Sensor device, system, method, and computer program for detecting electrical anomalies in association with electrical equipment
Patent Information
- Application Number
- ES2022800002T
- Authority / Receiving Office
- ES · ES
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2022-10-25
- Publication Date
- 2026-08-31
- Estimated Expiration
- 2042-10-25
Smart Images
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Abstract
Description
Sensor device, system, method, and computer program for detecting electrical anomalies in association with electrical equipment Technical field This description relates to a sensor device, a system, a method, and a software program for detecting electrical anomalies in association with electrical equipment. More specifically, the description relates to a sensor device, a system, a method, and a software program for detecting electrical anomalies in association with electrical equipment, as defined in the introductory portions of the independent claims. Background of the technique Electrical anomalies, such as sparks, arcing, and increased heat, can occur in association with electrical equipment, for example, due to various faults or overvoltages. Such anomalies can lead to a fire and, consequently, serious damage to the electrical equipment and its surroundings. In order to detect anomalies and thus prevent damage, various types of warning systems and devices exist, including voltage meters, optical sensors, and / or acoustic sensors. Most of these systems and devices, however, are very complex and expensive. Furthermore, many of these systems react to anomalies too late, when damage has already occurred or a fire has already started. As an example, US patent 2020 / 0144806 A1 describes a method and device for detecting the formation of an electrical arc in an electrical system based on its acoustic signature. The system comprises an acoustic sensor, such as an ultrasonic sensor, configured to detect acoustic waves in the electrical system. The sensor can be mounted on a wall of an electrical system enclosure or in physical contact with the electrical conductor being monitored. US patent 10366596 BB describes a monitoring system for detecting faults in electrical equipment. The system includes an ultrasonic sensor mounted, for example, inside a cabinet door or wall, facing the electrical equipment. The ultrasonic sensor can be used to establish a threshold sound level representative of the ultrasonic emissions radiated from electrical equipment in good working order. During monitoring, the ultrasonic sensor can detect when an arcing, tracking, or corona discharge event occurs, because the sound level will be above the ambient threshold. Document 2015 / 271936 describes a sensor configured to be mounted on an electrical conductor, such as a busbar. Electrical equipment mounting rails are commonly known and are typically strips used to mount and secure various electrical components, such as circuit breakers, terminal blocks, and power supplies, inside an electrical cabinet. They provide mechanical support but do not conduct electricity. While the systems mentioned above, based on prior art, address some of the problems associated with electrical anomaly detection systems, they often fail to provide accurate and reliable monitoring and frequently detect potential hazards too late. Therefore, there is a need for an improved sensor device and system for electrical anomaly detection in conjunction with electronic equipment. Compendium One objective of the present description is to mitigate, alleviate, or eliminate one or more of the deficiencies and disadvantages of the previous technique and to solve at least one of the current problems. A particular objective of the present description is to provide a sensor device and system for the detection of electrical anomalies that is easy to install and cost-effective. Another objective of the present description is to provide a sensor device and system for the detection of electrical anomalies in association with electrical equipment, specifically in power plants, electrical cabinets, electrical panels and electrical switchgear. Another objective of this description is to provide a sensor device and system for detecting electrical anomalies, which, through accurate and reliable monitoring, allows for timely alerts and thereby reduces the risk of serious damage. According to claim 1, a sensor device is provided for detecting electrical anomalies in association with electrical equipment. The sensor device comprises a housing; and an acoustic sensor element disposed inside the housing for recording acoustic signals reflecting the sound of the electrical equipment; wherein the acoustic sensor element is operatively connectable to at least one processor configured to detect the presence of electrical anomalies based on the acoustic signals recorded by the acoustic sensor element, wherein the sensor device is configured to be disposed on a mounting rail for electrical equipment and the sensor device is configured such that, when disposed on the mounting rail, the acoustic sensor element rests on the mounting rail. The sensor device is configured to record acoustic signals reflecting the sound from electrical equipment located on the mounting rail to which the sensor device is attached. The sound manifests as noise or vibrations transmitted by the structure on the mounting rail; these vibrations are picked up by the sensor device and converted into electrical signals. This sensor device is also referred to as an acoustic sensor device. Electrical equipment in electrical cabinets, switchboards, and equipment racks is typically mounted on mounting rails. One well-known standard mounting rail is the DIN rail, a metal rail used worldwide. There are three different types of DIN rails: one with a "top hat" cross-section, one with a C-section, and one with a G-section. The top hat section, with its hat-shaped cross-section, will also be referred to herein, as having a slightly U-shaped cross-section. DIN rails thus come in various shapes and sizes with different depths, but they typically include top and bottom flanges. The sensor device described herein can be configured to be mounted on a DIN rail.More specifically, the sensor device, as described herein, can be configured for mounting on a top hat rail. By configuring the sensor device so that the acoustic sensor element rests on the mounting rail, the sensor element will be able to detect vibrations and sound transmitted through the structure of all electrical equipment mounted on the rail. In an electrical cabinet or equipment rack, several mounting rails are typically attached to a common frame or structure. In this way, the different mounting rails are mechanically connected to each other via the frame / structure.The acoustic sensor described herein, when physically mounted on a mounting rail, is capable of detecting vibrations and sound transmitted through the structure from the electrical equipment on all mounting rails attached to the same frame / structure. This means that only one sensor is required to monitor multiple electrical components inside an electrical cabinet with high precision. This results in a simpler and more cost-effective method for detecting electrical faults in the equipment. Furthermore, by mounting the acoustic sensor on the mounting rail, the sensor can detect even small vibrations propagating through the rail. Therefore, a precise and reliable sensor for detecting electrical faults is achieved.The at least one processor to which the acoustic sensor element can be connected may be integrated into the sensor device or may be an external processor. If the at least one processor is integrated into the sensor device, it may be located inside or outside the housing. The sensor device may include a communication unit for communicating, for example, with the at least one processor. The sensor device may be