Patent Description:
Wind energy is often harnessed using wind turbines. However, wind turbines are subject to damage (such as leading-edge erosion or crack formation) because of factors such as: lightning, a harsh environment (e.g., temperature cycling, salt exposure, ice formation, etc.), infestation (e.g., insects), dust, algae, etc. Consequently, wind turbines require regular inspection and, as needed, maintenance.

Existing approaches to wind-turbine inspection typically involve ceasing operation of a wind turbine in order to perform visual inspection and/or measurements. However, ceasing operation of a wind turbine decreases its uptime and, thus, increases the cost of inspection. Moreover, this increased cost of inspection provides an incentive to decrease the frequency of inspection, which can adversely impact maintenance costs and/or the operating life of wind turbines. Documents <CIT> and <CIT> are prior art examples of inspection devices for a lightning-protection cable in a wind-turbine blade.

The invention discloses an integrated wind-turbine monitoring electronic device, comprising: a disconnect device configured to selectively electrically couple to a lightning-protection cable in a wind-turbine blade; and a measurement device, electrically coupled to the disconnect device, configured to perform, when the disconnect device is selectively electrically coupled to the lightning-protection cable, time-domain reflectometry measurements of lightning-protection cable by performing operations comprising: (i) providing an electrical signal to the lightning-protection cable; and (ii) measure reflected electrical signals from the lightning-protection cable. The electronic device may comprise a control logic configured to selectively provide a control signal to the disconnect device to change a state of the disconnect device from connected to disconnected and vice versa.

The measurement device can be configured to measure: an amplitude of the reflected electrical signals, a phase of the reflected electrical signals, or both. The measurement device can be further configured to analyze the measured reflected electrical signals to detect whether there is potential damage to the lightning-protection cable. The analysis can be based at least in part on a predetermined signature of the lightning-protection cable. The analysis can be performed using a pretrained predictive model, comprising a neural network; or a supervised-learning model. The analysis can be based at least in part on: a previous measurement performed on the wind-turbine blade; a previous measurement performed on a second wind-turbine blade in a wind turbine that comprises the wind-turbine blade and the second wind-turbine blade; or a previous measurement performed on a third wind-turbine blade in a different wind turbine than the wind turbine. The electronic device further comprises an orientation sensor electrically connected to the disconnect device, wherein the orientation sensor is configured to provide the electronic device data on position and/or orientation, and/or speed of rotation of the wind turbine blade. The electronic device may be further configured to be electrically coupled to the lightning-protection cable, when an orientation of the wind-turbine blade is within a range of pre-defined angles, such as angles below horizontal. The electronic device may further comprise a communication device configured to communicate the measurements to a master electronic device, or a remotely located computer.

The disconnect device may comprise a mechanical switch with a liquid conductor configured to selectively electrically couple to the lightning-protection cable for a range of orientation angles of the wind-turbine blade. The disconnect device may be configured to electrically couple to the lightning-protection cable for a range of orientation angles of the wind-turbine blade. Said range of orientation angles are preferably below a horizontal orientation of the wind-turbine blade. The electronic device may be mounted at or proximate to a root or hub of a wind-turbine blade, or inside of the hollow interior of the root or the hub, or within a wind-turbine blade, wherein the electronic device may further comprise a generator configured to provide power to the electronic device created at least in part as a result of motion of the wind-turbine blade.

An electronic device <NUM> that performs integrated monitoring of a wind turbine <NUM> (such as a land-based or an offshore wind turbine) is described. This electronic device <NUM> may be mounted at or proximate to a root or hub of a wind-turbine blade <NUM>. In some embodiments, the electronic device <NUM> may be included inside of the hollow interior of the root or the hub, or within a wind-turbine blade <NUM>. Moreover, the electronic device <NUM> may include a generator <NUM> that produces power for the electronic device <NUM> based on angular rotation of the wind turbine <NUM>.

