Lightning detection system, wind turbine and method for detecting lightning strike location and lightning intensity at wind turbine

Abstract

The invention relates to a lightning detection system (10) for detecting a lightning stroke position and a lightning intensity of a wind turbine (11), comprising: a lightning sensor unit (12) for detecting a lightning stroke and collecting lightning data (27) of the lightning stroke, the lightning sensor unit (12) being mountable on a tower (13) of the wind turbine (11); at least one lightning strike counter (14) for collecting lightning strike data (28) regarding a lightning strike count and a lightning strike time when the energy of the lightning strike exceeds a specific threshold, the at least one lightning strike counter (14) being mountable on a downlead (15) on at least one blade (16) of the wind turbine (11); a processing unit (17) for collecting lightning data (27) of the lightning sensor unit (12) and lightning strike data (28) of the at least one lightning strike counter (14) in order to process the data to determine the location of the lightning strike.

Description

[0001] The present invention relates to a lightning detection system, a wind turbine and a method for detecting a lightning strike position and lightning intensity at a wind turbine.

[0002] To date, wind turbines have been operated with the following types of lightning detection systems:

[0003] 1) A basic system comprising, for example, a lightning arrester mounted on wiring placed in the blade,

[0004] 2) a first advanced system comprising lightning detection sensors mounted on wiring in the blades, combined with a turbine controller to process the data measured by the sensors,

[0005] 3) A second advanced system comprising lightning detection sensors mounted on / around the tower (at ground level), combined with a turbine controller to process the data measured by the sensors.

[0006] A disadvantage is that these systems can provide information about lightning strikes, but the information is general and does not provide data about the area or exact location of the lightning strike.

[0007] This requires that maintenance and inspection runs be performed on a tighter schedule so that damage can be detected and remedied at an early stage.

[0008] The object of the present invention is to at least partially address the above mentioned drawbacks. In particular, it is an object of the present invention to provide a lightning detection system which enables a rougher maintenance and inspection process by optimizing lightning detection.

[0009] This object is achieved by a lightning detection system having the features of claim 1, a wind turbine having the features of claim 8, and a method for detecting the location and intensity of a lightning strike at a wind turbine having the features of claim 11. Further features and details of the invention result from the dependent claims, the description, and the drawings. Features and details described in conjunction with the lightning detection system according to the invention naturally also apply in conjunction with the wind turbine according to the invention and / or the method according to the invention, and vice versa in each case, so that reference is or can always be made to the disclosure of the various aspects of the invention.

[0010] According to a first aspect, the present invention discloses a lightning detection system for detecting a lightning strike location and lightning intensity of a wind turbine, comprising:

[0011] a lightning sensor unit for detecting a lightning strike and collecting lightning data of the lightning strike, the lightning sensor unit being mounted on a tower of the wind turbine;

[0012] a plurality of lightning strike counters for collecting lightning strike data regarding the number of lightning strikes and the time of the lightning strikes when the energy of the lightning strikes exceeds a certain threshold, whereby at least one lightning strike counter is mounted on a down conductor on each blade of the wind turbine, and whereby the lightning strike counter is mounted on a down conductor on the nacelle of the wind turbine;

[0013] a processing unit for collecting lightning data from the lightning sensor unit and lightning strike data from the plurality of lightning strike counters in order to process the data to determine the location of the lightning strike.

[0014] The lightning sensor unit may be mounted on the tower, in particular on the tower base.Further, it may be advantageous if the lightning sensor continuously samples the magnetic field in the vicinity of the tower of the wind turbine.

[0015] In order to determine where the lightning struck, it is advantageous if the processing unit compares the timestamps of the lightning data with the timestamps of the lightning strike data when one or more lightning strikes occurred or have occurred. This can be used to determine whether a lightning strike has occurred on at least one blade or on the tower.

[0016] Based on this information (ie information about the lightning strike and the location of its impact), it can be determined whether an on-site inspection is necessary or can be performed later.

[0017] Furthermore, it is conceivable that the processing unit is installed in the lightning sensor unit and has a display via which data can be read during control operation or via which access to individual sensors installed on the wind turbine is possible in order to be able to check their functionality.

[0018] Furthermore, any necessary maintenance measures can be better planned based on the recorded data about lightning strikes. This is possible because it is now possible to track how often lightning strikes the same location as well as the intensity of said lightning.

[0019] Hereby, a cost- and time-efficient maintenance and control of the individual wind turbines may be achieved.

