Warning device for detecting an approach towards an electrical facility

Abstract

The invention relates to a warning device (W) for detecting an approach towards an electrical facility, which warning device has at least one energised component (K), in particular an electrical line (L), which is surrounded by an electrical field (E). The warning device (W) has at least one sensor unit (SE), which detects the electrical field (E) of the at least one component (L) in the form of a measurement signal (M), an acceleration sensor (BS), which detects an acceleration of the warning device (W), preferably in a 3-dimensional space, in the form of acceleration data, and an evaluation unit (AW), which is designed to estimate a respective risk potential from the acceleration data (BD) detected by the acceleration sensor (BS) and from the measurement signal (M) detected by the sensor unit (SE), in order to control at least one output of at least one warning signal.

Description

[0001] Warning device for detecting an approach to an electrical installation

[0002] The present invention relates generally to the field of safety equipment, in particular to the area of ​​personal protection in the vicinity of electrical installations. Specifically, the present invention relates to a warning device for detecting an approach to an electrical installation which has at least one or more live components, in particular electrical conductors, surrounded by an electric field. The warning device comprises at least one sensor unit that detects the electric field in the form of a measurement signal, and an evaluation unit for evaluating the measurement signal detected by the sensor unit.

[0003] State of the art

[0004] Electrical power supply systems are widespread. Besides voltage conversion (e.g., substations, transformer stations, etc.), they also serve to transmit electrical energy over long distances (e.g., high- and medium-voltage networks or sections thereof) and to distribute energy to consumers (e.g., low-voltage networks or sections thereof) to supply power to buildings, machinery, or industrial plants. Typically, a number of different electrical systems are used in power supply. Electrical systems usually comprise a variety of components used for converting electrical energy, such as power transformers, switchgear, etc., and / or for transmitting and distributing electrical energy, such as transmission and distribution lines (e.g., cables and / or overhead lines), high-voltage cable terminations, etc.They are used. Such components carry current or are under voltage, which, depending on the application of the component, can be in the medium or high voltage range, such as in transmission lines, or in the low voltage range, such as in distribution lines.

[0005] Electrical power supply systems, with their numerous components, especially electrical lines for power transmission and distribution, require regular inspection, maintenance, and repair, and potentially expansion. These tasks are carried out by qualified personnel—sometimes even during the operation of the electrical systems or power supply system. This entails an inherent risk to these personnel, as unintentional proximity to live and / or energized components, particularly electrical lines, and / or unintentional contact with such components can result in a life-threatening electric shock or at least the risk of serious injury.Furthermore, there are usually people in the vicinity of an electrical installation who, in the event of incorrect behavior or a fault in the electrical system, may also be at risk, for example, of suffering an electric shock. Such a potential hazard can, of course, exist not only with electrical installations of a power supply system, but also during work (e.g., commissioning, maintenance and / or repair work, rescue operations, renovation work, etc.) in the vicinity of or near other installations with live and / or energized components, such as industrial plants, production machines, etc. This also applies to work with construction machinery such as cranes, excavators, etc., in the vicinity of components of electrical installations of an energy supply system, especially in the vicinity of transmission lines or distribution lines in the form of overhead lines or cables, there is a risk that, for example, a work machine will get too close to the line and / or unintentionally damage it.

[0006] Typically, safety regulations and practices are in place in sectors such as energy and industry to reduce the risk to people from electrical installations and to prevent accidents involving live components or damage to components caused by machinery. Especially in industrial settings, it is common for electrical installations to have an emergency stop function to de-energize the system, for example, if a live component is touched. While this increases the safety of people working near live components, particularly from electric shock due to accidental contact, at least one other person must be present to activate the emergency stop in case of a fault and, if necessary, call for help.This hardly prevents unintentional damage to electrical components, especially transmission lines (e.g. overhead lines, cables), caused by machinery.

[0007] Warning devices offer a way to increase the safety of people working in or near electrical installations, especially power supply systems, who are therefore at risk of dangerously close contact with live components, such as live wires. Various warning devices are available today for personal use. These devices can be used by people working in or around electrical installations to protect themselves from unintentional dangerous approaches to electrical components and electric shocks, particularly in medium- and high-voltage networks, but also in low-voltage networks. These warning devices typically detect the electric field generated by a live component, such as a power line.The electrical conductor is surrounded by a field whose strength and magnitude are proportional to the voltage level of the respective component, or, in the case of a current conductor, the magnetic field. These devices monitor, for example, compliance with exposure limits for electric fields and generate a warning signal when such limits or thresholds are exceeded, in order to prevent, for example, a dangerous approach and / or an electrical accident. Ideally, these warning devices are designed as compact, easily portable warning devices. The warning device can, for example, be designed so that it can be attached to and worn on the wrist, work clothing, and / or a helmet, so as not to hinder the person in their work.