During operation, the electronic device <NUM> may selectively electrically couple (or electrically decouple) from a lightning-protection system within a wind-turbine blade <NUM>. Notably, because a wind-turbine blade <NUM> can be struck by lightning, they often include electrical wiring inside of the hollow interior and along the length of the wind-turbine blade <NUM>. As shown in <FIG>, which presents a drawing illustrating an example of a wind-turbine blade, this lightning-protection electrical cable <NUM> or wire is coupled to the exterior surface of the wind turbine <NUM> by a set of connectors or studs (which are sometimes referred to as 'receptors') <NUM>, which are located as discrete potions along the length of the electrical wire (and, thus, the wind turbine). For example, the receptors <NUM> may be screw-type bolts, which may be made of tungsten, and which may be screwed into the wind-turbine blade <NUM> from the outside. The electronic device <NUM> may selectively electrically couple to the lightning-protection electrical cable <NUM> when the wind-turbine blade <NUM> is orientated below a horizontal direction (e.g., an orientation having an angle between <NUM>° and <NUM>°). When the wind-turbine blade <NUM> is oriented below the horizontal direction, the risk of a lightning strike on the wind-turbine blade <NUM> is reduced, which may reduce a risk of electrical damage to the electronic device <NUM>. Because the wind turbine <NUM> may have a rotation period of, e.g., <NUM>, the electronic device <NUM> may be electrically coupled to the lightning-protection cable <NUM> for up to, e.g., <NUM>.

In some embodiments, the electronic device <NUM> may selectively electrically couple (or decouple) from the lightning-protection cable <NUM> using an electrical switch, which may change its configuration based at least in part on a control signal provided by control logic in the electronic device <NUM>. However, in some embodiments, the electronic device <NUM> may selectively electrically couple (or decouple) from the lightning-protection cable <NUM> using a mercury switch. The mercury switch may electrically couple (or decouple) from the lightning-protection cable <NUM> mechanically, such as based on the gravity-induced motion of liquid mercury (or another liquid conductor). These embodiments may reduce the power consumption of the electronic device <NUM>.

When the electronic device <NUM> is electrically coupled to the lightning-protection cable <NUM>, the electronic device <NUM> may perform electronic measurements to characterize the lightning-protective system in the wind-turbine blade <NUM>. For example, the electronic device <NUM> may perform time-domain reflectometry measurements. The electronic device <NUM> may provide an electrical signal (such as an electrical pulse or a square-wave pattern) that propagates down the length of the lightning-protection cable <NUM>. The electrical signal may have a square shape with a fundamental frequency of <NUM>, a duty cycle of <NUM>%, a rise time of <NUM> ns and a fall time of <NUM> ns. Because of the electrical impedance of the lightning-protection cable <NUM> (such as the resistance, inductance and capacitance), the electrical signal may be broadened as it propagates. In addition, there may be reflections that occur at the locations of the set of receptors <NUM> and at the end of the lightning-protection cable <NUM> (near the tip of the wind-turbine blade <NUM>).

The resulting reflections of the broadened electrical pulse may be subsequently received at the electronic device <NUM>. For example, the electronic device <NUM> may: filter the reflected electrical signals (such as low-pass or bandpass filtering), amplify the reflected electrical signals, and convert the reflected electrical signals from the analog domain to the digital domain (e.g., using an analog-to-digital converter, e.g., using a sampling rate of <NUM>-<NUM> Hz and a sample resolution of <NUM> bits). The electronic device <NUM> may perform additional filtering (in the analog domain and/or the digital domain) to correct the reflected electrical signals for the transfer function or impulse response of the wind-turbine blade <NUM>. Moreover, the electronic device <NUM> may measure the amplitude and/or the phase of the reflected electrical signals. A clock signal that is used to gate the electrical signal provided by the electronic device <NUM> may be used as a reference during the time-domain reflectometry measurements, so that the phase of the reflected electrical signals can be measured. In some embodiments, the electronic device <NUM> may perform a discrete Fourier transform or another transform operation on the reflected electrical signals to determine: the amplitude of the reflected electrical signals, the phase of the reflected electrical signals, the power spectral density of the reflected electrical signal, etc. An example of measured electrical signals reflected from the cable <NUM> is shown on <FIG>.