configured to be included in a mounting rail module. Such a module may include a housing that accommodates the sensor device. The at least one processor connectable to the acoustic sensor element may also be accommodated in the module housing. Furthermore, the module housing may accommodate a memory and a communication unit. Electrical anomalies are defined in this document as deviations from normal operation and, as such, may pose a potential hazard. Electrical anomalies detected by the sensor device may include, but are not limited to, sparking, arcing, corona discharge, tracking, and sudden temperature increases in electrical equipment. According to some embodiments, the sensor device comprises a mounting arrangement for detachable attachment to the mounting rail. The mounting arrangement is advantageously configured to allow simple and user-friendly mounting of the sensor device to the mounting rail. The mounting arrangement may comprise an upper connection portion and a lower connection portion. Typically, the mounting arrangement is configured to interact with the mounting rail tabs. The upper connection portion of the mounting arrangement can thus be configured to interact with an upper tab of the mounting rail, and the lower connection portion can be configured to interact with a lower tab of the mounting rail. The upper connection part of the mounting arrangement can be hook-shaped so that it can be hung over an upper tab of the mounting rail. The lower connection part can also be hook-shaped to engage with the lower tab of the mounting rail. This securely fastens the sensor device to the mounting rail and prevents it from pivoting. The mounting arrangement can also be configured so that the sensor device slides along the mounting rail. This allows the sensor device to be easily moved laterally along the mounting rail. The mounting arrangement may include a snap-fit connection. The snap-fit connection may be formed to easily fit the sensor device onto the mounting rail. The snap-fit connection is configured to engage with at least one tab of the mounting rail. The snap-fit connection may include the upper connection portion and the lower connection portion, as previously mentioned. The fixing arrangement can be somewhat resilient, so as to allow minor deformation of the upper and lower connecting part in order to fix the sensor device to the mounting rail. In other embodiments, the mounting arrangement comprises an adjustable clamping element. The adjustable clamping element may comprise the lower connection portion. The upper connection portion may, for example, form part of a mounting plate connected to or integrated with the sensor housing. The adjustable clamping element may be movable relative to the upper connection portion. For example, the clamping element may be connected to the mounting plate by means of one or more removable fasteners. By loosening the fastener(s), the clamping element can then be moved to adjust the distance between the upper and lower connection portions. This facilitates the mounting of the sensor on the mounting rail.In another example, the upper connection part is part of a mounting plate, and the sensor housing is integrated with the movable clamping element. The housing can thus be positioned movably relative to the upper connection part. This allows the sensor to be adapted to different mounting rail sizes. The distance between the upper and lower connection parts can correspond to the width of the mounting rail.As an example, the sensor device can be mounted on the mounting rail by moving the clamping element to increase / maximize the distance between the upper and lower connection parts, hanging the sensor device from an upper tab of the mounting rail by means of the upper connection part, moving the clamping element so that the lower connection part rests / engages with the lower tab of the mounting rail, and securing the clamping element by tightening the fastener(s). To remove the sensor device, the fastener(s) are loosened and the clamping element is moved, increasing the distance between the upper and lower connection parts, so that the upper connection part can be lifted from the upper tab of the mounting rail. The mounting arrangement may further comprise a spring element designed to apply a spring force to the movable clamping element in the direction of the upper connection portion. The spring element may be positioned between the sensor housing and the clamping element. In this way, to increase the distance between the upper and lower connection portions, the clamping element moves in a direction opposite to the spring force, thereby compressing the spring element. When the sensor device is mounted on the mounting rail, the spring element ensures that the clamping element moves upward, so that the lower connection portion presses against the lower flange of the mounting rail. The mounting arrangement thus applies a clamping force to the mounting rail and secures the sensor device to the mounting rail. The acoustic sensor element may comprise a piezoelectric sensor element. In some embodiments, the acoustic sensor element may be a contact microphone for detecting sounds or vibrations transmitted through the structure on the mounting rail. The acoustic signals registered by the acoustic sensor element reflect sound waves generated by the electrical equipment and propagating from the electrical equipment to the acoustic sensor element via the mounting rail. The acoustic sensor element may be configured to convert the acoustic signals into electrical signals, which are then communicated to at least one processor. The acoustic sensor element may be connected to at least one processor via an electrical cable. According to some embodiments, the acoustic sensing element comprises a protrusion adapted to extend through an opening in the housing to rest on the mounting rail. In one example, the acoustic sensing element comprises the protrusion and a piezoelectric sensing element arranged in contact with each other. The protrusion can be arranged in physical contact with a central area of the piezoelectric element. When the sensing device is mounted on the mounting rail, the protrusion presses against the rail and can thereby detect sound and vibrations propagating along the rail. The protrusion can be movably positioned within the housing. The protrusion can be a probe or other device configured to transmit vibrations to the piezoelectric sensing element.The probe can be T-shaped, where the larger surface of the probe is arranged in contact with the piezoelectric sensing element. The sensor device is typically configured so that the acoustic sensing element rests on a flange section of the mounting rail. The sensor device can be configured so that the protrusion rests on a lower flange of the mounting rail. The sensor device housing may include an opening facing the mounting rail when the sensor device is installed on it. This opening is positioned at a predetermined angle corresponding to the position of the lower flange of the mounting rail. Mounting rails may have varying depths of the U-shaped section. By configuring the sensor device so that the acoustic sensing element rests on a flange section of the mounting rail, the sensor device can be used on various types and sizes of mounting rails. This results in a flexible and cost-effective sensor device. According to some embodiments, the sensor device further comprises a protective sheet arranged adjacent to the acoustic sensor element inside the housing. The protective sheet is arranged to protect the acoustic sensor element from any electrical interference. The protective sheet may comprise a plastic film. If the acoustic sensor element comprises a piezoelectric element, the protective sheet may be arranged in contact with the piezoelectric element. According to some embodiments, the sensor device also comprises a damping element arranged in connection