WIND TURBINE

Abstract

A wind turbine for generating electric energy including a tower equipped with rotatable nacelle with rotor which is rotatable about a horizontal rotational axis and which comprises an electric generator. The wind turbine additionally comprises a device for determining flow direction and speed of the wind and a device for or regulating the alignment of the rotor against the wind. The device for determining speed and flow direction comprises pair of receiving antennas, for obtaining electric signals using electrically influenced particles, molecules carried by the wind and are supplied to a correlation measurement device. Here, the time needed by the electrically influenced particles/molecules to traverse the distance between the receiving antennas of a pair of receiving antennas is determined. Subsequently, speed and flow direction of the wind are calculated in a computing device and are supplied to the device for controlling or regulating the alignment of the rotor.

Claims

1. A wind turbine comprising: a substantially vertical tower (1), a nacelle (3) arranged at a top of the tower (1) and rotatable about a longitudinal axis (2) of tower (1) in a controlled or regulated manner, a rotor (5) rotatable about a substantially horizontally aligned axis of rotation (4) having at least two rotor blades (6) arranged on a hub, an electrical generator (8) operatively connected to the hub, at least one device (10) for determining flow direction (s) and at least one device for determining speed (v) and the flow direction (s) of wind incident on the wind turbine, and a control or regulating device (9) at least for controlling or regulating alignment of the rotor (5) with respect to the wind incident on the wind turbine, wherein at least one device for determining the speed (v) and the flow direction (s) of the wind incident on the wind turbine comprises: at least four rectilinear receiving antennas (12.11, 12.12, 12.21, 12.22, . . . 12.N1, 12.N2) arranged to the hub, wherein N is a positive integer, that the incident wind flows past the receiving antennas (12.11, 12.12, 12.21, 12.22, 12.N1, 12.N2), and that the receiving antennas (12.11, 12.12, 12.21, 12.22, . . . 12.N1, 12.N2) are designed such that electrical signals are generated by electrostatic induction in the receiving antennas (12.11, 12.12, 12.21, 12.22, . . . 12.N1, 12.N2) by particles and molecules that are electrically influenced and carried in the incident wind and that move past the receiving antennas (12.11, 12.12, 12.21, 12.22, . . . 12.N1, 12.N2), with each two of the receiving antennas (12.11, 12.12, 12.21, 12.22, . . . 12.N1, 12.N2) forming a corresponding pair of receiving antennas ((12.11-12:12), (12:21-12:22) . . . (12.N1-12.N2)), wherein the receiving antennas (12.11, 12.12, 12.21, 12.22, . . . 12.N1, 12.N2) of a corresponding pair of receiving antennas ((12.11-12:12), (12:21-12:22) . . . (12.N1-12.N2)) are arranged in parallel at a predetermined distance (a) with respect to one another and in relation to the axis of rotation (4) of the rotor (5) one behind the other in such a way that at least part of the particles and molecules of the incident wind flow direction (s) of the incident wind moving past the first receiving antenna (12.11, 12.21, . . . 12.N1) of a corresponding pair of receiving antennas ((12.11-12.12), (12.21-12.22) . . . (12.N1-12.N2)) moves also past the second receiving antenna (12.11, 12.21, . . . 12.N1) of the corresponding pair of receiving antennas ((12.11-12.12), (12.21-12.22) . . . (12.N1-12.N2)), and the receiving antennas (12.11, 12.12, . . . 12.N1, 12. N2) of at least one corresponding pair of receiving antennas ((12.11-12.12), . . . (12.N1-12.N2)) are arranged at an angle α.sub.1 with 10°<α.sub.1<80°, with respect to the axis of rotation (4) of the rotor (5) or with respect to a plane spanned by a straight line (17) disposed between the pairs of receiving antennas ((12.11-12.12), (12.21-12.22) . . . (12.N1-12.N2)) and the axis of rotation (4) of the rotor (5), or with respect to a plane spanned by a straight line (17) disposed between the receiving antennas (12.21, 12.22, . . . 12.N1, 12.N2) of at least one other corresponding pair of receiving antennas ((12.21-12.22), . . . (12.N1-12.N2)) at an angle α.sub.2 with −10°>α.sub.2>−80°, with respect to the axis of rotation (4) of the rotor (5) or with respect to a plane spanned between the pairs of receiving antennas ((12.11-12.12), (12.21-12.22) . . . (12.N1-12.N2)) and the axis of rotation (4) of the rotor (5), at least one correlation measuring device (15) which is designed to determine by a correlation measurement time (t) needed by the electrically influenced particles and molecules carried in the incident wind to traverse the distance (a) between the receiving antennas (12.11, 12.12, 12.21, 12.22, . . . 12.N1, 12.N2) forming a corresponding pair of receiving antennas ((12.11-12.12), (12.21-12.22) . . . (12.N1-12.N2)), wherein the receiving antennas (12.11, 12.12, . . . 12.N1, 12.N2) of a first corresponding pair of receiving antennas ((12.11-12.12) . . . (12.N1-12.N2)), which are arranged at an angle a1, and the receiving antennas (12.21, 12.22 . . . 12.(N+1)1, 12.(N+1)2) of a second corresponding pair of receiving antennas ((12.21-12.22) . . . (12.(N+1)1-12.(N+1)2)), which is arranged at an angle a2 with respect to the axis of rotation (4) of the rotor (5) or with respect to a plane spanned by a straight line (17) disposed between the pairs of receiving antennas ((12.11-12.12), (12.21-12.22) . . . (12.N1-12.N2)) and the axis of rotation (4) of the rotor (5), are each connected to an input of a correlation measuring device (15), and a computing device (16) for calculating a respective speed (v.sub.1 . . . v.sub.n) from the distance (a) and time (t), which the electrically influenced particles and molecules carried in the incident wind need to traverse the distance (a) between the receiving antennas (12.11, 12:12, 12.21, 12.22 . . . 12.N1, 12.N2) forming a corresponding pair of receiving antennas ((12.11-12.12), (12.21-12.22) . . . (12.N1-12.N2)), wherein the respective speed (v.sub.1 . . . v.sub.n) is a directional component of the speed (v) of the incident wind that is perpendicular to the rectilinear receiving antennas (12.11, 12:12, 12.21, 12.22 . . . 12.N1, 12.N2) of a corresponding pair of receiving antennas ((12.11-12.12), (12.21-12.22) . . . (12.N1-12.N2)) and the speed (v) of the incident wind and the flow direction (s) of the incident wind is computed from the speeds (v.sub.1 . . . v.sub.n) of the directional components of the incident wind.

