Device for acoustic detection of electric arcs

Abstract

The present invention relates to an apparatus for acoustic detection of an electric arc, the apparatus comprising a tubular probe (10) adapted to be positioned next to an electrical device on which an electric arc (AR) may be formed. An internal space (12) defined by a wall (4) of the probe extends along the length of the probe (10). The internal space (12) is filled with fluid and is acoustically isolated from external noise by the wall (4). The probe (10) includes at least one vulnerable region (15) located around the internal space (12) and on the wall (4) of the probe (10), the at least one vulnerable region (15) being adapted to degrade under the action of the electric arc (AR) to expose a channel (16) for acoustic waves (OA) generated by the electric arc to pass into the internal space. The device also includes at least one acoustic sensor (7) adapted to detect sound waves traveling through the channel (16) and propagating in the internal space (12) of the probe.

Description

Technical Field

[0001] The field of this invention relates to electrical devices that may generate electric arcs, particularly cables.

[0002] More specifically, this invention relates to techniques for acoustic detection of electric arcs. Background Technology

[0003] In many industries, especially the aerospace industry, electrical wires are critical components of electrical systems. Various phenomena, such as cables becoming brittle over time, manufacturing defects within the cable, assembly problems, or even voltage overloads on external components, can lead to electric arcing on the cable. In turn, electric arcing can be a source of brittleness, persistent damage, or interference (electrical or electromagnetic interference) in electrical systems.

[0004] In order to intervene as quickly as possible, manufacturers are looking for technologies to detect the occurrence of electric arcs.

[0005] Arc detection techniques based on current and voltage measurements are the most common. However, these techniques face the complexity of wiring (too many cables, uncertain wiring, etc.). This has led to the search for alternative or complementary detection techniques.

[0006] Patent documents EP3232212, EP2896969, and EP3264116 describe devices for detecting electric arcs in electrical equipment, based on the detection of sound waves generated when an arc occurs. These devices are placed as close as possible to the potential location of an arc (in contact with electrical terminals or within the electrical module of the equipment) to detect the presence of an arc at that location. Therefore, these devices are unsuitable for detecting arcs over long distances, particularly arcs over cables several meters or tens of meters long. These devices make it even more impossible to pinpoint the location where an arc forms on a cable.

[0007] Therefore, a detection device is needed that at least partially overcomes the above-mentioned shortcomings. Summary of the Invention

[0008] This invention relates to an apparatus for the acoustic detection of electric arcs. The apparatus includes a tubular probe adapted to be positioned adjacent to an electrical device on which an electric arc may form. An internal space defined by the walls of the probe extends along the length of the probe. This internal space or cavity is filled with fluid and is acoustically isolated from external noise by the walls. The probe includes at least one vulnerable region surrounding the internal space and located on the walls of the probe, the vulnerable region being adapted to degrade under the influence of an electric arc, thereby exposing a pathway for sound waves generated by the arc to enter the internal space.

[0009] The device also includes at least one acoustic sensor adapted to detect sound waves traveling through the channel and propagating in the internal space of the probe.

[0010] The tubular probe is hollow to allow sound waves to propagate through its internal space before reaching the acoustic sensor.

[0011] The probe can extend a long distance, such as several meters. Because sound waves propagate inside the probe, they can be detected at a great distance from where the arc is formed (thus detecting the presence of the arc).

[0012] Therefore, this device allows for remote detection of the presence of electric arcs on electrical equipment. Specifically, the device can be used to detect the presence of electric arcs along one or more cables, in which case probes are positioned alongside and along the cables. When the cables are assembled into a harness, the probes can be integrated into the harness.

[0013] The fluid filling the internal space of the probe can be air. Air has a clear advantage in avoiding fluid loss and leakage. However, other fluids (gases, liquids, or gels) can also be used as long as the viscosity is not too high. In fact, the lower the fluid viscosity, the greater the distance the sound waves can travel. To improve detection speed, fluids that allow sound waves to travel faster than air can also be used. This is especially true for helium and, in general, for any gas with a specific ideal gas constant higher than that of air.

[0014] When the fluid is a gas, the acoustic sensor can be a microphone.

[0015] The probe's walls are generally tubular in shape. These walls surround the probe's internal space and can be single-layered or multi-layered.

[0016] The probe has one or more vulnerable areas on the wall. Each vulnerable area is adapted to be at least partially degraded by the electric arc, thereby exposing a channel leading to the probe's internal space. Sound waves generated by the electric arc can then penetrate through this channel into the probe's internal space and propagate therein.

