Influence of saturation in brushless permanent-magnet motor drives

There is currently much interest in a brushless permanent-magnet motor drives, often described as brushless DC motors. Systems with near-sinusoidal constant-current supply are often employed and it is clear that these are closely related to permanent-magnet synchronous machines with rotor angle control. Particular attention is directed towards ways of offsetting the increase of excitation EMF with speed, to achieve a wider speed range. The author shows the influence of saturation upon the performance characteristics of drives of this type