used to simulate the characteristic of various double stators. The result shows that DSPM-SR has 90.5% higher back electromotive force (emf) and 87.5% higher torque than DSPM-ST. Besides that, the DSPM-SR topology has higher torque constant density about 67.27% than other DSPM motors. As a conclusion, this paper provides the overview and comparison of torque constant densities of various DSPM motors.