[0017] In some embodiments, the at least one vulnerable region is a fusible region adapted to at least partially melt under the heat generated by the electric arc. However, in addition to melting, material degradation, such as deformation or cracking, can also be considered without departing from the scope of the invention. It is sufficient that the degradation of the vulnerable region caused by the electric arc results in a channel for acoustic waves to pass through the internal space of the probe.

[0018] When a probe has a vulnerable region, the vulnerable region can extend along the probe. For example, the vulnerable region can extend parallel to the probe's axis or extend spirally around the axis. When a probe has multiple vulnerable regions, these vulnerable regions can be distributed regularly or irregularly along the probe.

[0019] In some embodiments, the at least one fusible region is formed of a fusible film that covers the opening through the wall. When intact (i.e., unmelted), this film seals the opening and helps isolate the probe's internal space from external noise. By melting under the heat generated by the electric arc, the film releases the opening, allowing sound waves generated by the arc to reach and propagate within the probe's internal space.

[0020] In some implementations, the fusible membrane has the ability to shrink under heat, so there is no risk of the membrane blocking the probe opening or internal space when it melts. Therefore, the probe opening and internal space remain open to allow sound waves to propagate.

[0021] In some implementations, a fusible film covers the entire wall from the outside or the inside. In other words, the film forms an inner or outer sheath around the probe wall. Among other advantages, this configuration simplifies probe fabrication while enhancing isolation from external noise outside the vulnerable area.

[0022] In some embodiments, the at least one vulnerable region is formed by a region of reduced wall thickness. Because of the reduced thickness, this region is more vulnerable than the rest of the wall and deteriorates under the influence of an electric arc.

[0023] When an electric arc is formed at an electrical device, it degrades a vulnerable area, creating a channel leading to the internal space. Sound waves generated by the arc travel through this channel and propagate within the probe's internal space to an acoustic sensor located at a distance from the vulnerable area.

[0024] The acoustic sensor can be in contact with the internal space of the area, that is, directly connected to the space, or indirectly connected to the space via a connection. For example, in some embodiments, a tube extends from the internal space of the probe through the wall to the acoustic sensor. Sound waves then travel through the internal space, then through the tube, and then reach the acoustic sensor. This allows the acoustic sensor to be positioned at a distance from the probe. This configuration is advantageous, for example, when the probe is integrated into a cable harness. The acoustic sensor can then be positioned on the periphery of the harness or outside of it. To facilitate sensor positioning, the tube can be flexible.

[0025] In some implementations, the acoustic sensor is suitable for detecting sound waves with frequencies less than 1000 Hz, particularly less than 500 Hz. Low-frequency sound waves are preferred because the amplitude attenuation decreases as the wave propagates within the probe's internal space.

[0026] In some implementations, the cross-section of the probe's internal space is large enough that the acoustic attenuation along the probe for waves with frequencies between 100 Hz and 500 Hz is less than 2 dB / m. This allows the acoustic sensor to be positioned considerably far from the vulnerable area. For example, the distance between the acoustic sensor and the vulnerable area (i.e., the area furthest from the sensor if multiple vulnerable areas exist) can be several meters, or even ten meters or more.

[0027] This distance can be greater than two meters (2m), and even more specifically, it can be greater than five meters (5m).

[0028] In some embodiments, the device further includes a computing unit configured to determine the propagation time of sound waves from the deteriorated vulnerable area to the acoustic sensor based on measurement signals from the acoustic sensor, and to infer the location of the electric arc based on the propagation time. When the device is used with cables, this allows for the location of an electric arc forming on the cable.

[0029] The present invention also relates to a component comprising the detection device as described above and a wire harness including a plurality of cables, wherein a probe is integrated into the wire harness and arranged along the cables. Specifically, the cables of the wire harness may be distributed circumferentially around the probe.

[0030] In such a component, the detection device allows for the detection of arc formation at any point in the cable.

[0031] The features and advantages of the invention described above, as well as other features and advantages, will be explained in the following detailed description, which takes into account the accompanying drawings. Attached Figure Description

[0032] The accompanying drawings are schematic and not necessarily drawn to scale; they are primarily intended to illustrate the principles of the invention. In these drawings, the same elements (or portions of elements) are identified by the same reference numerals from one figure to another.

[0033] [ Figure 1 This diagram shows an example of a wire harness in cross-section.