[0008] Such a warning device is known, for example, from EP 1 296 150 A1, which can be worn by a person, e.g., on a helmet. This warning device has a housing in which a sensor circuit and an alarm circuit coupled to the sensor circuit are arranged. The sensor circuit detects an electric field and generates a signal that is proportional to the strength of the detected electric field. The alarm circuit generates an audible warning signal, the repetition rate of which is proportional to the strength of the detected electric field, and a visual warning signal, whereby the audible signal can be manually muted and reactivates after a predetermined period of time.

[0009] Another portable warning device is known, for example, from EP 4 276 478 A1, which also uses two sensor units to detect an electric field, in particular an electric field from a high-voltage line. This warning device emits an acoustic or visual warning signal that indicates to the wearer the strength and a general direction of the detected electric field. With this device as well, the acoustic warning signal can be muted by the user, and it reactivates automatically after a predetermined period.

[0010] Ideally, such warning devices should reliably warn the wearer of a dangerous approach to a live component, particularly an electrical line, at a safe distance. However, the functionality of these devices does not guarantee this completely. The electric field strength detected by the warning device can, for example, be the same at a dangerous distance from a low-voltage component (e.g., a conductor system in the range of 230 volts to approximately 1000 volts AC) as it is at a relatively safe distance from a medium- or high-voltage component (e.g., an electrical line with a voltage above approximately 1 kV AC). Thus, at a dangerous distance of approximately 20 cm from a low-voltage electrical component, the field strength can be almost the same (e.g., approximately 1 kV AC) in both situations.250 V / m) can be measured, for example, at a safe distance (e.g., approx. 4 m) from an electrical component or line in the 10 kV medium-voltage range, or at a very large distance (e.g., approx. 150 m) from a high-voltage component or line in the 420 kV range, taking into account that, for example, the electric field results from a ratio between voltage and distance to the electrical component. For an infinitely long conductor, the electric field, for example, depends on the distance to the conductor and is given by the following formula: where E represents the electric field or electric field strength, d represents a distance to the voltage-carrying conductor, U represents the voltage, and R represents a radius of the electrical conductor.

[0011] Warning devices that only consider a single detected field strength cannot, for example, distinguish between a dangerous approach to a low-voltage component and the electric field of a medium- or high-voltage component at a safe or even distant distance. With these devices, an alarm is triggered, for instance, when a field strength exceeding a predefined threshold is detected. Therefore, warning signals are often unnecessarily issued to the user, which can lead to the user muting the warnings or not using the device at all. Consequently, such devices are often set to specific voltage ranges within which they reliably issue warnings. However, this can mean that, for example,A person who carries out maintenance, servicing, repair and / or inspection work on electrical components, especially on electrical lines, must carry different warning devices suitable for the respective voltage range and must know the respective voltage range of the electrical component in order to use the appropriate warning device.

[0012] Furthermore, there are warning devices, such as those described in WO 2018 / 111474 A1, where, for example, the detection sensitivity and thus the alarm, especially the threshold for the audible alarm, can be adjusted to the ambient electric field strength upon arrival at an electrical component. This can be done, for example, by pressing a button on the warning device. The alarm remains silent as long as the measured electric field strength is below or constant, and is only activated once the measured values ​​exceed the threshold or the measured field strength increases. This means that, in the worst case, the warning device would have to be recalibrated for each electrical component, which represents an additional effort and could potentially be a source of error (e.g., setting an incorrect threshold) and thus a safety risk.

[0013] It would therefore be desirable if a warning device could reliably detect a dangerous approach (e.g., falling below a certain safety distance) to an electrical component, regardless of its voltage range, without additional effort and / or without changing the device, thereby increasing the safety for a user of the warning device.

[0014] Description of the invention

[0015] The object of the present invention is therefore to provide a warning device with which a dangerous approach to an electrical component or a reaching and / or possible falling below a respective safety distance can be detected in a simple and reliable manner, regardless of the voltage range of the component.

