DEVICE, SYSTEM AND METHOD FOR PERFORMING A CONTINUITY TEST OF AN ELECTRICAL CONDUCTION OF AN OBJECT

Description

Technical area

[0001] Embodiments according to the present invention are concerned with devices, systems and methods for performing a continuity test of an electrical line of an object. Background of the invention

[0002] Wind turbines already form an integral part of renewable energy sources in many countries. To ensure the safe and reliable operation of such wind turbines, it is therefore important to inspect them at regular intervals. Due to their design, e.g., the ever-increasing heights of towers and rotor blade lengths, wind turbines are particularly vulnerable to lightning strikes. To divert lightning energy in the event of a lightning strike and to prevent damage to the wind turbine, rotor blades of wind turbines are equipped with lightning rods. However, these lightning rods can be damaged or rendered unusable, for example, due to the mechanical stresses encountered during operation of the wind turbine or due to environmental influences such as oxidation. The lightning rods are usually located inside the rotor blades, making inspection difficult.Therefore, such testing is usually associated with high costs and effort.

[0003] US 2013 / 0336786 A1 discloses a system and method for automatically testing a lightning protection system on a wind turbine. The system and method may include a wind turbine having a plurality of rotor blades mounted on a hub, a lightning rod on each of the rotor blades, a lightning protection system extending from each of the lightning rods to a grounding grid, and a conductor that is part of a test system that extends from at least the inside of the hub through the inside of at least one of the rotor blades and is connected to the lightning rod, the conductor completing an electrical circuit extending from the lightning rod to the grounding grid. A test current signal may be introduced into the test system for a branch of the lightning protection system to be tested, and electrical continuity in the circuit may be determined using the test current signal.

[0004] US2022 / 0065228 A1 discloses a monitoring system for a wind turbine blade, wherein the wind turbine blade comprises an electrically conductive or semi-conductive structural component and a lightning protection system with an arrester electrically connected to a lightning receptor, wherein the arrester is electrically connected to the structural component by an equipotential connector so as to form a network of electrical impedances comprising the structural component, the equipotential connector and the arrester, wherein the hybrid monitoring system comprises a sensor device for the network,which comprises a transmitter for transmitting an electrical pulse into the network via a first connection and a receiver for receiving a reception pattern of the electrical pulse from the network via a second connection, as well as an evaluation device for evaluating the reception pattern to determine first health information regarding the lightning protection system and second health information regarding the structural component.

[0005] Therefore, there is a need for a concept that enables continuity testing of an electrical cable of an object, such as a wind turbine, with low complexity and effort and thus at low cost.

[0006] Such a need can be met by the subject-matter of the independent patent claims.

[0007] Further developments according to the invention are defined in the subclaims. Summary of the invention

[0008] Embodiments according to the present invention comprise a device for providing an electrical test signal for performing a continuity test of an electrical line (also referred to herein as an electrical conductor) of an object, comprising a communication module configured to receive an activation signal to switch the device from a passive operating mode to an active operating mode and to receive a deactivation signal to switch the device from the active operating mode to the passive operating mode. Furthermore, the device comprises a signal generator configured to generate the electrical test signal in the active operating mode. Furthermore, the device comprises a power source configured to supply power to the communication module and the signal generator.In addition, the device comprises a coupling module which is designed to couple the electrical test signal into the electrical line of the object in the active operating mode.

[0009] Embodiments according to the present invention are based on the core idea of ​​coupling a test signal into the electrical line of the object to be tested in order to subsequently record the test signal, for example non-invasively, with a measuring device in order to draw conclusions about the condition of the line of the object. For this purpose, the device comprises the signal generator, which is designed to provide the test signal to the coupling module. The inventors have recognized that the use of the communication module makes it possible to remotely control the device, so that the testing effort can be reduced, particularly for very large objects. For example, in the case of a wind turbine, it may not be necessary for a system tester to climb the tower of the wind turbine to the feed-in point of the electrical test signal in order to activate the device, or in other words, to put it into an active operating mode.This makes it possible for a device according to the invention to also be permanently connected to the object in order to activate the device only during an inspection and then deactivate it again.

[0010] Further embodiments according to the present invention include a method for performing a continuity test of an electrical line of an object, comprising supplying a communication module with energy from a power source and receiving an activation signal by means of the communication module in order to switch from a passive operating mode to an active operating mode. Furthermore, the method includes supplying a signal generator in the active operating mode with energy from the power source and generating an electrical test signal in the active operating mode by means of the signal generator. Furthermore, the method includes coupling the electrical test signal in the active operating mode into the electrical line of the object and receiving a deactivation signal by means of the communication module in order to switch from the active operating mode to the passive operating mode.

[0011] The method described above is based on the same considerations as the device described above. The device can be supplemented with all the features and functionalities described in connection with the device, both individually and in combination.

[0012] According to further embodiments of the present invention, the communication module is designed to receive the activation signal and / or the deactivation signal wirelessly. The inventors have recognized that wireless communication with the communication module enables a high degree of flexibility in the provision of the electrical test signal. Particularly in the case of very large objects, a location at which the test signal is fed into the object's line can be far away from a location at which the test signal must be detected. Thus, for example, particularly in the case of objects that are difficult to access, such as a wind turbine, the device can be put into active operating mode from various positions on the object in order to couple the test signal into the line.For example, a climber with a portable measuring device can activate the test signal while standing alone on the rotor blade in order to record the electrical test signal in the lightning rod of the rotor blade. This eliminates the need for a second person to control the device and coordinate with the climber. Furthermore, wireless communication also enables the use of automated testing procedures. For example, a drone flying over the object can activate the device via wireless communication to couple the test signal into the object's cable, subsequently measure the electrical test signal, and deactivate the device again via wireless communication after the measurement or inspection is completed. The communication module can be a radio module, for example.

[0013] According to further embodiments of the present invention, the communication module is configured to receive the activation signal or the deactivation signal via a wired connection. In a case where the device is, for example, permanently attached to the object, the object may, for example, have a wired communication line to the device, so that a connection option can be provided, for example, from an easily accessible location on or in the object to control the device.For example, in the case of an autonomous drone (optionally also a manually controlled drone or a semi-autonomous drone) designed to inspect the object and measure the test signal in the electrical line, the drone can be controlled or started using a computing unit at the base of the system, for example, and the device can simultaneously be put into active operating mode via a connection to the object. Furthermore, wired communication can be more interference-resistant than, for example, wireless communication. Furthermore, according to embodiments, the device can be configured wired, for example, via a USB connection.

[0014] According to further embodiments of the present invention, the energy source comprises at least one of an exchangeable energy store and / or a rechargeable energy store. Alternatively or additionally, the energy source is designed to be coupled to an external power supply. The inventors have recognized that by using an energy store, the device can be operated or used at least approximately or temporarily autonomously. For example, the device can be structurally connected to the object in order to be activated by means of the communication module to carry out the continuity test during an inspection. Accordingly, it is therefore not necessary for the device to be separately supplied with energy beforehand, e.g. by manually connecting a cable to the device.Specifically in the case of a wind turbine, the device can be installed near the base of the rotor blade, for example, in the nacelle, and activated, for example, by a drone via wireless communication. Both communication and the generation of the test signal can be enabled based on energy provided by a replaceable or rechargeable energy storage device. Appropriately dimensioned energy storage devices can thus be replaced or recharged at regular intervals during further routine inspections (e.g., at longer intervals than the time intervals between continuity tests), e.g., of the corresponding nacelle. This optimizes and saves labor and time.It should be noted that these advantages are not only relevant for wind turbines, but especially for any large object where a corresponding device for testing the continuity of a conductor must be installed, for example, in a location that is difficult to access.

[0015] Furthermore, the inventors have also recognized that, for example, in objects that serve to generate energy or that are constantly supplied with energy, the energy source can also be designed to be coupled to an external power supply, for example, a power supply of the object. This can also provide an efficient method of supplying energy to the device, allowing the device to be used for continuity testing even over long periods of time and with additional effort.

[0016] According to further embodiments of the present invention, the coupling module is designed to inductively couple the electrical test signal into the electrical line of the object in the active operating mode. Alternatively or additionally, the decoupling module is designed to capacitively couple the electrical test signal into the electrical line of the object in the active operating mode. The inventors have recognized that inductive or capacitive coupling of the test signal enables particularly advantageous line testing. On the one hand, objects can be retrofitted using the device without, for example, having to directly electrically contact difficult-to-access conductors that need to be tested.On the other hand, such coupling can also have particular advantages with regard to objects with movable electrical lines, where a corresponding continuity test is only possible, for example, in certain positions or orientations of the electrical line, wherein in a normal operation of the object it can be advantageous, for example, that the line can move relative to the continuity testing device.

[0017] According to further embodiments of the present invention, the coupling module is designed to be attached to the electrical line in a galvanically isolated manner such that the device is substantially protected from a voltage and / or current spike on the electrical line. Very large objects, in particular, can be susceptible to lightning strikes, which can lead to high voltages and / or currents on electrical lines within the object. By coupling the device to the line in a correspondingly galvanically isolated manner using the coupling module, damage to or destruction of the device, for example, in the event of such a lightning strike, can be prevented.

[0018] According to further embodiments of the present invention, the coupling module has an electrically switchable ohmic connection to the line of the object in order to couple the electrical test signal into the electrical line of the object in active operating mode. The inventors have recognized that in some cases, for example when the device is structurally connected to the object, the test signal can also be coupled into the object or the conductor of the object via a switchable ohmic connection. This allows, for example, a particularly interference-robust and direct test signal coupling to take place, for example for very strong electrical test signals, i.e. for example with high voltages or high currents. By using a switchable ohmic connection, appropriate decoupling can be ensured in order to be protected against lightning strikes, for example. With ohmic coupling, for example,In particular, test signals comprising low-frequency signals or clocked low-frequency signals can be used.

[0019] According to further embodiments of the present invention, the device is designed to reduce energy consumption of the device in passive operating mode compared to active operating mode, and to activate the communication module in passive operating mode at time intervals for a predetermined duration to receive the activation signal. The inventors have recognized that such a passive operating mode can save energy during periods in which no inspection, such as a continuity test of a line of the object, is necessary or planned. Accordingly, for example, with regard to replaceable or rechargeable energy storage devices, a period until replacement or recharging is necessary can be extended.Furthermore, the inventors have recognized that by cyclically activating the communication module to receive the activation signal, the device can be put into active operating mode for inspection with minimal effort. Thus, for example, it is no longer necessary for a person to manually activate the device to start an inspection.

[0020] According to further embodiments of the present invention, the energy source comprises at least one of an exchangeable energy storage device and / or a rechargeable energy storage device, and the communication module is designed to transmit a charge state of the energy storage device in the active operating mode. The inventors have recognized that this can improve the reliability of the device. Accordingly, the charge state of the energy storage device can be monitored during an inspection in order to obtain information about whether the inspection can be carried out with the remaining energy supply, for example to determine an aging state of the energy storage device, for example via an energy delta since the last inspection with transmission of the previous charge state, and / or to plan a replacement or recharging of the energy storage device.

