DEVICE, SYSTEM, AND METHOD FOR PERFORMING CONTINUITY TESTING ON ELECTRICAL PATHS OF AN OBJECT - Patent application

Abstract

An embodiment according to the invention includes a device for providing electrical test signals to perform continuity testing of electrical paths of an object, the device including a communication module configured to receive an activation signal to switch the device from a passive mode of operation to an active mode of operation and to obtain a deactivation signal to switch the device from the active mode of operation to a passive mode of operation. The device further includes a signal generator configured to generate the electrical test signals in the active mode of operation. In addition, the device includes an energy source configured to provide energy to the communication module and the signal generator. The device also includes a coupling module configured to couple the electrical test signals to the electrical paths of the object in the active mode of operation.

Description

[Technical field]

[0001] SUMMARY OF THE PRESENT EMBODIMENTS Embodiments in accordance with the present invention relate to devices, systems, and methods for performing continuity testing on electrical paths in an object. [Background technology]

[0002] Wind turbines already form an integral part of renewable energy sources in many countries. To ensure a safe and reliable operation of such wind turbines, it is therefore important to inspect them regularly. Due to their design, for example due to the increasingly high tower heights and the length of the rotor blades, wind turbines are particularly exposed to the risk of lightning strikes. To be able to dissipate the lightning energy in case of a lightning strike and to prevent damage to the wind turbine, lightning rods (or lightning arresters) are fitted to the rotor blades of wind turbines. However, these lightning rods can become damaged or unusable, for example due to mechanical stresses during wind turbine operation or environmental influences such as oxidation. Lightning rods are usually placed inside the rotor blades and therefore cannot be easily inspected. Their inspection therefore usually involves high costs and a great deal of effort. Summary of the Invention [Problem to be solved by the invention]

[0003] Therefore, there is a need for a concept that allows for continuity testing of electrical paths in objects such as wind turbines with low complexity, low effort, and therefore low cost. Such needs may be met by the subject matter of the independent claims. Further developments according to the invention are defined in the dependent claims. [Means for solving the problem]

[0004] An embodiment according to the invention includes a device for providing electrical test signals to perform continuity testing of electrical paths (also referred to herein as electrical conductors) of an object, the device including a communication module configured to receive an activation signal to set the device from a passive mode of operation to an active mode of operation and a deactivation signal to set the device from the active mode of operation to a passive mode of operation. The device further includes a signal generator configured to generate the electrical test signals in the active mode of operation. The device further includes an energy source configured to provide energy to the communication module and the signal generator. Additionally, the device includes a coupling module configured to couple the electrical test signals to the electrical paths of the object in the active mode of operation.

[0005] The embodiment according to the invention is based on the central idea of ​​coupling a test signal to an electrical path of the object to be tested in order to subsequently detect the test signal, for example non-invasively, and to draw conclusions about the state of the electrical path of the object by means of a measuring device. For this purpose, the device comprises a signal generator configured to supply the test signal to the coupling module. The inventors have realized that by using a communication module, it is possible to control the device remotely, so that the testing effort may be reduced, especially for very large objects. For example, in the case of a wind turbine, the system tester may not need to climb the tower of the wind turbine to the supply point of the electrical test signal in order to start the device, or in other words to put it into an active operating mode. This may allow the device according to the invention to be firmly connected to the object in order to start the device only in the course of the inspection and then to stop it again.

[0006] A further embodiment according to the invention includes a method for performing a continuity test on an electrical path of an object, the method including providing energy from an energy source to a communications module and obtaining an activation signal by the communications module to switch from a passive mode of operation to an active mode of operation. The method further includes providing energy from the energy source to a signal generator in the active mode of operation and generating an electrical test signal in the active mode of operation by the signal generator. Additionally, the method includes coupling the electrical test signal to the electrical path of the object in the active mode of operation and obtaining a stop signal by the communications module to switch from the active mode of operation to the passive mode of operation. The above described method is based on the same considerations as the above described device. Thus, the device may be supplemented with all the features and functions described in relation to the method, both individually and in combination.

[0007] According to a further embodiment of the invention, the communication module is configured to obtain the activation and / or deactivation signals in a wireless manner. The inventors have realised that the wireless communication of the communication module allows a high degree of flexibility in providing the electrical test signals. In particular, for very large objects, the location where the test signal is provided to the electrical paths of the object may be far away from the location where the test signal needs to be detected. Thus, for example, in particular for objects that are difficult to access such as wind turbines, the device may be set in active operation mode from various locations on the object in order to couple the test signal to the electrical paths. For example, a climber with only a portable measuring device on a rotor blade can activate the test signal to detect the electrical test signal in the lightning rod of the rotor blade. This means, for example, that a second person does not need to control the device and cooperate with the climber. Furthermore, the wireless communication also allows the use of automated testing methods. For example, a drone flying over the object can activate the device using wireless communication in order to couple the test signal to the electrical paths of the object and subsequently measure the electrical test signal, and deactivate the device again using wireless communication once the measurement or inspection is completed. The communication module may, for example, be a radio module.

[0008] According to a further embodiment of the present invention, the communication module is configured to obtain the activation or deactivation signal in a wired manner. For example, if the device is fixedly attached to the object, the object may have a wired communication line to the device, so that a connection from an easily accessible location on or in the object may be enabled, for example, to control the device. For example, in the case of an autonomous drone (optionally also in the case of a manually controlled or semi-autonomous drone) configured to inspect the object and measure test signals in the electrical circuit, the drone may thus be controlled or initiated at the base of the system with the computing unit, while the device may be set in an active operating mode by a connection on the object. Furthermore, wired communication may be more resistant to interference than, for example, wireless communication. Furthermore, according to an embodiment, the device may be configured in a wired manner, for example, via a USB connection.

[0009] According to a further embodiment of the invention, the energy source comprises at least one of an exchangeable energy storage device and / or a rechargeable energy storage device. Alternatively or additionally, the energy source is configured to be coupled to an external power source. The inventors have recognized that by using an energy storage device, the device may operate or be used at least approximately or temporarily self-sufficient. For example, the device may be structurally connected to the object in order to be activated by a communication module for performing continuity tests during inspection. Thus, the device does not need to be pre-energized, for example by manually connecting a cable to the device. In the case of a wind turbine, for example, the device may be installed near the rotor blade base, for example in a nacelle, and activated by a drone via wireless communication, and both communication and generation of the test signal may be enabled based on energy provided by the exchangeable or rechargeable energy storage device. Using an appropriately dimensioned energy storage device, the energy storage device may be exchanged or recharged, for example at regular intervals in the course of further routine inspections of the corresponding nacelle (for example at time intervals longer than the time intervals between continuity tests). This may optimize and save effort and time. It should be noted that these advantages are not only relevant for wind turbines, but in particular also for any large object where corresponding devices for continuity testing of conductors must be installed, for example in places that are difficult to access.

[0010] Furthermore, however, the inventors have also recognized that, for example, in the case of an object used to generate energy or, for example, always being energized, the energy source may also be configured to be coupled to an external power source, for example, the object's power supply. This may provide an efficient method of powering the device so that the device can be used for continuity testing with additional effort over an extended period of time.

[0011] According to a further embodiment of the invention, the coupling module is configured to inductively couple the electrical test signal to the electrical path of the object in the active operating mode. Alternatively or additionally, the coupling module is configured to capacitively couple the electrical test signal to the electrical path of the object in the active operating mode. The inventors have recognized that inductive or capacitive coupling of the test signal allows particularly advantageous electrical path testing. On the one hand, the object may, for example, be difficult to access and may be incorporated by the device without the need for direct electrical contact with the conductors that need to be tested. On the other hand, such coupling may also have certain advantages in relation to objects with moving electrical cables, where a corresponding continuity test is only possible at a certain position or orientation of the electrical cable, and it may, for example, be advantageous for the cable to be able to move relative to the continuity test device during normal operation of the object.

[0012] According to a further embodiment of the invention, the coupling module is configured to be attached to an electrical path in an electrically isolated manner such that the device is substantially protected from voltage and / or current spikes on the electrical path. In particular, very large objects may be susceptible to lightning strikes, which may result in high voltages and / or currents in electrical paths within the object. Coupling the device by the coupling module to an electrical path with adequate galvanic isolation may prevent damage or destruction of the device in the event of such a lightning strike, for example.

[0013] According to a further embodiment of the present invention, the coupling module comprises an electrically switchable ohmic connection to the electrical path of the object in order to couple the electrical test signal to the conductor of the object in an 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 may also be coupled to the object or the conductor of the object via a switchable ohmic connection. For example, this may provide a direct test signal coupling that is particularly interference-resistant for very strong electrical test signals, such as those with high voltages or high currents. The use of a switchable ohmic connection may ensure appropriate decoupling, for example to protect against lightning strikes. For example, test signals including low frequency signals or clocked low frequency signals may also be used for ohmic coupling.

[0014] According to a further embodiment of the invention, the device is configured to activate the communication module in the passive operation mode for a predefined duration at regular time intervals to obtain a wake-up signal, reducing the energy consumption of the device in the passive operation mode compared to the active operation mode. The inventors have recognized that such a passive operation mode may save energy during periods when an inspection, e.g. a continuity test of the object's electrical circuits, is not required or planned. Thus, for a replaceable or rechargeable energy storage device, the period before it needs to be replaced or recharged may be extended. Furthermore, the inventors have recognized that by periodically activating the communication module to obtain a wake-up signal, the device may be set in the active operation mode for inspection with little effort. This means, for example, that a person does not need to manually activate the device to start an inspection.

[0015] According to a further embodiment of the 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 configured to transmit the state of charge of the energy storage device in the active operating mode. The inventors have realized that this may improve the reliability of the device. Thus, the state of charge of the energy storage device may be monitored during the test in order to obtain information on whether the test can be performed with a remaining energy supply, for example to determine the aging state of the energy storage device via the energy delta since the last test with the previous transmission of the state of charge, and / or to plan the replacement or recharging of the energy storage device.

[0016] According to a further embodiment of the invention, the communication module is configured to transmit information about the operating state of the device. Thus, for example, the device can report back that it has obtained the wake-up signal by transmitting information about an active operating state after obtaining the wake-up signal. For example, this can ensure that the device is ready to generate a test signal before complex measurements are prepared on the electrical paths of the object.

[0017] 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 a high frequency signal, for example, often allows for efficient continuity testing of an electrical path of an object. Thus, for example, the radiated electric or electromagnetic field of a high frequency signal in an electrical path may be detected from a certain distance from the electrical path. For example, in the rotor blades of a wind turbine, there may be several connections (e.g. threaded connections) along the way of the down conductors (e.g. lightning arresters or lightning rods). Metal surfaces meet at these points, forming contact connections between the conductors that sometimes carry the current. In the presence of oxygen or other gases with a chemically aggressive effect, the surfaces of the base metals may react and form layers of oxides, sulfides, chlorides and similar substances. In addition, water films may form under standard atmospheric conditions.

[0018] Finally, contamination with oil, grease and dust, which cannot be prevented with respect to the construction, must also be taken into account. These changes or disturbances can result in a foreign layer on the material, which can significantly impede the current transfer or even completely block it.

[0019] The inventors have realised that the use of high frequency signals allows for advanced assessment to distinguish between areas that are problematic for lightning strikes and areas of the lightning rod (or arrester) that are only slightly oxidised or blocked. For example, to test the continuity of down conductors in rotor blades, the test method of the present invention can use an electrical induction field capable of bridging the above-mentioned discolored and foreign material layers by induction.