2. A wind turbine comprising: a substantially vertical tower (1), a nacelle (3) arranged at a top of the tower (1) and rotatable about a longitudinal axis (2) of the tower (1) in a controlled or regulated manner, a rotor (5) rotatable about a substantially horizontally aligned axis of rotation (4) having at least two rotor blades (6) arranged on a hub, an electrical generator (8) operatively connected to the hub, a lance (11) arranged at a tip of the hub in the axis of rotation (4) of the rotor (5) and pointing away from the hub, at least one device (10) for determining flow direction (s) and at least one device for determining speed (v) and the flow direction (s) of wind incident on the wind turbine, and a control or regulating device (9) at least for controlling or regulating alignment of the rotor (5) with respect to the wind incident on the wind turbine, wherein at least one device for determining the speed (v) and the flow direction (s) of the wind incident on the wind turbine comprises: at least four linear receiving antennas (12.11, 12.12, 12.21, 12.22, . . . 12.N1, 12.N2) arranged to the lance (11), wherein N is a positive integer, that the incident wind flows past the receiving antennas (12.11, 12.12, 12.21, 12.22, . . . 12.N1, 12.N2), and that the receiving antennas (12.11, 12.12, 12.21, 12.22, . . . 12.N1, 12.N2) are designed such that electrical signals are generated by electrostatic induction in the receiving antennas (12.11, 12.12, 12.21, 12.22, . . . 12.N1, 12.N2) by particles and molecules that are electrically influenced and carried in the incident wind and that move past the receiving antennas (12.11, 12.12, 12.21, 12.22, . . . 12.N1, 12.N2), with each two of the receiving antennas (12.11, 12.12, 12.21, 12.22, . . . 12.N1, 12.N2) forming a corresponding pair of receiving antennas ((12.11-12:12), (12:21-12:22) . . . (12.N1-12.N2)), wherein the receiving antennas (12.11, 12.12, 12.21, 12.22, . . . 12.N1, 12.N2) of a corresponding pair of receiving antennas ((12.11-12:12), (12:21-12:22) . . . (12.N1-12.N2)) are arranged in parallel at a predetermined distance (a) with respect to one another and in relation to the axis of rotation (4) of the rotor (5) one behind the other in such a way that at least part of the particles and molecules of the incident wind flow direction (s) of the incident wind moving past the first receiving antenna (12.11, 12.21, . . . 12.N1) of a corresponding pair of receiving antennas ((12.11-12.12), (12.21-12.22) . . . (12.N1-12.N2)) moves also past the second receiving antenna (12.12, 12.22, . . . 12.N2) of the corresponding pair of receiving antennas ((12.11-12.12), (12.21-12.22) . . . (12.N1-12.N2)), and the receiving antennas (12.11, 12.12, . . . 12.N1, 12.N2) of at least one corresponding pair of receiving antennas ((12.11-12.12), . . . (12.N1-12.N2)) are arranged at an angle α.sub.1 with 10°<α.sub.1 <−80°, with respect to the axis of rotation (4) of the rotor (5), and the receiving antennas (12.21, 12.22, . . . 12.N1, 12.N2) of at least one other corresponding pair of receiving antennas ((12.21-12.22), . . . (12.N1-12.N2)) are arranged at an angle α.sub.2 with −10°>α.sub.2>−80°, with respect to the axis of rotation (4) of the rotor (5), at least one correlation measuring device (15) which is designed to determine by a correlation measurement time (t) needed by the electrically influenced particles and molecules carried in the incident wind to traverse the distance (a) between the receiving antennas (12.11, 12.12, 12.21, 12.22, . . . 12.N1, 12.N2) forming a corresponding pair of receiving antennas ((12.11-12.12), (12.21-12.22) . . . (12.N1-12.N2)), wherein the receiving antennas (12.11, 12.12, . . . 12.N1, 12.N2) of a first corresponding pair of receiving antennas ((12.11-12.12) . . . (12.N1-12.N2)), which are arranged at an angle α.sub.1, and the receiving antennas (12.21, 12.22 . . .

