Field-circuit simulation of the dynamics of the outer rotor permanent magnet brushless DC motor

Purpose - The purpose of this paper is to elaborate a mathematical model of dynamic operation of the permanent magnet brushless DC (BLDC) motor with outer rotor and investigate the influence of magnets width on the dynamic parameters. Design/methodology/approach - The mathematical model of the devices includes: the equation of the electromagnetic field, the electric circuit equations and equation of mechanical motion. In elaborated algorithm, all these equations are coupled - therefore they are solved simultaneously. The numerical implementation is based on finite element method and step-by-step algorithm. The non-linear-coupled field-circuit equations have been solved by using the Newton-Raphson algorithm. The computer code for dynamics simulation of the machine has been developed. Findings - The elaborated algorithm and the computer code have been applied for the 2D simulation of BLDC motor dynamics. The algorithm has a good convergence and its usefulness was proved. Various results of the analysis are presented and discussed. Originality/value - The presented approach and computer code can be successfully applied to the design and optimization of different structure of the BLDC motors.