Printed circuit board based exciter

• US 10,256,758 B2
• Filed: 01/05/2018
• Issued: 04/09/2019
• Est. Priority Date: 11/26/2014
• Status: Active Grant

• Current Assignee: Discovery Energy LLC
• Original Assignee: Kohler Company
• Inventors: Frampton, Isaac S., Larson, Adam
• Primary Examiner(s): Cuevas, Pedro J
• Application Number:
  US15/863,509
• Publication Number:
  US 20180131302A1
• Time in Patent Office: 459 Days
• Field of Search: 322 17, 322 19, 322 20, 322 25, 322 28, 318400, 318700
• CPC Class Codes: H02K 11/042 Rectifiers associated with rotating parts, e.g. rotor cores or rotary shafts
• CPC Class Codes: H02K 19/38 Structural association of synchronous generators with exciting machines
• CPC Class Codes: H02K 3/26 consisting of printed conductors
• CPC Class Codes: H02K 7/1815 structurally associated with reciprocating piston engines general aspects of generating sets, e.g. housing, F02B63/04
• CPC Class Codes: H02P 2101/45 for motor vehicles, e.g. car alternators
• CPC Class Codes: H02P 9/00 Arrangements for controlling electric generators for the purpose of obtaining a desired output
• CPC Class Codes: H02P 9/009 Circuit arrangements for detecting rotor position
• CPC Class Codes: H02P 9/04 Control effected upon non-electric prime mover and dependent upon electric output value of the generator
• CPC Class Codes: H02P 9/14 by variation of field H02P9/08, H02P9/10 take precedence
• CPC Class Codes: H02P 9/302 Brushless excitation
• CPC Class Codes: H02P 9/48 Arrangements for obtaining a constant output value at varying speed of the generator, e.g. on vehicle H02P9/04 - H02P9/46 take precedence

Abstract

In one embodiment, a generator includes a rotor configured to rotate in cooperation with a stator to generate electrical power. An exciter of the generator includes at least one circuit board, a stationary exciter stator, and a control circuit. The circuit board is mechanically coupled to a rotor of the generator and includes at least one coil of an electrical conductor. The stationary exciter stator is configured to induce a current in the at least one coil of the at least one circuit board. The control circuit is configured to modify the current from the at least one coil and provide the modified current to a field of the generator.

Claims

1. An exciter for a generator, the exciter comprising:

at least one circuit board mechanically coupled to a rotor of the generator, the circuit board including at least one coil of an electrical conductor;

a stationary exciter stator configured to induce a current in the at least one coil of the at least one circuit board; and

a control circuit included in the at least one circuit board, the control circuit configured to modify the current from the at least one coil and provide the modified current to a field of the generator.

2. The exciter of claim 1, wherein the station exciter stator includes a permanent magnet.

3. The exciter of claim 2, wherein the permanent magnet is one of a plurality of magnets arranged radially around an exciter armature.

4. The exciter of claim 2, further comprising:

a flux shaping component configured to provide a low-reluctance path for magnetic flux generated by the permanent magnet.

5. The exciter of claim 1, wherein the at least one coil of an electrical conductor includes traces on multiple layers of the at least one circuit board.

6. The exciter of claim 1, wherein a voltage drop across the at least one coil is less that a predetermined value caused by the armature reactance.

7. The exciter of claim 1, wherein a switching time of a field current is less than a predetermined value caused by the armature reactance.

8. The exciter of claim 6, wherein the switching time is associated with a silicon controlled rectifier (SCR) or a diode used to control the field current.

9. The exciter of claim 1, further comprising:

a torque transfer device configured to move axially with respect to a shaft of the rotor and support the at least one circuit board.

10. The exciter of claim 1, wherein the at least one includes a plurality of printed circuit board spaced apart from one another by a minimum distance.

11. The exciter of claim 10, wherein the plurality of printed circuit boards are offset from one another by an angular offset that provides an electrical phase separation.

12. A generator comprising:

a rotating assembly;

a generator controller configured to rotate with the rotating assembly; and

a circuit board configured to rotate with the rotating assembly and including a first set of traces electrically connected to the generator controller and a second set of traces configured to induce a field current.

13. The generator of claim 12, further comprising:

a shaft rotatably supporting the rotating assembly;

at least one magnet positioned, with respect to the rotating assembly, in a direction parallel to the shaft.

14. The generator of claim 13, wherein the magnet is a first magnet, wherein the at least one magnet includes a first magnet in the direction and a second magnet, with respect to the rotating assembly, in a second direction opposite to the first direction.

15. The generator of claim 12, further comprising:

a flux shaping component configured to provide a low-reluctance path for magnetic flux generated by the permanent magnet.

16. The generator of claim 12, wherein a length of the at least one magnet in a perpendicular direction perpendicular to the shaft is greater than a width in the direction parallel to the shaft of the rotating assembly.

17. The generator of claim 12, further comprising:

a plurality of printed circuit board spaced apart from one another by a minimum distance, the circuit board included in the plurality of printed circuit boards.

18. The generator of claim 12, wherein the plurality of printed circuit boards are offset from one another by an angular offset that provides an electrical phase separation.

19. A method for axially positioning a printed circuit board connected to a rotating shaft, the method comprising:

supporting a printed circuit board to be movable in a direction parallel to the rotating shaft while maintaining a rotational connection to the rotating shaft; and

adjusting a position of the printed circuit board relative to the rotating shaft.

20. The method of claim 19, further comprising:

controlling a current through windings on the printed circuit board to provide a magnetic force that adjusts the position of the printed circuit board relative to the rotating shaft.