Hybrid excited generator with flux control of consequent-pole rotor
First Claim
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1. An electrical machine, comprising:
- a rotor having a plurality of poles, said poles including alternate high reluctance permanent magnet poles and low reluctance consequent ferromagnetic poles;
a stator assembly having a polyphase winding thereon;
a control coil mounted on said stator assembly for generating a control flux proportional to direct current supplied to said control coil, said control flux entering the stator assembly over the entire axial length thereof; and
a ferromagnetic frame for completing the path of said control flux generated by said control coil.
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Abstract
An electrical machine utilizes a consequent pole rotor with a polyphase stator assembly and a control coil to produce a widely variable voltage output. Either constant-speed--variable-voltage performance, or variable-speed--constant-voltage performance may be easily achieved by varying the magnitude and level of D.C. current supplied to the control coil. Single and double rotor embodiments are disclosed, with cogging being easily suppressible in the double rotor embodiments.
116 Citations
34 Claims
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1. An electrical machine, comprising:
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a rotor having a plurality of poles, said poles including alternate high reluctance permanent magnet poles and low reluctance consequent ferromagnetic poles; a stator assembly having a polyphase winding thereon; a control coil mounted on said stator assembly for generating a control flux proportional to direct current supplied to said control coil, said control flux entering the stator assembly over the entire axial length thereof; and a ferromagnetic frame for completing the path of said control flux generated by said control coil.
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2. An axial gap consequent pole electrical machine, comprising:
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a rotor having a first plurality of poles thereon, said poles being alternating high reluctance poles and low reluctance poles; a first stator assembly having a polyphase winding thereon for generating an output voltage, said first stator assembly being mounted about said rotor and producing an output voltage when said rotor is turned; means for providing a variable control flux to said first plurality of poles on said rotor to vary said output voltage comprising a voltage control coil for generating a control flux proportional to direct current supplied to said control coil, said output voltage varying in response to said control flux; and a ferromagnetic frame and a ferromagnetic shaft through said rotor, wherein said ferromagnetic frame completes the path of said control flux through said ferromagnetic shaft, through said rotor including said first plurality of poles, and through said first stator assembly. - View Dependent Claims (11, 12, 13)
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3. An electrical machine, comprising:
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a consequent pole rotor having a first plurality of poles thereon, said poles being alternating high reluctance poles and low reluctance poles; a first stator assembly having a polyphase winding thereon for generating an output voltage, said first stator assembly being mounted about said rotor and producing an output voltage when said rotor is turned; and means disposed on said first stator assembly for providing a variable control flux to said first plurality of poles on said rotor to vary said output voltage. - View Dependent Claims (4)
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5. A radial air gap consequent pole electrical machine, comprising:
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a rotor having a first plurality of poles thereon, said poles being alternating high reluctance poles and low reluctance poles; a first stator assembly having a polyphase winding thereon for generating an output voltage, said first stator assembly being mounted about said rotor and producing an output voltage when said rotor is turned; and means disposed on said first stator assembly for providing a variable control flux to said first plurality of poles on said rotor to vary said output voltage, said providing means comprising a voltage control coil for generating a control flux proportional to direct current supplied to said control coil and a ferromagnetic frame for completing the path of said control flux as it passes through said first plurality of poles, said output voltage varying in response to said control flux. - View Dependent Claims (6)
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7. An axial gap consequent pole electrical machine, comprising:
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a rotor having a first plurality of poles thereon, said poles being alternating high reluctance poles and low reluctance poles; a first stator assembly having a polyphase winding thereon for generating an output voltage, said first stator assembly being mounted about said rotor and producing an output voltage when said rotor is turned; and means disposed on said first stator assembly for providing a variable control flux to said first plurality of poles on said rotor to vary said output voltage, said providing means comprising a voltage control coil for generating a control flux proportional to direct current supplied to said control coil and a ferrogmagnetic frame for completing the path of said control flux as it passes through said first plurality of poles, said output voltage varying in response to said control flux. - View Dependent Claims (8, 9, 10)
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14. An electrical machine, comprising:
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a first stator assembly having a polyphase winding thereon; a second stator assembly having a polyphase winding thereon, said polyphase winding of said first stator assembly being electrically connected to said polyphase winding of said second stator assembly to provide an electrical output; a rotor having thereon a first set of poles at one end thereof, and a second set of poles at the other end thereof, said first and second sets of poles each including alternating high reluctance permanent magnet poles and low reluctance consequent ferromagnetic poles, said first set of poles being located within said first stator assembly and said second set of poles being located within said second stator assembly, said electrical output being provided when said rotor is rotated; a voltage control coil for generating a control flux proportional to direct current supplied to said control coil, said control coil being located between said first stator assembly and said second stator assembly and around said rotor; and a cylindrical ferromagnetic frame surrounding said first stator assembly, said control coil, and said second stator assembly, said ferromagnetic frame completing the path of said control flux as it passes through said first and second set of poles, said output voltage varying in response to said control flux. - View Dependent Claims (15, 16, 17, 18, 19)
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20. An electrical machine, comprising:
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a rotor having a plurality of poles, said poles including alternate high reluctance permanent magnet poles and low reluctance consequent ferromagnetic poles; a first stator assembly having a polyphase winding thereon; a control coil mounted on said first stator assembly for generating a control flux proportional to direct current supplied to said control coil; and a ferromagnetic frame for completing the path of said control flux generated by said control coil.