The time-domain reflectometry measurements may be used to characterize the lighting-protection system in the wind-turbine blade <NUM>. For example, the time-domain reflectometry signature of the lighting-protection system in the wind-turbine blade <NUM> may be characterized after manufacturing, and this predetermined signature may be used a reference for subsequent comparison. Alternatively, or additionally, time-domain reflectometry measurements may be simulated and compared to the measurements to identify potential damage, such as based atleastin part on a change in a reflected electrical signal associated with a portion of the lightning-protection system associated with a receptor <NUM> at a particular location along the length of a wind-turbine blade <NUM>. In some embodiments, the analysis is performed longitudinally (such as based at least in part on measurements performed on a wind-turbine blade <NUM> at different timestamps) and/or in aggregate (such as based at least in part on measurements performed on multiple wind-turbine blades <NUM> on one or more wind turbines <NUM>). Moreover, in some embodiments, the measurements for the wind-turbine blades <NUM> in a wind turbine <NUM> may be compared to each other in the analysis. This may allow the wind-turbine blades <NUM> in a wind turbine <NUM> to be used as references or baselines in order to detect changes as a function of time (such as following a lightning strike on at least one of the wind-turbine blades <NUM>).

Alternatively, or additionally, in some embodiments, the analysis may be performed using a supervised machine-learning technique. For example, measurements performed on one or more wind-turbine blades <NUM> may be aggregated along with information indicating identified damage to the one or more wind-turbine blades <NUM>. This dataset may then be used to train a predictive model. Subsequently measurements may be input to the pretrained predictive model, which then provides an output indicating whether potential damage (or a particular type of potential damage, such as a crack, lightning damage, leading-edge damage, etc.) to a wind-turbine blade <NUM> has been identified. In some embodiments, the supervised machine-learning technique may include: a neural network (such as a convolutional neural network or another type of neural network), a support vector machine technique, a classification and regression tree technique, logistic regression, LASSO, linear regression, a neural network technique and/or another linear or nonlinear supervised-learning technique. The pretrained predictive model may include a classifier or a regression model. Moreover, the pretrained predictive model may be updated or retrained as more measurements are performed on the one or more wind-turbine blades <NUM>.

In some embodiments, there may be a separate instance of the electronic device <NUM> in or associated with each wind-turbine blade <NUM> in a wind turbine <NUM>. For example, in a wind turbine <NUM> with three wind-turbine blades <NUM>, there may be three instances of the electronic device <NUM>. Alternatively, or additionally, in some embodiments, a single instance of the electronic device <NUM> may be dynamically shared by two or more wind-turbine blades <NUM> in a wind turbine <NUM>. Thus, the single instance of the electronic device <NUM> may be used to perform measurements on a given wind-turbine blade <NUM> when the given wind-turbine blade <NUM> has an orientation between <NUM>° and <NUM>° (or ±<NUM>° about the downward vertical axis).

Moreover, as shown in <FIG>, which presents a drawing illustrating an example of a wind turbine <NUM>, in some embodiments the electronic device <NUM> may perform the measurements and may use wirelessly (or wired) communication to convey the measurements to a master electronic device <NUM> located proximate to the wind turbine <NUM> (e.g., in a base or tower of the wind turbine). This master electronic device <NUM> may communicate, e.g., via a network <NUM>, such as a cellular-telephone network, the Internet, the measurements from the wind-turbine blades <NUM> in the wind turbine <NUM> to a remotely located computer <NUM> (such as a cloud-based computer system). In these embodiments, at least some of the analysis of the measurements (such as the identification of the potential damage) may be performed by the master electronic device <NUM> and/or the remotely located computer <NUM>. Thus, in general, the analysis may be performed in a centralized and/or in a distributed manner.

