Wind turbine blade and a lightning measurement system therein

Patent metadata

Field	Value
Publication number	US-9835141-B2
Application number	US-201213560508-A
Country	US
Kind code	B2
Filing date	Jul 27, 2012
Priority date	Jul 28, 2011
Publication date	Dec 5, 2017
Grant date	Dec 5, 2017

Abstract

The invention generally relates to a blade for a wind turbine, and to a blade for a wind turbine comprising a lightning measurement system. In particular, a lightning measurement system is provided, comprising a lightning current sensor located in the blade for more accurate lightning measurements. A method of measuring a lightning strike is also provided.

First claim

What is claimed is:

1. A wind turbine blade defining a proximal end and a distal end, the wind turbine blade configured to be attached with a rotor hub at a blade root disposed at the proximal end, the wind turbine blade comprising:
at least one lightning receptor exposed at a surface of the wind turbine blade and configured to receive a lightning strike;
a down conductor coupled with the lightning receptor and configured to conduct current from the lightning strike, the down conductor disposed within the wind turbine blade and configured to be coupled with an electrical ground; and
a current measurement system, comprising:
a first current sensor and a second current sensor, each comprising a metal coil substantially circumscribing the down conductor and configured to detect magnetic field fluctuations responsive to the conducted current from the lightning strike, wherein the first current sensor is configured to measure currents within a first current range and the second current sensor is configured to measure currents within a second current range wherein the first current range is smaller than the second current range;
an analytical system configured to determine, based on an output from at least the first current sensor, one or more parameters associated with the lightning strike, and
a signal conversion unit coupled between at least the first current sensor and the analytical system, wherein the signal conversion unit is disposed within the wind turbine blade with at least a predetermined spacing distance from the blade root to thereby reduce a risk of occurrence of a flashover due to the lightning strike.

2. The wind turbine blade according to claim 1 , wherein the current measurement system is disposed within the blade and is separated from the blade root by the predetermined spacing distance, thereby reducing the risk of occurrence of the flashover.

3. The wind turbine blade according to claim 2 , wherein the wind turbine blade is included in a wind turbine, wherein an output of the current measurement system is provided to a central controller in a nacelle of the wind turbine through fiber optic cabling.

4. The wind turbine blade according to claim 1 , wherein the down conductor is coupled with a blade band disposed on an exterior surface of a blade root portion of the wind turbine blade, the blade root portion extending to the blade root, and wherein the first current sensor is mounted on an internal surface of the wind turbine blade and circumscribes the down conductor.

5. The wind turbine blade according to claim 4 , wherein the blade band is secured to the exterior surface at a predetermined second distance from the blade root, and wherein the predetermined spacing distance is equal to or greater than the predetermined second distance.

6. The wind turbine blade according to claim 1 , wherein the first current sensor is a large frequency bandwidth current sensor.

7. The wind turbine blade according to claim 6 , wherein the frequency bandwidth of the first current sensor is from 0 to 10 megahertz (MHz).

8. The wind turbine blade according to claim 1 , wherein the first current sensor is configured to measure currents within a current range from ±20 amps (A) to ±400 kiloamps (kA).

9. The wind turbine blade according to claim 8 , wherein the first current sensor is configured to measure currents within a current range from ±100 A to ±10 kA.

10. The wind turbine blade according to claim 1 , wherein the first current range is between ±20 amps (A) and ±20 kiloamps (kA), and wherein the second current range is between ±400 A and ±400 kA.

11. The wind turbine blade according to claim 10 , wherein the first current sensor and the second current sensor are identical.

12. The wind turbine blade according to claim 1 , wherein the first current sensor is a Rogowski coil-based current sensor.

13. The wind turbine blade according to claim 1 , wherein the first current sensor further comprises a sensor protection system configured to prevent dielectric breakdown.

14. The wind turbine blade according to claim 13 , wherein the sensor protection system comprises an insulation layer disposed around the metal coil and having a dielectric breakdown voltage of at least 20 kilovolts (kV).

15. A wind turbine, comprising a wind turbine blade according to claim 1 .

Assignees

• Erichsen Hans V
• Mogensen Niels Birch
• Hansen Anders Niels
• Vestas Wind Sys As

Inventors

• Erichsen Hans V
• Mogensen Niels Birch
• Hansen Anders Niels

Classifications

• Y02E10/72

  Wind turbines with rotation axis in wind direction · CPC title

• F03D80/30 Primary

  Lightning protection · CPC title