STRANGE ATTRACTORS IN BRUSHLESS DC MOTORS

This paper deals with the open-loop dynamic characteristics of smooth- air-gap brushless dc motors. The steady-state characteristics of these systems, subject to constant input voltages and constant external tor ques, are formulated, whereby it is shown that the presence of viscous damping friction can cause the system to possess multiple physical eq uilibria. Furthermore, using an affine transformation, it is shown tha t the open-loop dynamics of smooth-air-gap brushless dc motors and the Lorenz system, a system known to possess chaotic behavior, are equiva lent. Finally, computer simulations are presented that verify the exis tence of strange attractors in the open-loop dynamics of brushless dc motors.