Patent ID: 9496768
Filing Date: 2016-11-15
CPC Classification: H02K,Y02E

Claim Text:
1. An electrical machine comprising: a first rotor/translator having an associated set of electromagnets exhibiting a respective first number of pole-pairs; a set of permanent magnets having a respective second number of pole-pairs such that the first and second numbers of pole-pairs are different; a plurality of pole-pieces arranged to modulate the fields of the sets of electromagnets and permanent magnets to produce mutually matching pole-pairs enabling magnetic coupling and hence torque transmission between the sets of electromagnets and permanent magnets; a winding selected to magnetically couple with a first harmonic of the set of electromagnets of the first rotor/translator; and a controller arranged to control a current provided to the set of electromagnets to maintain a load angle between the field generated by the set of electromagnets and the field generated by the set of permanent magnets and the plurality of pole-pieces in the range of 60° to 120°, wherein the controller is further arranged to, when the electrical machine is producing a torque less than the maximum torque of the electrical machine, reduce the current provided to the set of electromagnets to increase the load angle.