[0034] [ Figure 2 This diagram illustrates the process of an electric arc forming at one of the cables in this cable harness. Figure 1 The wiring harness in the middle.

[0035] [ Figure 3This figure shows an example of an acoustic arc detection device in axial cross section.

[0036] [ Figure 4 This figure shows another example of an acoustic arc detection device in axial cross section.

[0037] [ Figure 5 This diagram illustrates the process of arc formation. Figure 4 The device in the middle.

[0038] [ Figure 6 The diagram shows Figure 5 The propagation of sound waves generated by an electric arc in the device.

[0039] [ Figure 7 The figure is shown in a top view along the direction of arrow VII. Figure 3 or Figure 4 The probe of the device.

[0040] [ Figure 8 This diagram illustrates the process of arc formation. Figure 7 The probe in the middle.

[0041] [ Figure 9 This figure shows the theoretical sound attenuation in the air inside pipes with different inner diameters, depending on the frequency of the sound waves propagating in the pipe.

[0042] [ Figure 10 This figure shows another example of an acoustic detection device used for electric arcs. Detailed Implementation

[0043] The specific embodiments of the proposed detection device are described in detail below with reference to the examples shown in the accompanying drawings. These embodiments illustrate the features and advantages of the invention. However, it should be noted that the invention is not limited to these embodiments.

[0044] In these embodiments, the detection device includes a tubular probe 10 adapted to be positioned next to electrical equipment (particularly cable 1). The probe 10 is hollow, with its walls 4 surrounding and defining an internal space 12. This internal space 12 is filled with a fluid, in this example, air.

[0045] In the illustrated example, without external mechanical stress, probe 10 has a general shape of a rotating cylinder that rotates about axis X. The side surface or cylinder surface of probe 10 corresponds to the outer surface of wall 4. The internal space 12 or cavity of probe extends along axis X. The internal space 12 has a diameter D1 corresponding to the inner diameter of probe 10. Probe 10 can be flexible enough to bend, in which case axis X becomes curved. Probe 10 includes a vulnerable zone 15 distributed along the probe, which is located on the periphery of the internal space 12 of probe 10 and on wall 4. The vulnerable zone 15 can be regularly distributed according to the spacing E.

[0046] The device also includes at least one acoustic sensor, which in this example is a microphone 7 with a diaphragm, connected to the interior space 12 via a tube 6.

[0047] Figure 1 This is a cross-sectional view of an example of a wire harness 20 including multiple cables 1. These cables are grouped into bundles within the enclosure 2. A probe 10 is integrated at the center of the wire harness 20, and the cables 1 are distributed circumferentially around the probe 10. The cables 1 are in contact with the probe 10 or are very close to the probe 10.

[0048] Figure 2 Is with Figure 1 The same cross-sectional view shows the formation of an electric arc AR at one point in cable 1. The electric arc AR is schematically represented by a cone. The electric arc AR emits an intense but localized thermal field. For example, for an arc greater than 50 amperes (A), the temperature can reach over 700°C, and the thermal gradient can reach 500°C / mm from the start of the arc. Probe 10 is located near cable 1 where the electric arc AR is formed, and the temperature on the surface of probe 10 can reach several hundred degrees (°C).

[0049] The vulnerable region 15 of probe 10 is adapted to degrade under the heat generated by the electric arc (AR), thus creating a channel 16 leading to the internal space 12 of the probe. The acoustic wave (AO) generated by the electric arc will then pass through this channel 16 (see...). Figure 5 and Figure 6 (Example).

[0050] The vulnerable region 15 of the probe 10 can be generated in different ways. According to an exemplary embodiment (not shown), the wall 4 of the probe 10 is made of different materials, which are more or less heat-resistant, and at least one of the most heat-sensitive materials is likely to be degraded or destroyed by the thermal field generated by the arc AR. The vulnerable region 15 is made of this sensitive material, while the rest of the wall 4 is made of at least one more heat-resistant material.

[0051] according to Figure 3In another exemplary embodiment shown, the probe 10 has a uniform composition, and the vulnerable region 15 is the region where the thickness of the wall 4 is reduced. The reduction in thickness is manifested by the presence of a hollow or cavity 25 at the vulnerable region 15. The cavity 25 may exist on the inner surface of the wall 4, such as... Figure 3 As shown. Cavity 25 can also be formed on the outer surface of wall 4, especially for practical manufacturing reasons.