[0020] According to a further embodiment of the invention, the signal generator is configured to allow impedance matching with respect to the electrical path. The inventors have recognized that this may allow a particularly efficient coupling to the electrical path. Furthermore, the signal generator may be configured to perform calibrations, for example for different electrical paths of different objects, in order to perform the corresponding impedance matching as efficiently as possible. In particular, the generator output of a signal generator in the device may, for example, be impedance matched (radiated) within certain limits, i.e., an optimized value may be set at least approximately depending on the conductors of the system, e.g., the object.

[0021] According to a further embodiment of the present invention, the device comprises at least one protection diode, which is configured to protect the device from voltage and / or current spikes on the electrical path. For example, the protection diode may be configured to let off an overvoltage or overcurrent, or to dissipate a corresponding overcurrent or a corresponding overvoltage. For example, this may allow for a lightning strike or strong electrical feedback, for example, on an object configured to generate large amounts of energy.

[0022] For example, the protection diode may be a bipolar transient diode (or a transient voltage suppression diode). The diode does not need to be conductive, for example to earth, but is mounted internally in parallel with the coupling module, for example an induction coil, and thus can block overvoltage pulses, for example in the case of a lightning strike. For example, the coupling module may be bypassed by the protection diode. For example, this protection against lightning strikes may only be possible with the inventive solution (eg having an inductive coupling with galvanic isolation in the case of, for example, an inductive coil - no ohmic connection).

[0023] For example, this offers an advantage over an ohmic signal supply (eg by breaking the electrical path and supplying on both sides) since the risk of destruction or lightning protection in the event of a lightning strike may no longer be guaranteed.

[0024] The protection diode may generally be a transient voltage suppression (TVS) diode, such as a suppressor diode, such as a transistor diode or a silecter. For example, the protection diode may thus be an electrical component by which an electrical circuit, such as a device according to the invention, such as in particular a signal generator and a communication module, and the corresponding electrical path of the device, may be protected from voltage peaks induced in the electrical path. For example, such a protection diode can shunt an overcurrent if the induced voltage exceeds, for example, a breakdown voltage, for example, an avalanche breakdown voltage (for example, a pulse of current may be conducted through the protected component, for example, based on a parallel circuit). For example, the protection diode may be a clamp circuit (clamp device) and may be configured to suppress an overvoltage that exceeds the breakdown voltage.

[0025] For example, protection diodes can automatically reset themselves when an overvoltage is no longer present and can internally absorb more transient energy than similarly classified clamp circuits (Var devices), for example. Protection diodes may be configured unidirectional or bidirectional. Unidirectional diodes can function as forward rectifiers, like avalanche diodes, but may be constructed and tested to handle very large current peaks.

[0026] A bidirectional TVS diode may be represented by two opposing avalanche diodes connected in series with each other and in parallel with the component to be protected, for example, but this type of representation may only be roughly accurate physically, and such devices may be manufactured as separate components.

[0027] According to a further embodiment of the present invention, the protection diode is a suppressor diode, which is connected in parallel with the coupling module. For example, the suppressor diode may be a bipolar transistor diode. For example, such a diode does not need to be conducted down to ground, but is mounted internally in the device in parallel with the coupling module, for example an induction coil, and thus can dissipate overvoltage pulses, for example in the case of a possible lightning strike. According to a further embodiment of the invention, the test signal may include a modulated signal identifier. The inventors have realised that this can improve the robustness of the continuity test, for example by using the modulated identifier to distinguish the test signal from other or interfering signals during detection of the test signal.

[0028] According to a further embodiment of the invention, the object is a wind turbine with a plurality of rotor blades, each of which has an electrical path in the form of a lightning rod (or lightning arrester). Furthermore, the electrical path is the lightning rod of the rotor blade of the wind turbine. As explained before, the device of the invention has great advantages, in particular with regard to the continuity testing of the lightning rod of the rotor blade of the wind turbine.

[0029] For example, such an inspection may be performed by a single person on the ground activating a device in a wired or wireless manner to couple a test signal to the lightning rod of the rotor blade. For example, a drone may then fly over the rotor blade and record the test signal. This may indicate the status of the lightning rod. The device may then be shut down again accordingly. This may provide a continuity test with little manpower and time expenditure.

[0030] For example, the device may be located in the hub, in the flange, or in the rotor blade of the wind turbine. For example, the test signal may be efficiently coupled to the lightning rod of the rotor blade at its attachment (or base). Alternatively, for example, when flying across a wind turbine, the drone can provide an activation signal for the device. For example, for safety reasons or legal requirements, it may no longer be necessary for some service technician to enter the hub of the blade attachment to activate the corresponding device. Furthermore, the corresponding device may be permanently attached to the wind turbine, so that the corresponding device does not even need to be separately attached for inspection. For example, the coupling module may be a pair of pliers, for example induction pliers, or a ring, for example induction ring, attached to a corresponding lightning protection cable or permanently attached to the structure.

[0031] According to further embodiments of the invention, the coupling module is configured to be attached to and / or integrated into the lightning rod of the rotor blade. Alternatively or additionally, the coupling module is configured to be attached to and / or integrated into the supply line to the rotor blade and / or integrated into the supply line and / or attached to the rotor blade. The embodiments of the invention are not limited to a special attachment of the coupling module to the lightning rod. Depending on the design of the wind turbine or, for example, whether a device for the wind turbine is built in or already directly provided during the manufacture of the wind turbine, corresponding coupling modules may be used with a high degree of flexibility.

[0032] According to a further embodiment of the invention, the device has a number of coupling modules corresponding to a number of rotor blades, each coupling module being configured to couple an electric test signal for a continuity test of a respective lightning rod to a respective rotor blade. This means that a number of lightning rods on a rotor blade of a wind turbine can be tested with a single device. For example, the test signal may be coupled to various lightning rods in sequence, so that for example a single drone flies sequentially over the corresponding rotor blade with the coupled test signal in order to detect the test signal. Alternatively, however, the test signal may be coupled to multiple rotor blades simultaneously, for example with multiple drones simultaneously, for example to check the lightning rods of the rotor blades in a particularly time-efficient manner. For example, the coupling modules may be supplied by one signal generator.

[0033] According to a further embodiment of the present invention, the device has a plurality of coupling modules corresponding to a plurality of rotor blades, each coupling module being configured to couple a respective electrical test signal for a continuity test of a respective lightning rod to a respective rotor blade. Furthermore, the device has a plurality of signal generators corresponding to the plurality of coupling modules, each signal generator of the plurality of signal generators being configured to generate a respective electrical test signal for coupling to a respective lightning rod in an active operation mode. In brief, each coupling module of the device may have an associated signal generator, for example, for conducting a respective electrical test signal to a respective lightning rod of a rotor blade simultaneously or sequentially. Thus, for example, the device may be more modularized such that the device may include a separate coupling module and signal generator module for each rotor blade.

[0034] According to a further embodiment of the invention, the energy source is configured to supply energy to a plurality of signal generators. Alternatively, the device has a plurality of energy sources corresponding to a plurality of signal generators, each of the plurality of energy sources being configured to supply energy to a respective signal generator of the plurality of signal generators. Thus, for example, a single central energy source may be provided for the energy supply, which can then be replaced with particularly little effort. Alternatively, the device may be more modular, such that a coupling module, a signal generator and an associated energy source may be provided, for example, per rotor blade. Furthermore, there may be another additional energy source to supply the communication module. Depending on the particular application, the device may thus be designed to be particularly fail-safe, for example by being more modular, such that, for example, individual modules can be easily replaced or have fewer parts, for example with a centralized signal generator and / or a centralized energy source.

[0035] A further embodiment according to the invention comprises a system for providing electrical test signals to perform continuity testing of electrical paths of an object, the object being a wind turbine having a plurality of rotor blades, each of the rotor blades having an electrical path in the form of a lightning rod, the system further comprising a plurality of devices according to one or more of the embodiments disclosed herein, each of the coupling modules of each device being configured to couple a respective electrical test signal for continuity testing of the respective lightning rod to the respective rotor blade. In brief, a device according to the design of the invention may thus be provided for each rotor blade, for example for coupling a corresponding test signal. For example, the devices may each be controlled with different activation and deactivation signals, for repeatedly activating or deactivating the devices in sequence, for example for testing the respective lightning rods of the respective rotor blades. Furthermore, however, the devices may also be responsive to a common activation and / or deactivation signal, for example such that multiple test signals are simultaneously provided in the rotor blades. In such a case, for example, the identifiers modulated onto the respective test signals may be different so that the signals can be distinguished.

[0036] Further embodiments according to the present invention include a system for providing electrical test signals to perform continuity testing of electrical circuits of an object, the system comprising a device according to one or more of the embodiments disclosed herein, a communication unit configured to send activation and deactivation signals to a communication module of the device, and a measurement unit configured to detect the test signals. For example, the communication unit may be a unit that can be attached to a laptop or a drone. For example, in the case of a laptop, the activation signal may be provided through a port in the object that is connected to the communication module of the device. For example, during an inspection flight of a drone, the activation signal may be transmitted wirelessly to the communication module of the device by a communication unit attached to the drone. For example, the measurement unit may be a handheld device used, for example, by a technician or climber to detect the inspection signal near the electrical circuits of the object. However, for example, the measurement unit may also be configured to be attached to the drone such that the test signal can be detected when the object flies away. For example, this may achieve a high degree of automation of the inspection of electrical circuits of an object.

[0037] According to one embodiment of the present invention, the communication unit is configured to be mounted on a drone. As already explained above, the device may thus be activated during a manual, automatic, autonomous or semi-autonomous flight of the drone (e.g., by correction of, for example, a predefined flight direction or flight distance (e.g., from the object), e.g., via an additional measuring system, e.g., a lidar), along the object, e.g., in the course of a periodic inspection, and may also be stopped again, e.g., after completion of a transit inspection. For example, the drone may be controlled or launched from the ground, so that people do not have to go to high altitudes or difficult-to-access places to perform the inspection, in particular the continuity test, especially in the case of large objects.

[0038] According to a further embodiment of the invention, the measurement unit is mounted on a drone and configured to detect the test signal during an inspection flight of the drone along the object. As explained above, this can save human personnel during the measurement and reduce the risk to human personnel. The drone can also reach areas that are inaccessible or difficult to reach for humans to detect the test signal and determine the condition of the object or the electrical circuits of the object.

[0039] According to a further embodiment of the present invention, the object is a wind turbine having a plurality of rotor blades, each of the rotor blades having an electrical conductor in the form of a lightning rod, and the system further includes a plurality of devices according to one or more of the embodiments disclosed herein, each of the coupling modules of each device being configured to couple a respective electrical test signal for a continuity test of the respective lightning rod to the respective rotor blade. Further, the communication unit is configured to transmit a start signal and a stop signal to the respective communication module of the respective device. Further, the drone has a measurement unit, and the drone is configured to fly to the wind turbine and fly over the plurality of rotor blades.

[0040] In particular, the drone may be configured to autonomously approach the wind turbine and to fly autonomously over the rotor blades. In particular, the measurement unit may be configured to detect the test signal during the autonomous flight of the rotor blade. The inventors have realized that this can provide a simple and efficient automated system for testing the lightning rods of a wind turbine. By providing an inventive device for each lightning rod or each rotor blade, the system is particularly robust and also allows for simultaneous testing of multiple rotor blades, for example using corresponding multiple drones with a corresponding number of measurement units. It is noted again that the drone may be controlled manually, automatically or semi-autonomously.

