An analytical commutation law for parasitic forces and torques compensation in coreless linear motors

Abstract

For ideal coreless linear motors, simple classical commutation using three-phase sinusoidal currents is sufficient to achieve low propulsion force ripple and zero parasitic force and torque in non-driving directions. However, in nonideal coreless linear motors, there are various parasitic forces and torques for which the classical commutation cannot compensate. This paper proposes an analytical commutation law which can eliminate the parasitic forces and torques. Simulation results with a finite element method model are presented to demonstrate the effectiveness of the proposed commutation law.