12. (N+1)1-12.(N+1)2) of a second corresponding pair of receiving antennas ((12.21-12.22) . . . (12.(N+1)1-12.(N+1)2)), which is arranged at an angle α2 with respect to the axis of rotation (4) of the rotor (5), are each connected to an input of a correlation measuring device (15), and a computing device (16) for calculating a respective speed (v.sub.1 . . . v.sub.n) from the distance (a) and time (t), which the electrically influenced particles and molecules carried in the incident wind need to traverse the distance (a) between the receiving antennas (12.11, 12:12, 12.21, 12.22 . . . 12.N1, 12.N2) forming a corresponding pair of receiving antennas ((12.11-12.12), (12.21-12.22) . . . (12.N1-12.N2)), wherein the respective speed (v.sub.1 . . . v.sub.n) is a directional component of the speed (v) of the incident wind that is perpendicular to the linear receiving antennas (12.11, 12:12, 12.21, 12.22 . . . 12.N1, 12.N2) of a corresponding pair of receiving antennas ((12.11-12.12), (12.21-12.22) . . . (12.N1-12.N2)) and the speed (v) of the incident wind and the flow direction (s) of the incident wind in relation to the axis of rotation (4) is computed from the speeds (v.sub.1 . . . v.sub.n) of the directional components of the incident wind.

3. The wind turbine according to claim 1, wherein the receiving antennas (12.11, 12:12, 12.21, 12.22 . . . 12.N1, 12.N2), which form a corresponding pair of receiving antennas ((12.11-12.12), (12.21-12.22) . . . (12.N1-12.N2)) are constructed as mutually parallel rods or wires.

4. The wind turbine according to claim 1, further comprising a spinner (7) is arranged on the hub, and the receiving antennas (12.11, 12:12, 12.21, 12.22 . . . 12.N1, 12.N2) are arranged on a wall of the spinner (7).

5. The wind turbine according to claim 4, wherein the spinner (7) constructed of a dielectrically acting material is arranged on the hub, with the receiving antennas (12.11, 12.12, 12.21, 12.22 . . . 12.N1, 12.N2) arranged inside the wall of the spinner (7) or on an inner side of the wall of the spinner (7).

6. The wind turbine according to claim 1, wherein a spinner (7) is arranged on the hub, and a receiving antenna (12.11, 12:12, 12.21, 12.22 . . . 12.N1, 12.N2) is formed in each case by a plurality of electrically interconnected needles arranged in a line and protruding from the spinner (7).