[0021] According to further embodiments of the present invention, the communication module is configured to transmit information about the operating state of the device. Thus, for example, after receiving an activation signal, the device can acknowledge that it has received the activation signal by transmitting information about the active operating state. Thus, for example, it can be ensured that the device is ready to generate the test signal before, for example, preparing a complex measurement on the object's line.

[0022] According to further embodiments of the present invention, the electrical test signal is a high-frequency signal, a radio frequency signal, a low-frequency signal, and / or a clocked low-frequency signal. The inventors have recognized that, for example, a high-frequency signal often enables an efficient continuity test of an object's electrical line. Thus, for example, a radiated electrical or electromagnetic field of the high-frequency signal in the electrical line can be detected even from a certain distance from the electrical line.

[0023] For example, in a wind turbine rotor blade, there may be multiple connections (e.g., screw connections) along the down conductor (e.g., lightning conductor). At these points, metal surfaces meet and form contact connections between occasionally live conductors. In the presence of oxygen or other chemically aggressive gases, the surface of base metals reacts: Layers of oxides, sulfides, chlorides, and similar substances can form. Furthermore, under standard atmospheric conditions, a water film can form.

[0024] Finally, unavoidable contamination such as oil, grease, and dust must be taken into account. These changes or impairments can lead to foreign layers on the material, which can significantly disrupt or completely interrupt the electrical transmission.

[0025] The inventors have recognized that the use of a high-frequency signal enables a differentiated evaluation to distinguish between areas of a lightning rod that are problematic for a lightning strike and areas that are only slightly oxidized or interrupted.

[0026] For example, the test method according to the invention can use an electrically induced field to test the continuity of the conductors in the rotor blades, which field is capable of bridging the described starting and foreign layers by induction.

[0027] According to further embodiments of the present invention, the signal generator is designed to enable impedance matching to the electrical line. The inventors have recognized that this enables particularly efficient coupling into the electrical line. Furthermore, the signal generator can be designed to perform calibration, for example, for different electrical lines of different objects in order to perform corresponding impedance matching as efficiently as possible.

[0028] In concrete terms, the generator output of the signal generator within the device can, for example, carry out impedance matching (radiation) within certain limits, ie an optimized value can be set at least approximately depending on the system, e.g. the conductor of the object.

[0029] According to further embodiments of the present invention, the device comprises at least one protection diode, and the protection diode is configured to protect the device from a voltage and / or current spike on the electrical line. The protection diode can, for example, be configured to divert an overvoltage or overcurrent, or to dissipate a corresponding overcurrent or overvoltage. Thus, for example, a lightning strike or strong electrical feedback can be prevented, e.g., in objects designed to generate large amounts of energy.

[0030] The protection diode can be a bipolar transil diode, for example. The diode does not require a ground connection, but can be installed internally in parallel with the coupling module, such as the induction coil, and thus absorbs overvoltage pulses, such as those caused by a lightning strike. For example, the coupling module can be bypassed using the protection diode.

[0031] This protection against lightning strikes can, for example, only be possible with inventive solutions (e.g. with inductive coupling with galvanic isolation, e.g. in the case of an induction coil - no ohmic connection).

[0032] This offers advantages over, for example, an ohmic signal feed (e.g. by interrupting the line and feeding in on both sides), since in this case the risk of destruction or lightning protection can no longer be guaranteed in the event of a lightning strike.

[0033] The protection diode can generally be a transient voltage suppression (TVS) device, e.g., a suppressor diode, a transil diode, or a thyrector. The protection diode can therefore be, for example, an electrical component that can be used to protect electrical circuits, such as the device according to the invention, in particular the signal generator and the communication module, and corresponding lines of the device, from voltage peaks induced in lines.

[0034] Such a protection diode can, for example, shunt an overcurrent (the pulse current can be bypassed by the component to be protected, e.g., based on a parallel connection) if an induced voltage exceeds a breakdown voltage, e.g., an avalanche breakdown voltage. The protection diode can, for example, be a clamping device and can be designed to suppress overvoltages above a breakdown voltage.

[0035] The protection diode can, for example, reset automatically when the overvoltage is no longer present and can, for example, absorb a large amount of transient energy internally, more than a similarly rated clamp circuit (crowbar device). The protection diode can be designed unidirectionally or bidirectionally.

[0036] A unidirectional diode can act as a forward rectifier, like an avalanche diode, but can be designed and tested to handle very large current spikes.

[0037] Bidirectional TVS diodes can be represented by two opposing avalanche diodes connected in series and in parallel with the component to be protected. However, this representation may only be schematically correct; physically, such devices can be manufactured as a single component.

[0038] According to further embodiments of the present invention, the protective diode is a suppressor diode, and the suppressor diode is connected in parallel with the coupling module. The suppressor diode can be, for example, a bipolar transil diode. Such a diode does not require a ground connection, but can be installed internally in the device in parallel with the coupling module, for example, an induction coil, and can thus absorb overvoltage pulses, for example, in the event of a possible lightning strike.

[0039] According to further embodiments of the present invention, the test signal can have a modulated signal identifier. The inventors have recognized that this can improve the robustness of the continuity test, for example, by allowing the test signal to be distinguished from other signals or interference signals when the test signal is detected using the modulated identifier.

[0040] According to further embodiments of the present invention, the object is a wind turbine with a plurality of rotor blades, wherein the rotor blades each have electrical lines in the form of lightning rods. Furthermore, the electrical line is a lightning rod of a rotor blade of the wind turbine. As already explained above, the device according to the invention has significant advantages, particularly with regard to a continuity test of a lightning rod of a rotor blade of a wind turbine.

[0041] Such an inspection can, for example, be carried out by a single person who activates the device wired or wirelessly from the ground to couple a test signal into a lightning rod on a rotor blade. A drone, for example, can then be used to fly over the rotor blade and record the test signal. This allows conclusions to be drawn about the condition of the lightning rod. The device can then be deactivated accordingly. This allows a continuity test to be provided with minimal personnel and time expenditure.

[0042] The device can be located, for example, in the hub, the flange, or a rotor blade of the wind turbine. The test signal can, for example, be efficiently coupled into the rotor blade's lightning conductor at a hub on the rotor blade.

[0043] Alternatively, the drone can provide the activation signal for the device when flying over the wind turbine. This may eliminate the need for multiple service technicians to climb into the hub of the blade base to activate a corresponding device, for example for safety reasons or legal requirements. Furthermore, the corresponding device can also be permanently connected to the wind turbine, so that a corresponding device no longer even needs to be specially attached for inspection. The coupling module can be, for example, a pair of clamps, such as induction clamps, or a ring, such as an induction ring, which is attached to a corresponding lightning protection cable or is permanently attached to the structure.

[0044] According to further embodiments of the present invention, the coupling module is designed to be attached to the lightning rod of a rotor blade and / or to be integrated into the lightning rod of the rotor blade. Alternatively or additionally, the coupling module is designed to be attached to a feed line to the rotor blade and / or to be integrated into the feed line and / or to be integrated into a rotor blade and / or to be attached to a rotor blade. Embodiments of the present invention are not limited to a specific attachment of the coupling module to the lightning rod. Depending on the design of the wind turbine or, for example, whether the device is retrofitted to the wind turbine or is already provided directly during manufacture of the wind turbine, a corresponding coupling module with a high degree of flexibility can be used.

[0045] According to further embodiments of the present invention, the device has a plurality of coupling modules corresponding to the plurality of rotor blades, wherein a respective coupling module is designed to couple the electrical test signal for the continuity test of a respective lightning rod into a respective rotor blade. Thus, for example, a plurality of lightning rods of rotor blades of a wind turbine or a wind power plant can be tested using a single device. The test signal can, for example, be coupled into the various lightning rods one after the other, so that, for example, a single drone flies over a corresponding rotor blade with the test signal coupled in one after the other in order to record the test signal. Alternatively, however, the test signal can also be coupled into the plurality of rotor blades simultaneously, for example in order to simultaneously, for example,Using a large number of drones, it's particularly time-efficient to check the rotor blades' lightning rods. The coupling modules can be powered by a single signal generator, for example.

[0046] According to further embodiments of the present invention, the device comprises a plurality of coupling modules corresponding to the plurality of rotor blades, wherein a respective coupling module is designed to couple a respective electrical test signal for testing the continuity of a respective lightning rod into a respective rotor blade. Furthermore, the device comprises a plurality of signal generators corresponding to the plurality of coupling modules, wherein a respective signal generator of the plurality of signal generators is designed to generate the respective electrical test signal for coupling into a respective lightning rod in the active operating mode. Simply put, an associated signal generator can be present for each coupling module of the device, for example to conduct respective electrical test signals simultaneously or sequentially into respective lightning rods of the rotor blades.Thus, for example, the device can be more modularized so that the device can comprise a single coupling and signal generator module for each rotor blade.

[0047] According to further embodiments of the present invention, the energy source is designed to supply the plurality of signal generators with energy. Alternatively, the device has a plurality of energy sources corresponding to the plurality of signal generators, and a respective energy source of the plurality of energy sources is designed to supply a respective signal generator of the plurality of signal generators with energy. Thus, for example, a single central energy source can be provided for the energy supply, which can then, for example, be replaced with particularly little effort. Alternatively, the device can be more modularized, so that, for example, a coupling module, a signal generator, and an associated energy source can be present for each rotor blade. Furthermore, a further additional energy source can also be provided to supply the communication module.Thus, depending on the specific application, the device can be designed to be particularly fail-safe, for example through greater modularization so that individual modules are easily replaceable or with fewer components, for example with a centralized signal generator and / or a centralized energy source.

[0048] Further embodiments according to the present invention comprise a system for providing electrical test signals for performing a continuity test of electrical lines of an object, wherein the object is a wind turbine with a plurality of rotor blades, wherein the rotor blades each have electrical lines in the form of lightning rods, and wherein the system further comprises a plurality of devices according to one or more of the embodiments disclosed herein, wherein a respective coupling module of a respective device is designed to couple a respective electrical test signal for continuity testing of a respective lightning rod into a respective rotor blade. Simply put, a device according to the invention can therefore be provided for each rotor blade, for example, in order to couple in a corresponding test signal.The devices can each be controlled, for example, with different activation and deactivation signals, for example, to activate or deactivate the devices iteratively one after the other to test a respective lightning rod of a respective rotor blade. Furthermore, however, the devices can also respond to a common activation and / or deactivation signal, so that, for example, a plurality of test signals are provided simultaneously in the rotor blades. In such a case, for example, identifiers modulated onto a respective test signal can be different in order to distinguish between the signals.

