Field-weakening performance of interior permanent magnet motors

This paper compares the field-weakening under rated and overload conditions of synchronous reluctance and interior permanent magnet motors against that of a baseline 2.2 kW induction machine. Four prototype rotors based on axially-laminated and multiple-barrier designs were built and tested in the induction machine stator. Field-weakening performance was estimated based on 50 Hz load tests at reduced voltage. It was found that the performance of the axially-laminated synchronous reluctance machine was comparable with the induction machine while the interior permanent magnet motors offered significantly better output power above rated speed. The multiple-barrier interior permanent magnet motor design gave the most promising field-weakening performance