7. The wind turbine according to claim 1, further comprising at least one electrode (13) having at least one electrode segment with an electrode contour having an average radius r.sub.m with 0.01 mm≤r.sub.m≤1.2 mm, and arranged with respect to a first receiving antenna (12.11, 12.21 . . . 12.N1) in opposition of the flow direction (s) of the wind incident on the wind turbine with respect to the axis of rotation (4) of the rotor (5) and with respect to the direction of flow (s) of the wind incident on the wind turbine at a distance of 100 mm to 1500 mm, with respect to the flow direction (s) of the wind incident on the wind turbine in front of the first receiving antenna (12.11, 12.21 . . . 12.N1) such that at least part of the wind flowing around the electrode segment having an electrode contour with an average radius r.sub.m with 0.01 mm≤r.sub.m≤1.2 mm thereafter flows past the receiving antennas (12.11, 12:12, 12.21, 12.22 . . . 12.N1, 12.N2) at the distance of <500 mm, at least one counter-electrode (18) is formed which operates electrically relative to the electrode (13), and the wind turbine comprises a high voltage source (14) with a voltage U having a magnitude of 12 kV≤|U|≤20 kV, with the electrode (13) and the counter-electrode (18) being connected different poles of the high voltage source (14).

8. The wind turbine according to claim 7, wherein the wind turbine has an electrically conductive hub and the hub is connected electrically with respect to the electrode (13) as a counter-electrode (18), that is electrically connected to a pole of the high voltage source (14).

9. The wind turbine according to claim 2, wherein the electrically conductive lance (11) is arranged on the hub and the lance (11) is electrically connected with respect to the electrode (13) as a counter-electrode (18), that is electrically connected to a pole of the high-voltage source (14).

10. The wind turbine according to claim 7, further comprising an electrically conductive spinner (7) arranged on the hub and the spinner (7) is electrically connected with respect to the electrode (13) as a counter-electrode (18), that is electrically connected to a pole of the high voltage source (14).

11. The wind turbine according to claim 7, wherein the electrode (13) is connected as a cathode and the counter-electrode (18) is connected to ground potential.

12. The wind turbine according to claim 7, wherein the electrode (13) is constructed as at least one rod protruding from a spinner (7) or as at least one needle protruding from the spinner (7).

13. The wind turbine according to claim 7, wherein the electrode (13) has one or more tips or cutting edges with a contour having an average radius r.sub.m with 0.01 mm≤r.sub.m≤1.2 mm or is constructed as a wire having an average radius r.sub.m with 0.1 mm≤r.sub.m≤1, 2 mm.

14. The wind turbine according to claim 1, wherein the receiving antennas (12.11, 12:12, 12.21, 12.22 . . . 12.N1, 12.N2) are rigidly connected to the rotatable rotor (5) and a rotation angle detection device is provided detecting the angle of rotation of the rotatable rotor (5), and the rotation angle detection device is operatively connected to the computing device (16) and the rotation angle of the rotatable rotor (5) is included in the calculation of the direction of the incident wind.

15. The wind turbine according to claim 1, wherein the receiving antennas (12.11, 12:12, 12.21, 12.22 . . . 12.N1, 12.N2) are rigidly connected to the rotatable rotor (5) and a device for detecting at least one point rotating with the rotor (5) around the axis of rotation (4) of the rotor (5) is provided, and the device for detecting at least one point rotating with the rotor (5) about the axis of rotation (4) of the rotor (5) is operatively connected to the computing device (16) and the output signals from the device for detecting at least one point that rotates with the rotor (5) about the axis of rotation (4) of the rotor (5) is included in the calculation of the direction of the incident wind.

16. The wind turbine according to claim 1, wherein the angle α.sub.1 is 15°<α.sub.1<60°; while the angle α.sub.2 is −15°>α.sub.2>−60°.

17. The wind turbine according to claim 2, wherein the angle α.sub.1 Is 15°<α.sub.1<60°; while the angle α.sub.2 is −15°>α.sub.2>−60°.

18. The wind turbine according to claim 7, wherein the least one electrode (13) is arranged with respect to the first receiving antenna (12.11, 12.21 . . . 12.N1) in opposition of the flow direction (s) of the wind incident on the wind turbine with respect to the axis of rotation (4) of the rotor (5) and with respect to the direction of flow (s) of the wind incident on the wind turbine at a distance of approximately 200 mm.

19. The wind turbine according to claim 7, wherein the voltage U of the high voltage source (14) has a magnitude of 15 kV≤|U|≤17 kV.

