Fractional Slot Concentrated Winding PMSM With Consequent Pole Rotor for a Low-Speed Direct Drive: Reduction of Rare Earth Permanent Magnet

This paper deals with a 44pole-48slot fractional slot concentrated winding permanent magnet synchronous machine (FSCW PMSM) for a low-speed direct drive. Two different rotor topologies, a surface permanent magnet (SPM) rotor and a consequent pole (CP) rotor, are optimized and compared both analytically and experimentally. The experimental results confirmed that an FSCW PMSM with a CP rotor can achieve almost equivalent performance at the rated state when compared to an FSCW PMSM with an SPM rotor with 33% less permanent magnet material.