[0049] Further embodiments according to the present invention include a system for providing an electrical test signal for performing a continuity test of an electrical line of an object, comprising a device according to one or more of the embodiments disclosed herein, a communication unit configured to transmit the activation signal and the deactivation signal to the communication module of the device, and a measuring unit configured to detect the test signal. The communication unit can be, for example, a laptop or a unit attachable to a drone. For example, in the case of a laptop, an activation signal can be provided via a port in the object that is connected to the communication module of the device.During an inspection flight of a drone, for example, the activation signal can be transmitted wirelessly to a communication module of the device using a communication unit attached to the drone. The measuring unit can be a handheld device, for example, used by technicians or climbers to detect the test signal near the object's cable. Furthermore, the measuring unit can also be designed to be attached to a drone, for example, so that the test signal can be detected when the object is flown over. This allows, for example, a high degree of automation in the inspection of the object's cable to be achieved.

[0050] According to embodiments of the present invention, the communication unit is designed to be attached to a drone. As already explained above, during a manual, automatic, autonomous or, for example, semi-autonomous flight of the drone along the object, for example during a regular inspection, the device can be activated and, for example, deactivated again after completion of the continuity test. The drone can, for example, be controlled or launched from the ground, so that it is not necessary, for example, for people to go to high altitudes or to hard-to-reach locations to carry out an inspection, in particular a continuity test, particularly in the case of large objects.

[0051] According to further embodiments of the present invention, the measuring unit is designed to be attached to a drone and to capture the test signal during an inspection flight of the drone along the object. As already explained above, this also allows for the reduction of human personnel during the measurement and reduces the risk to human personnel. The drone can thus also penetrate areas that are inaccessible or difficult to reach for humans, capture the test signal there and determine the condition of the object or its line.

[0052] According to further embodiments of the present invention, the object is a wind turbine with a plurality of rotor blades, wherein the rotor blades each have electrical lines in the form of lightning rods, and wherein the system further comprises a plurality of devices according to one or more of the embodiments disclosed herein, wherein a respective coupling module of a respective device is designed to couple a respective electrical test signal for testing the continuity of a respective lightning rod into a respective rotor blade. Furthermore, the communication unit is designed to transmit the activation signal and the deactivation signal to a respective communication module of a respective device. Furthermore, a drone has the measuring unit, and the drone is designed to fly to the wind turbine and fly away from the plurality of rotor blades.

[0053] The drone can be designed, in particular, to autonomously approach the wind turbine and autonomously fly over the plurality of rotor blades. The measuring unit can be designed, in particular, to detect the test signal during the autonomous flight over the rotor blades. The inventors have recognized that this makes it possible to provide a simple and efficiently automated system for testing lightning rods of wind turbines. By providing a device according to the invention for a respective lightning rod or a respective rotor blade, the system is particularly robust and also enables simultaneous testing of the plurality of rotor blades, for example using a corresponding plurality of drones with a corresponding number of measuring units. It should again be noted that the drone can also be controlled manually, automatically, or semi-autonomously.

[0054] It should be noted again that the measuring unit can also be a portable device. Accordingly, exemplary embodiments are not limited to the use of drones. However, an inspection can also be carried out using a drone, for example, to determine the approximate area of ​​damage to a lightning protection line. Afterwards, climbers with portable measuring units can scan the wind turbine, or more precisely, the rotor blades, again to locate and repair the corresponding damage.

[0055] According to further embodiments of the present invention, a method according to the invention further comprises transmitting the activation signal by means of a communication unit to the communication module, scanning the object with a measuring unit, detecting the test signal when scanning the object and transmitting the deactivation signal by means of the communication unit to the communication module.

[0056] For example, rough information about damage to a lightning rod on a rotor blade may be known. To repair it, a climber can then, for example, climb onto the rotor blade and transmit the activation signal, for example wirelessly using a portable communications unit, to the device's communications module. The rotor blade can then be climbed down and the climber can record the test signal, for example using a portable measuring unit. This allows the damage location to be determined very precisely, for example by scanning at a very short distance, and repaired accordingly. After the recording or repair is complete, the deactivation signal can again be transmitted to the device's communications module to relieve the load on, for example, the device's replaceable energy storage device and ensure a long service life.

[0057] According to further embodiments of the present invention, a method according to the invention further comprises approaching the object with a drone, wherein the drone has a measuring unit, transmitting the activation signal by means of a communication unit to the communication module, flying over the object using the drone, detecting the test signal when flying over the object using the measuring unit, and transmitting the deactivation signal by means of the communication unit to the communication module. For example, in order to provide information for subsequent repairs, the object can thus be flown over manually, automatically, semi-autonomously, or autonomously using the drone. The transmission of the activation signal can take place, for example, when approaching the object, e.g.when the drone first approaches a rotor hub, whereby the drone can, for example, have the communication unit. Furthermore, the communication unit can also be a laptop on the ground of the wind turbine, which is also used to control the drone, for example. As mentioned before, the activation signal can then also be transmitted via a wired connection via a permanently installed cable in the object. As already mentioned, the approach to and departure from the object can be carried out automatically, semi-autonomously or autonomously, so that an inspection result can be provided with little time and personnel expenditure (it should be pointed out again that manual flight is also possible). The drone can alsoGenerally, the detector flies over the object's conductor at a very short distance to detect the test signal. After detecting the test signal, the deactivation signal is then transmitted to the communication module via the communication unit. This, in turn, saves energy after the inspection is complete.

[0058] According to further embodiments of the present invention, a method according to the invention further comprises activating the communication module in the passive operating mode at time intervals for a predetermined duration to receive the activation signal, transmitting the activation signal by means of the communication unit to the communication module during a time period that is greater than a time interval between two activations of the communication module, receiving the activation signal by means of the communication module in order to switch from the passive operating mode to the active operating mode, and transmitting information about the operating state by means of the communication module to the communication unit.

[0059] According to further embodiments of the present invention, for each detected value of the test signal, at least one of time information, absolute position information of the drone, and / or distance and / or attitude information of the drone relative to the rotor blade is stored together with the detected value of the test signal. The inventors have recognized that this enables precise localization of a damage location.

[0060] According to further embodiments of the present invention, a method according to the invention further comprises comparing the detected test signal with a reference signal, wherein the reference signal is a calculated signal profile of a detected test signal across the electrical line and / or a signal profile of the detected test signal across the electrical line measured during a previous measurement, in order to determine information about damage to the electrical line.

[0061] The calculated signal curve can, for example, be the result of a simulation, e.g., based on CAD data. This makes it possible, for example, to check whether the conductor or line is intact and / or has been correctly installed during a first flight on a newly constructed system. Furthermore, the inventors have also recognized that, for example, due to different environmental influences and local conditions at the location of the object, the line or conductor in the object can change in different ways, so that a previous measurement result can be used to assess the condition or change in condition.

[0062] According to further embodiments of the present invention, in a method according to the invention, the object is a wind turbine with a rotor hub and a plurality of rotor blades arranged on the rotor hub, wherein the rotor blades each have electrical lines in the form of lightning conductors. Furthermore, devices of a plurality of devices according to one or more of the embodiments disclosed herein are each coupled to a lightning conductor of a respective rotor blade. The method according to the invention further comprises approaching the wind turbine, e.g., the rotor hub or a rotor blade tip, by means of a drone, wherein the devices are each in passive operating mode during the drone's approach.Furthermore, the method comprises transmitting an activation signal by means of a communication unit of the drone to a communication module of one of the devices in order to put the one device into the active operating mode. The method also comprises coupling a test signal generated by the signal generator of one device into the lightning rod of the rotor blade coupled to the one device, by means of the coupling module of the one device. Furthermore, the method comprises flying over the rotor blade coupled to the one device with the drone while the test signal is coupled into the lightning rod of the rotor blade, and detecting the test signal by means of a measuring unit of the drone while the rotor blade is flying over it. Optionally, the method can, for example, comprise flying over the rotor hub or the rotor blade tip again.

[0063] The method further comprises transmitting a deactivation signal, via the drone's communication unit, to the communication module of one device in order to return the one device to passive operating mode. Furthermore, the method comprises iteratively repeating the steps of transmitting an activation signal, coupling a test signal, flying over the rotor blade, detecting the test signal (optionally flying over the rotor hub or the rotor blade tip again), and transmitting a deactivation signal for the additional devices and the additional rotor blades of the plurality of devices coupled to the devices.

[0064] In simple terms, the drone can approach the wind turbine, for example, the blade hub or a rotor blade tip. The drone flight can be manual, automated, semi-autonomous, or autonomous. The drone can then initiate a radio signal to put one of the devices into active operating mode or, simply put, to wake it up. The drone can wait a certain period of time, e.g., 75 seconds, and provide the activation signal to ensure that a wake-up interval of the communication module is met while one of the devices is in passive operating mode, or, simply put, is caught in time to transmit the activation signal and activate the device. Optionally, the communication module can also be used to transmit feedback from the device about the active operating mode back to the drone's communication unit after the device has been activated.The drone can then fly over the wing or rotor blade, e.g., manually, automatically, semi-autonomously, or autonomously, capture the test signal, optionally return to the hub, and then return the device to passive operating mode, such as sleep mode. This process can be repeated iteratively, for example, one after the other, with one drone to activate the other devices and inspect the other rotor blades.

[0065] It should be noted that embodiments according to the present invention are not limited with respect to a specific flight route guidance.

[0066] Thus, a device according to the invention can be activated by a communication unit of a drone from the hub as mentioned above, but activation can also occur during an approach of the drone to the hub, or an approach of the drone to a rotor blade tip or from a rotor blade tip.

[0067] Accordingly, the test signal can be acquired from a variety of possible starting points and with a variety of possible end points of the flight trajectory. For example, a rotor blade can be flown over starting from the rotor blade tip to acquire the test signal. Conversely, a test flight can also be initiated from the hub or the rotor blade flange.

[0068] For example, a device for inducing the test signal can be activated starting at the hub of the wind turbine, and the corresponding rotor blade can then be flown over. Starting at the rotor blade tip, the device can be deactivated again using the deactivation signal, and the drone can then fly to another rotor blade tip in a waiting mode. On the way to the next tip, a device associated with the rotor blade can be activated, for example, to record the test signal in the lightning rod of the rotor blade during this test flight, starting from the rotor blade tip to the hub.