Description

[0025] The invention will now be explained in more detail below with reference to two exemplary embodiments. The appended drawings show in

[0026] FIG. 1: a first embodiment of a wind turbine with a lance arranged at the tip of the hub and disposed in the axis of rotation of the rotor,

[0027] FIG. 2: as a detail, the lance with an electrode and receiving antennas arranged on the tip of the hub and disposed in the axis of rotation of the rotor,

[0028] FIG. 3: a second embodiment of a wind turbine with receiving antennas arranged on a spinner,

[0029] FIG. 4 the receiving antennas arranged on the spinner in detail,

[0030] FIG. 5 another variant of the second embodiment of a wind turbine with receiving antennas arranged in the wall of a spinner,

[0031] FIG. 6 the receiving antennas arranged in the wall of a spinner in detail,

[0032] FIG. 7 a section of a wall of a spinner with receiving antennas and counter-electrode arranged therein,

[0033] FIG. 8 a cross-section of a wall of a spinner with arranged receiving antennas and counter-electrode,

[0034] FIG. 9: a cross-section of a spinner with an electrode and receiving antennas arranged on the spinner, and

[0035] FIGS. 10a-e: plan views onto an electrode arranged on the spinner and onto receiving antennas arranged on the spinner.

[0036] FIG. 1 shows a first embodiment of a wind turbine with a substantially vertical tower 1, a nacelle 3 arranged at the top of the tower 1 and controllable for rotation about the longitudinal axis 2 of the tower 1. A rotor 5 having three rotor blades 6 arranged on a hub for rotation about a substantially horizontally oriented axis of rotation 4 is arranged on the nacelle 3. The hub carries as a casing a spinner 7 and is therefore not visible. An electrical generator 8 arranged in the nacelle 3 is operatively connected with the hub. The wind turbine further includes a control or regulating device 9 for controlling or regulating the alignment of the rotor 5 with respect to the wind incident on the wind turbine and a device designed as a wind vane 10 to determine the direction of flow s of the wind incident on the wind turbine. Finally, the wind turbine includes a device for determining the speed v and the direction of flow s of the wind incident on the wind turbine. The device for determining the speed v and the direction of flow s of the wind incident on the wind turbine consists of four receiving antennas 12,11, 12.12, 12.21 and 12.22 arranged on a lance 11, an electrode 13 arranged at the tip of the lance 11, a high-voltage source 14, a correlation measuring device 15 and a computing device 16.

[0037] The lance 11 is arranged on the hub and, as shown in FIG. 2, protrudes from the tip of the spinner 7. It is located in the axis of rotation 4 of the rotor 5. At the lance 11, the four receiving antennas 12.11, 12.12, 12.21 and 12.22 are electrically insulated against each other and against the lance 11. In each case two receiving antennas 12.11, 12.12 or 12.21, 12.22, respectively, are arranged parallel to one another with a distance a therebetween and thus form a first and a second corresponding pair of receiving antennas 12.11-12.12, 12.21-12.22. The first pair of receiving antennas 12.11-12.12 is arranged at the lance 11 at an angle α.sub.1 of 40° with respect to the axis of rotation 4 of the rotor 5, and the second pair of receiving antennas 12.21-12.22 is arranged at an angle α.sub.2 of −40° with respect to the axis of rotation 4 of the rotor 5. The magnitude of the angles α.sub.1 and α.sub.2 can, but do not have to be, identical. Each receiving antenna 12.11, 12.12, 12.21, 12.22 is electrically connected to one respective input of the correlation measuring device 15. The receiving antennas 12.11, 12.12, 12.21, and 12.22 are rod-shaped and have a length of approximately 1000 mm. An electrode 13 is arranged at the tip of the lance 11 at a distance of approximately 200 mm from the first receiving antennas 12.11 and 12.21 in the direction of flow s of the incident wind. The two ends of the electrode 13 are designed in the shape of blades with a radius r.sub.m of the blade of 0.8 mm. The electrode 13 is electrically insulated with respect to the lance 11 and is electrically connected to the negative pole of the high-voltage source 14. The positive pole of the high voltage source 14 is electrically connected to the tower 1.

