Multi-Objective Design Improvement of a Double-Stator Single-Rotor Axial Flux Brushless DC Motor with a Focus on Efficiency

Abstract

This study comprehensively analyzes the sizing and performance optimization of a double-stator single-rotor axial flux permanent magnet brushless DC (DSSR AFPM BLDC) motor. Key design parameters, such as outer and inner diameters, slot dimensions, number of turns per phase, and phase current, were analytically determined based on the required output power, voltage, and speed. Electrical and magnetic loadings were carefully evaluated, and total losses were calculated to estimate motor efficiency. Critical parameters, including magnet thickness, air gap length, magnetic flux densities in the stator yoke and teeth, and electric loading, were optimized using genetic algorithm (GA) and ant colony optimization (ACO) techniques to maximize efficiency. These optimization processes were carried out in MATLAB. Furthermore, the motor torque and efficiency characteristics were analyzed using the finite element method (FEM). From an application perspective, this study presents novel design improvements achieved through ACO. The initial motor efficiency of 91.01 % was improved to 91.57 % using the GA method and to 91.80 % using the ACO method.