with the acoustic sensing element. The damping element may be referred to as a weight and is arranged to reduce vibrations and oscillations in the acoustic sensing element itself. The damping element may be made of metal. The damping element may be arranged adjacent to the protective sheet. In this way, the protective sheet may be positioned between the acoustic sensing element and the damping element. According to some embodiments, the sensor device further comprises a pressure portion arranged to apply pressure to the acoustic sensing element. The pressure portion is deflectable and thereby applies a force to the acoustic sensing element, pressing it against the mounting rail. If the acoustic sensing element comprises a movably arranged protrusion, the pressure portion can apply a force to the acoustic sensing element, pressing the protrusion against the mounting rail. This improves the recording capability and accuracy of the sensor device. The pressure portion may comprise a spring, rubber, or similar element. The deflected pressure portion may be supported by the damping element, the protective sheet, or the acoustic sensing element.The sensor device can be configured to be included in a mounting rail module. Such a module may comprise a housing that accommodates the sensor device, at least one processor, a memory, and a communication unit. According to another aspect of this description, a system is provided for detecting electrical anomalies in association with electrical equipment. The system comprises a sensor device, as described herein, and at least one processor operatively connectable to the acoustic sensor element of the sensor device, wherein the processor is configured to detect the occurrence of electrical anomalies based on the acoustic signals recorded by the acoustic sensor element. At least one processor can be configured to determine at least one characteristic of the recorded acoustic signals and compare that characteristic to a predetermined characteristic threshold value. For example, if the characteristic is energy content, the processor can be configured to compare the energy content of the acoustic signals to a predetermined energy content threshold value and, based on this comparison, determine whether an electrical anomaly exists. The predetermined energy content threshold value can be determined based on the energy content values during normal operation of the electrical equipment. If the energy content of a recorded acoustic signal is above the threshold value, it indicates that an electrical anomaly has occurred in association with the electrical equipment.At least one processor in the system can thus be configured to detect electrical anomalies by determining whether the energy content of the recorded acoustic signals exceeds a threshold energy content value, indicating that an electrical anomaly has occurred. At least one processor can be configured to perform a calibration process to determine the threshold value. Thus, according to one aspect of the present description, a system is provided for detecting electrical anomalies in association with electrical equipment. The system comprises a sensor device for recording acoustic signals reflecting the sound of the electrical equipment as described herein, and at least one processor operatively coupled to the acoustic sensor element of the sensor device.In this example, at least one processor is configured to receive acoustic signals recorded by the sensor device during a calibration process; determine a threshold energy content value for acoustic signals within a frequency band to be monitored during the monitoring of electrical equipment after the calibration process, based on the acoustic signals recorded within that frequency band during the calibration process; detect, among the acoustic signals recorded by the sensor device during the monitoring of electrical equipment after the calibration process, an acoustic pulse within that frequency band; and classify the acoustic pulse as an electrical anomaly associated with the electrical equipment when the energy content of the acoustic pulse exceeds the threshold energy content value. The frequency band should preferably be selected to exclude high-energy acoustic signals generated by the electrical equipment during normal operation, i.e., to exclude frequencies containing a high level of background noise. Ideally, the frequency band should have a bandwidth of no more than 100 Hz, preferably no more than 75 Hz, and even more preferably no more than 50 Hz. A suitable center frequency for the frequency band may be approximately 1 kHz or 4.5 kHz in some applications. The frequency band can be preset or determined by at least one processor based on the acoustic signals recorded by the sensor device during the calibration process. In some embodiments, at least one processor is configured to compare the energy content of different frequencies of the acoustic signals recorded by the sensor device during the calibration process, and determine the frequency band to be monitored as a frequency band that has a relatively low energy content, based on the comparison. It has been found that the electrical pulses generated by the types of electrical anomalies mentioned above have a very short duration. Therefore, the characteristic of acoustic signals, determined by at least one processor, can include a pulse duration. The at least one processor can be configured to determine the pulse duration of the acoustic pulse and classify the acoustic pulse as an electrical anomaly only when the pulse duration falls below a maximum pulse duration threshold value. For example, the at least one processor can be configured to determine the pulse duration as the period of time during which the energy content of the acoustic pulse exceeds the energy content threshold value, where the maximum pulse duration threshold value can be set in the range of 15–50 ms.Preferably, the maximum pulse duration threshold value should be at most 40 ms, even more preferably at most 30 ms, and most preferably at most 20 ms. Furthermore, it has been found that the electrical pulses generated by the types of electrical anomalies mentioned above exhibit a very sudden increase and decrease in energy content. The characteristic of the acoustic signals determined by at least one processor can therefore comprise a rate of increase and / or a rate of decrease in the energy content of the acoustic signals. The processor can thus be configured to classify the acoustic pulse as an electrical anomaly based on a rate of increase and / or a rate of decrease in the energy content of the acoustic pulse. In some embodiments, at least one processor is configured to determine a measure indicative of the rate of increase of the acoustic pulse's energy content and to classify the acoustic pulse as an electrical anomaly only when the measured rate of increase exceeds a set threshold value. To this end, the at least one processor can be configured to determine the acoustic energy intensification time of the acoustic pulse and to classify the acoustic pulse as an electrical anomaly only if the acoustic energy intensification time is below a maximum acoustic energy intensification threshold value.At least one processor can be configured to determine the acoustic energy intensification time as a period of time from a first point in time where the energy content of the acoustic pulse exceeds the threshold energy content value to a second point in time where the energy content of the acoustic pulse reaches its maximum value, and use a maximum acoustic energy intensification threshold value in the range of 10–40 ms. Preferably, the maximum acoustic energy intensification threshold value should be at most 30 ms, even more preferably at most 20 ms, and most preferably at most 10 ms. Similarly, in some embodiments, at least one processor can be configured to determine a measure indicative of