[0038] The method is used to determine the speed v and the direction of flow s of the incident wind. The high voltage source 14 provides an electric voltage U of −17 kV which is applied to the electrode 13. At least part of the incident wind is exposed to the effect of this electrical voltage U of −17 kV. This voltage can be directly ionize air molecules and/or particles carried in the incident wind. In addition, the electrode 13 can emit free electrons by way of field emission or electrons can be released from molecules or particles carried in the incident wind by field ionization and electrically interact with air molecules and/or particles carried in the incident wind. This creates electrical charge carriers, which in turn interact with molecules carried in the incident wind and affect them electrically. When the electrically affected molecules of the incident wind 12 flow past at the receiving antennas 12.11, 12.12, 12.21 and 12.22, electrical signals can be produced through electrostatic induction in the receiving antennas 12.11, 12.12, 12.21 and 12.22. The time t needed by the electrically influenced molecules of the incident wind to traverse the distance a between the receiving antennas 12.12 and 12.12 and 12.21 and 12.22, respectively, of a corresponding pair of receiving antennas 12.11-12.12, and 12.21-12.22 is determined from the electrical signals of the pairs of receiving antennas 12.11-12.12 and 12.21-12.22 by a correlation measurement. Two speeds v.sub.1 and v.sub.2 are then calculated by the computing device 16 from the distance a between the receiving antennas 12.12 and 12.12, and 12.21 to 12.22, respectively, of a corresponding pair of receiving antennas 12.11-12:12 or 12.21-12.22, and the times t.sub.1 and t.sub.2 needed by the electrically influenced molecules of the incident wind to traverse this distance a, which each correspond to the directional components of the speed v of the incident wind that is perpendicular to the parallel rod-shaped receiving antennas 12.11 and 12.12 or 12.21 and 12.22, respectively, of a corresponding pair of receiving antennas 12.11-12:12 or 12.21-12.22. The speed v of the incident wind and the flow direction s of the incident wind are calculated from the speeds v.sub.1 and v.sub.2 of the directional components of the speed v of the incident wind by triangulation. FIG. 6a illustrates the speeds v.sub.1 and v.sub.2 of the directional components of the speed v of the incident wind. The speed v and the flow direction s of the incident wind are supplied to the control or regulating device 9. The alignment of the rotor R with respect to the wind incident on the wind turbine is then controlled or regulated by the control or regulating device 9.

[0039] FIGS. 3 and 4 show a second embodiment of the wind machine of the invention. In contrast to the first embodiment shown in FIGS. 1 and 2, the receiving antennas 12.11, 12.12, 12.21 and 12.22 in this second embodiment are not arranged on a lance 11 protruding from the tip of the spinner 7, but instead directly on the spinner 7. Arranged on the spinner 7 are four rod-shaped receiving antennas 12.11, 12.12, 12.21 and 12.22, which are electrically insulated from one another and from the spinner 7. In each case, two receiving antennas 12.11, 12.12, and 12.21 and 12.22, respectively, are arranged parallel to one another with a mutual distance a therebetween and thus form a first and a second corresponding pair of receiving antennas 12.11-12:12 and 12:21-12:22. The first receive antenna pair 12.11-12.12 is arranged at an angle α.sub.1 of 40° with respect to a plane spanned by a straight line 17 between the pairs of receiving antennas 12.11-12:12 and 12:21-12:22 and the axis of rotation 4 of the rotor 5. The second pair of receiving antennas 12.21-12.22 is arranged on the spinner 7 at an angle α.sub.2 of −40° with respect to the aforementioned plane. Each receiving antenna 12.11, 12.12, 12.21 and 12.22 is electrically connected to a corresponding input of the correlation measuring device 15. An electrode 13 is arranged on a lance 11 protruding from the tip of the spinner 7 at a distance of approximately 200 mm from the first receiving antennas 12.11 and 12.21 in the direction of flow s of the incident wind. The two ends of the electrode 13 are designed in the shape of blades with a radius r.sub.m of the blade of 0.8 mm. The electrode 13 is electrically insulated from the lance 11 and is electrically connected to the negative pole of the high-voltage source 14. All other features of the second embodiment of the wind turbine correspond to those previously described for the first embodiment.

[0040] FIGS. 5 and 6 show another variant of the second embodiment of the wind turbine according to the invention. In this variant of the second embodiment of the wind turbine according to the invention, the spinner 7 is made of glass-fiber-reinforced plastic, i.e. of a material having a dielectric effect. The receiving antennas 12.11, 12.12, 12.21 and 12.22 are arranged inside the wall of the spinner 7, i.e. inside the dielectrically acting material. A total of four rod-shaped receiving antennas 12.11, 12.12, 12.21 and 12.22 are arranged which are electrically isolated from one another and from all other parts of the wind turbine. Each of two receiving antennas 12.11, 12.12, 12.21 and 12.22 are arranged parallel to one another with a mutual distance a therebetween and thus form a first and a second corresponding pair of receiving antennas 12.11-12:12 and 12:21-12:22. A first pair of receiving antennas 12.11-12:12 is arranged at an angle ai of 60° with respect to a plane spanned by a straight line 17 between the pairs of receiving antennas 12.11, 12.12, and 12.21 and 12.22 and the axis of rotation 4 of the rotor 5, and a second pair of receiving antennas 12.21-12.22 is arranged at an angle α.sub.2 of −60° with respect to the aforementioned plane. The receiving antennas 12.11, 12.12 of the first pair of receiving antennas 12.11-12:12 intersect the receiving antennas 12.21, 12.22 of the second pair of receiving antennas 12.21-12.22. Each receiving antenna 12.11, 12.12, 12.21 and 12.22 is electrically connected to a corresponding input of the correlation measuring device 15. An electrode 13 protruding from the spinner 7 is arranged at a distance of approximately 200 mm from the first receiving antennas 12.11, 12.21 in the direction of flow s of the incident wind. The electrode 13 is rod-shaped and protrudes approximately 10 cm from the spinner skin. The electrode 13 has at the end protruding from the spinner 7 a tip with a radius r.sub.m of 0.8 mm. The electrode 13 is arranged in an electrically insulated manner and is electrically connected to the negative pole of the high voltage source 14. A counter-electrode 18 formed as a plate is disposed on the inside of the wall of the spinner 7 and is constructed and arranged so as to cover the area of the wall of the spinner 7, in which the receiving antennas 12.11, 12.12, 12.21 and 12.22 are arranged. The counter-electrode 18 is electrically insulated from the receiving antennas 12.11, 12.12, 12.21 and 12.22 and is electrically connected to the positive pole of the high voltage source 14. All further features of the other variant of the second embodiment of the wind turbine shown in FIGS. 5 and 6 correspond to those previously described for the first embodiment.