[0020] Advantageously, several lightning strike counters are provided, whereby at least one lightning strike counter can be mounted on each blade of the wind turbine.

[0021] This allows the processing unit to determine which blade was struck by lightning. Consequently, control and maintenance can now be performed based on a specific number of lightning strikes at a location, or lightning strike counter location. For example, if a wind turbine has three blades, at least one lightning strike counter can be provided on each blade. If lightning strikes during one or more thunderstorms, the number of lightning strikes on the corresponding blades may differ. For example, one blade may have received ten lightning strikes, while two others may have received only two. This necessitates a more rapid inspection of the blades with the higher number of lightning strikes.

[0022] It may be advantageous if at least one lightning strike counter can be mounted on a down conductor on the hub of the wind turbine and / or on a down conductor of a weather station of the wind turbine and / or on a tower of the wind turbine or on a down conductor on the tower.

[0023] In this way, lightning currents may be measured and / or detected in blades, hubs, generators, in the nacelle or in any other component made of metal or other current conducting material.

[0024] Towers can be made of metal, such as tubular towers or truss towers. These are often the conductors themselves for lightning. Towers made of concrete often have metal reinforcements. The downconductors in these towers can be reinforcements and / or downconductor cables.

[0025] It may be advantageous if at least one of the lightning strike counters has a fiber optic output for remote detection and collection of lightning strike data by a processing unit.

[0026] This enables simple data communication to provide the lightning strike counter data to the processing unit.

[0027] It may be advantageous if the threshold for the lightning strike counter to count lightning strikes is at least 2 kA.

[0028] This means that only lightning strikes with a certain force or current are counted as lightning strikes. The level of decisive current intensity is selected so that even minor lightning strikes that do not cause any damage are detected as lightning strikes. If a signal is triggered, such as when a strike current exceeding a threshold value is detected, the processing unit compares it with the data collected by the lightning sensor unit to evaluate or calculate the next check run.

[0029] It may be advantageous if the lightning sensor unit is designed to detect the following data:

[0030] - Peak current,

[0031] - rise time,

[0032] - electric charge,

[0033] -Specific energy,

[0034] - Complete waveform recording,

[0035] - Receptor mass loss / damage.

[0036] Based on this data collected by the lightning sensor units, more information can be gathered to assess the current status of the wind turbines after a thunderstorm. This current status then leads to efficient planning of maintenance and control operations.

[0037] It may be advantageous if the lightning sensor unit comprises a Rogowski coil.

[0038] A Rogowski coil is an electrical device used to measure alternating current (AC) or high-speed current pulses. It sometimes consists of a spiral coil with a wire lead passing from one end through the center of the coil and back to the other end, so that both terminals are at the same end of the coil.

[0039] Rogowski coils are therefore very accurate lightning sensors and are advantageously used as sensors in lightning sensor units.The base of a tower is the most advantageous positioning.

[0040] It may be advantageous if the processing unit is designed to forward the collected and processed data to an external computer system and / or a cloud system.

[0041] This makes it possible to access the data of the respective processing units in a simple manner. Furthermore, the storage device allows evaluation both ad hoc and over longer time periods in order to be able to plan and adapt control and maintenance cycles.

[0042] According to a second aspect, the present invention discloses a wind turbine comprising at least three blades, a hub, a nacelle, and a tower, and a lightning detection system as described above, whereby a lightning sensor unit is mounted on the tower and whereby at least one lightning strike counter is mounted on each blade. The advantages of the lightning detection system described in detail according to the first aspect of the present invention also apply to the wind turbine according to the second aspect of the present invention.

[0043] Lightning strike counters can be installed on each blade, hub, nacelle, and tower. Thus, at least three blades, hub, and nacelle should include downconductors to divert the current. Several lightning strike counters can be provided on the nacelle, for example at the transition from the nacelle to the hub or tower, or on one of the sidewalls or rear end, or in the area of ​​a weather station.

[0044] Towers can be made of metal, such as tubular towers or truss towers. These are often the conductors themselves for lightning. Towers made of concrete often have metal reinforcements. The downconductors in these towers can be reinforcements and / or downconductor cables.

[0045] The lightning sensor unit may be mounted in the tower base.

[0046] In particular, at least one lightning strike counter is mounted on a down conductor on the hub of the wind turbine and / or on a down conductor on the nacelle of the wind turbine and / or on a down conductor of a weather station of the wind turbine and / or on a tower of the wind turbine or on a down conductor on the pylon.