[0016] This problem is solved by a warning device for detecting an approach to an electrical component according to the independent claim. Advantageous embodiments of the present invention are described in the dependent claims.

[0017] According to the invention, the problem is solved by a warning device of the type specified above, wherein the warning device comprises a sensor unit which detects the electric field of the at least one component in the form of a measurement signal, an acceleration sensor which detects an acceleration of the warning device, preferably in a 3-dimensional space, in the form of acceleration data, and an evaluation unit which is configured to estimate a respective hazard potential from the acceleration data detected by the acceleration sensor and from the measurement signal detected by the sensor unit in order to control at least one output of at least one warning signal.

[0018] The main aspect of the warning device proposed according to the invention is that, by evaluating the movement of the warning device in the vicinity of the live component, especially in the vicinity of an electrical conductor, and the field strength values ​​of the electric field surrounding the component, which are recorded by means of the measuring signal during the movement of the warning device, a dangerous approach and / or reaching or even falling below a safe distance to the component can be detected in a simple and reliable manner. If such a hazard potential is detected by the warning device, the output of a warning signal is controlled in such a way that a warning signal is triggered.

[0019] Therefore, the evaluation unit of the warning device is ideally designed to determine, from the acceleration data recorded by the acceleration sensor, at least a current position of the warning device in relation to a position preceding the current position and an associated change in the measurement signal recorded by the sensor unit, and to estimate the respective hazard potential from the change in the measurement signal and a change in the position of the warning device between the respective determined current position in relation to the respective preceding position.

[0020] It is further advantageous if the evaluation unit is configured to estimate the voltage level of the component and the current distance between the warning device and the component from changes in the warning device's position and the associated changes in the measurement signal. The estimated voltage level and distance can then be used to better and more accurately assess the hazard potential posed by the component of the electrical system. This makes it very easy to determine whether the detected electric field originates, for example, from a low-voltage component located close to the warning device or from a distant medium- or high-voltage component. The warning signal output can then be easily adjusted accordingly.

[0021] Furthermore, it is advantageous if the evaluation unit is configured to assess the estimated hazard potential and, based on the evaluation result, activate or deactivate the output of at least one warning signal, whereby the output of the warning signal is adapted to the estimated hazard potential. Ideally, the estimated hazard potential can be compared with a predefined threshold value in order to activate the output of the warning signal, for example, if the threshold value is exceeded.

[0022] A preferred embodiment of the warning device provides that the warning device includes an alarm unit for outputting at least one warning signal. This at least one warning signal can be output by the alarm unit as a visual alarm, an audible alarm, and / or a vibration alarm. By controlling the evaluation unit, the volume, frequency, and / or intensity of the at least one warning signal can be adjusted to the assessed hazard potential.

[0023] It is also advantageous if the warning device has a local storage unit in which at least adaptation parameters for adjusting the output of the at least one warning signal to the respective estimated hazard potential, as well as at least one threshold value for the electric field, are stored. The evaluation unit can, for example, use the adaptation parameters for the warning signal stored in the memory unit (e.g., regarding frequency, volume, intensity, etc.) to adjust the output of the at least one warning signal to the respective estimated hazard potential, and thus control the output of the warning signal by the alarm unit very easily and simply.

[0024] A practical design for the warning device is that it is a portable unit that can be attached to a helmet or piece of clothing, or worn on the wrist. This allows a person to easily use the warning device, for example, during maintenance, repair, or inspection work in the vicinity of an electrical system or component, particularly an electrical cable, to receive early and reliable warnings of potential hazards. Alternatively, the portable warning device can be designed to be attached to a piece of machinery. This allows, for example, the timely detection of a piece of machinery (e.g., crane, excavator, etc.) approaching the component, especially the electrical cable, and potentially preventing damage to the component and / or the machinery.

[0025] Brief description of the characters

[0026] The present invention is explained in more detail below with reference to Figure 1, which shows an exemplary, schematic, and non-limiting embodiment of the invention. Figure 1 shows an embodiment of the warning device according to the invention for detecting an approach to an electrical installation with at least one component.