[0041] It should be noted again that the measurement unit may also be a portable device. Thus, the embodiment is not limited to the use of drones. For example, however, an inspection may be performed with a drone to determine the approximate damaged area of ​​a lightning protection circuit, and a climber with a portable measurement unit then scans the wind turbine, or more precisely, the rotor blade again, to find and repair the corresponding damaged area.

[0042] According to a further embodiment of the present invention, the method according to the present invention further includes sending a start-up signal to the communication module by the communication unit, scanning the object by the measurement unit, detecting a test signal when scanning the object, and sending a stop signal to the communication module by the communication unit. For example, general information about damage to the lightning rod of the rotor blade may be known. To repair it, a climber may then climb onto the rotor blade and transmit a start signal to the communication module of the device, for example in a wireless manner using a portable communication unit. The climber may then descend from the rotor blade and the test signal may be detected by the climber, for example with a portable measurement unit. In this way, the damaged area may be determined very accurately, for example by scanning at a very close distance, and may be repaired accordingly. At the end of the detection or repair, a stop signal may be transmitted to the communication module of the device, for example to reduce the load on the energy storage unit of the device, which may be replaceable, and to allow a long service life.

[0043] According to a further embodiment of the invention, the method according to the invention further comprises flying by a drone to the object, the drone having a measuring unit, transmitting an activation signal by the communication unit to the communication module, flying along the object by the drone, detecting the test signal when flying along the object by the measuring unit, and transmitting a stop signal by the communication unit to the communication module. For example, the drone can fly over the object manually, automatically, semi-autonomously or autonomously, using the drone to provide information for subsequent repairs. For example, the transmission of the activation signal may be transmitted when approaching the object, for example when the rotor hub is first approached by the drone, for example the drone may have a communication unit. Furthermore, however, the communication unit may be, for example, a laptop on the ground of the wind turbine, which is also used to control the drone. As mentioned above, the activation signal may then be transmitted by wire, for example via a fixed electrical path in the object. As mentioned above, the approach and take-off of the object may be automated, semi-autonomous or autonomous, so that the inspection results can be provided with little time and personnel effort (note again that manual flying is also possible). The drone may also fly over the rotor blades or conductors of the object, generally at a very short distance, to detect the inspection signal and then send a stop signal to the communication module by the communication unit after the inspection signal is detected, which may save energy after the inspection is completed.

[0044] According to a further embodiment of the present invention, the method of the present invention further comprises waking up the communication module in a passive operation mode for a predetermined duration at regular time intervals to obtain a wake-up signal, sending a wake-up signal by the communication unit to the communication module for a time span longer than the time interval between two wake-ups of the communication module, obtaining a wake-up signal by the communication module to switch from the passive operation mode to the active operation mode, and sending information regarding the operation state to the communication unit by the communication module. According to a further embodiment of the invention, at least one of the time information, the absolute position information of the drone, and / or the distance information and / or the position information of the drone relative to the rotor blades is stored together with the detection values ​​of the test signal for each detection value of the test signal. The inventors have realized that this may enable an accurate localization of the damaged area.

[0045] According to a further embodiment of the present invention, the method further comprises comparing the detected test signal with a reference signal, the reference signal being a calculated waveform of the detected test signal on the electrical circuit and / or a waveform of the detected test signal on the electrical circuit measured during a previous measurement, to determine information regarding damage to the electrical circuit. For example, the calculated signal waveforms may be the result of a simulation, for example based on CAD data. This means that it may also be possible to check whether the conductors or cables are intact and / or correctly installed during the first flight on a newly installed system. Furthermore, however, the inventors also recognized that the cables or conductors in the object may change in different ways, for example due to different environmental influences and local conditions at the object's location, so that previous measurements can be used to evaluate the condition or changes in conditions.

[0046] According to a further embodiment of the present invention, in the method according to the present invention, the object is a wind turbine having a rotor hub and a plurality of rotor blades arranged on the rotor hub, each of the rotor blades having an electrical path in the form of a lightning rod (or lightning arrester). Furthermore, the devices of the plurality of devices according to one or more of the embodiments disclosed herein are each coupled to the lightning rod of the respective rotor blade. The method of the present invention further comprises approaching the wind turbine, for example the rotor hub or the tip of the rotor blade, by a drone, the devices each being in a passive operating mode upon the approach of the drone. Furthermore, the method comprises sending an activation signal by the communication unit of the drone to a communication module of one of the devices to set the one device to an active operating mode. Furthermore, the method comprises coupling, by the coupling module of the one device, a test signal generated by a signal generator of the one device to the lightning rod of the rotor blade coupled to the one device. In addition, the method of flying along the rotor blade coupled to the one device with a drone while the test signal is coupled to the lightning rod of the rotor blade comprises detecting the test signal by a measurement unit of the drone during the flight along the rotor blade. Optionally, for example, the method may include flying again along the rotor hub or the tips of the rotor blades.

[0047] Further, the method includes transmitting a stop signal by the communication unit of the drone to the communication module of the one device to return the one device to a passive operation mode. Further, the method includes iteratively repeating the steps of transmitting the start signal, coupling the test signal, flying along the rotor blade, detecting the test signal, (optionally flying again to the rotor hub or the tip of the rotor blade), and transmitting a stop signal for the further device and further rotor blades of the multiple devices coupled with the device.

[0048] Briefly, the drone can fly to a wind turbine, e.g., a blade hub or a rotor blade tip. The drone flight can be, e.g., manual, automatic, semi-autonomous, or autonomous. The drone can then initiate a radio signal to put one of the devices into an active operating mode, or simply to wake it up. For example, the drone can wait for a certain time span, such as 75 seconds, and provide a wake-up signal to ensure that the wake-up interval of the communication module is reached in a passive operating mode of one device, or is captured, so to speak, to send a wake-up signal and wake up the device. Optionally, feedback from the device regarding the active operating mode may be further sent back to the communication unit of the drone by the communication module after the device is woken up. The drone can then fly, e.g., manually, automatically, semi-autonomously, or autonomously, along the wing or rotor blade, detect the test signal, and optionally return to the hub, and then return the device to a passive operating mode, e.g., a sleep mode. This process may be repeated iteratively, e.g., continuously, with one drone to wake up other devices and inspect other rotor blades.

[0049] It should be noted that embodiments in accordance with the present invention are not limited with respect to any particular flight path. Thus, the device according to the present invention may be activated by the communication unit of the drone from the hub as described above, but activation may also occur during the approach of the drone to the hub or during the approach of the drone to or from the tips of the rotor blades.

[0050] Thus, detection of the test signal may be performed from multiple possible start points and multiple possible end points of the flight trajectory. For example, a flight to a rotor blade may be performed from the tip of the rotor blade to detect the test signal. Conversely, the test flight may be initiated from the hub or rotor blade flange.

[0051] For example, starting from the hub of the wind turbine, the device may be activated to induce a test signal, and then a flight along the associated rotor blade may be performed. Starting from the tip of the rotor blade, for example, the device may be turned off again using a stop signal, and for example, the drone may fly in standby mode to the tip of another rotor blade. On the way to the other tip, for example, the device associated with the rotor blade may be activated to record a test signal at the lightning rod of the rotor blade during this test flight, starting from the tip of the rotor blade towards the hub. It should therefore be noted that embodiments in accordance with the present invention include multiple flight routes or patterns and therefore procedures for activating and deactivating devices in accordance with the present invention.

[0052] Examples according to the present disclosure are described in more detail below with reference to the attached drawings. With respect to the illustrated schematic diagrams, it is pointed out that the illustrated functional blocks should be understood as both elements or features of the device according to the present disclosure and corresponding method steps of the method according to the present disclosure, from which the corresponding method steps of the method according to the present disclosure can also be derived. [Brief description of the drawings]

[0053] [Figure 1] 1 is a schematic diagram of a device for providing an electrical test signal according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic diagram of a device having an optional protection diode, according to an embodiment of the present invention. [Diagram 3] 1 is a schematic side view of a wind turbine having an inventive device according to an embodiment of the present invention; [Figure 3a] 1 is a schematic side view of a wind turbine having an inventive device according to an embodiment of the present invention; [Figure 4] 1 illustrates a system for providing electrical test signals in accordance with an embodiment of the present invention. [Diagram 5]FIG. 2 illustrates a further system for providing an electrical test signal having further optional features in accordance with an embodiment of the present invention. [Figure 6] FIG. 2 is a schematic block diagram of the electronics of a device, in accordance with an embodiment of the present invention. [Figure 7] 1 is a schematic block diagram of a method according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0054] Before the embodiments of the present invention are described in more detail below with reference to the drawings, it should be noted that identical, functionally identical, or similarly operating elements, objects, and / or structures are provided with the same or similar reference numbers in different figures, such that the descriptions of these elements shown in different embodiments are interchangeable or may be applied to one another.

[0055] FIG. 1 shows a schematic diagram of a device for providing an electrical test signal according to an embodiment of the present invention. FIG. 1 shows a device 100 for providing an electrical test signal to perform a continuity test of an electrical path of an object. The device 100 includes a communication module 110 configured to receive an activation signal to set the device from a passive operation mode to an active operation mode and a deactivation signal to set the device from the active operation mode to a passive operation mode. Furthermore, the device 100 includes a signal generator 120 configured to generate an electrical test signal in the active operation mode. Furthermore, the device 100 includes an energy source 130 configured to provide energy to the communication module and the signal generator. Furthermore, the device 100 includes a coupling module 140 configured to couple an electrical test signal to an electrical path of the object in the active operation mode.

[0056] The method according to the invention may therefore be summarised as follows, for example with reference to FIG. supplying energy from the energy source 130 to the communications module 110 and obtaining a start signal by the communications module 110 to switch from a passive operating mode to an active operating mode; supplying energy from the energy source 130 to a signal generator 120 in the active operating mode, generating an electrical test signal by the signal generator 120 in the active operating mode, coupling the electrical test signal to an electrical path of the object in the active operating mode, and obtaining a stop signal by the communications module 110 to switch from the active operating mode to the passive operating mode.

[0057] The communication module 110 may optionally be configured to obtain the activation or deactivation signal in a wireless manner. Thus, the communication module may be, for example, a radio module. The communication may take place over any radio bandwidth, for example over Wi-Fi or mobile radio frequencies. In particular, the communication module may be configured to obtain a secure or encrypted activation and / or deactivation signal to prevent activation of the device by a third party. In particular, the device may include an antenna or, for example, a similar unit to improve the radiation and / or reception characteristics.

[0058] As mentioned above, suitable wireless communication allows the device to operate independently of the specific location of the device on or within the object, for example. The inventors have recognized that this may have great advantages, especially for large objects and / or objects that require electrical circuits in difficult-to-access areas to be inspected. Fewer personnel may be required, for example, since a technician does not need to operate the device on-site, for example, to activate the device to generate a test signal and then deactivate the device accordingly. In particular, the continuity test may be performed using an autonomously operating device, such as an autonomously or automatically flying drone, and the wireless communication with the communication module may be established by the communication unit of the drone. Thus, for example, the corresponding continuity test may be performed fully automatically or fully autonomously. Alternatively, however, the communication module 110 may be configured to receive the activation and / or deactivation signals over a wire, for example.