the rate of decline of the acoustic pulse's energy content and classify the acoustic pulse as an electrical anomaly only when the measured rate of decline exceeds a predetermined threshold value. For this purpose, at least one processor can be configured to determine the acoustic energy decline time of the acoustic pulse and classify the acoustic pulse as an electrical anomaly only if the acoustic energy decline time falls below a maximum acoustic energy decline threshold value.At least one processor can be configured to determine the acoustic energy decay time as a period of time from a first point in time where the energy content of the acoustic pulse reaches its maximum value to a second point in time where the energy content of the pulse falls below the threshold energy content value, and to use a maximum acoustic energy decay threshold value in the range of 10–40 ms. Preferably, the maximum acoustic energy decay threshold value should be at most 30 ms, even more preferably at most 20 ms, and most preferably at most 10 ms. The at least one processor can also be configured to generate an alarm signal and / or to automatically shut down electrical equipment in response to classifying the acoustic pulse as an electrical anomaly. In some embodiments, the alarm can be generated locally by the sensor device, for example, in the form of an audible and / or visual alarm to alert a local user. Instead of, or in addition to, a local alarm, the at least one processor can be configured to generate an alarm signal that is provided to the user via a user electronic device, which is operatively coupled to the sensor device, for example, through a network server.In some embodiments, the alarm signal can be provided to the user through a mobile application for the detection of electrical anomalies in association with electrical equipment, configured to be run on a mobile electronic device of the user, such as a mobile phone or tablet. It should be understood that all characteristics relating to the sensor device are also applicable to the system as described in this document. According to another aspect of this description, a method is provided for detecting electrical anomalies associated with electrical equipment by means of a system as described herein. The method comprises: i) record acoustic signals reflecting the sound of the electrical equipment by means of the sensor device; yi) detect electrical anomalies based on the recorded acoustic signals. The electrical anomaly detection step based on recorded acoustic signals may involve determining a threshold value for some characteristic of the acoustic signals, comparing the characteristic of the recorded acoustic signals with the threshold value, and detecting electrical anomalies based on that comparison. The threshold value typically corresponds to the characteristic of the acoustic signals during normal operation of the electrical equipment. The characteristic may include energy content, and the threshold value may be a threshold value for energy content. The electrical anomaly detection step may thus involve comparing the energy content of the recorded acoustic signals with the threshold value for energy content and, based on the comparison, determining whether an electrical anomaly is occurring in association with the electrical equipment.If the energy content of a recorded acoustic signal exceeds the threshold value for energy content, it indicates that an electrical anomaly is occurring. The method may include a calibration step to determine the threshold value. Thus, according to one aspect of the present description, a method is provided for detecting electrical anomalies associated with electrical equipment. The method comprises the steps of recording, by means of a sensor device as described herein, during a calibration process, the acoustic signals reflecting the sound of the electrical equipment during its normal operation; determining a threshold energy content value for the acoustic signals within at least one frequency band to be monitored during the monitoring of the electrical equipment after the calibration process, based on the acoustic signals recorded within that at least one frequency band during the calibration process;To detect, among the acoustic signals recorded by the sensor device during the monitoring of electrical equipment after the calibration process, an acoustic pulse within at least one frequency band, and to classify the acoustic pulse as an electrical anomaly associated with the electrical equipment when the energy content of the acoustic pulse exceeds the threshold energy content value for at least one frequency band. An acoustic pulse is thus an acoustic signal within the predetermined frequency band. As mentioned previously, the frequency band should preferably be selected to exclude high-energy acoustic signals generated by the electrical equipment during its normal operation; that is, to exclude frequencies containing a high level of background noise. In some implementations, the frequency band is preset based on the type of electrical equipment being monitored and / or the electrical surroundings of the equipment being monitored. Thus, the frequency band can be preset based on a known frequency spectrum of acoustic noise typically generated by the type of electrical equipment being monitored and / or by electrical appliances in its vicinity. In some embodiments, the frequency band is determined based on the acoustic signals recorded by the sensor device during the calibration process, generated by the electrical equipment during its normal operation, whose acoustic signals represent the background noise generated by the electrical equipment during its normal operation. In some embodiments, the method may comprise the steps of comparing the energy content of different frequencies of the acoustic signals recorded during the calibration process and determining the frequency band to be monitored as having a relatively low energy content, based on this comparison. The frequency band should preferably be narrow enough to exclude high-energy acoustic signals generated by the electrical equipment during its normal operation. Preferably, the frequency band should have a bandwidth of at most 100 Hz, preferably at most 75 Hz, and even more preferably at most 50 Hz. Depending on the background noise generated by the electrical equipment to be monitored and the electrical appliances in the vicinity of the electrical equipment to be monitored, a suitable center frequency of the frequency band may be 1 kHz or 4.5 kHz. To make the method more robust, preventing other sounds from being mistaken for an electrical anomaly, the method may include the steps of determining the pulse duration of the acoustic pulse and classifying the acoustic pulse as an electrical anomaly only if the pulse duration is below a maximum pulse duration threshold value. Defined as the time period during which the energy content of the acoustic pulse exceeds the energy content threshold value, the maximum pulse duration threshold value can be set, for example, in the range of 15–50 ms. Preferably, the maximum pulse duration threshold value should be at most 40 ms, even more preferably at most 30 ms, and most preferably at most 20 ms. To make the method even more robust, the classification of the pulse as an electrical anomaly can be performed based on a rate of increase and / or a rate of decrease of the acoustic pulse energy content. In some embodiments, the method may comprise the steps of determining a measure indicative of the rate of increase of the acoustic pulse's energy content, and classifying the acoustic pulse as an electrical anomaly only when the measured rate of increase exceeds a predetermined threshold value. This can be achieved, for example, by determining an acoustic energy intensification time for the acoustic pulse, and classifying the acoustic pulse as an electrical anomaly only if the