Inertial energy storage device and synchronous rotary electrical machine for use therein

• US 4,631,456 A
• Filed: 09/17/1984
• Issued: 12/23/1986
• Est. Priority Date: 03/22/1982
• Status: Expired due to Term

• Current Assignee: Charles Stark Draper Laboratory Incorporated
• Original Assignee: Charles Stark Draper Laboratory Incorporated
• Inventors: Eisenhaure, David B., Whipple, David C., Hockney, Richard L., Johnson, Bruce G., Drescher, Robert D., St. George, Emery Jr.
• Primary Examiner(s): Shoop, Jr., William M.
• Assistant Examiner(s): Ro, Bentsu
• Application Number:
  US06/651,071
• Time in Patent Office: 827 Days
• Field of Search: 318/140, 318/150, 318/161, 318/254, 322/4, 310/74, 310/153, 310/154, 310/113, 310/145, 310/156, 310/162, 310/164
• US Class Current: 318/140
• CPC Class Codes: H02K 21/44 with armature windings wound upon the magnets
• CPC Class Codes: H02K 29/06 with position sensing devices H02K29/03 takes precedence
• CPC Class Codes: H02K 7/025 for power storage
• CPC Class Codes: Y02E 60/16 Mechanical energy storage, e.g. flywheels or pressurised fluids
• CPC Class Codes: Y10T 74/2117 Power generating-type flywheel

Abstract

An inertial energy storage device including a synchronous rotary electrical machine for bidirectional conversion between mechanical and electrical energy including: a stator having two axially spaced sets of circumferentially spaced teeth; field excitation means disposed on the stator to provide an axially polarized magnetic field; stator windings including a plurality of coils, each of which surrounds at least one tooth from each set; and a rotor having a plurality of circumferentially spaced teeth facing the stator teeth, and a circumferential flywheel mass radially spaced from its rotational axis; and a motor control circuit including sensor means for sensing the position of the rotor relative to the stator; means, responsive to the sensor means, for generating a waveform for driving the machine when it is operating as a motor; a voltage control circuit for controlling the amplitude of the waveform for driving the machine; and a current control circuit for controlling amplitude of the current provided to the machine.

Claims

1. A synchronous rotary electrical machine for bidirectional conversion between mechanical and electrical energy comprising:

a stator having two axially spaced sets of circumferentially spaced teeth;

axially polarized field excitation means disposed on said stator to provide an axially polarized magnetic field;

a rotor having a plurality of circumferentially spaced magnetic poles facing said stator teeth and magnetic means interconnecting adjacent rotor poles; and

stator windings distinct from said field excitation means and including a plurality of coils, each of which surrounds, from one of said sets, at least one tooth which is covered by a rotor pole and, from the other of said sets, at least one tooth which is not simultaneously covered by a pole.

2. The machine of claim 1 in which said rotor is external to said stator.

3. The machine of claim 1 in which said rotor includes a circumferential flywheel mass radially spaced from its rotational axis.

4. The machine of claim 1 in which said field excitation means includes a permanent magnet.

5. The machine of claim 1 in which said field excitation means is disposed on said stator between said sets of teeth.

6. The machine of claim 1 in which the teeth of one of said sets of teeth on said stator are offset with respect to the teeth on the other set on said stator.

7. The machine of claim 1 in which said plurality of teeth on said rotor includes two axially spaced sets of circumferentially spaced teeth.

8. The machine of claim 1 in which the teeth of one of said sets of teeth on said rotor are offset with respect to the teeth on the other set on said rotor.

9. The machine of claim 1 further including rectifier means for converting an a.c. output of said stator windings to d.c. when said machine is operated as a generator.

10. The machine of claim 1 further including a motor control circuit including sensor means for sensing the position of said rotor relative to said stator and means, responsive to said sensor means, for generating a waveform for driving said machine when it is operating as a motor.

11. The machine of claim 10 in which said motor control circuit further includes a voltage control circuit for controlling the amplitude of said waveform for driving said machine.

12. The machine of claim 11 in which said voltage control circuit includes a frequency detector circuit for comparing the frequency of the output from said sensor means with the maximum frequency of said machine and providing a signal indicative thereof to adjust the amplitude of the input to said machine.

13. The machine of claim 10 in which said motor control circuit further includes a current control circuit for controlling the amplitude of the current provided to said machine.

14. The machine of claim 13 in which said current control circuit includes current sensor means for sensing the current flowing in said stator windings and means, responsive to said current sensor means, for adjusting the current supplied to said machine.

