Rotating electrical machine e.g. synchronous motor, has shape of pole pieces and magnets chosen so that difference between the direct axis inductance and quadrature inductance is minimal and teeth do not have constant size

摘要

A rotating electrical machine has a rotor (200) with flux concentration and permanent magnets which are located between pole pieces and a stator (100) with wound teeth. The shape of the pole pieces and the magnets are chosen so that the difference Ld-Lq is minimal, where Ld is the direct axis inductance and Lq is the quadrature axis inductance. The teeth do not have a constant size. They become bigger with increasing distance from the rotor going out from a certain distance from their free end.