[0041] FIG. 7 shows a cross-section through the wall of a spinner 7 with receiving antennas 12.11, 12.12, 12.21 and 12.22 arranged within the wall and a counter-electrode 18 arranged on the inner side of the wall of the spinner 7.

[0042] FIG. 8 shows a cross-section through the wall of a spinner 7 with receiving antennas 12.11, 12.12, 12.21 and 12.22 arranged on the inside of the wall of the spinner 7. The counter-electrode 18 is also arranged on the inside of the wall of the spinner 7 and is separated from the receiving antennas 12.11, 12.12, 12.21 and 12.22 by an electrical insulation.

[0043] FIGS. 7 and 8 show possible exemplary arrangements of receiving antennas 12.11, 12.12, 12.21 and 12.22 and of the counter-electrode 18. Other additional arrangements of receiving antennas 12.11, 12.12, 12.21 and 12.22 and of the counter-electrode 18 inside the wall of a spinner 7 are possible and may be technically advantageous.

[0044] FIG. 9 shows a detail of the surface of a spinner 7, illustrating the arrangement of four rod-shaped receiving antennas 12.11, 12.12, 12.21 and 12.22 on the spinner 7. The receiving antennas 12.11, 12.12, 12.21 and 12.22 are arranged on the spinner 7 and electrically insulated from one another and from the spinner 7. Each two receiving antennas 12.11, 12.12, 12.21 and 12.22 are arranged parallel to one another with a mutual distance a therebetween and thus form a first and a second corresponding pair of receiving antennas 12.11-12:12 and 12:21-12:22. The first pair of receiving antennas 12.11-12:12 is arranged at an angle ai of 30° with respect to a plane spanned by a straight lines 17 between the pairs of receiving antennas 12.11-12:12 and 12:21-12:22 and the axis of rotation 4 of the rotor 5. The second pair of receiving antennas 12:21-12:22 is arranged on the spinner 7 at an angle α.sub.2 of −30° with respect to the aforementioned plane. Each receiving antenna 12.11, 12.12, 12.21 and 12.22 is electrically connected to a corresponding input of the correlation measuring device 15. An electrode 13 is disposed on the spinner in the flow direction s of the incident wind at a distance of approximately 200 mm from the first receiving antennas 12.11 and 12.21. The electrode 13 protrudes from the spinner surface and has several tips with a radius r.sub.m of 0.8 mm. The electrode 13 is electrically insulated from the spinner 7 and is electrically connected to the negative pole of the high voltage source 14.

[0045] FIGS. 10a to d each show in form of a plan view on the surface of the spinner 7 further arrangements of receiving antennas 12.11, 12.12, 12.21 and 12.22 on the spinner 7. FIG. 10a shows a plan view of the arrangement already shown in FIG. 9. In the arrangements shown in FIGS. 10a and b, the receiving antennas 12.11, 12.12, 12.21 and 12.22 forming a pair of receiving antennas are 12.11-12.12 and 12.21-12:22, respectively, are shifted relative to each other in the longitudinal direction of the receiving antennas 12.11, 12.12, 12.21 and 12.22. This can be advantageous for achieving improved electrical signals at the receiving antennas 12.11, 12.12, 12.21 and 12.22. FIG. 10c shows an arrangement of the receiving antennas 12.11, 12.12, 12.21 and 12.22 wherein the receiving antennas 12.11, 12.12, 12.21 and 12.22 forming pairs of receiving antennas 12.11-12.12 and 12:21-12:22 have identical length and are not shifted relative to each other in the longitudinal direction of the receiving antennas 12.11, 12.12, 12.21 and 12.22. FIG. 10d shows an arrangement of the receiving antennas 12.11, 12.12, 12.21 and 12.22 wherein the receiving antennas 12.11, 12.12 of the first receive antenna pair 12.11-12.12 cross the receiving antennas 12.21, 12.22 of the second pair of receiving antennas 12:21-12:22. In the arrangement shown in FIG. 10d, all receiving antennas 12.11, 12.12, 12.21 and 12.22 are also electrically insulated from one another. An electrode 13 is arranged on the spinner 13 in the flow direction s of the incident wind at a distance of approximately 200 mm from the first receiving antennas 12.11 and 12.21.