acoustic energy intensification time is below a maximum acoustic energy intensification threshold value.When defined as the time period from a first point in time where the energy content of the acoustic pulse exceeds the threshold value of the energy content to a second point in time where the energy content of the acoustic pulse reaches its maximum value, the maximum acoustic energy intensification threshold value can be set, for example, at a value in the range of 10–40 ms. Preferably, the maximum acoustic energy intensification threshold value should be at most 30 ms, even more preferably at most 20 ms, and most preferably at most 10 ms. Similarly, in some embodiments, the method may comprise the steps of determining an indicative measure of the rate of energy content decay of the acoustic pulse, and classifying the acoustic pulse as an electrical anomaly only when the measured rate of decay exceeds a predetermined threshold value. This can be achieved, for example, by determining an acoustic energy decay time of the acoustic pulse, and classifying the acoustic pulse as an electrical anomaly only if the acoustic energy decay time is below a maximum acoustic energy decay threshold value.When defined as the time period from a first point in time where the energy content of the acoustic pulse reaches its maximum value to a second point in time where the energy content of the pulse falls below the threshold value, the maximum acoustic energy decay threshold value can be set, for example, in the range of 10–40 ms. Preferably, the maximum acoustic energy decay threshold value should be at most 30 ms, even more preferably at most 20 ms, and most preferably at most 10 ms. The method may also include generating an alarm signal and / or automatically shutting down the electrical equipment in response to classifying the occurrence of the acoustic pulse as an electrical anomaly. In this way, a user can be notified of the occurrence of electrical anomalies in the electrical equipment, and / or the electrical equipment can be shut down upon detection of the anomalies, thereby preventing, or at least mitigating, the risk of serious damage to the electrical equipment and its immediate surroundings. The method described above is typically a computer-implemented method that can be performed after the execution of a computer program by one or more processors of a system for the detection of electrical anomalies in association with electrical equipment. Thus, according to another aspect of the present description, a computer program is provided comprising computer-readable instructions which, when executed by at least one processor of a system for detecting electrical anomalies in association with electrical equipment, as described herein, causes the at least one processor to perform the following steps: - receive acoustic signals reflecting the sound of the electrical equipment recorded by a sensor device in the system; and - detect electrical anomalies based on the acoustic signals received. In some embodiments, a computer program comprising computer-readable instructions is provided which, when executed by at least one processor of a system for detecting electrical anomalies in association with electrical equipment, causes the at least one processor to perform the steps of: receiving acoustic signals reflecting the sound of the electrical equipment during normal operation thereof, recorded during a calibration process by a sensor device that is operatively coupled to at least one processor; determining a threshold energy content value for the acoustic signals within a frequency band to be monitored during the monitoring of the electrical equipment after the calibration process, based on the acoustic signals recorded within that frequency band during the calibration process;to detect, among the acoustic signals recorded by the sensor device during the monitoring of the electrical equipment after the calibration process, an acoustic pulse within said frequency band, and to classify the acoustic pulse as an electrical anomaly associated with the electrical equipment when an energy content of the acoustic pulse exceeds the threshold value of energy content.; The computer program may further comprise instructions to cause at least one processor of the system to perform any of, or a combination of, the method steps of the method described above. The software may reside entirely on the sensor device or it may be a distributed software program that resides partly on the sensor device and partly on a network server to which the acoustic sensor device is communicatively connected. The software may comprise several software components configured to perform the different steps of the method described above. For example, the software may comprise a first program, component, or application for data processing and communication, residing on the sensor device; a second program component or application for data analysis and communication, residing on the network server; and a third program component or application in the form of a client application for data presentation and user interaction, residing on a user's electronic device.The client application, for example, can be implemented in the form of a mobile application (app) configured to run on a mobile electronic device, such as a mobile phone or tablet. According to another aspect of the present description, a computer program product is provided comprising at least one computer-readable medium, such as non-volatile memory, that stores the aforementioned computer program. The present description will become evident from the detailed description given below. The detailed description and specific examples describe preferred embodiments of the description for illustrative purposes only. Those skilled in the art will understand, from the guidance in the detailed description, that changes and modifications may be made within the scope of the appended claims. Brief description of the drawings The foregoing objectives, as well as additional objectives, features, and advantages of the present description, will be more fully appreciated by reference to the following detailed, illustrative, and non-limiting description of example embodiments of the present description, when taken in conjunction with the accompanying drawings, of which: Figures 1A-B illustrate an exemplary embodiment of a sensor device fixed to a mounting rail according to the present description; Figures 2A-C illustrate exemplary embodiments of a sensor device fixed to a mounting rail according to the present description; Figure 3 illustrates an exemplary embodiment of a sensor device fixed to a mounting rail according to the present description; Figure 4 illustrates an exemplary embodiment of a system for detecting electrical anomalies according to the present description; Figure 5 illustrates an exemplary implementation of a method for detecting electrical anomalies according to the present description. Detailed description The foregoing description will now be described with reference to the accompanying drawings, which show preferred example embodiments of the description. The description can, however, be embodied in other ways and should not be interpreted as limited to the embodiments described herein. The embodiments described are provided merely to fully convey the scope of the description to a person skilled in the art. It is understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. It should be noted that, as used in the specification and accompanying claims, the terms "a," "an," "the," "said," and "said" are intended to mean that there is one or more of the elements, unless the context explicitly dictates otherwise. Thus, for example, a reference to "a unit" or "the unit" may include several devices, and so forth. Furthermore, the terms "comprising," "including," "containing," and similar expressions are intended to be open-ended, transient terms