METHOD FOR TESTING A LIGHTNING PROTECTION SYSTEM AND/OR A LIGHTNING DETECTION SYSTEM OF A WIND TURBINE

Abstract

A method for testing a lightning protection system and/or a lightning detection system of a wind turbine is provided, the method including usage of an unmanned aerial vehicle including an electrical impulse generator capable to simulate a lightning strike by discharging an electrical impulse, whereby the method includes the steps of: (a) maneuvering the unmanned aerial vehicle with the electrical impulse generator contacting the wind turbine or with the electrical impulse generator being within a range of the electrical impulse generator to the wind turbine such that the electrical impulse discharged by the electrical impulse generator will impact the wind turbine, and (b) discharging the electrical impulse by the electrical impulse generator such that the discharged electrical impulse impacts the wind turbine as an impacting electrical impulse.

Claims

1. A method for testing a lightning protection system and/or a lightning detection system of a wind turbine, the method comprising usage of an unmanned aerial vehicle comprising an electrical impulse generator capable of simulating a lightning strike by discharging an electrical impulse, the method comprising: (a) maneuvering the unmanned aerial vehicle with the electrical impulse generator contacting the wind turbine or with the electrical impulse generator being within a range of the electrical impulse generator to the wind turbine such that the electrical impulse discharged by the electrical impulse generator will impact the wind turbine; and (b) discharging the electrical impulse by the electrical impulse generator such that the discharged electrical impulse impacts the wind turbine as an impacting electrical impulse.

2. The method according to claim 1, wherein the electrical impulse generator comprises at least one electrode being fired from the unmanned aerial vehicle to impact the wind turbine, whereby the at least one electrode is electrically connected to the electrical impulse generator after firing for discharging the electrical impulse.

3. The method according to claim 1, wherein the unmanned aerial vehicle comprises a camera for inspecting the wind turbine for damages.

4. The method according to claim 1, wherein the lightning detection system comprises at least one detection point at which the lightning detection system detects the impacting electrical impulse.

5. The method according to claim 4, wherein the at least one detection point of the lightning detection system is located inside of a blade of the wind turbine, inside of a hub of the wind turbine, inside a nacelle of the wind turbine and/or at a tower of the wind turbine.

6. The method according to claim 5, wherein when impacting electrical impulse is not detected by the lightning detection system at the at least one detection point at the tower of the wind turbine after discharged electrical impulse has impacted the wind turbine, it is judged, that the lightning protection system has a malfunction.

7. The method according to claim 5, wherein the at least one detection point is a measurement point for measuring the impacting electrical impulse.

8. The method according to claim 7, wherein the at least one measurement point is formed by or comprises a Rogowski coil.

9. The method according to claim 7, wherein the method further comprising: (a) measuring the impacting electrical impulse at the at least one measurement point, and (b) comparing the impacting electrical impulse with the discharged electrical impulse.

10. The method according to claim 9, wherein the unmanned aerial vehicle comprises a first interface connected or connectable to an analysis unit the lightning detection system comprises a second interface connected or connectable to the analysis unit, whereby the analysis unit is arranged for comparing the impacting electrical impulse with the discharged electrical impulse.

11. The method according to claim 9, wherein the duration and/or magnitude of the discharged electrical impulse is predetermined, the duration and/or magnitude of the impacting electrical impulse is measured at the at least one measurement point and the duration and/or magnitude of the discharged electrical impulse and the impacting electrical impulse are compared.

12. The method according to claim 9, wherein when the impacting electrical impulse is detected at a measurement point at a tower of the wind turbine and the discharged electrical impulse and the measured impacting electrical impulse are different from one another in at least one of the at least one measurement points, it is judged, that the lightning detection system has a malfunction.

13. The method according to claim 1, wherein the electrical impulse is discharged by the electrical impulse generator on a blade of the wind turbine.

14. The method according to claim 1, wherein the discharging of the electrical impulse by the electrical impulse generator is performed several times and at different positions and/or blades of the wind turbine.

15. The method according to claim 1, wherein the discharging of the electrical impulse by the electrical impulse generator is performed several times at different form, duration and/or magnitude of the discharged electrical impulse.

Description

BRIEF DESCRIPTION

[0032] Some of the embodiments will be described in detail, with reference to the following figures, wherein like designations denote like members, wherein:

[0033] FIG. 1 shows a side perspective view on a wind turbine 10 being tested according to the method by an unmanned aerial vehicle 20. For visualization purposes only, the unmanned aerial vehicle 20 is scaled up compared to the wind turbine 10.