[0027] Implementation of the invention

[0028] The invention relates to a warning device W with which an approach to an electrical installation of a power supply system or to a component L of an electrical installation of a power supply system that is under voltage U can be detected. In Fig. 1, an electrical line or an electrical conductor system, such as a cable or an overhead line, or a section thereof, is shown in cross-section as an example of a component L that is under voltage U and therefore surrounded by an electric field E. The voltage U can be in a different voltage range, depending on whether the electrical line belongs to an electrical installation or a transmission and / or distribution network in the high, medium, or low voltage range. In the case of a line or conductor system in the low voltage range, which, for example,In a line consisting of three live conductors, a neutral conductor, and a protective conductor, the voltage U, for example, ranges from 230 V to 400 V, depending on whether the voltage U is considered between a live conductor and the neutral and protective conductors, or between two live conductors, but can reach up to approximately 1 kV. In a medium-voltage network, the voltage U between the live conductors can range from 1 kV to approximately 50 kV to 60 kV, with medium-voltage networks for the transmission and distribution of energy typically operating at, for example, 10 kV or 20 kV. In a high-voltage network, the voltage U between the live conductors can range from approximately 50 kV or 60 kV to over 400 kV, with high-voltage networks in Western Europe typically operating at 110 kV, 220 kV, or 380 kV, and occasionally at 420 kV.

[0029] The warning device W can also be used in the vicinity of another component L of an electrical system, such as a transformer, a switchgear, etc., which is surrounded by an electric field E, to detect a dangerous approach.

[0030] When approaching a live component U, e.g., an electrical conductor, or when reducing the distance d to component L, for example, during maintenance, repair, and / or inspection work, there is a potential hazard posed by component L. This could include a person getting too close to component L, receiving an electric shock, or unintentionally touching component L, particularly an electrical conductor. The same potential hazard can also exist when using machinery (e.g., cranes, excavators, etc.), for example, getting too close to component L, which could lead to damage to component L and / or the machinery, a short circuit, and malfunctions in the electrical system, etc. Therefore, it is important that both people and machinery maintain a safe distance from component L to prevent hazards (e.g., electric shock, unintentional contact, damage, etc.).The safety distance should be kept as low as possible. Depending on the voltage range – i.e., low, medium, or high voltage – of the voltage U of component L, a different safety distance may be necessary. For electrical lines, this safety distance can be approximately 0.5 m for a low-voltage line with a voltage U of 230 V or 400 V, approximately 1.5 m for a medium-voltage line with a voltage U of 10 kV between the conductors, or approximately 5 m for a high-voltage line with a voltage U of 420 kV between the conductors. When approaching component L, especially when the distance d to component L reaches or falls below this safety distance, the potential hazard to a person from component L, or the potential for damage and / or malfunction of component L by a machine, increases.

[0031] The warning device W, shown schematically and by way of example in Fig. 1, is located in the vicinity of the live component L, such as an electrical line, and is moved there, for example, by the person wearing the warning device W or by a machine to which the warning device W is attached, within a reference coordinate system with an x-axis, a y-axis, and a z-axis. The reference coordinate system is assumed, for example, such that a plane formed by the x-axis and y-axis is parallel to component L, and the z-axis is perpendicular to component L. This means that, for example, when the warning device W moves in the direction of the x-axis or y-axis, the distance d to component L remains largely constant, whereas when the warning device W moves in the direction of the z-axis, the distance d to component L changes, for example, becoming smaller or larger.

[0032] The warning device W, shown schematically and by way of example in Fig. 1, is therefore designed to warn of the potential hazard posed by component L during an approach to component L (i.e., when the warning device W moves with a component in the direction of the z-axis), especially before a safety distance is reached or breached – regardless of the voltage range of the voltage U of the energized component L. For this purpose, the warning device W, as shown by way of example in Fig. 1, has a sensor unit SE which continuously detects the electric field E surrounding component L in the form of a measurement signal M, for example, from the moment the warning device W is activated or switched on.

[0033] The sensor unit SE can comprise at least one sensor, and usually several, to detect the electric field E omnidirectionally. Using the at least one sensor, the sensor unit SE can detect the electric field E surrounding the component L and thus determine its strength and extent. The at least one sensor of the sensor unit SE can, for example, be a capacitive sensor, consisting, for instance, of two conductors arranged in space (e.g., plates of conductive material) between which a voltage is measured. The measurement signal M detected by the sensor unit SE is then transmitted—possibly after appropriate amplification by an amplifier unit—to an evaluation unit AW of the warning device W.