[0047] The presence of a down conductor, on which at least one lightning strike counter can be positioned, ensures that the metallic conductor can be used to dissipate and measure lightning strikes. If the current of the lightning strike is above a threshold, the lightning strike counter counts the lightning strikes and transmits the data to a processing unit. The transmission can be performed via an optical fiber output.

[0048] It may be advantageous if a processing unit is mounted on the tower or the tower base or integrated in the lightning sensor unit to forward the collected and processed data to an external computer system and / or a cloud system.

[0049] Mounting the lightning sensor unit in the lower part of the tower provides protection from external forces. Furthermore, it is conceivable that the processing unit is mounted in the lightning sensor unit and has a display via which data can be read during control operations or via which access is possible to the various sensors mounted on the wind turbine in order to be able to check their functionality.

[0050] According to a third aspect, the present invention discloses a method for detecting a lightning strike location and lightning intensity at a wind turbine as described above using the lightning detection system as described above, comprising the following steps:

[0051] - detecting a lightning strike using a lightning sensor unit and collecting lightning data of the lightning strike to detect lightning intensity;

[0052] - counting lightning strikes by collecting lightning strike data using at least one lightning strike counter when the energy of the lightning strike exceeds a certain threshold;

[0053] - collecting, with a processing unit, the lightning strike data collected by the lightning sensor units and the lightning strike data counted by the at least one lightning strike counter and processing the data to determine the location and intensity of the lightning strike at the wind turbine.

[0054] The advantages described in detail for the lightning detection system according to the first aspect of the invention and the wind turbine according to the second aspect of the invention also apply to the method for detecting a lightning strike location and lightning intensity at a wind turbine according to the third aspect of the invention.

[0055] Counting means that the corresponding lightning strike counter is sending a signal of the occurrence of a lightning strike to the processing unit.

[0056] It may be advantageous if the processing unit processes the data by correlating the lightning strike data with lightning data, in particular with the lightning strike time.

[0057] Based on the recorded and stored lightning and lightning strike data, the processing unit can assign lightning strike and lightning sensor unit lightning data to a specific lightning strike counter. This can be determined, for example, via the timestamps of the two sensors. Data on the current level, energy, and number of lightning strikes that occurred at that specific lightning strike counter can be correlated. This provides information on the status and condition of the lightning strike counter's location, enabling further planning and optimization of maintenance and inspection intervals.

[0058] It may be advantageous if the lightning sensor unit detects the following data of a lightning strike:

[0059] - Peak current,

[0060] - rise time,

[0061] - electric charge,

[0062] - specific energy,

[0063] - Complete waveform recording,

[0064] - Receptor mass loss / damage.

[0065] It may be advantageous if the data processed by the processing unit are forwarded to an external computer system and / or a cloud system.

[0066] This makes it possible to access the data of the respective processing units in a simple manner. Furthermore, the storage device allows both self-organization and evaluation over longer time periods in order to be able to plan and adapt control and maintenance cycles.

[0067] Further measures for improving the invention are derived from the following description of some examples of embodiments of the invention, which are schematically illustrated in the figures. All features and / or advantages arising from the claims, the description, or the drawings, including construction details, spatial arrangements, and process steps, may be essential to the invention both individually and in various combinations. It should be noted that the figures are merely illustrative and are not intended to limit the invention in any way.

[0068] They schematically show:

[0069] Figure 1 For lightning detection system;

[0070] Figure 2 For wind turbines with lightning detection systems;

[0071] Figure 3 A method for detecting the location and intensity of lightning strikes.

[0072] Figure 1 A lightning detection system 10 for detecting a lightning strike location and lightning intensity on a wind turbine 11 is shown, comprising:

[0073] a lightning sensor unit 12 for detecting a lightning strike and collecting lightning data 27 of the lightning strike, the lightning sensor unit 12 being mountable on a tower 13 of the wind turbine 11;

[0074] at least one lightning strike counter 14 for collecting lightning strike data 28 regarding the number of lightning strikes and the duration of lightning strikes when the energy of a lightning strike exceeds a certain threshold, said at least one lightning strike counter 14 being mountable on a down conductor 15 on at least one blade 16 of the wind turbine 11;

[0075] A processing unit 17 for collecting lightning data 27 of the lightning sensor units 12 and lightning strike data 28 of the at least one lightning strike counter 14 in order to process the data to determine the location of the lightning strike.

[0076] The illustrated embodiment shows at least two lightning strike counters 14. However, as indicated, several lightning strike counters 14 may also be provided, whereby at least one lightning strike counter 14 may be mounted on each blade 16 of the wind turbine 11.