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21. A method of assembling an electrical machine to provide a variable voltage, comprising the steps of:
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providing a stator assembly having a polyphase winding thereon; rotatably installing within said stator assembly a rotor having a plurality of high reluctance permanent magnet poles alternating with a plurality of low reluctance consequent ferromagnetic poles; and providing a direct current control coil on said stator assembly to apply a constant flux to the poles of said rotor with a direct current control coil so that when the current supplied to said control coil is varied, the control flux applied to the poles of said rotor is varied to cause the voltage supplied by said electrical machine to vary.
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22. An electrical machine, comprising:
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a permanent magnet rotor including a ferromagnetic yoke having a pair of oppositely disposed radially outwardly extending consequent ferromagnetic poles, a pair of permanent magnets oppositely disposed about the periphery of said ferromagnetic yoke generally between the consequent ferromagnetic poles thereof, non-ferromagnetic conducting material damper bars generally disposed between adjacent permanent magnets and ferromagnetic projections, and a retaining hoop disposed around said permanent magnets, said ferromagnetic projections, and said damper bars; a polyphase winding stator operably associated with said rotor to produce an output voltage when said rotor is turned; and means operably associated with said stator to control the output voltage therefrom. - View Dependent Claims (23, 24, 25, 26)
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27. An electrical machine, comprising:
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a permanent magnet rotor including a ferromagnetic yoke having a pair of oppositely disposed radially outwardly extending consequent ferromagnetic poles, a pair of permanent magnets oppositely disposed about the periphery of said ferromagnetic yoke generally between the consequent ferromagnetic poles thereof, non-ferromagnetic conducting material damper bars generally disposed between adjacent permanent magnets and ferromagnetic projections, and a retaining hoop disposed around said permanent magnets, said ferromagnetic projections, and said damper bars; a stator having a first polyphase winding core disposed about one end of said rotor and a second polyphase winding core disposed about the other end of said rotor and electrically connected to said first polyphase winding core; and a voltage control coil mounted on said stator between said first and second polyphase winding cores to generate a control flux proportional to direct current supplied to said voltage control coil.
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28. A method of developing a variable voltage from an electrical machine, comprising the steps of:
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rotating a rotor having a plurality of high reluctance permanent magnet poles alternating with a plurality of low reluctance consequent ferromagnetic poles within a stator assembly having a polyphase winding thereon; applying a constant flux to the poles of said rotor with a direct current control coil; and varying the current supplied to said control coil to vary the control flux applied to the poles of said rotor to cause the voltage supplied by said electrical machine to vary.
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29. An electrical machine comprising:
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a permanent magnet rotor including an axially extending ferromagnetic shaft, a ferromagnetic yoke disposed around one end of said axially extending ferromagnetic shaft and having a pair of oppositely disposed radially outwardly extending consequent ferromagnetic poles, a pair of permanent magnets oppositely disposed about the periphery of said ferromagnetic yoke generally between the consequent ferromagnetic poles thereof, non-ferromagnetic conducting material damper bars generally disposed between adjacent permanent magnets and ferromagnetic projections, and a retaining hoop disposed around said permanent magnets; a polyphase winding stator disposed about the other end of said axially extending ferromagnetic shaft; and a voltage control coil mounted on said stator opposite to said rotor to provide a variable control flux to said permanent magnet rotor.
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30. An electrical machine, comprising:
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a permanent magnet rotor having a first set of alternating high reluctance permanent magnet poles and low reluctance consequent ferromagnetic poles at one end thereof and a second set of alternating high reluctance permanent magnet poles and low reluctance consequent ferromagnetic poles at the other end thereof; a stator having a first polyphase winding core disposed about the first set of poles at one end of said rotor and a second polyphase winding core disposed about the second set of poles at the other end of said rotor and electrically connected to said first polyphase winding core; and a voltage control coil mounted on said stator between said first and second polyphase winding cores to generate a control flux proportional to direct current supplied to said voltage control coil. - View Dependent Claims (31, 32, 33, 34)
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Specification