[0034] Furthermore, the warning device W can include an acceleration sensor BS, which, as shown by way of example in Fig. 1, is integrated into the warning device W. The acceleration sensor BS can also be a separate component and be connected to the evaluation unit AW of the warning device W in a suitable manner. The acceleration sensor BS can detect movement or a change in position of the warning device W in the reference coordinate system, which is caused, for example, by a person carrying the warning device W or by a machine on which the warning device W is mounted. The acceleration sensor BS detects an acceleration of the warning device W, preferably in 3-dimensional space, e.g., in the form of acceleration data BD, and thereby provides, for example,Three linear acceleration values ​​are provided for translational motion in the three spatial directions, but it can also or additionally provide three rotational acceleration values ​​for rotational motion. From this, a linear acceleration in space can be determined, as well as, alternatively or additionally, a rotational acceleration state. The acceleration is usually referenced to a reference position or orientation, for example, the reference coordinate system.

[0035] The acceleration sensor BS is advantageously designed as an inertial measuring unit, which provides as measured values ​​or acceleration data BD three linear acceleration values ​​for translational motion and three angular velocities for the rotation rates of a person or machine on which the warning device 1 is located. From these acceleration data BD, the speed of the person or machine in space (for example, by integrating the linear accelerations), the position of the person or machine in space (for example, by integrating the linear accelerations twice), and / or the orientation of the person or machine in space (by integrating the angular velocities) can also be determined in order to, for example, estimate the position of the warning device W and thus a change in the position of the warning device W in space.The acceleration data BD, determined by the acceleration sensor BS and describing the position and / or change in position of the warning device W, are transmitted to the evaluation unit AW.

[0036] The evaluation unit AW is designed to evaluate, on the one hand, the acceleration data BD recorded by the acceleration sensor BS and, on the other hand, the measurement signal M recorded by the sensor unit SE. Based on this evaluation, the evaluation unit AW estimates the respective hazard potential, for example, for a person due to component L or for damage and / or malfunction of component L caused by a machine.

[0037] The evaluation unit AW can estimate at least the current position of the warning device W relative to a previous position from the acceleration data BD acquired by the acceleration sensor BS. This means that the evaluation unit AW can only ever determine relative positions of the warning device W from the acceleration data BD, specifically the current position compared to a previous position. The evaluation unit AW only considers changes in position between the current position and a previous position based on the acceleration data BD.

[0038] For each change in position of the warning device W – from its previous position to its current position – the evaluation unit AW determines the corresponding changes in the measurement signal M, with which the sensor unit SE detects the electric field E. That is, the evaluation unit AW determines a change in the position of the warning device W in the area of ​​component L and the corresponding change in the measured field strength E during this change in position, in order to estimate the respective hazard potential. For this estimation, the change in the measurement signal M or the measured field strength can be related to the change in position. This means that if, for example, the change in the measurement signal M is large in relation to the change in position of the warning device W, a relatively high hazard potential can be assumed.The evaluation unit AW therefore assesses a high hazard potential (e.g., component K is quite close to the warning device W) and controls the output of the warning signal WS accordingly. However, if, for example, the change in the measurement signal M or the measured field strength is small or even very small in relation to the change in position, a low to very low hazard potential can be assumed. The evaluation unit AW therefore assesses a small or very small hazard potential (e.g., component K is away from or far from the warning device W) and also controls the output of the warning signal WS accordingly.

[0039] When assessing the respective hazard potential, the warning device W or the evaluation unit AW establishes a relationship between the change in position between two relative positions of the warning device W and the change in the measurement signal M or the measured field strength values ​​at the two relative positions of the warning device W, as described above. For example, the difference in the measured field strength values ​​at the respective relative positions could be divided by the change in position (i.e., the distance between the two relative positions).

[0040] In the evaluation unit AW, for example, it can be assumed for the estimation of the hazard potential that the measurement signal M has a first field strength value at one time point and a second field strength value at a second time point. Using the acceleration sensor BS, it can be determined that the position of the warning device changes by 50 mm between the first and second time points.

[0041] If, for example, component L of the electrical system is a low-voltage electrical conductor (i.e., with a nominal voltage of 400V or 230V to earth), and the warning device W has a distance d of, for example, 250mm from the conductor at the first time and is, for example, 50mm closer to the conductor at the second time (distance d = 200mm), then the warning device W or the sensor unit SE – assuming an infinitely long conductor with a cross-section of 240mm² and a radius R of, for example, 8.74mm – would, according to the formula where E represents the electric field or electric field strength, d the distance to the live conductor, U the voltage, and R the radius of the conductor, at the first time, for example, a first field strength value of 275.5 V / m would be measured as the measurement signal M. At the second time, the measurement signal would yield, for example, a second field strength value of 368.9 V / m. The change in the two field strength values ​​in relation to the change in position of the warning device W would thus result, for example, in an estimated hazard potential of approximately 1850 V. This means a relatively high hazard potential for, for example, a person wearing the warning device W.