[0077] If already Figure 1 As indicated in , a further lightning strike counter 14 is provided, which can be mounted on the down conductor 15 on the hub 18 of the wind turbine 11 and / or on the down conductor 15 on the nacelle 19 of the wind turbine 11 and / or on the down conductor 15 of the weather station 20 of the wind turbine 11 and / or on the tower 13 of the wind turbine 11 or on the down conductor 15 on the tower 13.

[0078] In order to remotely monitor and collect lightning strike data 28 of the at least one lightning strike counter 14 by the processing unit 17 , the at least one lightning strike counter 14 has a fiber optic output 21 .

[0079] The lightning strike counters 14 are designed in such a way that they count lightning only when a threshold value is exceeded, whereby the threshold value is at least 2 kA.

[0080] The lightning sensor unit 12 is designed to detect the following data:

[0081] - Peak current,

[0082] - rise time,

[0083] - electric charge,

[0084] - specific energy,

[0085] - Complete waveform recording,

[0086] - Receptor mass loss / damage.

[0087] In order to accurately measure data using the lightning sensor unit 12 , it has a Rogowski coil 22 as a lightning sensor of the lightning sensor unit 12 .

[0088] Furthermore, the processing unit 17 is designed to forward the collected and processed lightning data 27 and lightning strike data 28 to the external computer system 23 and / or the cloud system 24 .

[0089] Figure 2 A wind turbine 11 is shown comprising at least three blades 16, a hub 18, a nacelle 19 and a tower 13 and a Figure 1 A lightning detection system 10 is provided, whereby a lightning sensor unit 12 is mounted on a tower 13 and whereby at least one lightning strike counter 14 is mounted on each blade 16 , in particular on a down conductor 15 of each of at least three blades 16 .

[0090] In addition, at least one lightning strike counter 14 is mounted on the down conductor 15 on the hub 18 of the wind turbine 11 and on the down conductor 15 on the nacelle 19 of the wind turbine 11 and on the down conductor 15 of the weather station 20 of the wind turbine 11 or the tower 13 of the wind turbine 11. Figure 2 The wind turbine 11 shown is a wind turbine 11 having a tubular tower 13 made of metal, so the entire tower 13 is a down conductor. In the case where the tower 13 is made of concrete, it may be necessary to provide a down conductor cable.

[0091] A processing unit 17 is integrated into the lightning sensor unit 12 to forward the collected and processed data to an external computer system 23 and / or a cloud system 24. A Rogowski coil 22 is provided on a tower base 25 of the wind turbine 11 to enable accurate and reliable measurement of lightning strike data 28.

[0092] Figure 3 Shows the use of Figure 1 The lightning detection system 10 is used to detect the Figure 2A method 100 for determining a lightning strike location and lightning intensity at a wind turbine 11 includes the following steps:

[0093] - detecting 110 a lightning strike using a lightning sensor unit 12 and collecting 130 lightning data 27 of the lightning strike to detect lightning intensity;

[0094] - counting 120 lightning strikes by collecting 130 lightning strike data 28 using at least one lightning strike counter 14 when the energy of the lightning strikes exceeds a certain threshold;

[0095] The lightning data 27 collected by the lightning sensor unit 12 and the lightning strike data 28 counted by the at least one lightning strike counter 14 are collected 140 by the processing 140 unit 17 and processed 150 to determine the location and intensity of the lightning strike at the wind turbine 11 .

[0096] In a further step, the processing unit 17 processes 150 the data by correlating the lightning strike data 28 with the lightning data 27 , in particular with the lightning strike time.

[0097] The lightning sensor unit 12 , in particular the Rogowski coil 22 used as a lightning sensor, detects the following data of a lightning strike:

[0098] - Peak current,

[0099] - rise time,

[0100] - electric charge,

[0101] - specific energy,

[0102] - Complete waveform recording,

[0103] - Receptor mass loss / damage.

[0104] In a further step, the data processed by the processing 150 unit 17 are forwarded 160 to the external computer system 23 and / or the cloud system 24 .

[0105] Via the display 26 of the processing unit 17 , lightning data 27 and / or lightning strike data 28 can be read during a control operation or access to individual sensors installed on the wind turbine 11 (e.g. the lightning strike counter 14 or the Rogowski coil 22 ) is possible in order to be able to check their functionality.

