Influence of current observers on the performances of a PMSM supplied by hysteresis current controlled VSI

Permanent magnet synchronous machines (PMSM) are becoming more and more attractive for use as actuators. In most industrial applications, PMSMs are supplied by trapezoidal phase current and driven by a six sector position sensor. Using classical current sensing modes, an overcurrent can appear during the commutation of the switches. The demagnetization of the PMSM rotor magnets and the increase of the torque ripple can result under such circumstances. The authors present an original means of phase current observing in a PMSM supplied by a trapezoidal hysteresis current controlled VSI. The efficiency of the proposed sensing mode has been tested by digital simulation and confirmed by experimental results