[0052] according to Figures 4 to 6 In another exemplary embodiment shown, the wall 4 is repeatedly perforated with holes 5 of diameter D2, and the wall 4 is surrounded by a non-perforated membrane 3. In other words, the membrane 3 encloses the wall 4 from the outside. The membrane 3 is fusible, meaning that the membrane 3 is suitable for melting under the heat generated by the electric arc. The melting temperature of the material constituting the membrane 3 is lower than the temperature emitted by the electric arc AR, while the melting temperature of the material constituting the wall 4 is higher than the temperature emitted by the electric arc AR.

[0053] Figure 5 The image shows the electric arc AR appearing near probe 10 and the radiation of the acoustic wave OA generated by the arc AR. The heat generated by the arc AR causes the portion of membrane 3 closest to the arc to melt, thereby exposing one of the holes 5. The uncovered hole 5 then forms a channel 16 for the acoustic wave OA to enter the internal space 12.

[0054] The melting of membrane 3 will not cause the pores 5 to be filled, because channels 16 will not be formed in this case. To avoid this, for example, membrane 3 is chosen to be thin enough that the molten material cannot fill the pores 5. Alternatively or additionally, the material constituting membrane 3 can be chosen such that membrane 3 shrinks upon melting.

[0055] The probe wall 4 may have more or less flexibility, depending on the intended use. For example, the wall 4 may have sufficient flexibility to adapt to a given harness configuration 20.

[0056] For example, wall 4 can be made of polymers (e.g., elastomers, silicone, fluoropolymers) or metals. Membrane 3 itself can be made of acrylonitrile butadiene styrene (ABS), polyoxymethylene (POM), or polyethylene (PE). For example, a stretchable polyethylene membrane 3 with a thickness between 15 and 30 micrometers (its melting temperature is between 85°C and 140°C) can be associated with a flexible silicone wall 4 with a thickness of at least 1 mm (its melting point is in the range of 300°C). According to another example, wall 4 can be made of polytetrafluoroethylene (PTFE) (its melting point is in the range of 330°C).

[0057] After the membrane 3 is melted and the arc AR is detected, a strip or a sheet of membrane 3 can be deposited on the exposed hole 5 to cover the exposed hole 5 so that the probe 10 can be reused.

[0058] Figure 6 The diagram illustrates the transmission of acoustic wave OA through channel 16 formed by exposed holes 5, its propagation within internal space 12 on either side of holes 5, and its propagation in tube 6 connected to microphone 7. In the example shown, holes 5 are circular, and are regularly spaced at intervals E along the axis X of probe 10, alternating on either side of probe 10, thus forming two rows of diametrically opposed holes (therefore, the spacing between two adjacent holes in the same row is twice the spacing E). Of course, other shapes and distributions of holes, such as other (angular) positions and other (irregular) spacings, can be considered without departing from the scope of the invention. The distribution of holes 5 affects the positioning accuracy of the arc AR. The spacing E between holes 5 must allow one or more holes to be exposed when the fusible membrane 3 melts. For example, the spacing E can be millimeters or centimeters, depending on the temperature range of the exposed membrane. Specifically, the spacing E between holes 5 can include between 2 mm and 2 cm.

[0059] The inner diameter D1 of probe 10 is selected to limit the attenuation of acoustic wave OA as it propagates within probe 10. Figure 9 The theoretical acoustic attenuation in air within pipes (similar to tubular probe 10) of varying inner diameters is shown under ambient temperature and pressure, depending on the frequency of the sound wave propagating within the pipe. Attenuation is denoted as "Att" and expressed in decibels per meter (dB / m). Frequency is denoted as "F" and expressed in hertz (Hz). The inner diameter of the pipe is denoted as "D1" and expressed in millimeters (mm). Attenuation is provided by viscous heat loss in the acoustic boundary layer surrounding the inner surface of the pipe. The thermoviscous phenomena within the hollow pipe generate acoustic resistance, which in turn attenuates the amplitude of the propagating wave. As shown, the larger the inner diameter D1, the smaller the acoustic attenuation. For example, a diameter D1 greater than 3.2 mm produces an acoustic attenuation of slightly less than 2 dB / m at 100 Hz. In this case, for a sound wave with a frequency of 100 Hz and a propagation distance between 1 m and 10 m, the amplitude attenuation varies between 2 dB and 20 dB.

