Wind turbine blade having an ice formation prevention sytem and a lightning protection system and method for manufacturing the blade

Patent metadata

Field	Value
Publication number	US-11873798-B2
Application number	US-202117557460-A
Country	US
Kind code	B2
Filing date	Dec 21, 2021
Priority date	Jan 12, 2021
Publication date	Jan 16, 2024
Grant date	Jan 16, 2024

Abstract

A blade for a wind turbine including heating means connected to power cables, a lightning protection system including a down conductor, and surge protection devices is provided. The heating means include a first radiant element and a second radiant element arranged adjacent to each other around a leading edge of the blade, the first radiant element being connected to the power supply cables through respective electrical connectors at the respective connection points, and the down conductor is connected to each power supply cable at the connection points through the respective surge protection device, the second radiant element being connected to the first radiant element so that the second radiant element is electrically supplied only through the first radiant element.

First claim

The invention claimed is:

1. A blade for a wind turbine comprising:
an ice formation prevention system having a heating means connected to power supply cables;
a lightning protection system including at least one lightning down conductor and configured to conduct lightning striking the blade to ground through the at least one lightning down conductor; and
surge protection devices that connect the ice formation prevention system with the lightning protection system ensuring an equipotentiality of both systems;
wherein the heating means comprise at least one first radiant element and at least one second radiant element arranged faced to each other around a leading edge of the blade, with the at least one first radiant element being connected to the power supply cables through respective connectors at respective connection points, and the at least one lightning down conductor is connected to each power supply cable at the respective connection points through a respective surge protection device, the at least one second radiant element being electrically connected to the at least one first radiant element so that the at least one second radiant element is electrically supplied only through the at least one first radiant element.

2. The blade according to claim 1 , wherein the at least one first radiant element is arranged on a bottom shell of the blade and the at least one second radiant element is arranged on an upper shell of the blade.

3. The blade according to claim 2 , wherein the lightning protection system comprises a further lightning down conductor in the upper shell connected to the at least one second radiant element through a further surge protection device, the at least one down conductor in the bottom shell and the further lightning down conductor in the upper shell being embedded in the corresponding shell, the lightning protection system being equipontentialized in both shells through the electrical connection between the at least one first radiant element and the at least one second radiant element.

4. The blade according to claim 1 , comprising a conducting means configured for electrically connecting the at least one second radiant element with the at least one first radiant element.

5. The blade according to claim 4 , wherein the at least one first radiant element and the at least one second radiant element comprise respectively a first terminal and a second terminal, with the first terminal and the second terminal of the at least one first radiant element being connected to the first terminal and the second terminal of the at least one second radiant element by the conducting means attached to the corresponding terminals.

6. The blade according to claim 5 , wherein the conducting means comprise a flat conductor or a metallic mesh directly attached to the corresponding terminals.

7. The blade according to claim 1 , wherein the at least one first radiant element is connected to a first power supply cable at a first connection point, including the blade an additional surge protection device that connects the at least one lightning down conductor with a second power supply cable at the first connection point.

8. The blade according to claim 1 , comprising spar caps extending longitudinally, each surge protector device being connected to a respective spar cap.

9. The blade according to claim 1 , wherein the heating means comprise a plurality of first radiant elements and a plurality of second radiant elements arranged around the leading edge of the blade.

10. A method for manufacturing a blade for a wind turbine according to claim 1 , comprising:
depositing in a first mold layers or sheets of fabric which form a bottom shell of the blade, the at least one first radiant element in a leading-edge area of the first mold, and at least one connecting element in contact with a cavity of the first mold and with one electrical terminal of the at least one first radiant element, the at least one connecting element being configured to define a contacting surface in the bottom shell over the electrical terminal of the at least one first radiant element;
molding the bottom shell;
connecting a first electric terminal of the at least one first radiant element to a first power supply cable, a second electric terminal of the at least one first radiant element to a second power supply cable, and the at least one lightning down conductor to each power supply cable through the respective surge protection device;
depositing in a second mold a plurality of layers or sheets of fabric which will form an upper shell of the blade, including the at least one second radiant element in a leading edge area of the second mold, and the at least one connecting element in contact with a cavity of the second mold and with one electrical terminal of the at least one second radiant element, the at least one connecting element being configured to define a contacting surface in the upper shell over the electrical terminal of the at least one second radiant element;
molding the upper shell;
closing both molds against each other, the at least one connecting element of the first mold and the at least one connecting element of the second mold facing each other, and sealing both shells forming the blade;
demolding the blade from molds removing the connecting elements; and
fixing conducting means to contacting surfaces generated by removing the connecting elements so that the at least one second radiant element is supplied electrically only through the at least one first radiant element.

11. The manufacturing method according to claim 10 , wherein a metallic block is fixed at least to the bottom shell or is embedded at least in the bottom shell, the at least one first radiant element and the first power supply cable being connected to the metallic block.

12. The manufacturing method according to claim 10 , wherein once the upper shell is formed and before closing both molds, the at least one second radiant element is connected to a further lightning down conductor through a further surge protection device housed in the upper shell, the lightning protection system being equipontentialized in both shells through the conducting means.

13. The manufacturing method according to claim 10 , wherein in each mold, the connecting elements are arranged in contact with the surface of the corresponding cavity and with the radiant elements.

14. The manufacturing method according to claim 10 , wherein the conducting means are adhered to the contacting surfaces by a curing adhesive.

15. The manufacturing method according to claim 10 , wherein the at least one connecting element is an adhesive strip which is placed in each mold for defining the contacting surfaces, the connecting elements being removed once the blade is demolded, the conducting means being adhered to the adhesive-impregnated contacting surfaces.

Assignees

• Siemens Gamesa Renewable Energy Innovation & Technology SL

Inventors

• Belmonte De Udaondo Esteban
• March Nomen Victor
• Echaniz Del Guayo Alberto

Classifications

• F03D80/30 Primary

  Lightning protection · CPC title

• B29C70/882

  partly or totally electrically conductive, e.g. for EMI shielding (conductive floors or floor coverings H05F3/025; EMI shielding in general H05K9/00) · CPC title

• B29D99/0025

  Producing blades or the like, e.g. blades for turbines, propellers, or wings · CPC title

• F03D80/301

  Lightning receptor and down conductor systems in or on blades · CPC title

• F03D80/40

  Ice detection; De-icing means · CPC title