[0059] In general, the device for providing electrical test signals according to the embodiments may be rigidly connected to the object or may only be attached to the object, or more precisely to the electrical circuits of the object, in the course of the inspection. For example, in the case of a rigid structural connection with the object, the communication lines may be provided within the object, so that the device may be controlled from a predefined, e.g. easily accessible, location on the object. This may, for example, ensure a robust communication that is particularly free of interference.

[0060] Optionally, the energy source 130 may be an energy storage device. The energy storage device may be replaceable and / or rechargeable. The inventors have recognized that such an energy storage device has advantages, in particular for devices that are connected to an object on a long-term basis, for example installed on the object. For example, the device may be remotely started and stopped, wirelessly or by wire, using a communication module, in order to perform an inspection without the need for a technician to access the device itself to establish an energy supply. The energy source in the form of an energy storage device may then be replaced or recharged, for example, at specific intervals. Such an energy storage device may therefore be dimensioned such that a number of continuity tests can be performed before replacement or recharging is required. For example, the energy storage device may be a battery, such as an accumulator or a lithium battery. In a particularly preferred embodiment, for example, the battery may be easily replaced by a technician. For example, the corresponding battery may have a capacity of at least 5000 mAh and at most 12000 mAh, for example, at a voltage between at least 10V and at most 14V. For example, a battery may have a capacity of 8000mAh with a tolerance of + / -10% at 12V with a tolerance of + / -10%.

[0061] Alternatively, however, the energy source 130 may be configured to be coupled to an external power source. For example, in the case of an object that is used to generate energy or configured to consume energy or power and is always energized, for example, existing power electronics may be used to provide energy to the device. The energy source may be configured to be coupled to and decoupled from an external power source during each test, or may be configured to be permanently connected to a corresponding power source, for example when the device is incorporated into the object.

[0062] Optionally, the coupling module 140 may be configured to inductively and / or capacitively couple electrical test signals to the electrical paths of the object in an active operating mode. The inventors have recognized that this allows a particularly efficient integration of existing objects to provide the functionality of continuity testing of electrical paths or conductors in the object. For example, this means that the electrical paths of the object do not need to be exposed in order to couple a test signal to them. Furthermore, this may provide, for example, a galvanic decoupling between the device or coupling module and the electrical paths. Thus, the device may, for example, be substantially protected from voltage peaks and / or current peaks on the electrical paths. Furthermore, this type of coupling has advantages with respect to parts that move relative to each other. If an object, such as a wind turbine, is configured to move, it may be advantageous that the coupling module is not rigidly connected to the electrical paths of the object, but that such a connection may be inductive.

[0063] Alternatively, however, the coupling module 140 may be configured to couple the test signal to the electrical path of the object in an active operating mode by a switchable ohmic connection. Thus, for example, the coupling module may be rigidly connected to the electrical path, and electrical conductivity may be established or broken, for example, by a switch. In this way, the device may be isolated (decoupled) from the electrical path, for example, to allow controlled operation, or even to protect the device from lightning strikes, especially in the case of particularly large objects that may attract lightning.

[0064] As a further optional feature, the communication module 110 may be configured to be woken up in the passive operation mode for a given duration at regular timed intervals to receive a wake-up signal. In this way, the device can consume less energy in the passive operation mode than in the active operation mode. For example, in simple terms, the device may be turned off in the passive operation mode to wake up the communication module only periodically to enable the transmission of the wake-up signal. Based on the wake-up signal, the device may then be switched on accordingly to generate and couple the test signal. For example, this may ensure a long-term energy supply, particularly by the energy storage device, so that the interval between replacement or recharging of the energy storage device may be set as a large time interval.

[0065] For example, if the energy source is an energy storage device, the communication module 110 may be configured to transmit the charging state of the energy storage device in an active operating mode. Optionally, however, the device may also be configured to perform a self-diagnosis and provide further information about the device by means of the communication module. In both cases, the robustness of the device may be improved, since it may be possible, for example, to estimate whether the amount of energy remaining in the energy storage device is sufficient to perform an inspection or to plan maintenance or replacement of the device. Furthermore, a recharge or replacement of the energy storage device may be planned accordingly.

[0066] As a further optional feature, the communication module 110 may be further configured to transmit information regarding the operating state of the device. In particular, the communication module 110 may be configured to indicate a change from a passive operating state to an active operating state. For example, this may indicate a successful transmission of the activation signal. In addition, it may transmit that the device is ready to perform a continuity test of the conductors of the object, in other words to provide a test signal, or even that a test signal has already been provided. The inventors have recognized that this may have great advantages, especially for objects where the conductors are difficult to access or reach, otherwise a climber or drone may be in a position to detect a test signal without being certain that the device for generating the test signal is ready to do so, or that there is, for example, a malfunction.

[0067] As a further optional feature, the signal generator 120 may be configured to generate radio frequency signals and / or high frequency signals and / or clocked low frequency signals as test signals. The inventors have recognized that high frequency signals may be used to generate particularly efficiently an electromagnetic field around a conductor that can be detected by, for example, a measurement unit. This means that the test signal may also be detected from a greater distance around the conductor of the object in order to draw conclusions about the conductor or electrical path. Furthermore, high frequency signals may be used to provide inductive or capacitive coupling to the conductor of the object. In addition, smaller conductor breaks may also be bridged that may not be associated with lightning strikes and therefore should not be detected as defects during continuity testing of a conductor, for example a lightning rod.

[0068] As a further optional feature, the signal generator 120 may be configured to provide impedance matching to the electrical path of the object. In other words, for example, the output of the generator may perform impedance matching (radiation) within certain limits, i.e. there may be an attempt to achieve an optimum value depending on the electrical path or conductor, for example depending on the length of the electrical path or conductor or depending on the type of electrical path or conductor. It should be noted that a uniformly reproducible field strength does not necessarily have to be achieved for all possible variations of an electrical conductor, for example a lightning rod or a lightning protection system. Impedance matching may therefore be used to improve the efficiency of the signal supply, for example to minimize signal reflections and losses. This may also extend the replacement interval or recharge interval of an energy storage device by saving energy during power supply and signal transmission.

[0069] As a further optional feature, the device may be configured to modulate a signal identifier onto the test signal. For example, this means that the test signal can be easily distinguished from other signals so that a robust and accurate evaluation of the continuity test is possible. Furthermore, the use of a signal identifier also allows multiple test signals to be fed in parallel, e.g., on different conductors, so that the signals can be spaced further apart. For example, this can make the inspection of an object with many conductors to be tested particularly time-efficient.

[0070] FIG. 2 shows a schematic diagram of a device with an optional protection diode according to an embodiment of the invention. FIG. 2 shows the device 200 including a communication module 240 in addition to the elements already described in the context of FIG. 1. As a further optional feature, the device 200 includes a protection diode 250 configured to protect the device 200 from voltage and / or current spikes on the electrical path of the object. As an optional feature, the protection diode 250 is a suppressor diode connected in parallel with the coupling module 240. As shown in FIG. 2, for example, the suppressor diode may be connected in parallel with the signal path of the coupling module or may optionally be an element placed, for example, external to the coupling module. In general, the protection diode may also be placed on or between other elements of the device. For example, the protection diode may be a transistor diode. For example, such a diode does not need to be led to ground, but is mounted internally in parallel with the coupling module, for example an induction coil, and thus can block overvoltage pulses. For example, lightning strikes may be blocked in this way so that the device is not destroyed. For example, a corresponding protection diode, for example in the form of a suppressor diode, may become conductive when a certain voltage threshold is exceeded. The corresponding current peak is then conducted in parallel past the protected component, for example in a coupling module. The diode may internally absorb the energy. Furthermore, the corresponding diode may be configured as a unidirectional or bidirectional diode.

[0071] Fig. 3 shows a schematic side view of a wind turbine with a device according to an embodiment of the invention. Fig. 3 shows a wind turbine 360 ​​with a tower 362, a nacelle 364 and a number of rotor blades 372, 374, 376, each with an electrical path 382, ​​384, 386 in the form of a lightning rod (or lightning arrester). It is noted that more generally, in the context of Fig. 3, the object may thus be the wind turbine 360 ​​or a rotor blade of such a wind turbine, and the device according to the invention is configured to test the electrical paths.

[0072] Furthermore, Fig. 3 shows a device 300 including a communication module 310 and, as shown as an optional feature, a number of coupling modules 342, 344, 346 corresponding to a number of rotor blades. However, it should be noted that a device according to the invention may also have only a single coupling module. Each coupling module 342, 344, 346 is configured to couple an electrical test signal to a respective rotor blade 372, 374, 376, each for a continuity test of a respective lightning rod 382, ​​384, 386. Optionally, one or more coupling modules 342, 344, 346 may be placed on the lightning rod of the 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 concept of the invention may already be built into the object, or more precisely, into the rotor blade. However, in the integrated state, in addition to a resistive connection, for example by a switch, the coupling module may also be configured to inductively or capacitively induce the test signal to the lightning rod, or to couple it, generally speaking.

[0073] As a further optional feature, the device 300 includes a plurality of signal generators 322, 324, 326 corresponding to a plurality of coupling modules 342, 344, 346, each signal generator configured to generate a respective electrical test signal for coupling to a respective lightning rod in an active operating mode of the device 300. It should be noted, however, that the presence of multiple signal generators is only optional. For example, there may be only a single signal generator 320 with multiple signal outputs. Similarly, as a further optional feature, a single energy source 330 or multiple energy sources 332, 334, 336 corresponding to the multiple signal generators 322, 324, 326 may be configured to supply energy to the respective signal generators.

[0074] Again, it should be noted that the wind turbine as an object is merely an example: for example, radio masts, wind turbine towers, large antennas, ships such as large container ships, port facilities, or other large structures may generally have electrical paths that are, for example, difficult to access, but still need to be tested.

[0075] Fig. 3a shows a schematic side view of a wind turbine with a device according to an embodiment of the present invention. Fig. 3a shows a wind turbine 360a with a tower 362a, a nacelle 364a, and a number of rotor blades 372a, 374a, 376a, each of which has an electrical trace 382a, 384a in the form of a lightning rod (for clarity, the lightning rod is not shown on the rotor blade 376a). Furthermore, the tower 362a includes a conductor 388a connected to the lightning rod 384a and a second conductor 389a. 3 further illustrates multiple devices 302a, 304a, 306a, each including a respective combining module 342a, 344a, 346a, a signal generator 322a, 324a, 326a, and an energy source 332a, 334a, 336a. For clarity, the respective communication modules are not shown.

[0076] For example, as shown as an optional feature in FIG. 3a, a coupling module 342a of the present invention may be integrated into a rotor blade 372a, eg, an airfoil. Additionally, tower 362a may include one or more conductors. Thus, for example, device 306a may be configured to provide a continuity test for conductor 389a. For example, a corresponding conductor in the tower, e.g., conductor 388a, may be configured to bleed overvoltages, e.g., due to a lightning strike, away from one or more lightning rods in the rotor blades. Thus, for example, device 304a may not only perform a continuity test on lightning rod 384a, but may also simultaneously test conductor 388a connected to lightning rod 384a.

