Performance analysis of brushless DC motors including features of the control loop in the finite element modeling

A time stepping finite element model for analyzing the performance of brushless DC motors is presented. The control loop is coupled into the system equations. The eddy-currents in the permanent magnets (PM) are also taken into account in the proposed circuit-field coupled method. By representing the PM as a "squirrel cage" then the eddy-current loss in the PM can be estimated. The model can directly take care of the nonsinusoidal quantities of the supplied voltages, the phase currents and the magnetic fields.