[0060] In practice, the selection of the diameter D1 of probe 10 depends on a trade-off between the available volume of the probe (e.g., the available volume within the wiring harness in which the probe is integrated) and the acceptable attenuation for the maximum propagation distance considered for the acoustic wave OA. For example, a diameter / propagation distance pair can be selected to ensure that the acoustic attenuation is less than 20 dB. The maximum propagation distance considered is, for example, in... Figure 6 In the device, the distance between microphone 7 and the most vulnerable area 15A furthest from microphone 7. Furthermore, as... Figure 9As shown, for a given diameter D1, the attenuation becomes more pronounced as the wave frequency increases. Therefore, it may be of greater interest to detect low-frequency sound waves, as these waves experience less attenuation as they propagate within the internal space 12 of the probe 10. For this purpose, the microphone 7 used can preferably be selected to detect sound waves with frequencies below 1000 Hz, particularly below 500 Hz.

[0061] The diameter D2 of aperture 5 is also chosen to limit the attenuation of the acoustic wave OA. Furthermore, the choice of diameter D2 may be limited by the diameter D1 and the selected perforation technique. In practice, the diameter D2 of aperture 5 can be on the order of millimeters. At this point, the inventors simulated a 200Hz wave passing through an aperture (similar to aperture 5) with a diameter of 1mm (similar to diameter D2), formed within the wall of a pipe (similar to tubular probe 10) with an inner diameter of 4mm (similar to diameter D1). The simulation considered the assumption of monopole excitation and thermoviscous phenomena in the aperture and pipe. If a wave positioned 1mm from the wall of the pipe generates an external wall pressure in the range of 152dB at the surface of the aperture, the pressure inside the pipe is uniform and in the range of 148dB.

[0062] Therefore, considering the acoustic emission level of the arc and the dynamics of microphone 7, the 4dB attenuation caused by the aperture crossing and associated thermoviscous effects is relatively low and perfectly acceptable.

[0063] The propagation of acoustic OA without attenuation in the internal space 12 of probe 10 and the good detection of acoustic OA also depend on the good acoustic isolation of the internal space 12 from external noise.

[0064] exist Figure 3 In the example, wall 4 ensures acoustic isolation (in the vulnerable areas 15, outside these areas 15). Figures 4 to 6 In the example, acoustic isolation is ensured by the membrane 3 in the vulnerable areas 15 and the wall 4 outside these areas 15. In this respect, it should be noted that the cylindrical shape of the wall 4 and the membrane 3 greatly contributes to the provided acoustic isolation. In fact, the curvature of the wall 4 and the membrane 3 results in frequencies called ring frequencies, below which the sound insulation index further increases as the frequency of the sound wave decreases. The ring frequency is the frequency at which the longitudinal wavelength corresponds to the circumference of the cylinder. Therefore, for a pipe with an outer diameter of 4 mm, a 1 mm thick elastomer wall, and a ring frequency in the range of 76000 Hz, the theoretical sound insulation index is greater than 90 dB for frequencies less than 200 Hz. In contrast, for a plate made of 1 mm thick elastomer (without a radius of curvature), the theoretical sound insulation index is only in the range of 5 dB to 6 dB. A method for detecting and locating electric arcs will now be described. (Reference) Figure 10In this figure, the detection device includes a probe 10, which includes vulnerable regions 15 distributed along the probe. The probe 10 can be similar to... Figure 3 or Figure 4 The device also includes a series of microphones arranged such that at least two microphones 71, 72 positioned on either side of the vulnerable area 15 affected by the arc AR can detect the acoustic wave OA generated by the arc and propagating within the probe 10. For example, the spacing between two adjacent microphones 71, 72 can be metric. For instance, this spacing can include between 2 meters and 20 meters, more specifically, between 5 meters and 20 meters.

[0065] The probe 10 has an open end or terminal that is equipped with a plug to absorb sound waves, preventing sound waves from being reflected (i.e., echoing). Sound wave OA propagates at speed c on either side of the vulnerable region 15 and is sensed by two microphones 71 and 72 at times t1 and t2, respectively. The distance separating the vulnerable region 15 from the first microphone 71 is denoted as d1, and the distance separating the vulnerable region 15 from the second microphone 72 is denoted as d2. Sound wave OA is sensed by microphones 71 and 72 with a time offset (t2-t1), which represents the difference in distance traveled. In this case:

[0066] [Mathematics 1]

[0067] d2-d1=c(t2-t1)

[0068] The distance between the microphones, L = d1 + d2, is predetermined, and the position of the arc AR relative to the microphone 71 can then be easily derived using the following formula:

[0069] [Mathematics 2]

[0070]

[0071] This calculation is performed by a computing unit (not shown) of a device for receiving measurement signals from microphones 71 and 72.