[0069] Accordingly, it should be noted that embodiments according to the present invention include a plurality of flight routes or flight patterns and, accordingly, also procedures for activating and deactivating devices according to the invention. Short character description

[0070] Examples according to the present disclosure are explained in more detail below with reference to the accompanying figures. With regard to the schematic figures shown, it should be noted that the illustrated functional blocks are to be understood both as elements or features of the device according to the disclosure and as corresponding method steps of the method according to the disclosure, and corresponding method steps of the method according to the disclosure can also be derived therefrom. They show: Fig. 1 shows a schematic view of a device for providing an electrical test signal according to embodiments of the present invention; Fig. 2 shows a schematic view of a device with an optional protective diode according to embodiments of the present invention; Fig. 3 shows a schematic side view of a wind turbine with a device according to the invention according to embodiments of the present invention; Fig. 3a shows a schematic side view of a wind turbine with devices according to the invention according to embodiments of the present invention; Fig. 4 shows a system for providing electrical test signals according to embodiments of the present invention; Fig. 5 shows a further system for providing an electrical test signal with further optional features according to embodiments of the present invention;Fig. 6 is a schematic block diagram of electronics of a device according to embodiments of the present invention; and Fig. 7 is a schematic block diagram of a method according to embodiments of the present invention. Detailed description of the examples according to the figures

[0071] Before exemplary embodiments of the present invention are explained in more detail below with reference to the drawings, it is pointed out that identical, functionally equivalent or equivalent elements, objects and / or structures in the different figures are provided with the same or similar reference numerals, so that the description of these elements shown in different exemplary embodiments is interchangeable or can be applied to one another.

[0072] Fig. 1 shows a schematic view of a device for providing an electrical test signal according to embodiments of the present invention. Fig. 1shows the device 100 for providing an electrical test signal for performing a continuity test of an electrical line of an object. The device 100 comprises a communication module 110, which is designed to receive an activation signal to switch the device from a passive operating mode to an active operating mode and to receive a deactivation signal to switch the device from the active operating mode to the passive operating mode. Furthermore, the device 100 comprises a signal generator 120, which is designed to generate the electrical test signal in the active operating mode. In addition, the device 100 comprises a power source 130, which is designed to supply the communication module and the signal generator with power.In addition, the device 100 comprises a coupling module 140 which is designed to couple the electrical test signal into the electrical line of the object in the active operating mode.

[0073] A method according to the invention can be Fig. 1can therefore be summarized, for example, as follows: supplying a communication module 110 with energy from an energy source 130 and receiving an activation signal by means of the communication module 110 in order to switch from a passive operating mode to an active operating mode and supplying a signal generator 120 in the active operating mode with energy from the energy source 130 and generating an electrical test signal in the active operating mode by means of the signal generator 120 and coupling the electrical test signal in the active operating mode into the electrical line of the object and receiving a deactivation signal by means of the communication module 110 in order to switch from the active operating mode to the passive operating mode.

[0074] The communication module 110 can optionally be configured to receive the activation signal or the deactivation signal wirelessly. Accordingly, the communication module can be a radio module, for example. Communication can take place, for example, via any radio bandwidth, for example, via WLAN or mobile radio frequencies. The communication module can in particular be configured to receive a secure or encrypted activation and / or deactivation signal in order to prevent activation of the device by third parties. The device can in particular comprise an antenna or, for example, a similar unit to improve the radiation and / or reception characteristics.

[0075] As already explained above, corresponding wireless communication enables operation of the device, for example, regardless of a specific location of the device on or in the object. The inventors have recognized that this can have significant advantages, particularly for large objects and / or objects where cables need to be inspected in hard-to-reach areas. For example, personnel can be saved because there is no need for an additional technician to operate the device on site, for example, to activate the device to generate the test signal and then deactivate it accordingly. In particular, the continuity test can be carried out using an autonomously operating device, such as an autonomously or automatically flying drone, wherein a communication unit of the drone can establish wireless communication with the communication module.This means, for example, that a corresponding continuity test can be carried out fully automatically or fully autonomously.

[0076] Alternatively, the communication module 110 can also be designed, for example, to receive the activation signal and / or the deactivation signal via a wired connection.

[0077] In general, the device for providing the electrical test signal can be permanently connected to the object according to embodiments, or it can also be attached to the object, or more precisely, to the object's electrical line, only during an inspection. For example, in the case of a fixed structural connection to the object, a communication line can be provided within the object, so that the device can be controlled from a fixed, easily accessible, position on the object. This ensures, for example, particularly interference-free and robust communication.

[0078] Optionally, the energy source 130 can be an energy storage device. The energy storage device can be replaceable and / or rechargeable. The inventors have recognized that such an energy storage device has advantages, particularly for devices that are connected to the object for a long time, for example, those built into the object. For example, the device can be remotely activated and deactivated wirelessly or via wire using the communication module in order to carry out inspections without a technician having to access the device itself to establish a power supply. The energy source in the form of the energy storage device can then, for example, be replaced or recharged at certain intervals. Accordingly, such an energy storage device can be dimensioned so that a large number of continuity tests can be carried out before replacement or recharging is necessary.For example, the energy storage device can be an accumulator or a battery, such as a lithium battery. In particularly preferred embodiments, the battery can be replaced by a technician in a simple operation. A corresponding battery can, for example, have a capacity of at least 5000 mAh and at most 12000 mAh, for example, at a voltage between at least 10 V and at most 14 V. For example, the battery can have a capacity of 8000 mAh with a tolerance of + / -10% at 12 V with a tolerance of + / -10%.

[0079] Alternatively, however, the energy source 130 can also be configured to be coupled to an external power supply. For example, in the case of objects that serve to generate energy or that are configured to consume energy or power, which are, for example, constantly supplied with energy, existing power electronics can be used to supply the device with energy. The energy source can be configured to be coupled to and decoupled from the external power supply during each inspection, or can be configured to be permanently connected to a corresponding power supply, for example, in the case where the device is integrated into the object.

[0080] Optionally, the coupling module 140 can be configured to inductively and / or capacitively couple the electrical test signal into the electrical line of the object in the active operating mode. The inventors have recognized that this enables particularly efficient retrofitting of existing objects to provide the functionality of a continuity test of a line or conductor in the object. Thus, for example, no electrical lines of the object need to be exposed in order to couple the test signal into them. Furthermore, galvanic decoupling between the device or the coupling module and the electrical line can also be provided, for example. Thus, the device can be substantially protected, for example, from voltage peaks and / or current peaks on the electrical line. Furthermore, such coupling has advantages with regard to components that are movable relative to one another.If the object, such as a wind turbine, is designed to move, it may be advantageous if the coupling module is not permanently connected to an electrical line of the object, but such a connection can be present inductively.

[0081] Alternatively, however, the coupling module 140 can also be configured to couple the test signal into the object's line in active operating mode by means of a switchable ohmic connection. Thus, the coupling module can be permanently connected to the line, for example, whereby electrical conductivity can be established or interrupted, for example, by means of a switch. Thus, the device can be decoupled from the line, for example, to enable regular operation or to protect the device from lightning strikes, for example, particularly in the case of particularly large objects that may attract lightning.

[0082] As a further optional feature, the communication module 110 can be configured to be activated in passive operating mode at intervals for a predetermined duration to receive the activation signal. In this case, the energy consumption of the device can be lower in passive operating mode than in active operating mode. For example, in simple terms, the device can be switched off in passive operating mode in order to only cyclically activate the communication module to enable transmission of an activation signal. Based on the activation signal, the device can then be switched on accordingly to generate and couple the test signal. Thus, for example, a long-term energy supply can be ensured, particularly with an energy storage device, so that replacement or recharging intervals for the energy storage device can be set as long time intervals.

[0083] For example, if the energy source is an energy storage device, the communication module 110 can further be configured to transmit a charge state of the energy storage device in the active operating mode. Optionally, however, the device can further be configured to perform self-diagnosis and also provide further information about the device via the communication module. In both cases, the robustness of the device can thus be improved since, for example, it can be estimated whether the remaining amount of energy in the energy storage device is sufficient to carry out an inspection or to plan maintenance or replacement of the device, for example. Furthermore, charging or replacement of the energy storage device can be planned accordingly.

[0084] As a further optional feature, the communication module 110 can further be configured to transmit information about the operating state of the device. In particular, the communication module 110 can be configured to indicate a change from the passive to the active operating state. Thus, for example, feedback can be provided that an activation signal was successfully transmitted. Furthermore, it can be transmitted that the device is ready to perform a continuity test of a conductor of an object or, in other words, to provide the test signal, or even that the test signal is already being provided.The inventors have recognized that this can be particularly advantageous for objects where the ladder is difficult to access or reach, since otherwise it may happen that, for example, a climber or a drone is in position to capture the test signal without being certain that the device for generating the test signal is even ready to do so, or that, for example, there is a fault.

[0085] As a further optional feature, the signal generator 120 can be configured to generate a radio frequency signal and / or a high frequency signal and / or a clocked low frequency signal as the test signal. The inventors have recognized that, for example, an electromagnetic field can be generated particularly efficiently around the conductor using a high frequency signal, which can be detected by a measuring unit. Thus, the test signal can be detected even from greater distances around the conductor of the object in order to draw conclusions about the conductor or line. Furthermore, the high frequency signal can be used to provide inductive or capacitive coupling into the line of the object.In addition, smaller conductor interruptions can also be bridged, for example, which may not be relevant for a lightning strike and therefore should not be detected as defects during a continuity test of the conductor, for example a lightning rod.

[0086] As a further optional feature, the signal generator 120 can be configured to enable impedance matching to the object's electrical line. In other words, the generator output can, for example, perform impedance matching (radiation) within certain limits. This means that an attempt can be made to achieve an optimal value depending on the line or conductor, for example, depending on the length of the line or conductor, or even depending on the type of line or conductor. It should be noted that a uniformly reproducible field strength does not necessarily have to be achieved for all possible variations of electrical conductors, such as lightning rods or lightning protection systems. Impedance matching can therefore, for example, be used to improve the efficiency of the signal feed, for example to minimize signal reflection and losses.This also allows the replacement interval or recharging interval of an energy storage device to be extended by saving energy during feed-in and signal transmission.

[0087] As a further optional feature, the device can be configured to modulate a signal identifier onto the test signal. This allows the test signal to be easily distinguished from other signals, for example, enabling a robust and accurate evaluation of the continuity test. Furthermore, the use of a signal identifier also enables the parallel input of a large number of test signals, for example, into different conductors, so that the signals can still be distinguished. This allows, for example, the inspection of an object with many conductors to be tested to be carried out particularly time-efficiently.

[0088] Fig. 2shows a schematic view of a device with an optional protection diode according to embodiments of the present invention. Fig. 2 shows the device 200 comprehensively, in addition to the elements already described in the context of Fig. 1 explained, a communication module 240. As a further optional feature, the device 200 comprises a protection diode 250, which is designed to protect the device 200 from a voltage and / or current spike on the electrical line of the object. As an optional feature, the protection diode 250 is a suppressor diode that is connected in parallel to the coupling module 240. As in Fig. 2As indicated, the suppressor diode can, for example, be connected in parallel to a signal path of the coupling module or, optionally, can also be an element arranged externally outside the coupling module. In general, the protective diode can also be arranged on or between other elements of the device. The protective diode can, for example, be a transil diode. Such a diode does not require a ground connection, but is installed internally in parallel with the coupling module, e.g., an induction coil, and can thus absorb overvoltage pulses. For example, a lightning strike can be absorbed in this way, preventing the device from being destroyed.