[0042] For example, assuming that component L is an electrical line with, say, 145 kV, i.e., from the high-voltage range, and that the warning device W is, for example, at a distance d of, say, 28.03 m from the line at the first time and is, for example, 50 mm closer to the line at the second time (distance d = 28.08 m), then the sensor unit SE of the warning device would, according to the formula above, measure a signal M with a field strength of, say, 368.9 V / m at the first time, but the signal M would show only a slightly different field strength (e.g., 370.0 V / m) at the second time. The change in the two field strength values ​​in relation to the change in position of the warning device W would thus yield, for example, approximately 14.8 V as the estimated hazard potential. This suggests, for example, that the distance of approximately 28 m to the 145 kV line is more than sufficient. Only at a significantly smaller distance to the line (e.g., at approximately 100 m) would the potential hazard become more significant.3m) would, for example, create a hazard potential of the same order of magnitude as the low-voltage line mentioned above.

[0043] For assessing the hazard potential, tables can be used in the evaluation unit AW, for example. However, it can also be estimated mathematically using formulas.

[0044] Furthermore, the evaluation unit AW is ideally also configured to estimate the voltage U of the component L under voltage U, as well as the current distance d between the warning device W and component L, from the change in position of the warning device W and the associated change in the measurement signal M. The estimated voltage U can be used, for example, to adjust the warning signal, and the determined current distance d of the warning device W can be used to better and more accurately assess the hazard potential. The output of the warning signal WS can then be even more precisely adapted to the existing hazard potential.

[0045] For this estimation of the voltage U and the distance d, the following formula can be used again, for example, in the case of an electrical line: where E represents the electric field or electric field strength, d a distance to the voltage-carrying conductor, U the voltage, and R a radius of the electrical conductor. If, for example, a typical conductor cross-section (and thus radius R of the conductor) is assumed, and that, for example, in the chosen coordinate system or reference coordinate system, the change in position in the x- and y-directions remains approximately constant, and the change in position of the warning device W corresponds to a change in the z-direction, then a system of equations can be set up using the formula, from which, for example, the unknown voltage U (of component L) and a distance d to component L can be estimated. Equivalently, for changes in all three spatial directions, a correspondingly more complex system of equations can be set up from which the voltage U and the distance d can be estimated.

[0046] Furthermore, the evaluation unit AW can be configured to evaluate the assessed hazard potential. Based on the evaluation result, the evaluation unit AW determines whether the output of at least one warning signal (WS) should be activated or deactivated. The output of the warning signal WS can be adapted to the assessed hazard potential. For evaluating the assessed hazard potential, the evaluation unit AW can, for example, use at least one predefined threshold value (e.g., 1000V as the threshold for activating or deactivating the output of the warning signal WS).

[0047] Alternatively, multiple threshold values ​​can be provided, which, for example, are determined based on the estimated voltage level U of component L of the evaluation unit AW to activate or deactivate the output of the warning signal WS. This means that the threshold value can be dynamically adjusted by the warning device W to a specific voltage range (e.g., low, medium, or high voltage) of component L. To determine the respective threshold value, the voltage level U can, for example, be estimated from the change in position of the warning device W, which is determined from the acceleration data BD, and the corresponding change in the measurement signal M of the electric field E. The at least one predefined threshold value, or the threshold values ​​predefined for, e.g., different voltage ranges, can be stored, for example, in the evaluation unit AW or in a local storage unit SP.

[0048] The evaluation unit AW then compares the estimated hazard potential with at least one predefined threshold. If the estimated hazard potential exceeds the threshold, the evaluation unit AW determines that the warning signal WS should be activated, provided it is not already being emitted. If the estimated hazard potential falls below the threshold, the evaluation unit AW can control the output of the warning signal WS, for example, to deactivate an already activated warning signal WS.

[0049] The evaluation unit (AW) can therefore be microprocessor-based hardware running corresponding software. However, the evaluation unit (AW) can also be implemented as an integrated circuit, such as a field-programmable gate array (FPGA) or an application-specific integrated circuit (ASIC). Other implementations are also conceivable in principle.