[0072] This method for locating electric arcs (ARs) has the advantages of reliability and relative simplicity. However, other methods could also be considered for locating arcs based on measurement signals from acoustic sensors.

[0073] For example, in the case where the sound wave is reflected at the end of probe 10, the time signal at the output of the acoustic sensor represents the incident wave and the reverse wave propagating from the nearest end. The time offset between wave detections and the distance between the acoustic sensor and the end can determine the location of the arc.

[0074] According to another example, frequency analysis can be performed using an acoustic propagation model of a plane wave with viscous thermal attenuation and calculations of the self-spectrum (SPLdB) of an acoustic sensor to infer the location of an electric arc.

[0075] The embodiments described in this disclosure are for illustrative and non-limiting purposes only. Those skilled in the art can readily modify these embodiments or consider other embodiments based on the content of this disclosure, while still remaining within the scope of this invention.

[0076] Specifically, if certain features of the above embodiments are sufficient on their own to provide one of the advantages of the present invention, those skilled in the art will readily conceive of variations that include only these features. Furthermore, the different features of these embodiments can be used individually or in combination with each other. When combined, these features can be described as described above or differently, and the present invention is not limited to the specific combinations described herein. Specifically, unless otherwise stated, features described in conjunction with one embodiment can be similarly applied to another embodiment.

Claims

1. An apparatus for acoustic detection of electric arc, the apparatus comprising a tubular probe (10) adapted to be positioned next to an electrical device on which an electric arc (AR) may be formed. in, An internal space (12) defined by the wall (4) of the probe extends along the length of the probe (10), the internal space (12) is filled with fluid and is acoustically isolated from external noise by the wall (4). The probe (10) includes at least one vulnerable area (15) located around the interior space (12) of the probe (10) and on the wall (4) of the probe (10). The at least one vulnerable area (15) is adapted to degrade under the action of the electric arc (AR) to expose a channel (16) for the acoustic wave (OA) generated by the electric arc to pass through to the interior space. The device further includes at least one acoustic sensor (7, 71, 72) adapted to detect sound waves traveling through the channel (16) and propagating in the internal space (12) of the probe.

2. The apparatus according to claim 1, wherein, The at least one vulnerable region (15) is a fusible region suitable for melting under the heat generated by the electric arc (AR).

3. The apparatus according to claim 2, wherein, The fusible region is formed by a fusible membrane (3) covering the opening (5) through the wall.

4. The apparatus according to claim 3, wherein, The fusible membrane (3) covers the entire wall (4) from the outside or the inside.

5. The apparatus according to claim 3 or 4, wherein, The fusible membrane (3) has the ability to shrink under heat.

6. The apparatus according to claim 1 or 2, wherein, The at least one vulnerable area (15) is formed by a region of reduced thickness of the wall (4).

7. The apparatus according to claim 1, wherein the apparatus comprises a plurality of vulnerable regions (15) distributed along the probe (10).

8. The apparatus according to claim 1, wherein, The fluid is air.

9. The apparatus according to claim 1, wherein, The tube (6) extends from the internal space (12) of the probe through the wall (4) to the acoustic sensor (7, 71, 72).

10. The apparatus according to claim 1, wherein, The acoustic sensors (7, 71, 72) are suitable for detecting acoustic waves (OA) with frequencies less than 1000 Hz.

11. The apparatus according to claim 1, wherein, The cross-section of the internal space (12) of the probe is large enough that for sound waves with frequencies between 100 Hz and 500 Hz, the acoustic attenuation along the probe (10) is less than 2 dB / m.

12. The apparatus of claim 1, further comprising a computing unit configured to determine the propagation time of the sound wave from the deteriorated vulnerable region (15) to the acoustic sensor based on measurement signals from at least one of the acoustic sensors (7, 71, 72), and to infer the location of the arc (AR) based on the propagation time.

13. A component comprising the means according to any one of claims 1 to 12 and a wire harness (20) comprising a plurality of cables (1), wherein, The probe (10) is integrated into the wire harness and arranged along the cable (1).

14. The component of claim 13, wherein, The cable (1) is distributed circumferentially around the probe (10).

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