Claims

1. A lightning detection system (10) for detecting a lightning strike location and lightning intensity of a wind turbine (11), comprising: a lightning sensor unit (12) for detecting a lightning strike and collecting lightning data (27) of the lightning strike, the lightning sensor unit (12) being mounted on a tower (13) of the wind turbine (11); - a plurality of lightning strike counters (14) for collecting lightning strike data (28) regarding lightning strike count and lightning strike time when the energy of the lightning strike exceeds a certain threshold, whereby at least one lightning strike counter (14) is mounted on a down conductor (15) on each blade (16) of the wind turbine (11), and whereby the lightning strike counter (14) is mounted on a down conductor (15) on a nacelle (19) of the wind turbine (11); - a processing unit (17) for collecting the lightning data (27) of the lightning sensor unit (12) and the lightning strike data (28) of the plurality of lightning strike counters (14) in order to process the data to determine the location of the lightning strike.

2. The lightning detection system (10) according to claim 1, Its characteristics are: At least one lightning strike counter (14) may be mounted on a down conductor (15) on the hub (18) of the wind turbine (11) and / or on a down conductor (15) of a weather station (20) of the wind turbine (11) and / or on the tower (13) of the wind turbine (11) or on a down conductor (15) on the tower (13).

3. A lightning detection system (10) according to any one of the preceding claims, Its characteristics are: The at least one lightning strike counter (14) has a fiber optic output (21) for remote monitoring and collection of counted lightning strikes by the processing unit (17).

4. A lightning detection system (10) according to any one of the preceding claims, Its characteristics are: The threshold value of the lightning strike counter (14) for counting lightning strikes is at least 2 kA.

5. A lightning detection system (10) according to any one of the preceding claims, Its characteristics are: The lightning sensor unit (12) is designed to detect the following data: - Peak current, - rise time, - electric charge, - specific energy, - Complete waveform recording, - Receptor mass loss / damage.

6. A lightning detection system (10) according to any one of the preceding claims, Its characteristics are: The lightning sensor unit (12) includes a Rogowski coil (22).

7. A lightning detection system (10) according to any one of the preceding claims, Its characteristics are: The processing unit (17) is designed to forward the collected and processed data to an external computer system (23) and / or a cloud system (24).

8. A wind turbine (11) comprising at least three blades (16), a hub (18), a nacelle (19) and a tower (13) and a lightning detection (10) system according to any one of claims 1 to 7, whereby the lightning sensor unit (12) is mounted on the tower (13) and whereby at least one lightning strike counter (14) is mounted on each of the blades (16).

9. The wind turbine (11) according to claim 8, Its characteristics are: At least one lightning strike counter (14) is mounted on a down conductor (15) on each of the at least three blades (16) and / or on a down conductor (15) on a hub (18) of the wind turbine (11) and / or on a down conductor (15) on a nacelle (19) of the wind turbine (11) and / or on a down conductor (15) of a weather station (20) of the wind turbine (11) and / or on the tower (13) of the wind turbine (11) or on a down conductor (15) on the tower (13).

10. A wind turbine (11) according to claim 8 or 9, Its characteristics are: The processing (140) unit (17) is installed on the tower (13) or the base of the tower (13) or integrated in the lightning sensor unit (12) to forward the collected and processed data to an external computer system (23) and / or a cloud system (24).

11. A method (100) for detecting a lightning strike location and lightning intensity at a wind turbine (11) according to claims 8 to 10 using a lightning detection system (10) according to claims 1 to 7, comprising the following steps: - detecting (110) a lightning strike using the lightning sensor unit (12) and collecting (130) lightning data (27) of the lightning strike to detect the lightning intensity; - counting (120) lightning strikes by collecting (130) lightning strike data (28) using the at least one lightning strike counter (14) when the energy of the lightning strike exceeds a certain threshold; - collecting (140) the lightning data (27) collected by the lightning sensor unit (12) and the lightning strike data (28) counted by the at least one lightning strike counter (14) using the processing (140) unit (17), and processing (150) the data to determine the location and intensity of the lightning strike at the wind turbine (11).

12. The method (100) according to claim 11, Its characteristics are: The processing unit (17) processes (150) the lightning strike data (28) by correlating the data with the lightning data (27), in particular with the lightning strike time.

13. The method (100) according to claim 11 or 12, Its characteristics are: The lightning sensor unit (12) detects the following data of the lightning strike: - Peak current, - rise time, - electric charge, - specific energy, - Complete waveform recording, - Receptor mass loss / damage.

14. The method (100) according to any one of the preceding claims 11 to 13, Its characteristics are: The data processed by the processing (150) unit (17) is forwarded (160) to an external computer system (23) and / or a cloud system (24).

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