Rotor blade for a wind turbine

Patent metadata

Field	Value
Publication number	US-12078144-B2
Application number	US-202118043120-A
Country	US
Kind code	B2
Filing date	Aug 27, 2021
Priority date	Aug 28, 2020
Publication date	Sep 3, 2024
Grant date	Sep 3, 2024

Abstract

A rotor blade for a wind turbine includes a blade skin forming a suction surface and a pressure surface. An electric heating arrangement has a heating strip with a width-thickness relation configured to reduce bonding between ice and the blade skin by electrically heating a respective surface of the blade skin and to conduct lightning-strike currents of at least 10 kA. An energy transfer arrangement supplies electrical energy to the heating arrangement. An integrated lightning arrangement includes a lightning receptor mounted to a tip section of the blade and electrically connected to the heating strip such that the lightning strike is conducted from the lightning receptor to the heating strip. A grounding device is connected to a grounding arrangement of the wind turbine such that electrical energy of the lightning strike is conducted from the heating strip through the grounding device and into the grounding arrangement.

First claim

The invention claimed is:

1. A rotor blade for a wind turbine, comprising:
a root section having a blade root; a tip section having a blade tip;
a middle section between the root section and the tip section;
a blade skin forming a suction surface and a pressure surface of the rotor blade;
an electric heating arrangement comprising at least one heating strip having a width-thickness relation configured to reduce an adhesive bonding between ice and the blade skin by electrically heating a respective surface of the blade skin and to conduct lightning-caused currents of at least 10 kA;
an energy transfer arrangement electrically connected to the heating arrangement to supply electrical energy to the heating arrangement; and
an integrated lightning arrangement, comprising:
a lightning receptor mounted to the tip section and electrically connected to the heating strip such that a totality of electrical energy of a lightning strike is conducted from the lightning receptor to the heating strip; and
a grounding device mounted to or in the root section and electrically connected to a grounding arrangement of the wind turbine such that electrical energy of a lightning strike is conducted from the heating strip through the grounding device and into the grounding arrangement.

2. The rotor blade according to claim 1 , wherein the at least one heating strip has a width-thickness relation of at least 50:1.

3. The rotor blade according to claim 1 , wherein the at least one heating strip extends over 50% of a total length of the rotor blade in a longitudinal direction of the rotor blade.

4. The rotor blade according to claim 1 , wherein the heating arrangement comprises a heating loop having two of the heating strips connected to each other in the tip section, each of the heating strips having a root portion arranged in the root section, at least one of the root portions electrically connected to the energy transfer arrangement.

5. The rotor blade according to claim 1 , wherein the at least one heating strip is laminated within the blade skin.

6. The rotor blade according to claim 1 , wherein the heating arrangement is configured to introduce at least 10 kW of heat energy into the blade skin, wherein the heat energy exceeds 0.1 kW/m 2 and is not more than 20 kW/m 2 of the surface of the blade skin.

7. The rotor blade according to claim 1 , wherein the at least one heating strip is laminated within the blade skin comprises one of: a continuous solid material, a plurality of electrically connected sub-strips, a mesh ribbon, or a woven matt.

8. The rotor blade according to claim 1 , wherein the at least one heating strip is made from copper or a copper alloy having a purity of more than 80%.

9. The rotor blade according to claim 1 , wherein the heating arrangement ( 200 ) comprises an even number of the heating strips formed into respective loops of two of the heating strips per loop.

10. The rotor blade according to claim 1 , wherein the at least one heating strip comprises a plurality of parallel aligned single conductors not exceeding 50 of the single conductors.

11. A rotor of a wind turbine, comprising:
a rotatable hub;
at least one rotor blade according to the rotor blade of claim 1 rotatably mounted to the hub; and
the hub comprising a pitch assembly that rotates the rotor blade about a pitch axis.

12. The rotor according to claim 11 , wherein the energy transfer arrangement comprises a transformer device having a blade transformer portion mounted to the root section and electrically connected to the heating arrangement and a hub transformer portion mounted to the hub, wherein the transformer device provides contactless transmission of electrical energy from the hub transformer portion to the blade transformer portion.

13. A wind turbine, comprising:
a rotor, the rotor further comprising a rotatable hub;
at least one rotor blade according to the rotor blade of claim 1 rotatably mounted to the hub; and
the hub comprising a pitch assembly that rotates the rotor blade about a pitch axis.

14. A rotor blade for a wind turbine, comprising:
a root section having a blade root; a tip section having a blade tip;
a middle section between the root section and the tip section;
a blade skin forming a suction surface and a pressure surface of the rotor blade;
an electric heating arrangement comprising at least one heating strip having a width-thickness relation configured to reduce an adhesive bonding between ice and the blade skin by electrically heating a respective surface of the blade skin and to conduct lightning-caused currents of at least 10 kA;
an energy transfer arrangement electrically connected to the heating arrangement to supply electrical energy to the heating arrangement;
an integrated lightning arrangement, comprising:
a lightning receptor mounted to the tip section and electrically connected to the heating strip such that electrical energy of a lightning strike is conducted from the lightning receptor to the heating strip;
a grounding device mounted to or in the root section and electrically connected to a grounding arrangement of the wind turbine such that electrical energy of a lightning strike is conducted from the heating strip through the grounding device and into the grounding arrangement; and

wherein the heating arrangement has an overall resistance of at least 0.1 ohm and not more than 1 ohm.

15. A rotor blade for a wind turbine, comprising:
a root section having a blade root; a tip section having a blade tip;
a middle section between the root section and the tip section;
a blade skin forming a suction surface and a pressure surface of the rotor blade;
an electric heating arrangement comprising at least one heating strip having a width-thickness relation configured to reduce an adhesive bonding between ice and the blade skin by electrically heating a respective surface of the blade skin and to conduct lightning-caused currents of at least 10 kA;
an energy transfer arrangement electrically connected to the heating arrangement to supply electrical energy to the heating arrangement;
an integrated lightning arrangement, comprising:
a lightning receptor mounted to the tip section and electrically connected to the heating strip such that electrical energy of a lightning strike is conducted from the lightning receptor to the heating strip;
a grounding device mounted to or in the root section and electrically connected to a grounding arrangement of the wind turbine such that electrical energy of a lightning strike is conducted from the heating strip through the grounding device and into the grounding arrangement; and

wherein the energy transfer arrangement comprises a transformer device having a blade transformer portion mounted to the root section and electrically connected to the heating arrangement and a hub transformer portion mounted to a rotor hub of a rotor of the wind turbine, wherein the transformer device provides contactless transmission of electrical energy from the hub transformer portion to the blade transformer portion.

Assignees

• General Electric Renovables Espana Sl

Inventors

• Dharmadhikari Parag Rameshchandra

Classifications

• F05B2240/85

  Electrical connection arrangements · CPC title

• F03D80/40

  Ice detection; De-icing means · CPC title

• F03D80/30

  Lightning protection · CPC title

• Y02E10/72

  Wind turbines with rotation axis in wind direction · CPC title

• F05B2260/20

  Heat transfer, e.g. cooling · CPC title