15. The machine of claim 10 in which said sensor means includes an optical sensor.

16. The machine of claim 10 in which said means for generating a waveform includes a signal generator and a phase detector, responsive to said sensor means and said signal generator, for keeping said signal generator output in phase with the output from said sensor means.

17. The machine of claim 16 in which said signal generator includes a voltage controlled oscillator.

18. The machine of claim 16 in which said means for generating a waveform includes a switching circuit driven by the output of said signal generator.

19. The machine of claim 16 in which said means for generating a waveform includes a starter circuit for initially driving said signal generator;

switching means for supplying the input of said signal generator an output from one of said starter circuit and said phase detector; and

detector means for operating said switching means to connect said phase detector to said signal generator and disconnect said starter circuit when said phase detector first detects a phase null.

20. The device of claim 1 in which said rotor includes a pair of axial spaced sets of said poles.

21. The device of claim 20 in which said poles in one set are offset with respect to said poles in the other set.

22. The device of claim 1 in which said teeth in one of said axially spaced sets are aligned with those in the other said set.

23. A synchronous rotary electrical machine for bidirectional conversion between mechanical and electrical energy comprising:

a stator having two axially spaced sets of circumferentially spaced teeth;

axially polarized field excitation means disposed on said stator to provide an axially polarized magnetic field;

a rotor having a plurality of circumferentially spaced magnetic poles facing said stator teeth and magnetic means interconnecting adjacent rotor poles;

stator windings distinct from said field excitation means and including a plurality of coils, each of which surrounds, from one of said sets, at least one tooth which is covered by a rotor poles and, from the other of said sets, at least one tooth which is not simultaneously covered by a pole; and

a motor control circuit including sensor means for sensing the position of said rotor relative to said stator;

means, responsive to said sensor means, for generating waveform for driving said machine when it is operating as a motor;

a voltage control circuit for controlling the amplitude of said waveform for driving said machine;

said voltage control circuit including a frequency detector circuit for comparing the frequency of the output from said sensor means with a maximum frequency of said machine and providing a signal indicative thereof to adjust the amplitude of the input to the machine.

24. The machine of claim 23 in which said motor control circuit further includes a current control circuit for controlling the amplitude of the current provided to said machine.

25. The machine of claim 24 in which said current control circuit includes current sensor means for sensing the current flowing in said stator windings and means, responsive to said current sensor means, for adjusting the current supplied to said machine.

26. The machine of claim 23 in which said sensor means includes an optical sensor.

27. the machine of claim 23 in which said means for generating a waveform includes a signal generator and a phase detector, responsive to said sensor means and said signal generator, for keeping said signal generator output in phase with the output from said sensor means.

28. The machine of claim 27 in which said signal generator includes a voltage controlled oscillator.

29. The machine of claim 27 in which said means for generating a waveform includes a switching circuit driven by the output of said signal generator.

30. The machine of claim 27 in which said means for generating a waveform includes a starter circuit for initially driving said signal generator;

switching means for supplying the input of said signal generator an output from one of said starter circuit and said phase detector circuit; and

detector means for operating said switching means to connect said phase detector to said signal generator and disconnect said starter circuit when said phase detector first detects a phase null.

31. A motor control circuit for a synchronous rotary electrical machine having a rotor and a stator, comprising:

means for sensing the position of the rotor relative to the stator;

means, responsive to said sensing means, for generating a waveform for driving said machine as a motor;

a voltage control circuit for controlling the amplitude of said waveform for driving said machine; and

a current control circuit for controlling amplitude of the current provided to said machine;

said means for generating a waveform including a signal generator, a phase detector, responsive to said sensing means and said signal generator, for keeping said signal generator output in phase with the output from said sensing means, a starter circuit for initially driving said signal generator, switching means for supplying the input of said signal generator with output from one of said starter circuit and said phase detector, and detector means for operating said switching means to connect said phase detector to said signal generator and disconnect said starter circuit when said phase detector first detects a phase null.

32. The machine of claim 31 in which said motor control circuit further includes a voltage control circuit for controlling the amplitude of said waveform for driving said machine.

33. The machine of claim 32 in which said voltage control circuit includes a frequency detector circuit for comparing the frequency of the output from said sensing means with the maximum frequency of said machine and providing a signal indicative thereof to adjust the amplitude of the input to said machine.

34. The machine of claim 31 in which said sensing means includes an optical sensor.

35. The machine of claim 31 in which said signal generator includes a voltage controlled oscillator.

36. The machine of claim 31 in which said means for generating a waveform includes a switching circuit driven by the output of said signal generator.