Furthermore, when potential damage of a wind-turbine blade is identified or detected, the remotely located computer <NUM>, the master electronic device <NUM> and/or the electronic device <NUM> may perform a remedial action. For example, the remedial action may include provide a notification about the potential damage to an operator of the wind turbine <NUM> and/or a third party that performs inspection and/or maintenance on the wind turbine <NUM> (such as providing the notification to an inspection device associated with the third party). The notification may include: recommending visual inspection of the wind-turbine blade, recommending maintenance of the wind-turbine blade, replacement of the wind-turbine blade and/or another operation. In some embodiments, the notification may specify a type of the potential damage and/or an approximate location (along the wind-turbine blade <NUM>) of the identified potential damage. The analysis may indicate a range of locations along the wind-turbine blade <NUM> where the identified potential damage is expected.

While the preceding discussion illustrated the integrated inspection techniques with time-domain reflectometry measurements, a wide variety of measurements and physical properties may be used to assess or monitor the wind-turbine blade <NUM>. For example, the measurements may include: electrical impedance, resistance, inductance, capacitance, etc. Moreover, these measurements may be performed in the analog domain and/or in the digital domain.

In some embodiments, the lightning-protection system in a wind-turbine blade may include components that facilitate the analysis, such as the identification of the potential damage, the type of potential damage and/or a location (or a range of locations) of the potential damage. For example, electrical components that undergo a change in a physical property (such as a dielectric disk having an associated capacitance) following one or more instances of heating (such as each instance) associated with the large electrical currents associated with one or more instances of a lightning strike may be included in the set of connectors or studs and at discrete locations along the length of the electrical wire. The change in the physical property may allow the location of a lightning strike on a wind-turbine blade to be spatially localized. Note that the electrical components may not be destroyed or damaged by the lightning strike. Consequently, the electrical components may not need to be replaced, thereby allowing such spatial localization of instances of the lightning strike (and, thus, potential damage to a wind-turbine blade <NUM>) to be performed over the operating life of the wind-turbine blade <NUM>. In some embodiments, temperature sensors or probes (e.g., using optical fibers) may be included in the wind-turbine blade <NUM>, which may allow the transient temperature increase following an instance of a lighting strike to be detected, and thus the location(s) of potential damage to a wind-turbine blade <NUM> to be localized.

While preceding discussion illustrated the use of electrical measurements to monitor or inspect the wind-turbine blade <NUM>, more generally the electronic device <NUM> may monitor or assess the wind-turbine blade <NUM> using a variety of measurements, which may be used instead of or in addition to the electrical measurements. Notably, the measurements performed by the electronic device <NUM> may include: pressure measurements, humidity measurements, acoustic measurements (and, more generally, sonic measurements), vibration measurements, acceleration measurements, orientation measurements (e.g., using a gyroscope or a magnetometer), temperature measurements, electrical measurements (such as time-domain reflectivity measurements, S-parameter frequency-domain measurements, radio-frequency transmission using a phased-antenna array on the ground, in a wind-turbine tower or in a wind-turbine blade, etc.), monitoring of a lightning-protection system, displacement measurements (such as distance or three-dimensional sensing of, e.g., wind-turbine blade flexibility), crack measurements, spark-gap measurements (such as using an external, e.g., ground or drone-based, marx generator and an antenna array), mechanical or electrical noise measurements, connector, stud or receptor measurements, optical-fiber measurements, image measurements (e.g., using a visible spectra, ultraviolet or infrared camera, a spectral camera, a passive camera, a flash or thermal impulse-assisted camera), strain measurements (e.g., using a smart nut or bolt or an optical fiber installed at a particular location in a wind-turbine blade), MEMS-based measurements, iterative measurements following mechanical assistance or repairs (such as fixing a crack or a cable, etc.) and/or another type of measurement. For example, the acoustic or sonic measurements may be performed using: a single sensor (such as a microphone), a multi-sensor, or a phased microphone array. In some embodiments, the measurements may be facilitated using active elements (such as elements that have a temporarily or permanently change to a physical property after an instance of lightning). Note that for radio-frequency transmission using a phased-antenna array on the ground, the lightning cable mounted inside a wind-turbine blade may be used as an antenna. In particular, a phased-antenna array on the ground may be able to assess the power radiated by each part of the lightning cable. Therefore, such an antenna array may be able to detect the exact shape of the radiation pattern, which may be used to evaluate if all parts of the lighting system are radiating. If some parts are not radiating (or have a change in their radiation pattern), this may indicate that they are disconnected from the main conductor (or that the impedance of their connection has changed) and that is repair is needed.

