Wind turbine generators

Patent metadata

Field	Value
Publication number	US-9871407-B2
Application number	US-201214416328-A
Country	US
Kind code	B2
Filing date	Jul 23, 2012
Priority date	Jul 23, 2012
Publication date	Jan 16, 2018
Grant date	Jan 16, 2018

Abstract

A wind turbine generator (WTG) is connected to an electricity grid via a switchgear. A control system disconnects the WTG from the grid in the event of a fault and also if the grid voltage falls below its normal value for a predetermined time, to prevent the WTG from being connected when the control system is not functional. A back-up generator is started manually to recharge a battery and supply power to the control system . When the control system is fully functional, the WTG is manually re-connected to the grid. Alternatively, the control system enters a sleep mode during which the grid voltage continues to be monitored. When the grid voltage returns, the control system reverts to its wake mode and draws sufficient power from the battery to become fully functional, at which point the WTG is re-connected to the grid.

First claim

What is claimed is:

1. A method of operating a wind turbine generator (WTG) configured to selectively connect to an electricity grid, wherein the WTG comprises an auxiliary power supply and one or more auxiliary circuits, the method comprising:
(a) disconnecting, using a control system coupled with the WTG, the WTG from the electricity grid in response to detecting a condition in which a grid voltage of the electricity grid is less than a predetermined level for more than a predetermined time;
(b) transitioning the control system from a first mode into a second, low-power mode in response to detecting the condition;
(c) in response to detecting a return of the grid voltage to at least the predetermined level, (i) transitioning the control system from the second mode to the first mode and (ii) connecting the auxiliary power supply to the one or more auxiliary circuits; and
(d) in response to determining that the one or more auxiliary circuits are in a fully functional state, reconnecting the WTG to the electricity grid.

2. The method as claimed in claim 1 , wherein the method is performed automatically by the control system.

3. The method as claimed in claim 1 , wherein steps (c)(ii) and (d) are performed manually.

4. The method of claim 1 , wherein disconnecting the WTG from the electricity grid comprises communicating a first control signal to a switchgear arranged between the WTG and the electricity grid.

5. The method of claim 1 , further comprising:
in response to detecting that the grid voltage is less than the predetermined level, and prior to disconnecting the WTG from the electricity grid, transitioning the one or more auxiliary circuits from being powered by the electricity grid to being powered by the auxiliary power source.

6. The method of claim 5 , wherein transitioning the control system from a first mode into a second, low-power mode comprises:
disconnecting the one or more auxiliary circuits from the auxiliary power source,
wherein the control system is configured to monitor the grid voltage while in the second mode.

7. The method of claim 5 , wherein the auxiliary power supply comprises a battery, and wherein the predetermined time is selected such that the battery retains a residual power.

8. The method of claim 7 , wherein the auxiliary power supply further comprises a diesel generator configured to, responsive to disconnecting the WTG from the electrical grid, perform at least one of recharging the battery and powering the one or more auxiliary circuits.

9. The method of claim 1 , wherein the one or more auxiliary circuits comprises at least one of an arc detector and fault detection circuitry.

10. A control system for operating a wind turbine generator (WTG) configured to selectively connect to an electricity grid, wherein the WTG comprises an auxiliary power supply and one or more auxiliary circuits, the control system comprising:
means for monitoring a grid voltage of the electricity grid;
means for disconnecting the WTG from the electricity grid in response to detecting a condition in which the grid voltage is less than a predetermined level for more than a predetermined time, wherein the control system is configured to transition from a first mode into a second, low-power mode in response to detecting the condition;
means for connecting the auxiliary power supply to the one or more auxiliary circuits in response to detecting a return of the grid voltage to at least the predetermined level, wherein the control system is further configured to transition from the second mode to the first mode in response to detecting the return; and
means for reconnecting the WTG to the electricity grid in response to determining that the one or more auxiliary circuits are in a fully functional state.

11. The control system of claim 10 , wherein the first mode is a normal operation mode of the control system, and wherein transitioning into the second, low-power mode occurs responsive to disconnecting the WTG from the electricity grid.

12. The control system of claim 11 , wherein the second, low-power mode comprises a sleep mode of the control system.

13. The control system of claim 11 , wherein the control system comprises the one or more auxiliary circuits.

14. The control system of claim 10 , wherein the auxiliary power supply comprises a diesel generator.

15. The control system of claim 10 , wherein the auxiliary power supply comprises a battery.

16. The control system of claim 10 , wherein the means for disconnecting the WTG from the electricity grid and the means for reconnecting the WTG to the electricity grid comprises a single switching means.

17. The control system of claim 16 , wherein the single switching means comprises:
a switchgear arranged between the WTG and the electricity grid, the switchgear responsive to control signals transmitted by the control system.

18. A non-transitory computer-readable storage medium having encoded thereon computer-executable instructions that, when executed by at least one computer processor, causes the at least one computer processor to carry out an operation comprising:
disconnecting a wind turbine generator (WTG) from an electrical grid in response to detecting a condition in which a grid voltage of the electrical grid is less than a predetermined level for more than a predetermined time;
transitioning from a first mode into a second, low-power mode in response to detecting the condition;
in response to detecting a return of the grid voltage to at least the predetermined level, (i) transitioning from the second mode to the first mode and (ii) connecting an auxiliary power supply of the WTG to one or more auxiliary circuits of the WTG; and
in response to determining that the one or more auxiliary circuits are in a fully functional state, reconnecting the WTG to the electrical grid.

19. A method of operating a wind turbine generator (WTG) configured to selectively connect to an electrical grid, the method comprising:
responsive to determining that a grid voltage of the electrical grid is less than a predetermined level, transitioning one or more auxiliary circuits of the WTG from being powered by the electrical grid to being powered by an auxiliary power source of the WTG;
responsive to determining that the grid voltage is less than the predetermined level for more than a predetermined time, disconnecting the one or more auxiliary circuits from the auxiliary power source;
responsive to determining that that grid voltage has returned to at least the predetermined level, reconnecting the auxiliary power supply to the one or more auxiliary circuits; and
responsive to determining that the one or more auxiliary circuits are in a fully functional state, connecting the WTG to the electrical grid from an unconnected state.

20. A control system for a wind turbine generator (WTG), the control system comprising:
one or more computer processors configured to:
monitor a grid voltage of an electricity grid;
responsive to determining that the grid voltage is less than a predetermined level, transition one or more auxiliary circuits of the WTG from being powered by the electrical grid to being powered by an auxiliary power source of the WTG;
responsive to determining that the grid voltage is less than the predetermined level for more than a predetermined time, disconnect the one or more auxiliary circuits from the auxiliary power source;
responsive to determining that that grid voltage has returned to at least the predetermined level, reconnect the auxiliary

Assignees

• Nielsen Jesper
• Hansen Kenneth G
• Vestas Wind Sys As

Inventors

• Nielsen Jesper
• Hansen Kenneth G

Classifications

• F03D9/255

  connected to electrical distribution networks; Arrangements therefor · CPC title

• H02J9/061 Primary

  for DC powered loads · CPC title

• F05B2270/10711

  applying a low voltage ride through method · CPC title

• Y02E10/723

  Cross-Sectional Technologies · mapped topic

• G05B11/01

  electric · CPC title