[0089] For example, a corresponding protection diode, e.g., in the form of a suppressor diode, can become conductive when a specific voltage threshold is exceeded. A corresponding current peak is then conducted in parallel to the component to be protected, for example, the coupling module. The diode can absorb the energy internally. Furthermore, a corresponding diode can be designed as a unidirectional or bidirectional diode.

[0090] Fig. 3 shows a schematic side view of a wind turbine with a device according to the invention according to embodiments of the present invention. Fig. 3 shows a wind turbine 360 ​​with a tower 362, a nacelle 364 and a plurality of rotor blades 372, 374, 376, wherein the rotor blades each have electrical lines 382, ​​384, 386 in the form of lightning conductors. In general, in the context of Fig. 3It should be noted that an object can thus be a wind turbine 360 ​​or a rotor blade of such, wherein a device according to the invention is designed to test electrical lines.

[0091] Furthermore, Fig. 3The device 300 comprises a communication module 310 and, as shown as an optional feature, a plurality of coupling modules 342, 344, 346 corresponding to the plurality of rotor blades. However, it should be noted that devices according to the present invention can also have only a single coupling module. The respective coupling modules 342, 344, 346 are each designed to couple the electrical test signal for the continuity test of a respective lightning rod 382, ​​384, 386 into a respective rotor blade 372, 374, 376. Optionally, the one or more coupling modules 342, 344, 346 can be arranged on a lightning rod of a rotor blade, on a supply line to the rotor blade, or integrated into the rotor blade. For example, when building a new system, a device according to the invention can already be integrated into the object, or more precisely, the rotor blade.In the integrated state, however, the coupling module can be designed not only to be ohmic, for example with a switch, but also to induce or, more generally, to couple the test signal into the lightning rod inductively or capacitively.

[0092] As a further optional feature, the device 300 comprises a plurality of signal generators 322, 324, 326 corresponding to the plurality of coupling modules 342, 344, 346, wherein a respective signal generator is configured to generate the respective electrical test signal for coupling into a respective lightning rod in the active operating mode of the device 300. However, it should be noted that the presence of a plurality of signal generators is merely optional. For example, only a single signal generator 320 with multiple signal outputs may be present.

[0093] Analogously, as a further optional feature, a single energy source 330 or one of the plurality of energy sources 332, 334, 336 corresponding to the plurality of signal generators 322, 324, 326 may be configured to supply energy to a respective signal generator.

[0094] It should be noted that a wind turbine, as an object, serves only as an example. Radio masts, wind turbine towers, large antennas, ships (e.g., large container ships), port facilities, or other large structures may also contain electrical cables that are difficult to access but still require inspection.

[0095] Fig. 3a shows a schematic side view of a wind turbine with inventive devices according to embodiments of the present invention. Fig. 3ashows a wind turbine 360a with a tower 362a, a nacelle 364a, and a plurality of rotor blades 372a, 374a, 376a, wherein the rotor blades each have electrical lines 382a, 384a (for the sake of clarity, lightning conductors in rotor blade 376a are not shown) in the form of lightning conductors. Furthermore, the tower 362a includes a conductor 388a connected to the lightning conductor 384a, as well as a second conductor 389a.

[0096] Furthermore, Fig. 3 a plurality of devices 302a, 304a, 306a each comprising a coupling module 342a, 344a, 346a, a signal generator 322a, 324a, 326a, and a power source 332a, 334a, 336a. For the sake of clarity, the respective communication modules are not shown.

[0097] As an optional feature in Fig. 3a As shown, a coupling module 342a according to the invention can be integrated, for example, into a rotor blade 372a, i.e., for example, a wing.

[0098] Furthermore, a tower 362a may include one or more conductors. Thus, a device 306a, for example, may be configured to provide a continuity test for conductor 389a.

[0099] A corresponding conductor in the tower, e.g., conductor 388a, can be designed, for example, to divert an overvoltage, e.g., due to a lightning strike, from one or more lightning conductors in the rotor blades. Thus, a device 304a can, for example, not only perform a continuity test on the lightning conductor 384a but also simultaneously test the conductor 388a connected to the lightning conductor 384a.

[0100] For the sake of completeness, it should be noted that a respective signal generator 322a, 324a, 326a is each designed to generate the electrical test signal for coupling by means of a respective coupling module 342a, 344a, 362a in the active operating mode of the respective device, and that a respective energy source 332a, 334a, 336a is each designed to supply a respective communication module (not shown) and a respective signal generator 322a, 324a, 326a with energy in the active operating mode of the respective device.

[0101] Furthermore, it should be noted that the Fig. 3aThe features shown are optional and can thus be used individually or in combination according to embodiments. For example, a tower 362a can have only a single conductor or a plurality of conductors. The different arrangements and configurations of the devices 302a, 304a, 306a are not to be construed as limiting, but rather serve to clearly explain various embodiments according to the present invention.

[0102] Fig. 4 shows a system for providing electrical test signals according to embodiments of the present invention. Fig. 4 shows a wind turbine 360 ​​according to Fig. 3, as well as the system 400 comprising a plurality of devices 410, 420, 430 according to one or more of the exemplary embodiments described herein, wherein a respective coupling module of a respective device is designed to couple a respective electrical test signal for continuity testing of a respective lightning rod 382, ​​384, 386 into a respective rotor blade 372, 374, 376. In simple terms, a system 400 according to the invention can therefore comprise a plurality of devices according to the invention corresponding to the number of lines. Thus, a separate device can be provided for each line to be tested, which device can accordingly also be individually controlled, i.e., activated and deactivated. Coupling modules of the devices 410, 420, 430 can, for example, be attached to a lightning rod of a rotor blade or in a supply line to the rotor blade, or integrated into a rotor blade.

[0103] Fig. 5shows another system for providing an electrical test signal with further optional features according to embodiments of the present invention. Fig. 5 shows a wind turbine 360 ​​with the already in the context of Fig. 3 and Fig. 4 It should be noted that a wind turbine 360 ​​is merely an illustrative example of an object. It should be mentioned again that cranes, antenna masts, radio masts, large ships, or entire port facilities, for example, may also have electrical cables that must be inspected at regular intervals.

[0104] Based on Fig. 5A variety of exemplary embodiments of the system 500 are explained below. It should be noted that, unless otherwise stated, individual features, details, and functionalities are highlighted here together to clarify the functionality of the invention; however, these do not all need to be present simultaneously in the exemplary embodiments.

[0105] As an example, the system 500 comprises a plurality of devices according to one or more of the explained embodiments, namely the devices 510, 520 and 530. The devices are arranged in the vicinity of the lightning rods of the rotor blades in order to couple a test signal into the corresponding rotor blade 372, 374, 376 or, more precisely, into the corresponding lightning rod 382, ​​384, 386 by means of a respective coupling module.

[0106] It should again be noted that, for example, only one device may be present in the system, which device has a plurality of coupling modules, so that the test signal can be fed into the lightning conductors 382, ​​384, 386, for example from a common signal generator or from a plurality of signal generators, via the plurality of coupling modules.

[0107] Furthermore, the system 500 comprises a communication unit, for example a communication unit 542 and / or a communication unit 544 and / or a communication unit 546, which is designed to transmit the activation signal and the deactivation signal to a communication module of one of the devices 510, 520, 530.

[0108] The system 500 further comprises a measuring unit, for example a measuring unit 252 or a measuring unit 554 or a measuring unit 556, which is designed to detect the test signal.

[0109] In Fig. 5 Accordingly, several options for the communication unit and the measuring unit are shown, which will be explained in more detail below. It should be noted that the system and, in particular, the method according to the invention can comprise such units individually, jointly, in combination, or individually. This will be explained in more detail below.

[0110] For example, a drone 562 can be used to perform a continuity test on an object's electrical line. It should be noted that the system 500 can optionally also include the drone 562. The drone can be launched from the ground, for example, using a laptop. The drone can be configured to then be directed, for example, autonomously, semi-autonomously, or automatically, or even manually, to one of the devices 530 and thus, for example, as in Fig. 5 shown, to fly to the rotor hub 364. To activate the device 530, the activation signal can now be transmitted to the communication module of the device 530 by means of the communication unit 542. Accordingly, a communication unit according to the invention can be designed, such as the communication unit 542, to be attached to a drone.

[0111] For example, in order to receive a corresponding activation signal 570, the communication module of the device 530 can be activated at intervals for a predetermined duration. Accordingly, the communication unit can be configured to provide the activation signal 570 for a period of time that is greater than the period between two activations of the communication module.

[0112] Accordingly, the activation signal 570 can be received by the device 530, or more precisely, by the communication module of the device 530, in order to switch from the passive operating mode to the active operating mode. Consequently, a method according to the invention can comprise transmitting the activation signal by means of the communication unit 542 to the communication module during a period of time that is greater than a time interval between two activations of the communication module. Optionally, information about the operating state of the device can be transmitted back from the communication module of the device 530 to the communication unit 542. In the active operating mode of the device, the test signal can then be introduced into the lightning rod accordingly.Starting from an activated device, a drone, such as that shown with drone 564, can fly over a rotor blade 374 in an automated, autonomous, semi-autonomous, or even manual manner. The drone can have a measuring unit that is accordingly configured to be attached to a drone, for example, like the measuring units 552 and 554 in FIG. Fig. 5 .

[0113] It should be noted that drones 542 and 544 and, correspondingly, communication units 542 and 544 and measuring units 552 and 554 are each the same objects which carry out the steps explained here one after the other.

[0114] In the following, it is assumed that device 520 is in the activated state, for example, due to a previous activation, as explained with drone 562 and rotor blade 376. Device 520 can accordingly couple a test signal 580 into conductor 384 using the associated signal generator and the coupling module. The coupling can be effected, for example, inductively, capacitively, or via an ohmic switchable connection.

[0115] The measuring unit 554 can optionally be configured to detect the test signal 580 during an inspection flight of the drone 564 along the object, for example, along the rotor blade 374. Accordingly, an interruption in the conductor can be inferred if such a signal is weaker than expected or not present. Subsequently, the drone 564 can, for example, return to a respective device, for example, device 530, as explained above, or device 552, and then, for example, in a position as shown with drone 562, transmit the deactivation signal to terminate the coupling of the test signal. Accordingly, an automatable method for testing the continuity of lightning rods can be provided.

[0116] It should be noted, however, that by means of the communication unit 542, the activation and / or deactivation signal can also be transmitted from any position on a flight path of the drone 562, 564, for example during a flight from one rotor blade to the next rotor blade, for example from a hub of the wind turbine, or for example from a rotor blade tip.

[0117] Generally speaking, the object can be approached by a drone 562, 564, for example, automatically, semi-autonomously, autonomously, or manually, wherein the drone has the measuring unit 552, 554. An activation signal can then be transmitted to a communication module of a device 520, 530 by means of a communication unit 542, 544. It should be noted that, for example, only a single device can be present, with a single communication module, but, for example, a plurality of coupling modules for coupling the electrical test signal, so that, for example, the activation signal is transmitted only to that single communication module.

