Claims
- 1. A brushless electrical machine comprising:
an unmagnetized rotor; an unmagnetized stator; at least one phase winding arranged to establish flux in a magnetic circuit in the machine including the rotor and stator; and transducer means arranged in relation to the magnetic circuit to produce a flux signal indicative of the flux in a flux path associated with the at least one phase winding.
- 2. A machine as claimed in claim 1 in which the transducer means includes a Hall-effect device.
- 3. A machine as claimed in claim 1 in which the transducer means is arranged in the flux path.
- 4. A machine as claimed in claim 3 in which the rotor defines rotor poles and the stator defines stator poles, the rotor and the stator being arranged for relative rotation to define an air gap between coincident rotor and stator poles, the transducer means being disposed adjacent the said air gap.
- 5. A machine as claimed in claim 1 in which the transducer means is attached to the stator pole of the at least one phase winding.
- 6. A machine as claimed in claim 5 in which the stator poles define pole faces, the transducer means being mounted on one of the pole faces of the at least one phase winding.
- 7. A machine as claimed in claim 6 in which the stator has an axial dimension, the transducer means being mounted part way along the said axial dimension.
- 8. A machine as claimed in claim 1 in which transducer means is operable to produce the flux signal as a voltage or current directly proportional to the flux.
- 9. A machine as claimed in claim 1 constructed as a reluctance machine.
- 10. A brushless electrical machine drive system comprising:
a brushless electrical machine having a rotor, a stator and at least one phase winding arranged to establish flux in a magnetic circuit in the machine; transducer means arranged in relation to the magnetic circuit to produce a flux signal indicative of the flux in a flux path associated with the at least one phase winding; switch means electrically connected with the at least one phase winding; and flux control means having an input signal representing the demanded output of the machine, which control means is responsive to the input signal and the flux signal to produce control signals for controlling the flux in the or each phase winding.
- 11. A system as claimed in claim 10 in which the transducer means is a Hall-effect device.
- 12. A system as claimed in claim 10 in which the transducer means is arranged in the flux path of at least one phase winding.
- 13. A system as claimed in claim 12 in which the rotor defines rotor poles and the stator defines stator poles, the rotor and stator being arranged for relative rotation to define an air gap between coincident rotor and stator poles, the transducer means being disposed adjacent the air gap.
- 14. A system as claimed in claim 12 in which the transducer means is attached to the stator pole for the at least one phase winding.
- 15. A system as claimed in claim 14 in which the stator poles define pole faces, the transducer means being mounted on the pole face of one of the stator poles for the at least one phase winding.
- 16. A system as claimed in claim 15 in which the stator has an axial dimension, the transducer means being mounted part way along said axial dimension.
- 17. A system as claimed in claim 10 in which the transducer means is operable to produce the flux signal as a voltage or current directly proportional to the flux.
- 18. A system as claimed in claim 10 constructed and arranged as a switched reluctance machine drive.
- 19. A system as claimed in claim 10 in which the flux control means is responsive to the input signal and the flux signal to produce the control signals according to a proportional, proportional-plus-integral, proportional/integral/derivative, time optimal or feedback linearized control law.
- 20. A system as claimed in claim 10, including rotor position detection means operable to produce a rotor position signal indicative of the position of the rotor relative to the stator, and in which the flux control means include timing means responsive to the rotor position signal for timing the control signals for controlling the flux in the at least one phase winding.
- 21. A system as claimed in claim 10 in which the input signal to the flux control means is a flux demand signal.
- 22. A method of controlling a brushless electrical machine having a rotor, a stator and at least one phase winding, the method comprising:
arranging transducer means in a magnetic circuit of the machine to produce a flux signal indicative of the flux in the at least one phase winding; producing an input signal representing a demanded output of the machine; and controlling energization of the at least one phase winding in response to the input signal and the flux signal.
Priority Claims (1)
Number |
Date |
Country |
Kind |
9929995.0 |
Dec 1999 |
GB |
|
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The subject matter of this application is related to the subject matter of Application No. GB 9929995.0, filed Dec. 17, 1999, priority to which is claimed under 35 U.S.C. § 119 and which is incorporated herein by reference.