In some embodiments, the measurements may be performed passively, such as based at least in part on the vibrations of a wind-turbine blade associated with airflow, wind direction and, more generally, the aerodynamics of the wind-turbine blade <NUM>. For example, the electronic device <NUM> may measure: resonance frequencies, damping, noise, sound waves or tones in the hollow interior of the wind-turbine blade <NUM>, etc. The aerodynamics may depend on factors such as: the wind magnitude, the wind direction, an angle of the wind-turbine blade, weather conditions (such as humidity, temperature, etc.), leading-edge quality (and, thus, potential damage), etc. Alternatively, or additionally, in some embodiments, the measurements may be performed actively, such as by using mechanical tapping or an acoustic or ultrasound source. The electronic device <NUM> may apply a mechanical impulse or a sound wave to the wind-turbine blade, and the electronic device <NUM> may perform measurements of: the induced acoustic reflections, the mechanical transfer function, frequency response, resonance frequencies, damping, etc. Once again, the analysis of the measurements may involve comparison to at least another wind-turbine blade in the same wind turbine and/or to a predetermined signature of the wind-turbine blade. In general, measurements performed by the electronic device <NUM> may be made using one or more sensors, probes or measurement devices <NUM> that are included in the electronic device and/or the are coupled (e.g., electrically or optically) to the electronic device <NUM>. Thus, the one or more sensors, probes or measurement devices <NUM> may be remotely located from the electronic device <NUM>.

We now further discuss embodiments of the integrated inspection techniques. Notably, the electronic device <NUM> may provide a set of wind turbine <NUM> monitoring tools to achieve higher sampling rate monitoring of a wind-turbine blade <NUM> without the need to stop the turbine <NUM> for inspections. A wind-turbine blade <NUM> that includes an instance of the electronic device <NUM> is sometimes referred to as a 'smart blade.

As shown in <FIG>, which presents a drawing illustrating a wind-turbine blade <NUM>, in embodiments of integrated monitoring of a lightning-protection system in a wind-turbine blade <NUM>, an electronic device <NUM> that performs time-domain reflectometry measurements may be mounted inside a wind-turbine blade <NUM> and selectively electrically coupled to a lightning-protection cable <NUM>. A disconnect device <NUM> (such as a switch or a relay) may be installed between the electronic device <NUM> and the lightning-protection cable <NUM> to keep the electronic device <NUM> disconnected or electrically decoupled from the lightning-protection cable <NUM> at most times, but electrically coupled to the lightning-protection cable <NUM> when an instance of a measurement is performed. This selective and dynamic electrical coupling may protect the electronic device <NUM> in case lightning strikes the wind-turbine blade <NUM>.

Moreover, a mechanical power generation unit <NUM> may be included in the electronic device <NUM> or the wind-turbine blade <NUM> to provide power for the electronic device <NUM> and the disconnect device <NUM>. Furthermore, the electronic device may include a communication device <NUM> that is capable of wireless communication. Additionally, an orientation sensor <NUM> may be included in the disconnect device <NUM>, so that the electronic device <NUM> may be electrically coupled to the lightning-protection cable <NUM> when an orientation of the wind-turbine blade <NUM> is within a range of angles (such as angles below horizontal). This may reduce the possibility of the electronic device <NUM> being damaged from an instance of a lightning strike. The orientation sensor <NUM> can be configured to provide the electronic device <NUM> data on location and/or orientation, and/or speed of rotation of the wind turbine blade <NUM>. This data can be used to determine whether the wind turbine blade <NUM> is rotating or not, what is its position in respect to the line of horizon, what is its speed of rotation, how many revolutions has made the wind turbine blade <NUM>. Depending on the needs, this information may further be used by the electronic device <NUM> to calculate when the electronic device <NUM> should be connected to and/or disconnected from the lightning-protection cable <NUM>. According to one embodiment, the electronic device may be configured to provide a command to electrically connect it to the lightning-protection cable <NUM>, when the wind turbine blade <NUM> has made certain number of revolutions (e.g. each <NUM> of revolutions), thereby ensuring regular measurement of the lightning-protection cable <NUM>, and/or to provide a command to electrically connect the electronic device <NUM> to the lightning-protection cable <NUM>, when the wind turbine blade <NUM> is positioned below a horizontal orientation.