37. The machine of claim 31 in which said current control circuit includes current sensor means for sensing the current flow in said stator windings and means, responsive to said current sensor means, for adjusting the current supplied to said machine.

38. An inertial storage device comprising:

a synchronous rotary electrical machine for bidirectional conversion between mechanical and electrical energy, including a stator having two axially spaced sets of circumferentially spaced teeth;

field excitation means disposed on said stator to provide an axially polarized magnetic field;

stator windings including a plurality of coils, each of which surrounds at least one tooth from each set; and

a rotor having a plurality of circumferentially spaced teeth facing said stator teeth and a circumferential flywheel mass radially spaced from its rotational axis; and

a motor control circuit including sensor means for sensing the position of said rotor relative to said stator;

means, responsive to said sensor means, for generating a waveform for driving said machine when it is operating as a motor;

a voltage control circuit for controlling the amplitude of said waveform for driving said machine; and

a current control circuit for controlling amplitude of the current provided to said machine;

said means for generating a waveform including a signal generator, a phase detector, responsive to said sensor means and said signal generator, for keeping said signal generator output in phase with the output from said sensor means, a starter circuit for initially driving said signal generator, switching means for supplying the input of said signal generator with output from one of said starter circuit and said phase detector circuit, and detector means for operating said switching means to connect said phase detector to said signal generator and disconnect said starter circuit when said phase detector first detects a phase null.

39. A motor control circuit for generating a waveform for driving a synchronous rotary electrical machine having a stator including two axially spaced sets of circumferentially spaced teeth, field excitation means on said stator, stator windings including a plurality of coils each of which surrounds at least one tooth from each set and rotor having a plurality of circumferentially spaced teeth, and means for sensing the position of the rotor relative to the stator, the circuit comprising:

means, responsive to said sensing means, for generating a waveform for driving said machine as a rotor;

a voltage control circuit for controlling the amplitude of said waveform for driving said machine;

a current control circuit for controlling amplitude of the current provided to said machine;

said means for generating a waveform including a signal generator, a phase detector, responsive to said sensing means and said signal generator, for keeping said signal generator output in phase with the output from said sensing means, a starter circuit for initially driving said signal generator, switching means for supplying the input of said signal generator with output from one of said starter circuit and said phase detector, and detector means for operating said switching means to connect said phase detector to said signal generator and disconnect said starter circuit when said phase detector first detects a phase null.

40. A synchronous rotary electrical machine for bidirectional conversion between mechanical and electrical energy comprising:

a stator having two axially spaced sets of circumferentially spaced teeth;

field excitation means disposed on said stator to provide an axially polarized magnetic field;

stator windings including a plurality of coils, each of which surrounds at least one tooth from each set;

a rotor having a plurality of circumferentially spaced teeth facing said stator teeth; and

a motor control circuit including means for sensing the position of said rotor relative to said stator and means, responsive to said sensing means, for generating a waveform for driving said machine when it is operating as a motor, said means for generating a waveform including voltage controlled oscillator and a phase detector, responsive to said sensing means and said voltage controlled oscillator, for keeping said voltage controlled oscillator output in phase with the output from said sensing means.

41. A synchronous rotary electrical machine for bidirectional conversion between mechanical and electrical energy comprising:

a stator having two axially spaced sets of circumferentially spaced teeth;

field excitation means disposed on said stator to provide an axially polarized magnetic field;

stator windings including a plurality of coils, each of which surrounds at least one tooth from each set;

a rotor having a plurality of circumferentially spaced teeth facing said stator teeth; and

a motor control circuit including means for sensing the position of said rotor relative to said stator and means, responsive to said sensing means, for generating a waveform for driving said machine when it is operating as a motor, said means for generating a waveform including a signal generator and a phase detector, responsive to said sensoring means and said signal generator, for keeping said signal generator output in phase with the output from said sensing means, said means for generating a waveform including a starter circuit for initially driving said signal generator, switching means for supplying the input of said signal generator an output from one of said starter circuit and said phase detector, and detector means for operating said switching means to connect said phase detector to said signal generator and disconnect said starter circuit when said phase detector first detects a phase null.

42. A synchronous rotary electrical machine for bidirectional conversion between mechanical and electrical energy comprising:

a stator having two axially spaced sets of circumferentially spaced teeth;

field excitation means disposed on said stator to provide an axially polarized magnetic field;

stator windings including a plurality of coils, each of which surrounds at least one tooth from each set;

a rotor having a plurality of circumferentially spaced teeth facing said stator teeth; and

a motor control circuit including means for sensing the position of said rotor relative to said stator;

means, responsive to said sensing means, for generating a waveform for driving said machine when it is operating as a motor;

a voltage control circuit for controlling the amplitude of said waveform for driving said machine;

said voltage control circuit including a frequency detector circuit for comparing the frequency of the output from said sensing means with a maximum frequency of said machine and providing a signal indicative thereof to adjust the amplitude of the input to the machine, said means for generating a waveform including a voltage controlled oscillator and a phase detector, responsive to said sensing means and said voltage controlled oscillator for keeping said signal generator output in phase with the output from said sensing means.