[0077] For completeness, it should be noted that the respective signal generators 322a, 324a, 326a are in each case configured to generate electrical test signals in the active operating mode of the respective devices for coupling by the respective coupling modules 342a, 344a, 362a, and the respective energy sources 332a, 334a, 336a are in each case configured to supply energy to the respective communication modules (not shown) and the respective signal generators 322a, 324a, 326a in the active operating mode of the respective devices.

[0078] It should also be noted that the features shown in Fig. 3a are optional and therefore may be used individually or in combination according to the embodiment. For example, tower 362a may have only a single conductor or may have multiple conductors. The different arrangements and embodiments of devices 302a, 304a, 306a should not be understood as limiting but rather serve to clearly illustrate different embodiments according to the present invention.

[0079] Fig. 4 shows a system for supplying an electrical test signal according to an embodiment of the present invention. Fig. 4 shows a system 400 including a wind turbine 360 ​​according to Fig. 3 and a number of devices 410, 420, 430 according to one or more of the embodiments described herein, each coupling module of each device being configured to couple a respective electrical test signal to each rotor blade 372, 374, 376 for continuity testing of each lightning rod 382, ​​384, 386. In brief, the system 400 according to the present invention may thus include a number of devices according to the present invention corresponding to the number of electrical paths. Thus, a separate device may be provided for each electrical path to be tested, and the devices may be individually controlled, i.e. activated and deactivated, accordingly. The coupling modules of the devices 410, 420, 430 may be attached to the lightning rods of the rotor blades or in the supply lines to the rotor blades, or may be integrated into the rotor blades.

[0080] Fig. 5 shows a further system for providing electrical test signals, with further optional features, according to an embodiment of the present invention. Fig. 5 shows a wind turbine 360, with the features already described in the context of Fig. 3 and Fig. 4. It should be noted that the wind turbine 360 ​​here is again just an illustrative example of an object. It should be mentioned again that cranes, antenna masts, radio masts, large ships or even entire port facilities, for example, may have electrical circuits that need to be tested at regular intervals.

[0081] A number of embodiments are described below with reference to Figure 5 and system 500. It should be noted that, unless otherwise stated, individual features, details, and functions are emphasized together herein to explain the functionality of the present invention, but they do not all have to be present together at the same time in an embodiment. As an example, system 500 includes multiple devices according to one or more of the described embodiments, namely devices 510, 520, and 530, positioned in proximity to the lightning rods of the rotor blades for coupling test signals to corresponding rotor blades 372, 374, 376, or more specifically to corresponding lightning rods 382, ​​384, 386, by respective coupling modules.

[0082] It should again be pointed out that, for example, a system may have only one device with multiple coupling modules such that test signals may be supplied to the lightning rods 382, ​​384, 386, for example, from a common signal generator or multiple signal generators via multiple coupling modules. Furthermore, the system 500 includes a communication unit, such as the communication unit 542 and / or the communication unit 544 and / or the communication unit 546, configured to transmit activation and deactivation signals to a communication module of one of the devices 510, 520, 530.

[0083] The system 500 further includes a measurement unit, such as the measurement unit 252 or the measurement unit 554 or the measurement unit 556, configured to detect the test signal. Thus, Fig. 5 shows several options for the communication unit and the measurement unit, which are explained in more detail below. It should be noted that the system, and in particular the method of the invention, may have such units individually, together, in combination or individually. This is explained in more detail below.

[0084] For example, the drone 562 may be used to perform a continuity test on the wires of the object. It is noted that the system 500 may also optionally include the drone 562. For example, the drone may be launched from the ground using a laptop computer. The drone may then be configured to fly, for example autonomously, semi-autonomously, or automatically, or by manual control, to one of the devices 530, as shown in FIG. 5, and thus, for example, to the rotor hub 364. To wake up the device 530, an awakening signal may now be sent by the communication unit 542 to the communication module of the device 530. Thus, a communication unit according to the device of the present invention, such as the communication unit 542, may be configured to be attached to the drone.

[0085] For example, the communication module of the device 530 may be activated for a predefined duration at regular time intervals so as to be able to receive a corresponding activation signal 570. The communication unit may thus be configured to provide the activation signal 570 for a time span that is longer than the time span between two activations of the communication module.

[0086] Thus, the wake-up signal 570 may be received by the device 530, or more precisely, by the communication module of the device 530, in order to switch from a passive to an active operating mode. As a result, the method of the invention may include transmitting a wake-up signal by the communication unit 542 to the communication module during a time span longer than the time interval between two wake-ups of the communication module. Optionally, information about the operating state of the device may be sent back from the communication module of the device 530 to the communication unit 542 accordingly. Thus, in the active operating mode of the device, the test signal may then be introduced to the lightning rod. Starting from the activated device, the drone may fly automatically, autonomously, semi-autonomously or even manually along the rotor blade 374, as for example shown by the drone 564. The drone may have a measurement unit configured to be attached to the drone, for example the measurement units 552 and 554 of FIG. 5. It should be noted that drones 542 and 544, and correspondingly communication units 542 and 544 and measurement units 552 and 554, are the same object, each of which sequentially performs the steps described herein.

[0087] In the following, it is assumed that device 520 is in an activated state, e.g., by having been previously activated, as described for drone 562 and rotor blade 376. Thus, device 520 may couple test signal 580 to conductor 384 by means of an associated signal generator and coupling module. The coupling may be an inductive, capacitive, or ohmic switchable connection. The measurement unit 554 may 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. Thus, if such a signal is weaker than expected or absent, a conductor interruption may be inferred. Thereafter, for example, the drone 564 may return to a respective device, such as device 530 or device 552 as previously described, and then transmit a stop signal, for example at a position as shown by the drone 562, to terminate the coupling of the test signal. Thus, an automatable method of continuity testing of lightning rods may be provided. However, it should be noted that the communications unit 542 may also be used to transmit start and / or stop signals from any location on the flight path of the drones 562, 564, e.g., during flight from one rotor blade to the next, e.g., from the hub of the wind turbine, or e.g., from the tips of the rotor blades.

[0088] Generally speaking, the object may accordingly be approached by, for example, flying an automatic, semi-autonomous, autonomous or manual drone 562, 564, the drone comprising a measurement unit 552, 554. An activation signal may then be transmitted by the communication unit 542, 544 to the communication module of the device 520, 530. It is noted here that, for example, there may only be a single device with a single communication module, but there may be multiple combining modules, for example for combining electrical test signals, so that, for example, the activation signal is transmitted only to that single communication module. The drone may then be used to fly along the object and the test signal 580 or multiple test signals of several rotor blades may be detected by the measurement units 552, 554. After taking off, the device or devices may then be switched back again to a passive operating mode by a stop signal, e.g., switched off.

[0089] The detected test signal may then be evaluated. For example, the method of the invention may comprise comparing the detected test signal with a reference signal. For example, the reference signal may be a theoretical reference signal that can be determined using nominal data of the test signal and the lightning rod, or a historical reference signal, for example detected during previous measurements. In particular, this may also provide information on trends such as the deterioration of the lightning rod over time, for example to predict maintenance that may not be immediately necessary but should be performed in the long term. In this way, information on damage to the electrical line or the lightning rod may be determined. Typically, the data stored by the measurement unit may be at least one of time information, absolute position information of the drone, distance information and / or position information of the drone relative to the rotor blades in addition to the actually detected value of the test signal. For example, the drone may have a GPS receiver or may use a relative positioning system to determine its own position.

[0090] The results of such an evaluation based on the detected information may be used to locate the damaged area and to plan replacement or repair. For example, a climber 566 may be used for this purpose. For a particularly precise localization, the measurement unit 556 may be a portable device, for example, so that a climber in the immediate vicinity of the rotor blades can locate the damaged area more precisely. A signal line 590 is shown as an example for activating the device 510. The activation signal may thus be transmitted by wire to the communication module of the device 510 by the communication unit 546. In the case of a wind turbine, for example, this may be an electric line laid along the tower to the base of the turbine, if the device 510 is firmly connected to the rotor hub. Thus, for example, a laptop, which may also be used to control a drone, may be used to activate the device 510. It should be noted that a corresponding wired signal transmission may therefore also be used in embodiments using drones. Alternatively, however, for example, the climber 566 may also carry a portable communication unit, which may be used to activate the corresponding device 510, as described in the course of the drone 562.

[0091] In summary, the activation signal may thus be transmitted by the communication unit in a wired or wireless manner to the communication module of the device or the device, for example if only one device is installed in the wind turbine with multiple coupling modules. Then, for example, a climber may scan the lightning rod by the handheld device 556 and detect the corresponding test signal. After detection of the test signal, the corresponding device 510 may be deactivated by the communication module. The measurement unit 556 may be able to transmit measurement data in a wireless manner, for example to enable an immediate evaluation during an inspection, so that the exact location of the damaged area can be directly determined and repairs can be started immediately.

[0092] In the description of FIG. 5, several optional procedures according to the invention have been presented, but it should be pointed out again that these may be used individually or in combination. For example, a drone may be used to activate a number of devices in sequence, in each case repeatedly flying along these rotor blades in sequence until all corresponding lightning rods have been inspected, repeatedly coupling a test signal to one of the rotor blades and deactivating the activated device again after each flight to activate another device. However, a drone relay may also be used such that the device activates several coupling modules so that all devices are activated simultaneously, so that some or all rotor blades are flown simultaneously, or in the case of a single device, the device is activated and thus introduces a respective test signal to the respective lightning rod with the help of one or more signal generators. As explained above, the flight may be, for example, manual, automatic, autonomous or semi-autonomous. For example, a semi-autonomous flight may include, for example, a correction of a given flight direction or distance (for example from an object), for example via an additional measurement system, for example a LIDAR. Alternatively, the starting and stopping, as well as the scanning of the corresponding conductors of the wind turbine may of course be performed manually, for example by a climber.

[0093] In the following, further embodiments and the previously described, in other words summarized, embodiments are described for an object in the form of a wind turbine or a rotor blade of a wind turbine. According to one embodiment, for example, the coupling module may be a clamp, for example an inductive clamp. For example, the communication module may be configured as a wireless module or an integrated wireless module, for example, the wireless module may be configured to switch the device from a passive operating mode, for example a sleep mode, to an active operating mode, for example an active mode or active mode.

[0094] For example, a drone with a measurement unit may be used to detect test signals so that, after, for example, a test flight, the device may be returned to a passive operating mode, for example a sleep mode, for example by a wireless module. For example, to test a lightning protection system of a wind turbine, the central idea according to such an embodiment is a non-invasive injection of an electromagnetic field into the lightning protection system and a non-contact, e.g. autonomous flight along the rotor blades by a measurement unit, e.g. a drone, which may be equipped with a special sensor for measuring the electric field. This measurement can be performed using special measurement techniques and mathematical / algorithmic processing to quickly, efficiently and accurately determine the functionality of the lightning protection system.

[0095] Briefly, embodiments are therefore based on inductively supplying an electric field to, for example, a rotor blade lightning protection system and measuring the radiated electric field with a measurement unit, such as an electric field sensor on a drone. According to embodiments it is possible to precisely localize any damaged areas which are detected and which can then be tracked at any time with another measuring unit, for example a separate hand sensor for repair purposes.