An energy storage device <NUM> (such as a rectifier and a battery) may be used to accumulate generated electricity and to provide it to the electronic device <NUM> and/or the disconnect device <NUM> when the wind-turbine blade <NUM> is not rotating or providing sufficient mechanical energy to the power generation unit <NUM>.

During an instance of the measurement, the electronic device <NUM> may provide an electrical signal into the lightning-protection cable <NUM> and then may measure the reflected electrical signals (which are sometimes referred to as a signature). Instance of the signature may be measured periodically (such as every half-rotation period or the wind turbine blade <NUM>) or as-need and wirelessly reported (e.g., to the master electronic device <NUM>), such as when a change in the signature (relative to a predetermined signature) is detected. In general, a change in the signature may indicate that a physical property of the lightning-protection cable <NUM> has changed and that a new inspection of the wind-turbine blade <NUM> is needed.

<FIG> present drawings illustrating an example of the disconnect device <NUM>. The disconnect device <NUM> may include: a hinge <NUM> having a rotation center point; a rotating lever <NUM> with connection points; a permanent magnet34; an electro-magnet <NUM>, a cable <NUM> to the electronic device <NUM> that performs the measurements; a connection socket one <NUM>; a connection socket two <NUM>; a cable <NUM> to the lightning-protection cable; and connection points <NUM> that go into connection sockets one <NUM> and two <NUM>. The disconnect device <NUM> may be installed on or inside of a wind-turbine blade <NUM>. The hinge <NUM>, the permanent magnet <NUM>, the electromagnet <NUM>, the cable <NUM>, the connection sockets one <NUM> and two <NUM> may have fixed positions relative to the wind-turbine blade <NUM>, and the rotating lever <NUM> may be connected with the hinge <NUM> at the rotation center point.

The rotating lever <NUM> is typically connected to the permanent magnet <NUM>, and may rotate together with the wind-turbine blade <NUM>. As shown in <FIG>, the permanent magnet <NUM> may be strong enough to keep the rotating lever <NUM> attached at all wind-turbine blade rotation angles. This may also mean that the connection sockets one <NUM> and two <NUM> remain disconnected most of the time.

As shown in <FIG>, in order to connect connection sockets one <NUM> and two <NUM> to make measurements, a short impulse may be sent to the electro-magnet <NUM> at blade <NUM> rotation angle when the rotating lever <NUM> is parallel to the ground (or the horizontal orientation) on the right side of the hinge <NUM> (as shown in <FIG>). The electro-magnet <NUM> may pull the lever <NUM> and overcome the force of the permanent magnet <NUM>. As the lever <NUM> gets disconnected from the permanent magnet <NUM>, gravity may pull it down and connect the connection sockets one <NUM> and two <NUM> with the connection points <NUM>. Both connection points <NUM> may be connected by the lever <NUM>, thereby providing electrical connections to connection sockets one <NUM> and two <NUM>.

Moreover, as shown in <FIG>, as the wind-turbine blade <NUM> continues rotation (e.g., clockwise), after <NUM>° of rotation the lever <NUM> is on the left side of the hinge <NUM>. Gravity then pulls it out of the connection sockets one <NUM> and two <NUM> and it may fall back and connect with the permanent magnet <NUM>.

The disconnection device <NUM> may offer several benefits, including: it may not consume electricity in a standby state; in order to establish a connection only a short electro-magnetic pulse is needed; the isolation distance is relatively large; it may be very reliable because there are few moving components; and/or it may ensure that a connection will be made only when the wind-turbine blade <NUM> has an orientation below horizontal (e.g., when it is pointing downward).

