Commutation torque ripple minimization for permanent magnet synchronous machines with Hall effect position feedback

A permanent magnet synchronous motor (PMSM) with sinusoidal flux distribution is commonly commutated using discrete rotor position feedback from Hall sensors. A commonly used stator current excitation strategy used in such a system is a six-step current waveform. Application of sinusoidal current waveforms is shown to produce smooth torque in the PMSM. This paper shows how a pseudo-sensorless rotor position estimator may be used with Hall sensors to provide sinusoidal current excitation in place of six-step currents to reduce the torque ripple associated with the six-step strategy. Performance evaluation of the rotor position estimator in a PMSM drive is provided through simulation.