Power generation with speed dependent magnetic field control

Patent metadata

Field	Value
Publication number	US-2020295640-A1
Application number	US-201916354731-A
Country	US
Kind code	A1
Filing date	Mar 15, 2019
Priority date	Mar 15, 2019
Publication date	Sep 17, 2020
Grant date	—

Abstract

An apparatus for generating electrical power includes a rotor configured to be rotated about a longitudinal axis by fluid flow, the rotor including a plurality of permanent magnets, and a stator including conductor windings and a core. The core includes a conductor assembly having a plurality of conductors that extend axially through the core, the plurality of conductors electrically connected and short-circuited by a conductive connector at each end of the stator. The conductor assembly is configured to limit an induced output voltage to a selected maximum value, and the induced output voltage depends on a rotor speed.

First claim

What is claimed is:

1 . An apparatus for generating electrical power, the apparatus comprising:
a rotor configured to be rotated about a longitudinal axis by fluid flow, the rotor including a plurality of permanent magnets; and a stator including conductor windings and a core, wherein the core includes a conductor assembly having a plurality of conductors that extend axially through the core, the plurality of conductors electrically connected and short-circuited by a conductive connector at each end of the stator, the conductor assembly configured to limit an induced output voltage to a selected maximum value, the induced output voltage depending on a rotor speed.

2 . The apparatus of claim 1 , wherein the apparatus is configured to supply power to a downhole component and further comprises a turbine that is mechanically connected to the rotor, the turbine configured to be rotated by downhole fluid.

3 . The apparatus of claim 2 , wherein the rotor and the stator are disposed in a housing configured to be disposed in a borehole, the housing including one or more fluid conduits, the turbine configured to be rotated by fluid circulated through the borehole and the one or more fluid conduits.

4 . The apparatus of claim 1 , wherein the conductor assembly is configured to limit the induced output voltage and supply an at least substantially constant amount of the induced output voltage at rotor speeds that exceed a threshold speed.

5 . The apparatus of claim 1 , wherein the conductor assembly is configured as a squirrel cage, and each conductive connector is a conductive ring disposed at or near an end of the stator core.

6 . The apparatus of claim 1 , wherein the plurality of conductors are circumferentially arrayed around the longitudinal axis.

7 . The apparatus of claim 6 , wherein each conductor is a solid bar made from an electrically conductive material.

8 . The apparatus of claim 1 , wherein the stator core includes a plurality of circumferentially arrayed teeth configured to support conductor windings, and each conductor of the plurality of conductors is disposed within a gap between adjacent teeth.

9 . The apparatus of claim 1 , wherein the stator surrounds the rotor.

10 . The apparatus of claim 1 , wherein each conductor of the plurality of conductors is disposed within an elongated conduit formed in a yoke of the stator core.

11 . A method of generating electrical power, the method comprising:
deploying a power generation assembly in fluid communication with a source of a fluid, the power generation assembly including: a rotor configured to be rotated about a longitudinal axis by fluid flow, the rotor including a plurality of permanent magnets; and a stator including conductor windings and a core, wherein the core includes a conductor assembly having a plurality of conductors that extend axially through the core, the plurality of conductors electrically connected and short-circuited by a conductive connector at each end of the stator, the conductor assembly configured to limit an induced output voltage of the power generation assembly to a selected maximum value, the induced output voltage depending on a rotor speed; and rotating the rotor by fluid flow, generating electricity by an interaction between magnetic fields generated by the rotor and the stator, and supplying the electricity to a component.

12 . The method of claim 11 , wherein the power generation assembly is configured to supply the electricity to a downhole component, and rotating the rotor includes rotating a turbine by downhole fluid, the turbine mechanically connected to the rotor.

13 . The method of claim 12 , wherein the rotor and the stator are disposed in a housing configured to be disposed in a borehole, the housing including one or more fluid conduits, and rotating the rotor includes rotating the turbine by downhole fluid flowing through the one or more fluid conduits.

14 . The method of claim 11 , wherein the conductor assembly is configured to limit the induced output voltage and supply an at least substantially constant amount of the induced output voltage at rotor speeds that exceed a threshold speed.

15 . The method of claim 11 , wherein the conductor assembly is configured as a squirrel cage, and each conductive connector is a conductive ring disposed at or near an end of the stator core.

16 . The method of claim 11 , wherein the plurality of conductors are circumferentially arrayed around the longitudinal axis.

17 . The method of claim 16 , wherein each conductor is a solid bar made from an electrically conductive material.

18 . The method of claim 11 , wherein the stator core includes a plurality of circumferentially arrayed teeth configured to support conductor windings, and each conductor of the plurality of conductors is disposed within a gap between adjacent teeth.

19 . The method of claim 11 , wherein the stator surrounds the rotor.

20 . The method of claim 11 , wherein each conductor of the plurality of conductors is disposed within an elongated conduit formed in a yoke of the stator core.

Assignees

• Tegeler Sebastian
• Quattrone Francesco
• Baker Hughes Oilfield Operations Llc

Inventors

• Tegeler Sebastian
• Quattrone Francesco

Classifications

• H02P9/107

  for limiting effects of overloads · CPC title

• E21B41/0085

  Adaptations of electric power generating means for use in boreholes · CPC title

• H02K7/1823 Primary

  structurally associated with turbines or similar engines · CPC title

• H02K17/00

  Asynchronous induction motors; Asynchronous induction generators · CPC title

• H02K3/18

  Windings for salient poles · CPC title