[0096] As explained above, for example, the energy source may be configured as a replaceable energy storage device. For example, a lithium battery or a lithium accumulator may be used for this purpose. (Note again that according to embodiments, a cable may also be used as an alternative to supplying the device with energy by an external power source.) As an example, such an energy storage device may have a capacity of about 8000mAh (e.g., with up to + / -5% tolerance, or with up to + / -10% tolerance, or with up to + / -50% tolerance, or with up to + / -100% tolerance, or with up to + / -1000% tolerance), for example, at about 12V (e.g., with up to + / -5% tolerance, or with up to + / -10% tolerance, or with up to + / -50% tolerance, or with up to + / -100% tolerance, or with up to + / -1000% tolerance).

[0097] In particularly preferred embodiments, for example, such an energy storage device may be replaced with, for example, a handle with little effort, for this purpose, for example, the device may have a simple plug-in and snap-in connection for such an energy storage device. As explained above, the communication module, e.g., wireless module, may optionally be activated in a passive operation mode at timed intervals for a predefined duration to receive an activation signal. The corresponding replaceable energy storage device may be designed for a long-term service life so that the device according to the invention can operate for a long period of time without requiring any special maintenance.

[0098] For example, power consumption in a passive operating mode, e.g., a sleep mode, may be configured as follows: For example, an electronic device may require about 15 microamps in sleep mode and be "woke" for about 0.1 seconds every 60 seconds to query a radio signal that requires about 15 mA for about 0.1 seconds. This results in an annual consumption of about 500 mAh or 2000 mAh for 4 years.

[0099] The power consumption in an active operating mode, e.g. inspection mode, may be configured as follows for the example of lightning rod inspection on a wind turbine: Approximately 800mA, i.e. a maximum test time of 15 minutes per wing, approximately 4000mAh for about 20 tests. Thus, in the above mentioned example of an energy storage system with about 8000mAh at about 12 volts, if we assume or calculate 2-3 inspections, for example per year after a lightning strike (e.g. the legal requirement is a maximum of 1 inspection every 2 years) and taking into account the certain self-discharge of the energy storage system, e.g. a Li battery, the battery would only have to be replaced approximately every 6 years as part of the prescribed service (e.g. the normal prescribed service in the system is every 2 years).

[0100] Thus, the device according to the invention can operate for long periods without maintenance. As explained above, for example during each test or at least during some tests (e.g. in an active operating mode, i.e. when the device is active), the charge state of the energy storage device (e.g. battery) may be queried by the drone via the communication module (e.g. wireless module) every time, optionally for safety reasons.

[0101] According to further embodiments, as already explained above, the device or only the coupling module, for example in the form of an induction clamp, may be firmly connected to the wind turbine or to the rotor blade of the wind turbine. For example, the device or the coupling module of the device may be attached to the lightning rod of the rotor blade and / or in the supply line to the rotor blade, or the device or the coupling module may be integrated, for example, in the rotor blade.

[0102] For example, to operate a device, such as the one described above, a coupling module, for example in the form of an induction clamp, may be attached (e.g. glued) once to the lightning rod at the start of the blade by the service team and may remain there for the entire life cycle of the system (wind turbine) (e.g. about 25 years). The coupling module may be integrated into the hub of the wind turbine, into the rotor blade flange, or into the rotor blade itself.

[0103] The main advantage of the embodiment of the galvanic isolation between the coupling module and the electrical path of the object, for example by inductive coupling, for example by a non-invasive induction process according to the method of the present invention, is that the device (for example the coupling module in the form of an inductive clamp) does not need to be directly (electrically) connected to the lightning rod, so that damage to the system or device may not occur, for example in the case of a lightning strike. Optionally, for example a protective diode in the form of a so-called transil diode may be arranged or attached between the coupling module (according to the embodiment, generally configured, for example, as an inductive coil or inductive ring) and the output transistor (for example of the signal generator) for further protection. Corresponding embodiments may enable the use of such diodes for the first time.

[0104] In the following, an example of an inspection procedure according to an embodiment is described on the basis of a wind turbine for measuring lightning protection according to an embodiment. For example, the inventive device described above may be used for this purpose. For example, a device having a coupling module in the form of a clamp, for example an induction clamp, may be placed on each rotor blade, or simply on the wing, of the wind turbine. Furthermore, the detection of the test signal may be realized by a drone comprising a measurement unit. Thus, for example, the following sequence of steps may be performed according to an embodiment:

[0105] 1. The drone is flown autonomously, for example, to the blade hub of a wind turbine (as explained above, this is just one option depending on the embodiment, it could also be flown to the tip of the rotor blade, for example, or manual, automatic, or semi-autonomous flight could be performed as options). 2. The drone initiates a wake-up signal, e.g., a radio signal, to wake up or simply "wake up" the first device (e.g., wing 1). The drone waits a prescribed time interval, e.g., about 75 seconds, to actually capture the wake-up interval (e.g., every 60 seconds) (in other words, the waiting time, e.g., the time when the wake-up signal is sent, may be longer than the period between two wake-ups of the communication module in a passive operating mode). In addition, it optionally receives feedback from the device via the radio module that the device is in an active operating mode, e.g., active. 3. The drone flies, e.g., autonomously (or manually, or automatically, or semi-autonomously), along the wing, returns to the hub (or, e.g., returns to the tip of the rotor blade or to another rotor blade, or remains on the wing tip after take-off from the hub, or remains on the hub after take-off from the wing tip), and returns the device to a passive operating mode, e.g., a sleep mode. 4. The drone then launches the next device (e.g., the next rotor blade), and so on.

[0106] In the following, the advantages of a device comprising a coupling module in the form of a clamp, for example a lightning protection clamp according to an embodiment, said module being firmly connected to a wind turbine, are explained using an example. Some procedures may require two service workers to travel by elevator to the nacelle (hub) so that clamps can be installed on the lightning protection cables at their respective wing attachments (flanges) (e.g. required by law for safety reasons if technicians have to climb from the hub to the wing attachments). An energy source, e.g. in the form of a power supply unit, may then be connected to each of the three clamps (one device per rotor blade) via e.g. a 10m long cable, and the clamps may be switched on / off in turn by a service technician on the power supply unit, e.g. via a rotary switch, depending on the drone's position (blade 1, 2, or 3).

[0107] The drone can then fly along the wing, for example from the wing base (flange) to the wing tip (optionally by manual, automatic, autonomous or semi-autonomous flight, for example over a distance of about 5 m (i.e., for example, a distance of at least 4 m and at most 6 m, or at least 1 m and at most 10 m)), at a speed of, for example, 0.25 m / s (i.e., for example, a speed of at least 0.1 m / s and at most 0.3 m / s, or at least 0.2 m / s and at most 0.3 m / s), and scan the radiated electric field of the test signal. This means that for a wing length of 60 meters, for example, the entire lightning protection inspection of the wing takes about 4 minutes. The drone can then optionally also fly autonomously (or manually, or automatically, or semi-autonomously) at a higher speed to the hub (e.g., taking about 1 minute) or to another point on the wind turbine, for example an adjacent blade tip. The service engineer may then switch to the next pair of clamps and the next blade may be inspected. This means, for example, that an entire inspection, including approach / launch (drone flight time without scaffolding) can take around 25 minutes.

[0108] Optionally, according to embodiments, regions of the object may be inspected in more detail or even further, for example individual regions of the wing, such as receptors, may also be inspected, however this may add several minutes to the inspection time. For example, an advantage of embodiments in which the device is rigidly connected to the object is that two service technicians do not need to ride an elevator into the tower to set up and dismantle the device and thus, for example, the clamp. This may eliminate the need for one service technician to return to operate the drone while the other operates the power unit from the hub. This may also eliminate the need for a second technician to return again to remove the clamp once the inspection is complete.

[0109] This can save a great deal of time. However, it should be noted that embodiments having a device that must be assembled and disassembled, such as those described above, have even greater advantages over traditional approaches having a rope climber, for example. For example, an average inspection with a system according to the invention may take about 1.5 hours (compared to traditional methods where a rope climber would take about 8 hours), and according to embodiments, this duration can be further reduced by the device being permanently placed on the object.

[0110] Thus, the embodiment has great advantages, especially for objects that are difficult to access. In the case of offshore installations (access by vessels, height of installations) a complete inspection may take several days. In addition to personnel costs, downtime costs due to downtime during the inspection play a significant role (e.g. up to 2000 euros per hour). According to an embodiment, significant time and cost savings are therefore possible.

[0111] The method of the invention thus makes it possible to eliminate the above mentioned drawbacks and to provide a highly effective system for testing the continuity of lightning rods of wind turbines. According to a further embodiment of the invention, the signal generator can induce a conditioned signal at the base of the rotor blade into the lightning rod, thereby generating a test signal, e.g., a near-field of substantially constant electric field along the rotor blade within a frequency range approved by the grid authority. According to an embodiment, the signal may be non-invasively induced in the lightning protection cable.

[0112] According to embodiments, for example according to the embodiments described above, the device may for example have a coupling module in the form of an inductive clamp or for example in the form of an inductive ring. For example, when building a new wind turbine, an induction ring may be integrated directly into the rotor blade. Simply put, a corresponding induction ring can be slid over a lightning rod on the rotor blade. Alternatively, cables in existing turbines may be cut open to mount an induction ring. The induction ring may have advantages in terms of the signal quality of the test signal supplied. Furthermore, a supply using an induction ring may also be particularly robust. For example, the induction clamp may be configured to only partially surround the lightning rod (e.g., be an open-ended clamp) in order to induce the test signal, which means, for example, that the cable does not have to be cut open (compared to conventional methods with the aid of continuity measurements, e.g., ohmic continuity measurements) or any other intervention has to be performed.

[0113] According to such an embodiment, the signal generator may have a connection that is optimized and, for example, matched via an impedance exactly or at least approximately, to a corresponding inductive ring or to a corresponding inductive clamp. Any deviations from the standard or default impedance value (e.g. caused by different lengths of lightning protection cables, branched lightning protection structures, etc.) may optionally be automatically adjusted by the output stage of the signal generator. Each device, including for example an inductive clamp, may optionally have its own communication module in the form of a radio module (e.g. having an 868 MHz ISM radio) and may be individually controlled from the ground by an operator via radio for measurements.

[0114] For example, this has the advantage that all three rotor blades of a wind turbine can be connected simultaneously before the measurement and, for the actual measurement, the signal supply to the rotor blades can be controlled individually by an operator from the ground via radio. It is noted that the coupling module of the device, for example in the form of an induction clamp, may also be permanently attached to the lightning rod of the rotor blade or to the corresponding supply line.

[0115] To avoid measurement inaccuracies due to interference in the widely used ISM band (13.56 MHz), for example, the identifier may optionally be modulated onto a test signal that is removed by the sensor processor (e.g., measurement unit) and used only to calculate the value. This can, for example, ensure that influences on the measurement caused by external signals or interference are excluded.

[0116] Optionally, other, eg alternative, frequencies, eg radio frequencies and / or low frequencies, eg clocked, may be used.

[0117] Fig. 6 is a schematic block circuit diagram of the electronics of the device according to an embodiment of the present invention. Fig. 6 shows a microcontroller 610 configured to control, for example, a communication module 630, to switch on (for example, in an active operation mode or in a periodic standby for receiving a wake-up signal in a passive operation mode) and / or to switch off (for example, in a passive operation mode). As an optional example, the communication module 630 is a radio module configured to transmit and / or receive at a frequency of 868 MHz. Further, the device electronics includes a signal generator 620 optionally including a clock generator 622 having an optional clock frequency of 160 MHz, a direct digital synthesis digital-to-analog converter (DDS-DAC) configured to provide an analog signal, for example a sinusoidal analog signal having an optional frequency of 13.565 MHz, a multiplier and / or adder 626 (Mult.Add.), and a signal amplifier 628 (power amplifier - PA10W) having a power of, for example, at least 1 Watt and at most 20 Watts, for example 10 Watts (for example, with a tolerance of at least + / - 5%), or having a power of, for example, at least 1 Watt and at most 5 Watts, for example 2 Watts (for example, with a tolerance of at least + / - 5%).