[0046] FIG. 10e shows a plan view on the surface of the spinner 7, wherein a total of eight receiving antennas 12.11, 12.12, 12.21, 12.22, 12.31, 12.32 and 12.41, 12.42 are arranged on the spinner. Each of two mutually parallel receiving antennas 12.11, 12.12, 12.21, 12.22, 12.31, 12.32 and 12.41, 12.42 form a pair of receiving antennas 12.11-12.12, 12.21-12.22, 12.31-12.32 and 12.41-12.42. The pairs of receiving antennas 12.11-12.12 and 12.31-12.32 are arranged at an angle α.sub.1 with respect to a plane spanned between straight lines 17 disposed between the pairs the receiving antennas 12.11-12.12, 12.31-12.32, and 12.21-12.22 and 12.41-12.42 and the axis of rotation 4 of the rotor 5. The pair of receiving antennas 12.21-12.22 and 12.41-12.42 are arranged at an angle α2 with respect to this plane. In this case, the angle α.sub.1, at which the pair of receiving antennas 12.11-12.12 is arranged with respect to this plane, is 30°. The pair of receiving antennas 12.31-12.32 is arranged at an angle α.sub.1 of 75° with respect to this plane. The angle α2 at which the pair of receiving antennas 12.12-12.22 is arranged in relation to this plane is −30° . The pair of receiving antennas 12.41-12.42 is arranged at an angle α.sub.2 of −60° with respect to this plane. For determining the flow direction s and the speed v of the incident wind, one pair of receiving antennas 12.11-12.12 or 12.31-12.32 that is arranged at an angle ai with respect to this plane, and one pair of receiving antennas 12.21-12.22 or 12.41-12.42, and that is arranged at an angle α.sub.2 with respect to this plane, are electrically connected to the inputs of the correlation measuring device 15. Of course, it is conceivable and possible to operate multiple correlation measuring devices 15 in parallel and to connect respective corresponding pairs of receiving antennas 12.11-12.12 or 12.31-12.32, and 12.21-12.22 or 12.41-12.42, respectively, to the inputs of a correlation measuring device 15. For the arrangement illustrated in FIG. 10e, it would be conceivable to electrically connect each of the pairs of receiving antennas 12.11-12.12 and 12.21-12.22, 12.11-12.12 and 12.41-12.42, 12.31-12.32 and 12.21-12.22, as well as 12.31-12.32 and 12.41-12.42 to a correlation measuring device and to thus determine the flow direction s and the speed v of the incident wind by using four combinations of electrical signals generated at the receiving antennas. An improvement in the accuracy of the determination of the direction of flow s and the speed v of the incident wind and, as a result, the alignment of the rotor 5 with respect to the wind incident on the wind turbine can thus be achieved.

LIST OF REFERENCE SYMBOLS

[0047] 1 tower

[0048] 2 longitudinal axis of the tower

[0049] 3 nacelle

[0050] 4 axis of rotation of the rotor

[0051] 5 rotor

[0052] 6 rotor blades

[0053] 7 spinner

[0054] 8 electric generator

[0055] 9 control or regulating device

[0056] 10 wind vane

[0057] 11 lance

[0058] 12 receiving antennas

[0059] 13 electrode

[0060] 14 high voltage source

[0061] 15 correlation measuring device

[0062] 16 computing device

[0063] 17 straight line

[0064] 18 counter-electrode

[0065] 19 electrical insulation

[0066] a distance between the corresponding receiving antennas of a pair of receiving antennas

[0067] s flow direction of the incident wind

[0068] t, t.sub.1, t.sub.2 time

[0069] v speed of the incident wind

[0070] v.sub.1, v.sub.2 directional components of the speed v of the incident wind

[0071] α.sub.1, α.sub.2 angle