43. A synchronous rotary electrical machine for bidirectional conversion between mechanical and electrical energy comprising:

a stator having two axially spaced sets of circumferentially spaced teeth;

field excitation means disposed on said stator to provide an axially polarized magnetic field;

stator windings including a plurality of coils, each of which surrounds at least one tooth from each set;

a rotor having a plurality of circumferentially spaced teeth facing said stator teeth; and

a motor control circuit including means for sensing the position of said rotor relative to said stator;

means, responsive to said sensing means, for generating a waveform for driving said machine when it is operating as a motor, a voltage control circuit for controlling the amplitude of said waveform for driving said machine, said voltage control circuit including a frequency detector circuit for comparing the frequency of the output from said sensing means with a maximum frequency of said machine and providing a signal indicative thereof to adjust the amplitude of the input to the machine, said means for generating a waveform including a signal generator, a phase detector, responsive to said sensing means and said signal generator, for keeping said signal generator output in phase with the output from said sensing means, a starter circuit for initially driving said signal generator, switching means for supplying the input of said signal generator an output from one of said starter circuit and said phase detector and detector means for operating said switching means to connect said phase detector to said signal generator and disconnect said starter circuit when said phase detector first detects a phase null.

44. An inertial energy storage device comprising:

a synchronous rotary electrical machine for bidirectional conversion between mechanical and electrical energy including a stator having two axially spaced sets of circumferentially spaced teeth;

axially polarized field excitation means disposed on said stator to provide an axially polarized magnetic field;

a rotor having a plurality of circumferentially spaced magnetic poles facing said stator teeth and magnetic means interconnecting adjacent rotor poles;

stator windings distinct from said field excitation means and including a plurality of coils, each of which surrounds, from one of said sets, at least one tooth which is covered by a rotor pole and, from the other of said sets, at least one tooth which is not simultaneously covered by a pole; and

a motor control circuit including sensor means for sensing the position of said rotor relative to said stator; and

means, responsive to said sensor means, for generating a waveform for driving said machine when it is operating as a motor.

45. A synchronous rotary electrical machine for bidirectional conversion between mechanical and electrical energy comprising:

a stator having two axially spaced sets of circumferentially spaced teeth, the teeth in one set being aligned with those in the other set;

axially polarized field excitation means disposed on said stator to provide an axially polarized magnetic field;

a rotor having a plurality of circumferentially spaced magnetic poles facing said stator teeth and magnetic means interconnecting adjacent rotor poles; and

stator windings distinct from said field excitation means and including a plurality of coils, each of which surrounds, from one of said sets, at least one tooth which is covered by a rotor pole and, from the other of said sets, at least one tooth which is not simultaneously covered by a pole.

46. A synchronous rotary electrical machine for bidirectional conversion between mechanical and electrical energy comprising:

a stator having two axially spaced sets of circumferentially spaced teeth, the teeth in one set being offset from those in the other set;

axially polarized field excitation means disposed on said stator to provide an axially polarized magnetic field;

a rotor having a plurality of circumferentially spaced magnetic poles facing said stator teeth and magnetic means interconnecting adjacent rotor poles; and

stator windings distinct from said field excitation means and including a plurality of coils, each of which surrounds, from one of said sets, at least one tooth which is covered by a rotor pole and, from the other of said sets, at least one tooth which is not simultaneously covered by a pole.

47. A synchronous rotary electrical machine for bidirectional conversion between mechanical and electrical energy comprising:

a stator having two axially spaced sets of circumferentially spaced teeth;

axially polarized field excitation means disposed on said stator to provide an axially polarized magnetic field;

a rotor having a plurality of circumferentially spaced magnetic poles facing said stator teeth and magnetic means interconnecting adjacent rotor poles;

stator windings distinct from said field excitation means and including a plurality of coils, each of which surrounds, from one of said sets, at least one tooth which is covered by a rotor pole and, from the other of said sets, at least one tooth which is not simultaneously covered by a pole;

a motor control circuit including sensor means for sensing the position of said rotor relative to said stator; and

means, responsive to said sensor means, for generating a waveform for driving said machine when it is operating as a motor.