[0118] In the example of FIG. 6, impedance matching to the object's electrical path is prioritized as an option, such that the coupling module and the object's electrical path are represented as ohmic resistance 640 . In general, for example, the output stage of the signal generator may be a differential output stage. In the following, the combination module according to one embodiment is described again in other words and with further optional details. As explained above, according to an embodiment, a test signal may be induced in a wind turbine conductor in the form of a lightning protection cable using the non-invasive method of the invention with the help of a device including a coupling module in the form of an inductive clamp, an inductive ring or a measuring ring.

[0119] A particularly preferred embodiment includes a coupling module in the form of an inductive clamp. Such an approach may have several important advantages. a) The lightning protection cable does not need to be interrupted or disconnected from earth. For example, an induction clamp may be tucked under the cable at an accessible point. b) If the cable is permanently laminated, the induction clamp may simply be placed onto the cable and then attached (eg, using adhesive tape). c) Because the signal (generator output) is fitted to the induction clamp, for example, only once, there are no problems with misfits, including standing waves with different rotor blade configurations and lengths. d) With optimal, or at least near-optimal matching, there are no or very few vibrations or interference waves, e.g. signals may only or essentially propagate in a specified, e.g. very narrow, frequency range. e) Consistent and repeatable measurement behavior for the same blade design.

[0120] According to an embodiment, for example, a test signal generated along the rotor blade, for example a vertical radiation field (linear near field) with an electric field strength E, may decrease in the order of two with respect to the distance between the drone and the rotor blade. The counterpart, for example a measurement unit, may be a highly sensitive electric field sensor, for example a 1D, 2D or 3D electric field sensor with a very low bandwidth and a high sampling rate, which may be integrated as a payload into an optional autonomously (or, for example, manually or automatically or semi-autonomously) flying drone. If the sensor does not receive a signal at the tip of the rotor blade or receives an insufficient signal strength, the lightning rod along the rotor blade may be damaged or blocked.

[0121] According to some embodiments, the conductor may form a (grounded) monopole, e.g. the conductor need not be cut but may remain connected to ground, e.g. the signal generator of the test system, i.e. the device, may preferably operate at a frequency of 13.56 MHz within the ISM shortwave band (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%).

[0122] The test signal generated by induction, e.g. a near-field of a vertical constant electric field, may be detected by a measurement unit, e.g. an electric field sensor on a drone flying along the rotor blade, and a continuity test of the lightning rod is performed based on the radiated electric field. For example, the direction and intensity of the detected electric field strength (e.g., when using a 3D electric field sensor) may be evaluated to determine whether a conductor is interrupted. If the measurements indicate a continuous electric field within a predetermined tolerance, it may be concluded, for example, that the electrical path is not interrupted, i.e., the lightning rod is functioning. If the electric field strength deviates from a predetermined range at one or more locations along the conductor, this may indicate, for example, an interrupted electrical path.

[0123] 7 shows a schematic block diagram of a method according to an embodiment of the present invention. FIG. 7 shows a method 700 for performing a continuity test on an electrical path of an object, including providing energy of an energy source to a communication module (710), obtaining a start signal by the communication module to switch from a passive operation mode to an active operation mode (720), providing energy of an energy source to a signal generator in the active operation mode (730), generating an electrical test signal by the signal generator in the active operation mode (740), coupling the electrical test signal to the electrical path of the object in the active operation mode (750), and obtaining a stop signal by the communication module to switch from the active operation mode to a passive operation mode (760).

[0124] All lists of materials, environmental effects, electrical properties, and optical properties given herein should be considered exemplary and not exhaustive. Although some aspects are described in the context of a device, it is understood that said aspects also represent a description of a corresponding method, so that blocks or structural parts of the device should also be understood as corresponding method steps or features of method steps. By analogy therewith, aspects described in the context of or as method steps also represent details of the description or features of the corresponding blocks of the corresponding device. Some or all of the method steps may be performed using hardware devices such as microprocessors, programmable computers, or electronic circuits. In some embodiments, some or some of the most important method steps may be performed by such devices.

[0125] Depending on the specific implementation requirements, the embodiments of the present 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 disk, a CD, a ROM, a PROM, an EPROM, an EEPROM, or a flash memory, a hard disk, or any other magnetic or optical memory, storing electronically readable control signals, which can cooperate or cooperate with a programmable computer system to execute the respective methods. This is why the digital storage medium may be computer readable.

[0126] Some embodiments according to the invention thus include a data carrier including electronically readable control signals capable of cooperating with a programmable computer system to cause any of the methods described herein to be performed. In general, embodiments of the present invention may be implemented as a computer program product having program code that operates to perform any of the methods when the computer program product is executed on a computer. The program code may for example be stored on a machine readable carrier.

[0127] Other embodiments comprise the computer program for performing any of the methods described herein, said computer program stored on a machine readable carrier. In other words, an embodiment of the inventive method is thus a computer program having a program code for performing any of the methods described herein, when the computer program runs on a computer. The data carrier, digital storage medium, or recorded medium is typically tangible or non-volatile.

[0128] A further embodiment of the inventive method is thus a data carrier (or a digital storage medium or a computer readable medium) on which is recorded a computer program for performing any of the methods described herein. The data carrier, digital storage medium, or computer readable medium is typically tangible and / or non-volatile or non-transitory.

[0129] A further embodiment of the inventive method is thus a data stream or a sequence of signals representing the computer program for performing any of the methods described herein, The data stream or the sequence of signals may for example be arranged to be transmitted via a data communication link, for example via the Internet. A further embodiment comprises a processing means, for example a computer, or a programmable logic device, configured to or adapted to perform any of the methods described herein. A further embodiment comprises a computer having installed thereon the computer program for performing any of the methods described herein.

[0130] Further embodiments according to the invention include a device or system configured to transmit a computer program for performing at least one of the methods described herein to a receiver. The transmission may be, for example, electronic or optical. The receiver may be, for example, a computer, a mobile device, a memory device, or a similar device. The device or system may, for example, include a file server for transmitting the computer program to the receiver.

[0131] In some embodiments, a programmable logic device (e.g., a field programmable gate array, FPGA) may be used to perform some or all of the functions of the methods described herein. In some embodiments, a field programmable gate array may cooperate with a microprocessor to perform any of the methods described herein. In general, the methods are performed in some embodiments by any hardware device. The hardware device may be any universally applicable hardware, such as a computer processor (CPU), or may be method-specific hardware, such as an ASIC.

[0132] The devices described herein may be implemented, for example, using a hardware device, or using a computer, or using a combination of a hardware device and a computer. The devices described herein, or any components of the devices described herein, may be implemented at least in part in hardware and / or in software (computer programs). The methods described herein may be implemented, for example, using a hardware device, or using a computer, or using a combination of a hardware device and a computer. The methods described herein, or any components of the methods described herein, may be configured at least in part in hardware and / or software.

[0133] The above-described embodiments merely represent illustrations of the principles of the present invention. It is understood that those skilled in the art would appreciate modifications and variations of the arrangements and details described herein. Therefore, it is intended that the present invention be limited only by the scope of the following claims and not by the specific details presented herein by way of the description and discussion of the embodiments.

Claims

1. 1. A device (100, 200, 300, 302a, 304a, 306a, 410, 420, 430, 510, 520, 530) for providing an electrical test signal (580) to perform a continuity test on an electrical path (382, 382a, 384, 384a, 386, 388a, 389a) of an object (360, 360a, 362a, 372, 372a, 374, 374a, 376, 376a), comprising: receiving a wake-up signal (570) to switch said device from a passive mode of operation to an active mode of operation; Obtaining a stop signal to switch the device from the active mode of operation to the passive mode of operation. A communication module (110, 310) configured as described above; a signal generator (120, 320, 322, 322a, 324, 324a, 326, 326a) configured to generate the electrical test signal in the active mode of operation; an energy source (130, 330, 332, 332a, 334, 334a, 336, 336a) configured to provide energy to the communication module and the signal generator; Coupling the electrical test signal to the electrical path of the object in the active mode of operation. A coupling module (140, 240, 342, 342a, 344, 344a, 346, 346a) configured as above. A device (100, 200, 300, 302a, 304a, 306a, 410, 420, 430, 510, 520, 530).

2. The device (100, 200, 300, 302a, 304a, 306a, 410, 420, 430, 510, 520, 530) of 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.

3. The device (100, 200, 300, 302a, 304a, 306a, 410, 420, 430, 510, 520, 530) of claim 1, wherein the communication module (110, 310) is configured to obtain the start signal (570) and / or the stop signal in a wired manner.

4. the energy source (130, 330, 332, 332a, 334, 334a, 336, 336a) comprises at least one of a replaceable energy storage device and / or a rechargeable energy storage device; and / or the energy source is configured to be coupled to an external power source; A device (100, 200, 300, 302a, 304a, 306a, 410, 420, 430, 510, 520, 530) according to any one of claims 1 to 3.

5. the coupling module (140, 240, 342, 342a, 344, 344a, 346, 346a) is configured to inductively couple the electrical test signal (580) to the electrical paths (382, 382a, 384, 384a, 386, 388a, 389a) of the object (360, 360a, 362a, 372, 372a, 374, 374a, 376, 376a) in the active mode of operation; and / or the coupling module (140, 240, 342, 342a, 344, 344a, 346, 346a) is configured to capacitively couple the electrical test signal (580) to the electrical paths (382, 382a, 384, 384a, 386, 388a, 389a) of the object (360, 360a, 362a, 372, 372a, 374, 374a, 376, 376a) in the active mode of operation; A device (100, 200, 300, 302a, 304a, 306a, 410, 420, 430, 510, 520, 530) according to any one of claims 1 to 4.

6. The device (100, 200, 300, 302a, 304a, 306a, 410, 420, 430, 510, 520, 530) of any one of claims 1 to 5, wherein the coupling module (140, 240, 342, 342a, 344, 344a, 346, 346a) is configured to be attached to the electrical path in a galvanically isolated manner such that the device is substantially protected from voltage and / or current spikes on the electrical path (382, 382a, 384, 384a, 386, 388a, 389a).

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

8. reducing energy consumption of the device in the passive mode of operation compared to an active mode of operation; waking up the communication module (110, 310) for a predetermined duration at regular time intervals to obtain the wake-up signal (570) in the passive operating mode. A device (100, 200, 300, 302a, 304a, 306a, 410, 420, 430, 510, 520, 530) according to any one of claims 1 to 7, configured as follows:

9. the energy source (130, 330, 332, 332a, 334, 334a, 336, 336a) comprises at least one of a replaceable energy storage device and / or a rechargeable energy storage device; the communication module (110, 310) is configured to transmit a state of charge of the energy storage device in the active operating mode; A device (100, 200, 300, 302a, 304a, 306a, 410, 420, 430, 510, 520, 530) according to any one of claims 1 to 8.