[0118] The drone can then fly over the object, and the test signal 580 or the plurality of test signals from multiple rotor blades can be detected by the measuring unit 552, 554. After the flight, the one or more devices can then be transferred back to passive operating mode, for example, switched off, using a deactivation signal.

[0119] The acquired test signal can then be evaluated. For example, a method according to the invention can comprise comparing the acquired test signal with a reference signal. The reference signal can be, for example, a theoretical reference signal, which can be determined using nominal data of the test signal and the lightning rod, or also, for example, a historical reference signal, which was acquired, for example, during a previous measurement. In this way, information about a trend, for example a temporal degradation of the lightning rod, can be provided, for example to predict maintenance that may not be necessary immediately but should be carried out in the long term. In this way, information about damage to the electrical line or the lightning rod can be determined.

[0120] In general, the data stored by the measuring unit can include, in addition to the actual recorded value of the test signal, at least one of time information, absolute position information of the drone, and distance and / or attitude information of the drone relative to the rotor blade. For this purpose, the drone can, for example, be equipped with a GPS receiver or determine its own position using relative positioning systems.

[0121] The result of such an evaluation based on the acquired information can be used to locate a damage site and plan a replacement or repair. Climbers 566, for example, can be used for this purpose. For particularly precise localization, a measuring unit 556 can, for example, be a portable device, so that a climber in the immediate vicinity of the rotor blade can determine a damage site more precisely. As an example, a signal line 590 is shown here for activating the device 510. Accordingly, the activation signal can, for example, be transmitted by wire to the communication module of the device 510 via a communication unit 546. In the case of the wind turbine, this can, for example, be an electrical line laid along the tower to the base of the turbine if the device 510 is permanently connected to the rotor hub.Thus, for example, a laptop, which can also be used to control a drone, can be used to activate device 510. Accordingly, it should be noted that a corresponding wired signal transmission can also be used with embodiments using drones. Alternatively, however, a climber 566 can also carry a portable communication unit, with which a corresponding device 510 can be activated, as explained in connection with drone 562.

[0122] In summary, the activation signal can be transmitted wired or wirelessly by means of a communication unit to the communication module of a device or to the device, for example, if only one device is installed in the wind turbine, with a plurality of coupling modules. A climber, for example, can then scan the lightning rod using a handheld device 556 and detect a corresponding test signal. After detecting the test signal, the corresponding device 510 can be deactivated again using the communication module. A measuring unit 556 can, for example, be capable of transmitting the measured data wirelessly in order to enable immediate evaluation during inspection, for example, so that an exact location of the damage site can be determined directly and repairs can be initiated immediately.

[0123] It should be noted again that in the course of the explanation of Fig. 5Several optional procedures were presented according to the invention, but these can be used individually or in combination. For example, a drone can be used to activate a plurality of devices one after the other, and a test signal can be coupled iteratively into each of the rotor blades in order to fly over these rotor blades iteratively one after the other. After each flight, the activated device can be deactivated again to activate another device until all corresponding lightning rods have been inspected.Furthermore, a drone squadron can also be used, so that all devices are activated simultaneously and several rotor blades or all rotor blades are flown over. Or, in the case of a single device, that same device is activated so that the device activates a plurality of coupling modules in order to introduce respective test signals into the respective lightning rods with the help of one or more signal generators. As previously explained, the flight can be carried out manually, automatically, autonomously, or semi-autonomously. A semi-autonomous flight can, for example, include a correction of a predetermined flight direction or a distance (e.g. from the object) using an additional measuring system, e.g. LiDAR.Alternatively, activation and deactivation can of course also be carried out manually, for example by climbers, as well as by scanning the corresponding conductor of the wind turbine.

[0124] In the following, further embodiments, and previously explained embodiments, summarized in other words, for objects in the form of wind turbines or rotor blades of wind turbines, are discussed.

[0125] According to some embodiments, the coupling module can be, for example, a clamp, e.g., an induction clamp. The communication module can be designed, for example, as a radio module or an integrated radio module, wherein the radio module can be designed to transfer or switch the device, for example, from the passive operating mode, e.g., a sleep mode, to the active operating mode, e.g., an active mode or an active mode.

[0126] To record the test signal, a drone with a measuring unit can be used, for example, so that after an inspection flight, for example using the radio module, the device can be put back into passive operating mode, i.e. sleep mode.

[0127] For example, for testing a lightning protection system on a wind turbine, the core idea according to such embodiments is the non-invasive injection of an electromagnetic field into the lightning protection system and the contactless, e.g., autonomous, flight of the rotor blades using a drone, which can be equipped with a measuring unit, such as a special sensor for field measurement. The measurement thus obtained can quickly, efficiently, and accurately determine the functionality of the lightning protection system using special measurement technology and mathematical / algorithmic processing.

[0128] In simple terms, embodiments are based on, for example, the inductive feeding of an electric field into the lightning protection system of the rotor blade, as well as the measurement of the radiated electric field with a measuring unit, e.g. a field sensor on a drone.

[0129] According to the exemplary embodiments, the localization of any damage points discovered is precisely possible and can be subsequently reproduced at any time using an additional measuring unit, e.g. a separate hand sensor for the purpose of repair.

[0130] As already explained above, the energy source can be designed, for example, as a replaceable energy storage device. For this purpose, a lithium battery or a lithium accumulator can be used, for example. (It should be noted again that, in general, according to exemplary embodiments, a cable can also be used to supply energy to the device via an external power supply, for example.)

[0131] As an example, such an energy storage device can comprise approx. 8000 mAH (e.g. with a tolerance of up to + / -5% or with a tolerance of up to + / -10% or with a tolerance of up to + / -50% or with a tolerance of up to + / -100% or with a tolerance of up to + / -1000%), e.g. at approx. 12 V (e.g. with a tolerance of up to + / -5% or with a tolerance of up to + / -10% or with a tolerance of up to + / -50% or with a tolerance of up to + / -100% or with a tolerance of up to + / - 1000%).

[0132] In particularly preferred embodiments, such an energy storage device can be replaced with little effort, for example, in a single operation. For this purpose, the device can, for example, have simple plug-in and snap-in connections for such an energy storage device.

[0133] As already explained above, the communication module, e.g., the radio module, can optionally be activated in passive operating mode at intervals for a predetermined duration to receive the activation signal. A corresponding replaceable energy storage device can be designed, for example, for a service life of many years, so that a device according to the invention can operate for long periods without requiring any special maintenance.

[0134] For example, power consumption in passive operating mode, e.g., sleep mode, can be broken down as follows: For example, the electronics may require approximately 15 microamperes in sleep mode, and they can be "woken up" every 60 seconds for approximately 0.1 seconds to query the radio signal - approximately 15 mA for 0.1 seconds. This results in an annual consumption of approximately 500mAh or 2000 mAh for 4 years.

[0135] Power consumption in active operating mode, e.g. inspection mode, can be as follows for the example of lightning rod inspection on a wind turbine: Approx. 800 mA, ie with a maximum of 15 minutes inspection time per blade, ie approx. 4000mAh for approx. 20 inspections.

[0136] Accordingly, for the previous example of the energy storage unit with approximately 8000 mAh at approximately 12 volts, if, for example, 2-3 inspections per year are scheduled or calculated, e.g. after a lightning strike (legally prescribed, for example, a maximum of 1 inspection every 2 years), and if a certain self-discharge of the energy storage unit, e.g. the Li battery, is taken into account, the battery only needs to be replaced approximately every 6 years (normal prescribed service in the system is, for example, every 2 years) as part of the prescribed service.

[0137] Thus, a device according to the invention can operate without maintenance for extended periods. As previously explained, the drone can optionally query the charge level of the energy storage device (e.g., battery) via the communication module (e.g., radio module) each time during, for example, every or at least some inspections (e.g., in active operating mode, i.e., when the device is active).

[0138] According to further embodiments, as already explained above, the device, or for example just the coupling module, for example in the form of an induction clamp, can be permanently connected to the wind turbine or a rotor blade of the wind turbine. For example, the device or the coupling module of the device can be attached to the lightning rod of a rotor blade and / or in a supply line to the rotor blade, or the device or the coupling module can be integrated into a rotor blade, for example.

[0139] For example, to commission the device described above, the coupling module, e.g., in the form of an induction clamp, can be attached (e.g., glued) to the lightning conductor at the blade end by a service team once only. It can remain there throughout the entire lifecycle of the system (e.g., approximately 25 years for a wind turbine). The coupling module can be integrated, for example, into the hub of the wind turbine, into a rotor blade flange, or into the rotor blade itself.

[0140] A major advantage of embodiments with galvanic isolation between the coupling module and the object's line, for example with inductive coupling, for example with a non-invasive induction method according to the invention, is that the device (e.g. the coupling module in the form of induction clamps) does not have to be directly (electrically) connected to the lightning conductor, so that, for example, a lightning strike cannot cause damage to the system or device. Optionally, protective diodes, for example in the form of so-called transil diodes, can be arranged or attached between the coupling module (according to embodiments, very generally designed, for example, as an induction coil or induction ring) and output transistors (e.g. of the signal generator) for additional protection. Corresponding embodiments can enable the use of such diodes in the first place.

[0141] The following explains an example of an inspection procedure according to an embodiment of a wind turbine for lightning protection measurements according to embodiments. For this purpose, a device according to the invention as explained above can be used, for example. For example, a device with a coupling module in the form of a clamp, such as an induction clamp, can be arranged on each rotor blade, or simply expressed, each wing, of the wind turbine. Furthermore, the acquisition of the test signal can be realized using a drone comprising a measuring unit. Thus, for example, the following sequence of steps can be carried out according to embodiments. 1. The drone flies, e.g. autonomously, to the blade hub of the wind turbine (as previously explained, this is only an option according to the exemplary embodiments; for example, a rotor blade tip can also be flown to; furthermore, a manual, automated, or semi-autonomous flight can also be carried out optionally). 2. The drone initiates the activation signal, e.g. a radio signal, to activate the first device (e.g., wing 1), or simply put, to "wake it up." The drone waits for a defined time interval, e.g., approximately 75 seconds, to actually catch the wake-up interval (e.g., every 60 seconds). (In other words, a waiting time, e.g., a time during which the activation signal is transmitted, can be longer than the period between two activations of the communication module in passive operating mode). In addition, it optionally receives feedback from the device via the radio module that the device is in active operating mode, e.g.,active, is 3. The drone flies, e.g. autonomously (or manually, or automatically, or semi-autonomously), over the wing and returns to the hub (or e.g. to the rotor blade tip or to another rotor blade, or remains at the wing tip after taking off from the hub, or remains at the hub after taking off from the wing tip) and switches the device back to passive operating mode, e.g. sleep mode 4. The drone then wakes up the next device (e.g. of the next rotor blade) and so on.

