Sensorless electric machine
View Patent ↗An electric machine that includes a rotor core made of magnetic steel; a stator configured with stationary windings therein; openings disposed within or on the rotor core; and a rotor circuit that is configured to introduce saliency based on an orientation of part of the rotor circuit in relationship to a pole location of the electric machine, where the rotor circuit is made of a conductive, non-magnetic material. A rotor component and various embodiments of electric machines are also disclosed. The present invention has been described in terms of specific embodiment(s), and it is recognized that equivalents, alternatives, and modifications, aside from those expressly stated, are possible and within the scope of the appending claims.
1. An electric machine comprising:
a rotor core comprising magnetic steel;
a stator configured with a plurality of stationary windings therein;
a plurality of openings disposed within or on the rotor core;
a plurality of permanent magnets disposed in the plurality of openings; and
a rotor circuit configured to introduce saliency based on an orientation of a portion of the rotor circuit in relationship to a pole location of the electric machine, said rotor circuit made of a conductive, non-magnetic material, wherein a portion of the rotor circuit and the plurality of permanent magnets are disposed in the same plurality of openings.
2. The electric machine of claim 1 , wherein the plurality of permanent magnets are disposed in a plurality of rows.
3. The electric machine of claim 1 , wherein the electric machine is one of an interior permanent magnet (IPM) machine and a permanent magnet (PM) machine.
4. The electric machine of claim 3 , the IPM machine comprising one of a single layer IPM, a multi-layer IPM, and a spoke-type IPM.
5. The electric machine of claim 1 , wherein the electric machine comprises a traction motor.
6. The electric machine of claim 1 , wherein the rotor circuit comprises a plurality of rotor conductors connected to a plurality of connection elements.
7. The electric machine of claim 6 , wherein at least one of the plurality of rotor conductors comprise one of a rotor bar, a multi-stranded bar, a multi-stranded wire, and a litz wire.
8. The electric machine of claim 6 , wherein a cross-sectional shape of the plurality of rotor conductors is contoured to fit a shape of the plurality of openings.
9. The electric machine of claim 1 , wherein the rotor circuit defines a configuration of at least one of a loop, a shifted loop, a cage, a shifted cage, and combinations thereof.
10. The electric machine of claim 1 , the rotor circuit comprising a plurality of rotor conductors and one or more connection elements, wherein the plurality of rotor conductors are disposed in a plurality of openings adjacent the plurality of permanent magnets.
11. The electric machine of claim 10 , further wherein the plurality of rotor conductors is disposed in one of the plurality of openings.
12. The electric machine of claim 1 , the rotor circuit comprising at least one pole circuit.
13. The electric machine of claim 12 , wherein the at least one pole circuit comprises a plurality of pole circuits.
14. The electric machine of claim 12 , wherein a quantity of the at least one pole circuit equals a quantity of poles.
15. The electric machine of claim 1 , further comprising a shaft configured to rotate within the electric machine.
16. The electric machine of claim 1 , the rotor core further comprising a plurality of laminations.
17. The electric machine of claim 16 , the plurality of openings disposed through the plurality of laminations.
18. A vehicle comprising at least one electric machine of claim 1 thereon, said electric machine configured as a traction motor; and
a vehicle support frame connected to said electric machine.
19. The vehicle of claim 18 , wherein the vehicle comprises one of an off-highway vehicle (OHV), a locomotive, a mining vehicle, and an electric-motorized railcar.