that do not preclude the possibility of additional elements or steps. Figure 1A schematically illustrates an exemplary embodiment of the sensor device 30 when fixed to the mounting rail 10. The sensor device 30 comprises a housing 32 and an acoustic sensor element 301 disposed inside the housing 32 for recording acoustic signals. The acoustic sensor element 301 is operatively connectable to at least one processor 303 configured to detect the presence of electrical anomalies based on the acoustic signals recorded by the acoustic sensor element 301. The at least one processor 303 to which the sensor element 30 is connectable may be incorporated within the sensor device 30 or may be an external processor. The sensor device 30 comprises a mounting arrangement 40 for detachable attachment to the mounting rail 10. The mounting arrangement 40 may comprise an upper connection portion 42 and a lower connection portion 44. The upper connection portion 42 of the mounting arrangement 40 may be configured to interact with the upper tab 12 of the mounting rail 10, and the lower connection portion 44 may be configured to interact with a lower tab 14 of the mounting rail 10. The mounting arrangement 40 may also include a snap-fit connection. The snap-fit connection may be formed to easily fit the sensor device 30 onto the mounting rail 10. The snap-fit connection may comprise the upper connection portion 42 and the lower connection portion 44.The fixing mechanism 40 can be somewhat resilient, so as to allow minor deformation of the upper 42 and lower 44 connecting part in order to fix the sensor device 30 to the mounting rail 10. Figure 1B illustrates some internal components of an exemplary embodiment of the sensor device 30. In this example, the sensor device 30 comprises an acoustic sensor element 301, at least one processor 303, a memory 305, and a communication unit 307, all of which are arranged inside the housing 32. However, it is understood that the at least one processor 303, the memory 305, and / or the communication unit 307 may be arranged externally to the housing 32. The acoustic sensor element 301 is connectable via a wired or wireless connection to the processor 303, the memory 305, and the communication unit 307. In some embodiments (not shown), the sensor device 30 is configured to form part of a standard mounting rail module. Such a module may comprise an external housing that accommodates the sensor device 30, the at least one processor 303, the memory 305, and the communication unit 307.The mounting rail module can also be equipped with a fixing arrangement for detachable attachment to the mounting rail 10. The acoustic sensor element 301 of the sensor device 30 is configured to record acoustic signals reflecting sound generated by nearby electrical equipment. The sound may manifest as noise or vibrations carried by the structure on the mounting rail 10, which vibrations are picked up by the sensor element 301 and converted into electrical signals by the acoustic sensor element 301. In some embodiments, the acoustic sensor element 301 may comprise a piezoelectric sensor element. In some embodiments, the acoustic sensor element 301 may be a contact microphone for recording sound carried by the structure on the mounting rail 10. At least one processor 303 is configured to detect electrical anomalies associated with nearby electrical equipment, based on acoustic signals recorded by acoustic sensor 301 of sensor device 30. This is achieved by at least one processor 303 following the execution of a computer program stored in memory 305. Memory 305 may be integrated or embedded in at least one processor 303, or it may be a separate hardware memory device. The memory may include random-access memory (RAM), read-only memory (ROM), a hard disk, an optical disk, a magnetic medium, high-speed memory, or any other mechanism capable of storing instructions or data. At least one processor 303 may include any physical device that has an electrical circuit that performs logical operations on input data.For example, the at least one processor 303 may include one or more integrated circuits, microchips, microcontrollers, microprocessors, all or part of a central processing unit (CPU), a digital signal processor (DSP), a field-programmable gate array (FPGA), or other circuitry for executing instructions or performing logic operations. Unless otherwise stated, it should be understood that the actions and method steps described hereafter are performed by the at least one processor 303 after the execution of the computer program stored in memory 305. Figures 2A-C schematically illustrate exemplary embodiments of the sensor device 30. The sensor device 30 can be configured as described in Figures 1A-B. Figure 2A describes an example where the fastening arrangement 40 comprises an adjustable clamping element 400. The adjustable clamping element 400 may comprise the lower connecting portion 44 of the fastening arrangement 40. The upper connecting portion 42 of the fastening arrangement 40 may be hook-shaped so that it can be hung over the upper tab 12 of the mounting rail 10. The lower connecting portion 44 may also be hook-shaped to engage with the lower tab 14 of the mounting rail 10. The upper connection part 42, for example, can be part of a mounting plate 43 connected to or integrated with the housing 32 of the sensor device 30. The adjustable clamping element 400 can be movably positioned relative to the mounting plate 43. The clamping element 400 can therefore be moved to adjust the distance between the upper connection part 42 and the lower connection part 44 of the mounting arrangement 40. This facilitates the mounting of the sensor device 30 on the mounting rail 10. The clamping element 400 can be secured to the mounting plate 43 by means of fasteners, which are loosened to allow the clamping element 400 to be moved. Figure 2B schematically illustrates a cross-sectional view of the sensor device 30 according to an example. The figure shows the housing 32 and the acoustic sensor element 301 arranged inside the housing 32. In this example, the acoustic sensor element 301 comprises a piezoelectric sensor element 301a and a protrusion 301b. The protrusion 301b and the piezoelectric sensor element 301a are supported by each other. In some embodiments, the acoustic sensor element may be a contact microphone for detecting sound transmitted through the structure on the mounting rail. The protrusion 301b is adapted to extend through an opening 33 in the housing 32 to rest on the mounting rail 10 during operation of the sensor device 30. When the sensor device 30 is mounted on the mounting rail 10, the protrusion 301b presses against the mounting rail 10 and can therefore record sound and vibrations propagating in the mounting rail 10. The protrusion 301b can be movably arranged inside the housing 32. The protrusion 301b can be a probe or other device configured to transmit vibrations to the piezoelectric sensing element 301a. The sensor device 30 is typically configured so that the acoustic sensor element 301 rests on a flange section of the mounting rail 10. The opening 33 of the housing 32 can thus be arranged to face the flange section of the mounting rail 10 when the sensor device 30 is positioned on the mounting rail 10. The opening 33 is appropriately positioned in a predetermined location that corresponds to the position of the lower flange 14 of the mounting rail 10. Figure 2B also shows a connection opening 34 in the housing 32 through which an electrical cable can be extended to connect the acoustic sensing element 301 to the at least one processor 303. Figure 2C schematically illustrates a cross-sectional view of the sensing device 30, according to one example. In this example, the sensing device 30 further comprises a protective sheet 35 arranged adjacent to the acoustic sensing element 301 inside the housing 32. The protective sheet 35 is arranged to