[0050] Furthermore, an alarm unit AL can be provided. The alarm unit AL is then configured – controlled by the evaluation unit AW – to issue a correspondingly adapted warning signal WS in order to warn according to the hazard potential assessed by the evaluation unit AW. The alarm unit AL can, for example, output the warning signal WS as a visual alarm and / or audible alarm and / or vibration alarm. The alarm unit AL can also include a visual indicator, such as an LED or a small display. The LED or display can, for example, flash at a frequency that the evaluation unit AW adjusts to the assessed hazard potential from component L by means of appropriate control of the alarm unit AL. That is, if the evaluation unit AW determines, for example, a high or increasing hazard potential from component L, because, for example,When a person wearing the warning device W approaches component L or is already very close to it, the flashing frequency of the LED or display increases. If the perceived hazard potential from component L decreases, for example because the person moves away from it, the flashing frequency can be reduced accordingly, or the visual alarm can be deactivated until the perceived hazard potential increases again.

[0051] Furthermore, the alarm unit AL can include an acoustic output unit, such as a loudspeaker. This acoustic output unit can, for example, emit an audible alarm, such as a warning tone or a whistle signal. Similar to a visual alarm, the volume, pitch, and / or repetition frequency of an audible alarm can be adjusted by component L according to the estimated hazard potential. This means that the volume, pitch, and / or repetition frequency can be changed according to the estimated hazard potential – for example, increased when the hazard potential is high and decreased when it is low. In cases of very low estimated hazard potential, it is possible, for example, to mute the audible alarm temporarily.

[0052] Additionally or alternatively, the AL alarm unit can also have a vibration motor for issuing a vibration alarm, whereby, for example, the frequency and / or intensity of the vibration alarm can be adapted to the respective estimated hazard potential via appropriate control of the AW evaluation unit.

[0053] Furthermore, the warning device W can include a local storage unit SP. The local storage unit SP can, for example, contain at least one predefined threshold value for the detected electric field E. Additionally, different threshold values ​​can be stored in the local storage unit SP for different voltage ranges, in order, for example, to adapt the threshold for activating or deactivating the warning signal WS to the voltage U of the energized component L.

[0054] Furthermore, the local storage unit SP can also contain adaptation settings for adjusting the warning signal WS. For example, the storage unit SP can contain adaptation settings for the warning signal WS for different magnitude ranges of the estimated hazard potential—for instance, for changes in the measurement signal M relative to a change in the position of the warning device W from a previous position to its current position. These adaptation settings allow the output of the warning signal WS to be adjusted, for example, in volume, frequency, and / or intensity, to the estimated hazard potential of component L. The adaptation settings can be stored in the storage unit SP, for example, in the form of a table, with each predefined magnitude range corresponding to an adaptation setting for the warning signal WS.

[0055] Furthermore, the warning device W can have a power supply, such as a suitable battery, accumulator, or similar. This power supply primarily provides the evaluation unit AW and the alarm unit AL with the necessary energy.

[0056] Furthermore, the warning device W can be designed as a mobile device. For this purpose, the warning device W can have a housing in which at least the sensor unit SE, the evaluation unit AW, the alarm unit AL, the local storage unit SP, and the power supply are arranged. The accelerometer BS can also be located in the housing of the warning device W. Alternatively, the accelerometer BS can also be a separate component and be connected to the evaluation unit AW of the warning device W in a suitable manner. As a mobile device, the warning device W can, for example, be attached to a helmet or an article of clothing, or worn on a person's wrist to detect a potential hazard posed by the live component U to the person and to warn the person of a dangerous approach (e.g., when a safety distance is reached or breached).Furthermore, the warning device W can also be arranged on a working machine, such as a crane or an excavator, in particular on an excavator bucket, in order to detect when the working machine comes dangerously close to the component L, to send at least a warning signal WS and, if necessary, to stop the working machine, for example by means of a control signal from the evaluation unit AW of the warning device W.