[0142] In the following, the advantages of devices comprising coupling modules in the form of clamps, e.g. lightning protection clamps, which are permanently connected to the wind turbine, will be discussed using an example.

[0143] In some procedures it may be necessary (e.g. legally required for safety reasons when technicians have to climb from the hub into the wing base) for two service personnel to take the elevator into the gondola (hub) in order to then be able to attach the pliers to the lightning protection cable at the respective wing bases (flange).

[0144] The energy source, e.g. in the form of a power supply, can then be connected to each of the three clamps (one device per rotor blade) via a cable e.g. 10m long, and the clamps can be switched on / off in sequence by a service technician on the power supply, e.g. via a rotary switch, depending on the position of the drone (wing 1, 2 or 3).

[0145] The drone can then fly along the wing (distance e.g. approx. 5 m (e.g. a distance of at least 4 m and a maximum of 6 m or of at least 1 m and a maximum of 10 m) - optionally by means of manual, automated, autonomous or semi-autonomous flight) at a speed of, for example, 0.25 m / sec (i.e., a speed of at least 0.1 m / sec and a maximum of 0.3 m / sec or of at least 0.2 m / sec and a maximum of 0.3 m / sec) - e.g. from the wing base (flange) to the wing tip and can scan the radiated electric field of the test signal. This means that with a wing length of, for example, 60 meters, the entire lightning protection inspection for one wing takes approx. 4 minutes. The drone can then optionally fly autonomously (or manually, or automatically, or semi-autonomously) at a higher speed back to the hub (this takes about 1 minute) or to another point on the wind turbine, e.g. a neighboring wing tip.The service engineer can then switch to the next clamp and inspect the next wing. This means that the entire inspection (flight time of the drone without equipment), including takeoff and landing, can take approximately 25 minutes.

[0146] Optionally, according to the exemplary embodiments, specific areas of the object can be inspected in particular or additionally. For example, individual areas of the wing, such as receptors, can also be inspected. However, this can increase the inspection time by several minutes.

[0147] Advantages of embodiments in which the device is permanently connected to the object include, for example, that two service technicians do not have to take the elevator up to the tower to set up and dismantle the devices, and thus, for example, the clamps. This eliminates the need for one service technician to return down to operate the drone while the other service technician operates the power supply from the hub. Accordingly, it also eliminates the need for the second technician to return up to the tower after the inspection to remove the clamps.

[0148] This allows for significant time savings. However, it should be noted that designs using devices that require assembly and disassembly, as previously explained, still offer significant advantages over conventional approaches, such as rope climbers.

[0149] For example, an average inspection with a system according to the invention can take approximately 1.5 hours (compared to approximately 8 hours with the conventional method using rope climbers). This time can be further reduced according to embodiments with devices permanently mounted on the object.

[0150] These examples therefore offer significant advantages, especially for objects that are difficult to access. For offshore installations (accessibility by ship, height of the installation), a complete inspection can take several days. In addition to personnel costs, downtime costs due to downtime during the inspection play a significant role (e.g., up to €2,000 per hour). Considerable time and cost savings are therefore possible according to these examples.

[0151] Methods according to the invention thus make it possible to eliminate the disadvantages described above and to provide an extremely effective system for testing the continuity of a lightning rod of a wind turbine.

[0152] According to further embodiments of the present invention, the signal generator can induce a tuned signal into the lightning conductor at the root of a rotor blade and, in doing so, generate a test signal along the rotor blade, for example, a nearly constant electric near field within a frequency range approved by the grid agency. According to embodiments, the signal can be induced non-invasively into the lightning protection cable.

[0153] According to embodiments, for example according to the embodiments explained above, the device can have, for example, a coupling module in the form of an induction clamp, or for example a coupling module in the form of an induction ring.

[0154] For example, in the construction of a new wind turbine, an induction ring can be integrated directly into a rotor blade. Simply put, a corresponding induction ring can be pushed over a lightning rod on the rotor blade. Alternatively, a cable in an existing turbine can be cut open to install the induction ring. An induction ring can offer advantages with regard to the signal quality of a fed-in test signal. Furthermore, a feed-in using an induction ring can also be implemented in a particularly robust manner.

[0155] For example, an induction clamp can be designed to only partially enclose a lightning rod (i.e., a clamp with an open end) to induce the test signal. This eliminates the need to cut cables (unlike common methods using continuity measurements, such as resistive continuity measurements) or perform any other interventions in existing systems.

[0156] According to such embodiments, the signal generator can have a connection that is optimized for a corresponding induction ring or a corresponding induction clamp and that is adapted exactly or at least approximately via impedance, for example.

[0157] Any deviations from a standard or preset impedance value (e.g., caused by varying lengths of lightning protection cables, branched lightning protection structures, etc.) can optionally be automatically adjusted by an output stage of the signal generator. Each device, for example, comprising an induction clamp, can optionally be equipped with its own communication module in the form of a radio module (e.g., with 868 MHz, ISM radio) and can be individually controlled by an operator from the ground via radio for measurement.

[0158] This has the advantage that, for example, all three rotor blades of a wind turbine can be connected simultaneously before the measurement, and for the actual measurement, the signal feed to the rotor blades can be individually controlled by the operator via radio from the ground. It should be noted that the devices, such as coupling modules in the form of induction clamps, can also be permanently attached to the lightning rods of the rotor blades or to corresponding supply lines.

[0159] To avoid measurement inaccuracies caused by interference on the heavily used ISM band (13.56 MHz), for example, an optional identifier can be modulated onto the test signal. This identifier is filtered out by the sensor processor (e.g., the measuring unit) and used exclusively for calculating the values. Influences on the measurements caused by external signals or interference can thus be reliably eliminated.

[0160] Optionally, other, e.g. alternative, frequencies, e.g. radio frequencies and / or, e.g. clocked, low frequencies can also be used.

[0161] Fig. 6 shows a schematic block diagram of electronics of a device according to embodiments of the present invention. Fig. 6shows a microcontroller 610, which is designed, for example, to control the communication module 630, i.e., for example, to switch the communication module 630 on (e.g., for the active operating mode or for cyclically being ready to receive the activation signal in the passive operating mode) and / or off (e.g., for the passive operating mode). As an optional example, the communication module 630 is a radio module designed to transmit and / or receive on a frequency of 868 MHz. Furthermore, the electronics of the device comprise a signal generator 620, which, as optional features, has a clock generator 622 with an optional clock frequency of 160 MHz, a direct digital synthesis digital / analog converter (DDS-DAC), which, as optionally shown, is designed to generate an analog signal, e.g.to provide a sinusoidal analog signal with a frequency of 13.565 MHz, as well as a multiplier and / or adder 626 (Mult. Add.) and a signal amplifier 628 (power amplifier - PA 10W), e.g. with a power of at least 1 watt and a maximum of 20 watts, e.g. with a power of 10 watts (e.g. with a tolerance of at least + / -5%) or e.g. with a power of at least 1 watt and a maximum of 5 watts, e.g. with a power of 2 watts (e.g. with a tolerance of at least + / -5%).

[0162] In the example of Fig. 6 As an optional feature, there is an impedance match to the line of the object, so that the coupling module and the line of the object are represented as an ohmic resistor 640.

[0163] In general, for example, the output stage of a signal generator can be a differential output stage.

[0164] In the following, coupling modules according to embodiments are explained again in other words and with further optional details

[0165] As explained above, according to embodiments, the test signal can be induced into the conductor of the wind turbine in the form of a lightning protection cable using a non-invasive method according to the invention with the aid of a device comprising a coupling module in the form of an induction clamp, an induction ring or a measuring ring.

[0166] Particularly preferred embodiments include coupling modules in the form of induction clamps. Such methods can offer a number of significant advantages: a) The lightning protection cable does not need to be interrupted or separated from the earthing. The induction clamp can, for example, be pushed underneath the cable at an accessible point. b) If the cable is firmly laminated, the induction clamp can also simply be placed on the cable and then only needs to be secured (e.g. using adhesive tape). c) The signal (generator output), for example, is only adjusted to the induction clamp once. Consequently, there are no problems with incorrect adjustments, including standing waves, with different rotor blade designs and lengths. d) With optimal or at least approximately optimal adjustment, there are no or very few vibrations or interference waves - the signal can, for example, only or mainly propagate in the specified, e.g. extremely narrow-band frequency range. e) Consistent, repeatable measurement behavior with the same blade designs.

[0167] According to exemplary embodiments, the test signal generated along the rotor blade, e.g., a vertically radiating field with field strength E (linear near field), can decrease, for example, quadratically with the distance between the drone and the rotor blade. The counterpart, i.e., for example, the measuring unit, can be a highly sensitive electric field sensor, e.g., a 1D, 2D, or 3D field sensor, e.g., with extremely low bandwidth and high sampling rate, which can be integrated as payload into the optionally autonomously (or, for example, manually, automatically, or semi-autonomously) flying drone. If the sensor receives no signal or an insufficient signal strength at the rotor blade tip, the lightning rod along the rotor blade may be damaged or interrupted.

[0168] According to some embodiments, the conductor may form a (grounded) monopole - for example, the conductor does not have to be separated, but can remain connected to ground - and the signal generator of the test system, i.e. the device, may, for example, preferably operate at a frequency of 13.56 MHz in the ISM shortwave band (for example, with a tolerance of up to + / -5% or with a tolerance of up to + / -10% or with a tolerance of up to + / -50% or with a tolerance of up to + / -100% or with a tolerance of up to + / -1000%).

[0169] The test signal generated by the induction, e.g. a vertical constant electric near-field, can be detected by a measuring unit, e.g. by a field sensor on a drone that flies over the rotor blade, and a continuity test of the lightning rod can be carried out based on the radiated field.

[0170] The direction (e.g., when using a 3D field sensor) and intensity of the detected field strength can be evaluated, for example, to determine whether the conductor is open. If the measurement shows a continuous field within predetermined tolerances, this can be concluded that the line is unbroken, i.e., a functioning lightning rod. If the field strength deviates from a predetermined range at one or more locations along the conductor, this can be concluded that the line is open.

[0171] Fig. 7 shows a schematic block diagram of a method according to embodiments of the present invention. Fig. 7shows a method 700 for carrying out a continuity test of an electrical line of an object, comprising supplying (710) a communication module with energy from an energy source and receiving (720) an activation signal by means of the communication module in order to switch from a passive operating mode to an active operating mode and supplying (730) a signal generator in the active operating mode with energy from the energy source and generating (740) an electrical test signal in the active operating mode by means of the signal generator and coupling (750) the electrical test signal in the active operating mode into the electrical line of the object and receiving (760) a deactivation signal by means of the communication module in order to switch from the active operating mode to the passive operating mode.

[0172] All lists of materials, environmental influences, electrical properties and optical properties listed herein are to be considered exemplary and not exhaustive.