In some embodiments, the electronic device <NUM> may perform measurements using receptors <NUM> monitoring. For example, an optical-fiber thermometer (which may include a gallium arsenide (GaAs) semiconductor crystal) may be attached to each wind-turbine blade receptors <NUM>. The optical fiber may be routed to the nearest processing unit (such as the electronic device <NUM>, which may be located near the root of the wind-turbine blade <NUM>). In case of a lightning strike, the receptors <NUM> will heat up and this may be detected by the optical-fiber thermometer. A similar component or device may be attached to the main lightning-protection cable <NUM> near the root of the wind-turbine blade <NUM>. By detecting instances of lightning on the main lightning-protection cable <NUM> and on the connectors or receptors <NUM>, it may be possible to detect if a lightning strike hit a particular connector or receptor <NUM> or did damage to the wind-turbine blade <NUM>.

As noted previously, separately or in addition to the time-domain reflectometry measurements, the electronic device <NUM> may perform one or more other types of measurements. For example, in order to monitor a drainage hole in the wind-turbine blade <NUM>, the electronic device <NUM> may include a humidity sensor and/or an air-pressure sensor. While it may be difficult to monitor the drainage hole directly, it may be possible to assess its functionality by measuring the overall humidity level in the wind-turbine blade <NUM>. Moreover, a pressure sensor may be used to measure pressure changes for a stationary and a rotating wind-turbine blade <NUM>. Notably, because the drainage hole is mounted on a low-pressure position of the wind-turbine blade <NUM>, rotating the wind-turbine blade may lower the overall pressure inside the wind-turbine blade <NUM>.

Alternatively, or additionally, the electronic device <NUM> may include one or more image sensors (such as a visible or an infrared camera). For example, a pan, tilt and zoom camera may allow the electronic device <NUM> to inspect the wind-turbine blade for cracks (e.g., at the root). In some embodiments, the electronic device <NUM> may include a light source, which may be synchronized to operation of the one or more image sensors for efficient power usage.

In yet some embodiments, the electronic device <NUM> may include or may be coupled to one or more microphones. For example, one or more optical-fiber microphones may be installed inside the wind-turbine blade <NUM> at different locations. As the wind-turbine blade <NUM> rotate, it may create turbulence in the air that results in specific sound vibrations. If the wind-turbine blade <NUM> is damaged, then the turbulence may change, which in turn may change the sound. Note that the leading-edge erosion level may be detected based at least in part on the change in the sound.

Moreover, in some embodiments, the electronic device <NUM> may perform measurements that detect potential cracks in the wind-turbine blade <NUM>. Typically, wind-turbine blades <NUM> are made out of webs that are glued to an outer shell in order to achieve lightweight and a strong structure. However, if a web gets disconnected from the outer shell, then the wind-turbine blade <NUM> may break. Currently, inspection is done using internal inspection robots or humans that go inside the wind-turbine blade <NUM> and look for cracks in the joint sections. As shown in <FIG>, which presents a drawing illustrating an example of a wind-turbine blade <NUM>, in the disclosed integrated inspection techniques there may be displacement sensors (such as optical displacement sensors) that are located (e.g., glued) at joint locations <NUM>, <NUM>, <NUM> and <NUM>. Moreover, serially connected optical fibers may connect the optical displacement sensors. The electronic device <NUM> may perform displacement measurements via the optical fibers (e.g., via a reflective termination of an optical fiber or a returning loop).

Furthermore, in some embodiments, the electronic device <NUM> may perform integrated inspection of a wind-turbine blade <NUM> in conjunction with an internal crawler robot or drone. For example, a crawler robot or drone may be installed inside of a wind-turbine blade <NUM> for visual or other inspection. Different techniques may be used to move the crawler robot or drone inside the wind-turbine blade <NUM>. The crawler robot or drone may wait for low wind conditions when the wind-turbine blade <NUM> is stationery before moving and performing measurements. Alternatively, or additionally, a rail or rope may be installed inside the wind-turbine blade <NUM> and the crawler robot or drone may use wind-turbine blade <NUM> rotation for its advantage to move along the length of the wind-turbine blade <NUM>. If the crawler robot or drone wants to move away from the root of the wind-turbine blade <NUM> towards the tip, then it may wait when the tip is pointing downwards and then ease or release a brake to slide towards the tip. In order to get back, the crawler robot or drone may ease or release a brake when the tip of the wind-turbine blade is pointing up or vertically.

