This paper introduces a new method to track the saliency of an AC motor fed
by a multilevel converter through measuring the dynamic current response of
the motor line currents due the IGBT switching actions. The method uses
only the fundamental PWM waveform (i.e there is no modification to the
operation of the multilevel converter) similar to the fundamental PWM
method proposed for a 2-level converter. Simulation results are provided to
demonstrate the performance of the complete sensorless speed control of a
PM motor driven by such a converter over a wide speed range. Finally the
paper introduces a comparison between the 2-level converter and the
multilevel converter in terms of the reduction of the total harmonic distortion
(THD) using the fundamental PWM method in both cases.