Torque control of a three-phase direct reluctance motor

This paper describes an open-loop torque control for a three-phase direct reluctance motor which can generate high torque at low speed. The command strategy presented in this paper consists of feeding the motor with three-phase sinewave currents. The torque ripple at low speed is considerably reduced. Moreover, the reference currents of the motor are optimised by the use of a correction factor in such a manner that the ripple torque is minimised in steady-state conditions. The correction factor is stored once off-line and can be used in-line for any application. The acoustic noise level is also reduced by the proposed driving method.