Additionally, in some embodiments, the integrated inspection techniques may be used with a ground-based inspection device (such as a ground-based lightning-protection inspection device). For example, a system may include: a transportation vehicle, a high-voltage generator, a winch, an electrical cable and a drone that is used to generate a high-voltage spark for a wind-turbine lightning-protection system test.

The drone may be tethered to the winch with a light, but conductive cable. Moreover, the winch may be positioned on top of the high-voltage generator. Furthermore, the high-voltage generator may be optionally mounted on an elevated isolation platform. Additionally, the drone may include multiple image sensors (such as cameras).

As shown in <FIG>, which presents drawings illustrating a lightning-protection system test, during operation the drone may be flown up to a height that is, e.g., about one meter below the tip of the wind-turbine blade <NUM>. Then, the high-voltage generator may charge to a voltage that can create spark exceeding the distance from the drone to the tip of the wind-turbine blade <NUM>. If the wind-turbine blade <NUM> has a working lightning-protection system, then flash-over will happen from the drone to the tip of the wind-turbine blade <NUM>. This flash-over may be photographed with several cameras to assess the spark length. Moreover, the spark length may be analyzed to determine the spark-gap sizes inside the wind-turbine blade. Additionally, an antenna cluster may be set up on the ground to triangulate and locate or determine the spark locations and sizes.

While the preceding embodiments were illustrated with particular architectures, in other embodiments there may be: fewer or additional components, positions of one or more components may be changed, two or more components may be combined, and/or a single component may be divided into two or more components. Furthermore, while the embodiments of the integrated inspection techniques were illustrated with particular operations, in other embodiments, there may be fewer or additional operations, the order of at least two operations may be changed, two or more operations may be combined, and/or a single operation may be divided into two or more operations.

In the preceding embodiments, some components are shown directly connected to one another, while others are shown connected via intermediate components. In each instance the method of interconnection, or 'coupling,' establishes some desired electrical communication between two or more circuit nodes, or terminals. Such coupling may often be accomplished using a number of circuit configurations, as will be understood by those of skill in the art, for example, AC coupling and/or DC coupling may be used.

In some embodiments, functionality in these circuits, components, electronic devices and/or computers is implemented in hardware and/or in software as is known in the art. For example, some or all of the functionality of these embodiments may be implemented in one or more: application-specific integrated circuit (ASICs), field-programmable gate array (FPGAs), graphics processing units (GPUs) and/or one or more digital signal processors (DSPs). Furthermore, the circuits and components may be implemented using bipolar, PMOS and/or NMOS gates or transistors, and signals in these embodiments may include digital signals that have approximately discrete values and/or analog signals that have continuous values.

Claim 1:
An integrated wind-turbine monitoring electronic device (<NUM>), comprising:
a disconnect device (<NUM>) configured to selectively electrically couple to a lightning-protection cable (<NUM>) in a wind-turbine blade (<NUM>); and
a measurement device (<NUM>), electrically coupled to the disconnect device (<NUM>), configured to perform, when the disconnect device (<NUM>) is selectively electrically coupled to the lightning-protection cable (<NUM>), time-domain reflectometry measurements of lightning-protection cable (<NUM>) by performing operations comprising: (i) providing an electrical signal to the lightning-protection cable (<NUM>); and (ii) measure reflected electrical signals from the lightning-protection cable (<NUM>); wherein the electronic device (<NUM>) being characterized in that it further comprises an orientation sensor (<NUM>) electrically connected to the disconnect device (<NUM>), wherein the orientation sensor (<NUM>) is configured to provide the electronic device (<NUM>) data on position and/or orientation, and/or speed of rotation of the wind turbine blade (<NUM>).