10. The device (100, 200, 300, 302a, 304a, 306a, 410, 420, 430, 510, 520, 530) of any one of claims 1 to 9, wherein the communication module (110, 310) is configured to transmit information regarding the operating state of the device.

11. the electrical test signal (580) being a high frequency signal, a radio frequency signal, a low frequency signal, and / or a clocked low frequency signal; A device (100, 200, 300, 302a, 304a, 306a, 410, 420, 430, 510, 520, 530) according to any one of claims 1 to 10.

12. The device (100, 200, 300, 302a, 304a, 306a, 410, 420, 430, 510, 520, 530) of any one of claims 1 to 11, wherein the signal generator (120, 320, 322, 322a, 324, 324a, 326, 326a) is configured to enable impedance matching to the electrical path (382, 382a, 384, 384a, 386, 388a, 389a).

13. the device comprises at least one protection diode (520); the protection diode (520) is configured to protect the device from voltage and / or current spikes on the electrical path (382, 382a, 384, 384a, 386, 388a, 389a); A device (100, 200, 300, 302a, 304a, 306a, 410, 420, 430, 510, 520, 530) according to any one of claims 1 to 12.

14. 14. The device (100, 200, 300, 302a, 304a, 306a, 410, 420, 430, 510, 520, 530) of claim 13, wherein the protection diode is a suppressor diode (520), and the suppressor diode (520) is connected in parallel with the coupling module (140, 240, 342, 342a, 344, 344a, 346, 346a).

15. The device (100, 200, 300, 302a, 304a, 306a, 410, 420, 430, 510, 520, 530) of any one of claims 1 to 14, wherein the test signal (580) comprises a modulated signal identifier.

16. the object (360, 360a) being a wind turbine having a plurality of rotor blades (372, 372a, 374, 374a, 376, 376a), each of the rotor blades having an electrical path (382, 382a, 384, 384a, 386, 388a, 389a) in the form of a lightning rod; The electrical path is a lightning rod of a rotor blade of the wind turbine. A device (100, 200, 300, 302a, 304a, 306a, 410, 420, 430, 510, 520, 530) according to any one of claims 1 to 15.

17. the coupling module (140, 240, 342, 342a, 344, 344a, 346, 346a) is configured to be attached to and / or integrated into the lightning rod of the rotor blade; and / or the coupling module (140, 240, 342, 342a, 344, 344a, 346, 346a) is configured to be attached to and / or integrated into a supply line to the rotor blades; and / or the coupling module (140, 240, 342, 342a, 344, 344a, 346, 346a) is configured to be integrated into and / or attached to a rotor blade; 17. The device (100, 200, 300, 302a, 304a, 306a, 410, 420, 430, 510, 520, 530) of claim 16.

18. the device comprises a plurality of coupling modules (140, 240, 342, 342a, 344, 344a, 346, 346a) corresponding to the plurality of rotor blades; a respective coupling module configured to couple the electrical test signal (580) to a respective rotor blade for continuity testing of a respective lightning rod; 18. A device (100, 200, 300, 302a, 304a, 306a, 410, 420, 430, 510, 520, 530) according to claim 16 or 17.

19. the device comprises a plurality of coupling modules (140, 240, 342, 342a, 344, 344a, 346, 346a) corresponding to the plurality of rotor blades; a respective coupling module configured to couple a respective electrical test signal (580) to a respective rotor blade for continuity testing of a respective lightning rod; the device comprising a plurality of signal generators (120, 322, 324, 326) corresponding to the plurality of coupling modules, each signal generator of the plurality of signal generators configured to generate a respective electrical test signal for coupling the respective electrical test signal to a respective lightning rod in the active mode of operation.

18. A device (100, 200, 300, 302a, 304a, 306a, 410, 420, 430, 510, 520, 530) according to claim 16 or 17.

20. the energy source (130, 330, 332, 332a, 334, 334a, 336, 336a) is configured to provide energy to the plurality of signal generators (120, 322, 324, 326); or the device comprises a plurality of energy sources (130, 330, 332, 332a, 334, 334a, 336, 336a) corresponding to the plurality of signal generators, each of the plurality of energy sources being configured to supply energy to a respective one of the plurality of signal generators; 20. The device (100, 200, 300, 302a, 304a, 306a, 410, 420, 430, 510, 520, 530) of claim 19.

21. 1. A system (400, 500) for providing an electrical test signal (580) to perform continuity testing of electrical paths (382, 382a, 384, 384a, 386, 388a, 389a) of an object (360, 360a), the object being a wind turbine having a plurality of rotor blades (372, 372a, 374, 374a, 376, 376a), each rotor blade having an electrical path in the form of a lightning rod, the system comprising: a plurality of devices (100, 200, 300, 302a, 304a, 306a, 410, 420, 430, 510, 520, 530) according to any one of claims 1 to 17, wherein a respective coupling module (140, 240, 342, 342a, 344, 344a, 346, 346a) of each device is configured to couple a respective electrical test signal to a respective rotor blade for continuity testing of a respective lightning rod, System (400, 500).

22. 1. A system (400, 500) for providing an electrical test signal (580) to perform a continuity test on an electrical path (382, 382a, 384, 384a, 386, 388a, 389a) of an object (360, 360a, 362a, 372, 372a, 374, 374a, 376, 376a), comprising: A device (100, 200, 300, 302a, 304a, 306a, 410, 420, 430, 510, 520, 530) according to any one of claims 1 to 20, Sending the activation signal (570) and the deactivation signal to the communication module (110, 310) of the device. A communication unit (542, 544, 546) configured as described above; a measurement unit (552, 554, 556) configured to detect said test signal (580); A system (400, 500).

23. The system (400, 500) of claim 22, wherein the communication unit is configured to be mounted on a drone (562, 564).

24. The measuring unit (552, 554, 556) Attached to drones (562, 564), Detecting the test signal (580) during a test flight of the drone along the object (360, 360a, 362a, 372, 372a, 374, 374a, 376, 376a).

24. The system (400, 500) of claim 22 or 23, configured to:

25. the object (372, 372a, 374, 374a, 376, 376a) being a wind turbine having a plurality of rotor blades (372, 372a, 374, 374a, 376, 376a), each of the rotor blades including an electrical conductor (382, 382a, 384, 384a, 386, 388a, 389a) in the form of a lightning rod; and the system: A method for testing a rotor blade according to any one of claims 1 to 17, further comprising: a plurality of devices (100, 200, 300, 302a, 304a, 306a, 410, 420, 430, 510, 520, 530) according to any one of claims 1 to 17, wherein a respective coupling module (140, 240, 342, 342a, 344, 344a, 346, 346a) of each device is configured to couple a respective electrical test signal (580) to a respective rotor blade for continuity testing of a respective lightning rod; said communication units (542, 544, 546) are configured to transmit said activation signal (570) and said deactivation signal to respective communication modules (110, 310) of respective devices; a drone (562, 564) is equipped with the measurement unit (552, 554, 556), the drone being configured to fly to the wind turbine and fly along the plurality of rotor blades; A system (400, 500) according to any one of claims 21 to 24.

26. The system (400, 500) of claim 22 or 23, wherein the measurement unit (552, 554, 556) is a portable device.

27. 1. A method (700) for performing a continuity test on an electrical path (382, 382a, 384, 384a, 386, 388a, 389a) of an object (360, 360a), comprising: Supplying (710) energy from an energy source (130, 330, 332, 332a, 334, 334a, 336, 336a) to a communication module (110, 310); Obtaining (720) an activation signal (570) by the communication module to switch from a passive mode of operation to an active mode of operation; providing (730) energy from the energy source to a signal generator (120, 320, 322, 322a, 324, 324a, 326, 326a) in the active mode of operation; generating (740) an electrical test signal (580) with the signal generator in the active mode of operation; coupling (750) the electrical test signals to the electrical paths (382, 382a, 384, 384a, 386, 388a, 389a) of the object in the active mode of operation; obtaining a stop signal by the communication module to switch from an active mode of operation to a passive mode of operation (760); The method (700).

28. transmitting said wake-up signal (570) to said communication module (110, 310) by a communication unit (542, 544, 546); Scanning the object (360, 360a) with a measurement unit (552, 554, 556); detecting the test signal (580) as the object is scanned; transmitting said stop signal to said communication module (110, 310) by said communication unit; 30. The method (700) of claim 27, further comprising:

29. flying a drone (562, 564) to the object (360, 360a), the drone having a measurement unit (552, 554, 556); transmitting said wake-up signal (570) to said communication module (110, 310) by a communication unit (542, 544, 546); Flying the drone along the object; and detecting the test signal (580) by the measurement unit as it flies along the object; transmitting said stop signal to said communication module by said communication unit (542, 544, 546); 30. The method (700) of claim 27, further comprising:

30. waking up the communication module (110, 310) at regular time intervals for a predetermined duration to receive the wake-up signal (570) in the passive mode of operation; transmitting said wake-up signal by said communication units (542, 544, 546) to said communication modules during a time span longer than the time interval between two wake-ups of said communication modules; obtaining the wake-up signal by the communication module to switch from the passive mode of operation to the active mode of operation; transmitting information regarding said operating state to said communication units (542, 544, 546) by said communication module; 30. The method (700) of claim 29, further comprising:

31. 31. The method (700) according to claim 29 or 30, wherein for each detection value of the test signal (580), at least one of time information, absolute position information of the drone (562, 564), and / or distance and / or position information of the drone relative to the rotor blades is stored together with the detection value of the test signal.

32. and comparing the detected test signal (580) to a reference signal, the reference signal comprising: Used to determine information about damage to electrical cables, a calculated signal curve of the detected test signal across said electrical paths (382, 382a, 384, 384a, 386, 388a, 389a); and / or a signal curve of the detected test signal across the electrical path measured during a previous measurement; The method (700) of any one of claims 28 to 31, wherein

33. the object (360, 360a) being a wind turbine having a rotor hub and a number of rotor blades (372, 372a, 374, 374a, 376, 376a) disposed on the rotor hub, each of the rotor blades having an electrical path (382, 382a, 384, 384a, 386, 388a, 389a) in the form of a lightning rod; A device of the plurality of devices according to any one of claims 1 to 17 is each coupled to a lightning rod of a respective rotor blade, The method further comprising: approaching the wind turbine by a drone (562, 564), the device being in the passive mode of operation when the drone approaches; sending a wake-up signal (570) by a communication unit (542, 544, 546) of the drone to a communication module (110, 310) of one of the devices to set the one of the devices in the active operating mode; coupling a test signal (580) generated by the signal generator (120, 320, 322, 322a, 324, 324a, 326, 326a) of the one device to the lightning rod of the rotor blade coupled to the one device by the coupling module (140, 240, 342, 342a, 344, 344a, 346, 346a) of the one device; Flying along the rotor blade coupled to the one device with the drone while the test signal is coupled to the lightning rod of the rotor blade; Detecting the test signal by a measurement unit (552, 554, 556) of the drone during the flight along the rotor blade; sending a stop signal by the communication unit (542, 544, 546) of the drone to the communication module (110, 310) of the one device to configure the one device back to the passive operating mode; iteratively repeating the steps of transmitting a start signal, coupling a test signal, flying along the rotor blades, detecting the test signal, and transmitting a stop signal to additional devices of the plurality of devices and to additional rotor blades coupled to the devices; Further comprising: The method (700) of any one of claims 27 to 32.

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