protect the acoustic sensing element 301 from any electrical interference. The protective sheet 35 may comprise a plastic film. If the acoustic sensing element 301 comprises a piezoelectric element 301a, the protective sheet 35 may be arranged in contact with the piezoelectric element 301a. The sensor device 30 may also include a damping element 36 arranged in connection with the acoustic sensor element 301. The damping element 36 may be referred to as a weight and is arranged to reduce vibrations and oscillations in the acoustic sensor element 301 itself. The damping element 36 may be made of metal. The damping element 36 is arranged adjacent to the protective sheet 35. In this way, the protective sheet 35 can be arranged between the acoustic sensor element 301 and the damping element 36. Furthermore, the sensor device 30 may comprise a pressure portion 37 arranged to apply pressure to the acoustic sensing element 301. The pressure portion 37 may be deflected and thereby apply a force to the acoustic sensing element 301, such that the acoustic sensing element 301, 301a, is pressed against the mounting rail 10. The pressure portion 37 may comprise a spring, rubber, or similar element. The deflected pressure portion 37 may be supported by the damping element 36, the protective sheet 35, or the acoustic sensing element 301. It should be understood that, although this figure shows the protective sheet 35, the damping element 36 and the pressure part 37 all arranged inside the housing 32, the sensor device 30 may comprise only one or two of these components. Figure 3 schematically illustrates an exemplary embodiment of a sensor device 30 fixed to a mounting rail 10 according to the present description. The sensor device 30 can be configured as shown in either Figure 1A-B or 2A-C. In this example, the fastening arrangement 40 further comprises a spring element 46 arranged to apply a spring force to the movable clamping element 400 in the direction of the upper connecting portion 42. The spring element 46 can be positioned between the housing 32 and the clamping element 400. In this way, to increase the distance between the upper and lower connecting portions 42, 44, the clamping element 400 moves in a direction opposite to the spring force, thereby compressing the spring element 46. When the sensing device 30 is arranged on the mounting rail 10, the spring element 46 ensures that the clamping element 400 moves upward, so that the lower connecting portion 44 presses against the lower flange 14 of the mounting rail 10. Figure 4 illustrates a system 1 for detecting electrical anomalies in association with electrical equipment according to an exemplary embodiment of the present description. The system 1 comprises a sensor device 30 for recording acoustic signals reflecting the sound generated by the electrical equipment. The sensor device 30 is fixed herein to a mounting rail 10, for example, in an electrical cabinet 2. The sensor device 30 can be configured as described in any of Figures 1a-b, 2a-c, and 3. The system 1 further comprises at least one processor 303, 803 that is configured to detect electrical anomalies based on the acoustic signals recorded by the sensor device 30. System 1 may further comprise a network server 80 operatively connected to the sensor device 30. The network server 80 may comprise a processor 803. System 1 can be configured to generate an alarm signal and / or automatically shut down electrical equipment upon detection of electrical anomalies associated with the electrical equipment. In some embodiments, System 1 can be configured to generate a local alarm upon detection of electrical anomalies associated with the electrical equipment. For this purpose, the sensor device 30 may comprise means 308 for generating an audible and / or visual alarm signal for a local user, such as an audible signal generator and / or a light indicator. In some embodiments, System 1 can be configured to alert a remote user 60 upon detection of electrical anomalies associated with the electrical equipment by displaying an alert on a user electronic device, such as a portable electronic device in the form of, for example, a tablet 70A, a mobile phone 70B, or a laptop or desktop computer 70C.In this latter scenario, the sensor device 30 can be operationally connected to the network server 80, which, in turn, can be configured to communicate information relating to the detection of electrical anomalies to one or more of the user's electronic devices 70A-C 60. The network server 80 can be, for example, a cloud server connected to the Internet, and the communication unit (307 in Figure 1B) of the sensor device 30 can be configured to communicate with the network server 80 using any known communication protocol. The functionality for detecting electrical anomalies associated with electrical equipment may reside in either or both of the sensor device 30 or the network server 80. When residing in the network server 80, the acoustic signals or acoustic signal characteristics recorded by the sensor device 30 can be transmitted to the network server 80, after which the processor 803 of the network server 80 processes the signals or signal characteristics. Any detected electrical anomalies can then be communicated by the network server 80 to the sensor device 30 for the generation of a local alarm, and / or to one or more of the user's electronic devices 70A-70C for the generation of a remote alarm on the electronic device.When residing in sensor device 30, the acoustic signals recorded by sensor device 30 can be processed locally by the processor 303 of sensor device 30, after which sensor device 30 can communicate any detection of electrical anomalies to network server 80, so that network server 80 can alert user 60 of the detection of electrical anomalies through one or more of the user's electronic devices 70A-70C. At least one System 1 processor (303, 803) can be configured to detect electrical anomalies by determining whether a predetermined characteristic of the recorded acoustic signals exceeds a characteristic threshold value, indicating that an electrical anomaly has occurred. More specifically, at least one System 1 processor (303, 803) can be configured to detect electrical anomalies by determining whether the energy content of the recorded acoustic signals exceeds a certain energy content threshold value, indicating that an electrical anomaly has occurred. Furthermore, at least one processor 303, 803 can be configured to receive acoustic signals recorded by the sensor device 30 during a calibration process. These acoustic signals indicate background noise generated by electrical equipment and, possibly, other electrical and non-electrical objects in the vicinity of the sensor device 30. In some embodiments, the calibration process may last for a predetermined period of time, for example, one hour or one day. In other embodiments, the calibration process may continue until no acoustic signals with an energy content exceeding that of previously recorded acoustic signals have been recorded for a certain period of time. The acoustic signals recorded by the sensor device 30 during the calibration process are used by at least one processor 303, 803 to determine a threshold energy content value for detecting electrical anomalies during subsequent monitoring of the electrical equipment in a monitoring phase following the calibration process. The threshold energy content value is determined for at least one specific frequency band to be monitored during the monitoring phase, and is based on the acoustic signals recorded within that specific frequency band during the calibration process.Preferably, the energy content threshold value is set at a value slightly above the energy content of the background noise recorded within the frequency band during the calibration process; for example, slightly above the maximum energy content of any acoustic signal recorded within