DETAILED DESCRIPTION

[0034] The wind turbine 10 comprises a tower 11 and a nacelle 12 resting on top of the tower 11. The tower 11 is erected on a ground 30. At the front of the nacelle 12, a hub 13 is attached. Three blades 14.1, 14.2, 14.3 are attached to the hub 13 for rotation therewith. However, the number of blades 14 may be amended as needed. For example, two or more than three blades 14 may be used in the wind turbine 10.

[0035] Each of the blades 14.1, 14.2, 14.3 comprises a down conductor 15.1, 15.2, 15.3 inside of the respective blade 14.1, 14.2, 14.3. The down conductors 15.1, 15.2, 15.3 are provided as part of a lightning protection system for conducting electrical impulse injected from a lightning strike via the hub 13, the nacelle 12 and the tower 11 to the ground 30. For this purpose, the hub 13, the nacelle 12 and the tower 11 may comprise further down conductors not shown in FIG. 1. Also, or alternatively, the tower 11 itself may act, i.e., be used, as a down conductor.

[0036] At each of the down conductors 15.1, 15.2, 15.3 and the tower 11 a measurement point 16.1, 16.2, 16.3, 16.4 of a lightning detection system is provided. These measurement points 16.1, 16.2, 16.3, 16.4 may be provided with a Rogowski coils wrapping the down conductors 15.1, 15.2, 15.3 and the tower 11 and an ohmmeter to measure electrical impulse or electrical energy flowing inside the down conductors 15.1, 15.2, 15.3 and the tower 11.

[0037] The unmanned aerial vehicle 20 is provided as a quadcopter in this embodiment but may be of any other type of unmanned aerial vehicle 20. An electrical impulse generator 21 is attached to the unmanned aerial vehicle 20. Further, a camera 23 is attached to the unmanned aerial vehicle 20. The electrical impulse generator 21 is maneuvered in range to the blade 14.1 of the wind turbine 10 such that the electrical impulse generator 21 is able to discharge electrical impulse impacting the blade 14.1 of the wind turbine 10.

[0038] The blade 14.1 of the wind turbine 10 is at a position of 12 o clock. From this position, the electrical impulse generator 21 discharges an electrical impulse via a wired electrode 25 fired at the blade 14.1 and impacting the blade 14.1. The electrode 25 sticks to the blade 14.1 due to the electrical impulse being discharged to the blade 14.1, i.e., it's down conductor 15.1. The electrode 25 is connected to electrical impulse generator 21 by a wire 24 limiting the range of the electrical impulse generator 21 at which it is able to discharge electrical impulse at the wind turbine 10. The discharged electrical impulse flows as impacting electrical impulse or electrical energy through the down conductors 15 of the lightning protection system of the wind turbine 10. From the down conductor 15.1 of the blade 14.1, the impacting electrical impulse or electrical energy flows via the down conductors (not shown) in the hub 13, nacelle 12 and via the tower 11 to the ground 30.

[0039] The impacting electrical impulse or electrical energy is measured at the measurement point 16.1 of the blade 15.1 and the measurement point 16.4 of the tower 11. Since the discharged electrical impulse is predetermined, i.e., its duration and magnitude are known, it may be compared to the impacting electrical impulse measured at the measurement point 16.1 of the blade 15.1 and the measurement point 16.4 of the tower 11.

[0040] A first interface 22 of the unmanned aerial vehicle 20 wirelessly transmits information, i.e., duration and magnitude, of the discharged electrical impulse or electrical energy to an analysis unit 17 located at the wind turbine 10. The analysis unit 17 further receives the information about the impacting electrical impulse or electrical energy measured at the measurement point 16.1 of the blade 15.1 and the measurement point 16.4 of the tower 11 and then compares the discharged electrical impulse and the impacting electrical impulse or electrical energy. If the analysis unit 17 finds that the impacting electrical impulse or electrical energy is conducted down to the measurement point 16.4 of the tower 11, but that the electrical impulse or electrical energy does not match in either of the measurement point 16.1 of the blade 15.1 and the measurement point 16.4 of the tower 11, it may judge that the lightning detection system does not properly work, i.e. one of the measurement points 16.1, 16.4 did not deliver accurate measurements, and give an alarm or warning.

[0041] If, however, no impacting electrical impulse or electrical energy is measured at the measurement point 16.4 of the tower 11, it may be judged that the lightning protection system does not work properly. This might mean, that the impacting electrical impulse or electrical energy has caused damage to the wind turbine 10 and thus the wind turbine 10 may be inspected by the unmanned aerial vehicle 20 and its camera 23, for example, to find a damaged spot and thereby the location of the malfunction of the lightning protection system.

[0042] Although the present invention has been disclosed in the form of embodiments and variations thereon, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention.

[0043] For the sake of clarity, it is to be understood that the use of “a” or “an” throughout this application does not exclude a plurality, and “comprising” does not exclude other steps or elements.