[0173] Although some aspects have been described in connection with a device, it should be understood that these aspects also represent a description of the corresponding method, so that a block or component of a device can also be understood as a corresponding method step or as a feature of a method step. Analogously, aspects described in connection with or as a method step also represent a description of a corresponding block, detail, or feature of a corresponding device. Some or all of the method steps may be carried out by (or using) a hardware device, such as a microprocessor, a programmable computer, or an electronic circuit. In some embodiments, some or more of the key method steps can be carried out by such an device.

[0174] Depending on specific implementation requirements, embodiments of the invention may be implemented in hardware or software. The implementation may be performed using a digital storage medium, such as a floppy disk, a DVD, a Blu-ray Disc, a CD, a ROM, a PROM, an EPROM, an EEPROM, or a FLASH memory, a hard disk, or other magnetic or optical storage device storing electronically readable control signals that can interact or cooperate with a programmable computer system to perform the respective method. Therefore, the digital storage medium may be computer-readable.

[0175] Some embodiments according to the invention thus comprise a data carrier having electronically readable control signals capable of interacting with a programmable computer system such that one of the methods described herein is carried out.

[0176] In general, embodiments of the present invention may be implemented as a computer program product having a program code, wherein the program code is effective to perform one of the methods when the computer program product is run on a computer.

[0177] The program code can, for example, also be stored on a machine-readable medium.

[0178] Other embodiments include the computer program for performing one of the methods described herein, wherein the computer program is stored on a machine-readable carrier.

[0179] In other words, an embodiment of the method according to the invention is thus a computer program which has a program code for carrying out one of the methods described herein when the computer program runs on a computer.

[0180] A further embodiment of the method according to the invention is thus a data carrier (or a digital storage medium or a computer-readable medium) on which the computer program for performing one of the methods described herein is recorded. The data carrier, the digital storage medium, or the computer-readable medium is typically physical and / or non-perishable or non-transient.

[0181] A further embodiment of the method according to the invention is thus a data stream or a sequence of signals that represents the computer program for carrying out one of the methods described herein. The data stream or the sequence of signals can be configured, for example, to be transferred via a data communication connection, for example, via the Internet.

[0182] A further embodiment comprises a processing device, for example a computer or a programmable logic device, which is configured or adapted to carry out one of the methods described herein.

[0183] A further embodiment comprises a computer on which the computer program for performing one of the methods described herein is installed.

[0184] A further embodiment according to the invention comprises a device or system designed to transmit a computer program for performing at least one of the methods described herein to a recipient. The transmission can be electronic or optical, for example. The recipient can be, for example, a computer, a mobile device, a storage device, or a similar device. The device or system can, for example, comprise a file server for transmitting the computer program to the recipient.

[0185] In some embodiments, a programmable logic device (e.g., a field-programmable gate array, an FPGA) may be used to perform some or all of the functionalities of the methods described herein. In some embodiments, a field-programmable gate array may interact with a microprocessor to perform any of the methods described herein. In general, in some embodiments, the methods are performed by any hardware device. This may be general-purpose hardware such as a computer processor (CPU) or method-specific hardware such as an ASIC.

[0186] The devices described herein may be implemented, for example, using a hardware apparatus, or using a computer, or using a combination of a hardware apparatus and a computer.

[0187] The devices described herein, or any components of the devices described herein, may be implemented at least partially in hardware and / or in software (computer program).

[0188] The methods described herein may be implemented, for example, using a hardware apparatus, or using a computer, or using a combination of a hardware apparatus and a computer.

[0189] The methods described herein, or any components of the methods described herein, may be implemented at least partially by hardware and / or by software.

[0190] The above-described embodiments are merely illustrative of the principles of the present invention. It is understood that modifications and variations of the arrangements and details described herein will be apparent to others skilled in the art. Therefore, it is intended that the invention be limited only by the scope of the following claims and not by the specific details presented in the description and explanation of the embodiments herein.

Claims

1. Device (100, 200, 300, 302a, 304a, 306a, 410, 420, 430, 510, 520, 530) for providing an electrical test signal (580), for performing a continuity test of an electrical line (382, 382a, 384, 384a, 386, 388a, 389a) of an object (360, 360a, 362a, 372, 372a, 374, 374a, 376, 376a), including: a communication module (110, 310) configured to: obtain an activation signal (570) to switch the device from a passive operating mode to an active operating mode, and obtain a deactivation signal to switch the device from the active operating mode to the passive operating mode; and a signal generator (120, 320, 322, 322a, 324, 324a, 326, 326a) configured to generate the electrical test signal in the active operating mode; an energy source (130, 330, 332, 332a, 334, 334a, 336, 336a) configured to supply the communication module and the signal generator with energy, and a coupling-in module (140, 240, 342, 342a, 344, 344a, 346, 346a) configured to: couple the electrical test signal into the electrical line of the object in the active operating mode.

2. Device (100, 200, 300, 302a, 304a, 306a, 410, 420, 430, 510, 520, 530) according to claim 1, wherein the communication module (110, 310) is configured to obtain the activation signal (570) and / or the deactivation signal in a wireless manner; or wherein the communication module (110, 310) is configured to obtain the activation signal (570) and / or the deactivation signal in a wired manner.

3. Device (100, 200, 300, 302a, 304a, 306a, 410, 420, 430, 510, 520, 530) according to any of the preceding claims, wherein the coupling-in module (140, 240, 342, 342a, 344, 344a, 346, 346a) is configured to inductively couple the electrical test signal (580) into the electrical line (382, 382a, 384, 384a, 386, 388a, 389a) of the object (360, 360a, 362a, 372, 372a, 374, 374a, 376, 376a) in the active operating mode; and / or wherein the coupling-in module (140, 240, 342, 342a, 344, 344a, 346, 346a) is configured to capacitively couple the electrical test signal (580) into the electrical line (382, 382a, 384, 384a, 386, 388a, 389a) of the object (360, 360a, 362a, 372, 372a, 374, 374a, 376, 376a) in the active operating mode.

4. Device (100, 200, 300, 302a, 304a, 306a, 410, 420, 430, 510, 520, 530) according to any of the preceding claims, wherein the coupling-in module (140, 240, 342, 342a, 344, 344a, 346, 346a) is configured to, in a galvanically isolated manner, be attached to the electrical line such that the device is substantially protected from a voltage and / or current spike on the electrical line (382, 382a, 384, 384a, 386, 388a, 389a).

5. The device (100, 200, 300, 302a, 304a, 306a, 410, 420, 430, 510, 520, 530) according to any of claims 1 to 4, wherein the coupling-in module (140, 240, 342, 342a, 344, 344a, 346, 346a) has an electrically switchable ohmic connection with the line (382, 382a, 384, 384a, 386, 388a, 389a) of the object (360, 360a, 362a, 372, 372a, 374, 374a, 376, 376a) in order to couple the electrical test signal (580) into the electrical line of the object in the active operating mode.

6. Device (100, 200, 300, 302a, 304a, 306a, 410, 420, 430, 510, 520, 530) according to any one of the preceding claims, configured to: reduce energy consumption of the device in the passive operating mode compared to active operating mode, and activate the communication module (110, 310) in the passive operating mode at time intervals for a predetermined duration for obtaining the activation signal (570).

7. Device (100, 200, 300, 302a, 304a, 306a, 410, 420, 430, 510, 520, 530) according to any of the preceding claims, wherein the energy source (130, 330, 332, 332a, 334, 334a, 336, 336a) comprises at least one of a replaceable energy storage and / or a rechargeable energy storage; and wherein the communication module (110, 310) is configured to transmit a charge state of the energy storage in the active operating mode.

8. Device (100, 200, 300, 302a, 304a, 306a, 410, 420, 430, 510, 520, 530) according to any of the preceding claims, wherein the communication module (110, 310) is configured to transmit an information about the operational state of the device.

9. Device (100, 200, 300, 302a, 304a, 306a, 410, 420, 430, 510, 520, 530) according to any of the preceding claims, wherein the device comprises at least one protective diode (520), and wherein the protective diode (520) is configured to protect the device from a voltage and / or current spike on the electrical line (382, 382a, 384, 384a, 386, 388a, 389a).

10. Device (100, 200, 300, 302a, 304a, 306a, 410, 420, 430, 510, 520, 530) according to any of the preceding claims, wherein the test signal (580) comprises a modulated signal identifier.

11. Device (100, 200, 300, 302a, 304a, 306a, 410, 420, 430, 510, 520, 530) according to any of the preceding claims, wherein the object (360, 360a) is a wind turbine with a plurality of rotor blades (372, 372a, 374, 374a, 376, 376a), the rotor blades each having electrical lines (382, 382a, 384, 384a, 386, 388a, 389a) in the form of lightning rods; and where the electrical line is a lightning rod of a rotor blade of the wind turbine.

12. System (400, 500) for providing electrical test signals (580), for performing a continuity test of electrical lines (382, 382a, 384, 384a, 386, 388a, 389a) of an object (360, 360a), wherein the object is a wind turbine with a plurality of rotor blades (372, 372a, 374, 374a, 376, 376a), the rotor blades each having electrical lines in the form of lightning rods, and wherein the system further includes: a plurality of devices (100, 200, 300, 302a, 304a, 306a, 410, 420, 430, 510, 520, 530) according to any of claims 1 to 17, wherein a respective coupling-in module (140, 240, 342, 342a, 344, 344a, 346, 346a) of a respective device is configured to couple a respective electrical test signal into a respective rotor blade for continuity testing of a respective lightning rod.

13. System (400, 500) for providing an electrical test signal (580), for performing a continuity test of an electrical line (382, 382a, 384, 384a, 386, 388a, 389a) of an object (360, 360a, 362a, 372, 372a, 374, 374a, 376, 376a), including: a device (100, 200, 300, 302a, 304a, 306a, 410, 420, 430, 510, 520, 530) according to any of claims 1 to 11; a communication unit (542, 544, 546) configured to: transmit the activation signal (570) and the deactivation signal to the communication module (110, 310) of the device; and a measuring unit (552, 554, 556) configured to detect the test signal (580).

14. System (400, 500) according to claim 13, wherein the communication unit is configured to be attached to a drone (562, 564).

15. Method (700) of performing a continuity test of an electrical line (382, 382a, 384, 384a, 386, 388a, 389a) of an object (360, 360a), including: supplying (710) a communication module (110, 310) with energy of an energy source (130, 330, 332, 332a, 334, 334a, 336, 336a); and obtaining (720) an activation signal (570) by means of the communication module to switch from a passive operating mode to an active operating mode; and supplying (730) a signal generator (120, 320, 322, 322a, 324, 324a, 326, 326a) with energy of the energy source in the active operating mode; and generating (740) an electrical test signal (580) by means of the signal generator in the active operating mode; and coupling (750) the electrical test signal into the electrical line (382, 382a, 384, 384a, 386, 388a, 389a) of the object in the active operating mode; and obtaining (760) a deactivation signal by means of the communication module to switch from active operating mode to passive operating mode.