[0057] The warning device W ensures, for example, that a warning signal WS is emitted that is adapted to the estimated hazard potential of component L. Furthermore, the threshold for triggering the warning signal can be dynamically adjusted to the voltage range of component L, primarily by estimating the voltage U of component L. This means that, for example, with a component L such as a low-voltage line (e.g., 230V / 400V), a threshold for triggering the warning signal WS can be used that is reached very close to the line (e.g., at approximately 1 m). Due to the high estimated hazard potential, the output of the warning signal WS is controlled in such a way that, for example, a brightly flashing visual alarm and / or a loud audible alarm with, for example, a high repetition frequency and / or pitch and / or an intense vibration alarm is emitted.Using the same threshold value, for example when approaching a component L, such as a medium-voltage line (e.g., 10 kV), the threshold would be reached at a relatively safe distance d from the line. This means the hazard potential estimated by the warning device W is lower, and the output of the warning signal WS can be adjusted accordingly. This means, for example, a slower flashing visual alarm and / or a quiet audible alarm with a lower repetition frequency and / or pitch and / or an intense vibration alarm is emitted compared to reaching the threshold when approaching a low-voltage line. Upon further approach to the medium-voltage line, the warning signal output can then be adjusted accordingly, for example, by...The flashing frequency, the volume and / or repetition frequency of the audible alarm, and / or the intensity of the vibration alarm can be adjusted to reflect an increase in the estimated hazard potential. Additionally, the threshold for activating the warning signal could, for example, be adjusted to the medium-voltage range.

[0058] When approaching a component L, such as a high-voltage line (e.g., 420 kV), the warning device can, for example, suppress the output of the warning signal WS. This is because, for instance, at the same threshold as for a low-voltage line, a safe distance d to the line still exists, and the signal is only output upon further approach. Additionally, the triggering threshold could also be adjusted accordingly by estimating the voltage U.

Claims

Patent claims 1. Warning device (W) for detecting an approach to an electrical installation which has at least one live component (L), in particular an electrical conductor (L) which is surrounded by an electric field (E), wherein the warning device (W) at least comprises: - a sensor unit (SE) which captures the electric field (E) of at least one component (L) in the form of a measurement signal (M); - an acceleration sensor (BS) which detects an acceleration of the warning device (W), preferably in a 3-dimensional space, in the form of acceleration data; and - an evaluation unit (AW) which is set up to estimate a respective hazard potential from the acceleration data (BD) recorded by the acceleration sensor (BS) and from the measurement signal (M) recorded by the sensor unit (SE) in order to control at least one output of a warning signal.

2. Warning device (W) according to claim 1, characterized in that the evaluation unit (AW) of the warning device (W) is configured to determine, from the acceleration data (BS) detected by the acceleration sensor (BD), at least one current position of the warning device (W) in relation to a position preceding the respective current position and an associated change in the measurement signal (M) detected by the sensor unit (SE), and to estimate the respective hazard potential from the change in the measurement signal (M) and a change in the position of the warning device (W) between the respective determined current position in relation to the respective preceding position.

3. Warning device (W) according to claim 2, characterized in that the evaluation unit (AW) is configured to estimate the voltage level (II) of the component (L) and the current distance (d) of the warning device (W) to the component (L) from the change in position of the warning device (W) and the associated change in the measurement signal (M).

4. Warning device (W) according to one of claims 1 to 3, characterized in that the evaluation unit (AW) is configured to evaluate the respective estimated hazard potential and to activate or deactivate the output of the at least one warning signal (WS) based on an evaluation result, wherein the output of the warning signal (WS) is adapted to the respective estimated hazard potential.

5. Warning device (W) according to one of claims 1 to 4, characterized in that the evaluation unit (AW) is configured to compare the estimated hazard potential with a predetermined threshold value for evaluation purposes.

6. Warning device (W) according to one of claims 1 to 5, characterized in that the warning device (W) has an alarm unit (AL) for outputting the at least one warning signal (WS), wherein the alarm unit (AL) outputs the at least one warning signal (WS) as a visual alarm and / or acoustic alarm and / or vibration alarm, and wherein, by means of control by the evaluation unit (AW), a volume and / or frequency and / or intensity of the at least one warning signal (WS) is adapted to the respective estimated hazard potential during output.

7. Warning device (W) according to one of claims 1 to 6, characterized in that the warning device (W) has a local storage unit (SP) in which at least adaptation specifications for adapting the output of the at least one warning signal (WS) to the respective estimated hazard potential and the at least one threshold value for the electric field (E) are stored.

8. Warning device (W) according to one of claims 1 to 7, characterized in that the warning device (W) is designed as a mobile device which can be attached to a helmet or to a piece of clothing or worn on the wrist, or which is designed such that the warning device (W) can be attached to a working machine.

Images