Predicted and experimental anisotropy of a dual three-phase interior permanent magnet motor for sensorless rotor position control

The interest for fractional-slot permanent magnet (PM) synchronous machines is more and more increasing in re cent years. Particularly attractive is the interior PM (IPM) machine that is characterized by a rotor anisotropy. Thanks to this feature, the IPM rotor position can be detected with out sensor also at zero speed, by means of techniques based on high-frequency signal injection. The aim of this paper is to investigate, using both finite element simulations and experimental tests, the sensorless position detection capability of an IPM dual three-phase machine equipped with two fractional-slot windings. These two windings are designed to be supplied by two separate converters, yielding an increase of the fault-tolerant capability of the machine.