that frequency band during the calibration process. The at least one processor 303, 803 can be further configured to detect an acoustic pulse among the acoustic signals recorded by the sensor device 30 during the monitoring phase, within the monitored frequency band (corresponding to the frequency band to be monitored mentioned above), and to classify the acoustic pulse as an electrical anomaly associated with the electrical equipment when an energy content of the acoustic pulse exceeds the threshold value of energy content. Figure 5 is a flowchart illustrating an exemplary embodiment of a method for detecting electrical anomalies by means of a system 1, as described, for example, in Figure 4. The method will be described below with simultaneous reference to the above drawings. The method comprises the steps of recording S1 the acoustic signals that reflect sound from the electrical equipment by means of the sensor device 30; and detecting S2 the electrical anomalies based on the recorded acoustic signals. The S2 electrical anomaly detection step, based on recorded acoustic signals, may involve comparing a predetermined characteristic of the acoustic signals with a characteristic threshold value. If the characteristic of an acoustic signal exceeds the characteristic threshold value, it can be concluded that an electrical anomaly has occurred in association with the electrical equipment. The S2 electrical anomaly detection step may thus involve determining a characteristic threshold value that typically corresponds to a characteristic value during the normal operation of the electrical equipment. In one example, the characteristic comprises the energy content, and the threshold value is a threshold value for that energy content.The S2 electrical anomaly detection step can thus involve comparing the energy content value of the recorded acoustic signals with the energy content threshold value and, based on this comparison, determining whether an electrical anomaly is occurring. If the energy content value of a recorded acoustic signal exceeds the energy content threshold value, it indicates that an electrical anomaly is occurring. The acoustic signal can then be classified as an electrical anomaly. The S1 acoustic signal recording step may involve recording, during a calibration process, acoustic signals that reflect the sound of the electrical equipment during its normal operation. The S2 electrical anomaly detection step may comprise determining a threshold energy content value for acoustic signals within at least one frequency band to be monitored during the monitoring of electrical equipment after the calibration process, based on the acoustic signals recorded within that at least one frequency band during the calibration process. It may also comprise detecting, among the acoustic signals recorded by the acoustic sensor device 30 during the monitoring of electrical equipment after the calibration process, an acoustic pulse within that at least one frequency band and classifying the acoustic pulse as an electrical anomaly associated with the electrical equipment when the energy content of the acoustic pulse exceeds the threshold energy content value. At least one frequency band can be selected to exclude high-energy acoustic signals generated by electrical equipment during normal operation. The S2 electrical anomaly detection step may involve comparing the energy content of different frequencies of the acoustic signals recorded during the calibration process and determining at least one frequency band to be monitored as having a relatively low energy content, based on the comparison. Each of the at least one frequency band has a bandwidth of at most 100 Hz, preferably at most 75 Hz, and even more preferably at most 50 Hz. In some embodiments, the characteristic includes the pulse duration. The S2 electrical anomaly detection step may then comprise determining the pulse duration of the acoustic pulse and classifying the acoustic pulse as an electrical anomaly only when the pulse duration is below a maximum pulse duration threshold value. In some embodiments, the feature comprises an indicative measure of a rate of increase of the energy content, and the method may comprise determining an indicative measure of a rate of increase of the energy content of the acoustic pulse, and classifying the acoustic pulse as an electrical anomaly only when the measure of the rate of increase exceeds a set threshold value. In some embodiments, the feature comprises an indicative measure of a rate of decrease in energy content, and the method may comprise determining an indicative measure of a rate of decrease in the energy content of the acoustic pulse, and classifying the acoustic pulse as an electrical anomaly only when the measure of the rate of decrease exceeds a set threshold value. The method may also include generating an alarm signal and / or automatically shutting down electrical equipment in response to classifying the acoustic signal / pulse as an electrical anomaly. As is clear from the preceding description, the method is typically a computer-implemented method performed by one or more processors 303, 803 of system 1 following the execution of a computer program. Also clear from the preceding description, the computer program may be a distributed computer program comprising program components residing on both the sensor device 30 and the network server 80. Therefore, the method can be performed by either the processor 303 of the acoustic sensor 30 or the processor 803 of the network server 80. A person skilled in the art will realize that the present description is not limited to the embodiments described above. A person skilled in the art will further realize that modifications and variations within the scope of the appended claims are possible. For example, it should be noted that all or part of the functionality described herein as residing in network node 80 may, in other embodiments, reside in sensor device 30. In still other embodiments, all or part of the functionality described herein as residing in network node 80 may reside in a client device in direct communication with sensor device 30, such as electronic device 70A-70C.Accordingly, it should be noted that improvements and modifications can be made to the present invention described in detail above, insofar as they fall within the scope of the invention as set forth in the accompanying claims.
Claims
1. A sensor device (30) for detecting electrical anomalies in association with electrical equipment, the sensor device (30) being configured to be disposed on a mounting rail (10) for the electrical equipment and comprising: - a housing (32); and - an acoustic sensor element (301) disposed inside the housing (32) for recording acoustic signals reflecting sound originating from the electrical equipment disposed in association with the mounting rail (10) to which the sensor device (30) is fixed, the sound manifesting as sound or vibrations carried by the structure on the mounting rail (10); wherein the acoustic sensor element (301) is operatively connectable to at least one processor (303, 803) configured to detect the presence of electrical anomalies based on the acoustic signals recorded by the acoustic sensor element (301), wherein the sensor device (30) is configured such that,1. The acoustic sensing element (301) rests on the mounting rail (10) when arranged on the mounting rail (10).
2. The sensing device (30) according to claim 1, wherein the sensing device (30) comprises a fixing arrangement (40) for detachable fixing onto the mounting rail (10).
3. The sensing device (30) according to claim 2, wherein the fixing arrangement (40) comprises a press-fit connection.
4. The sensing device (30) according to claim 2, wherein the fixing arrangement (40) comprises an adjustable clamping element (400).
5. The sensing device (30) according to any of the preceding claims, wherein the acoustic sensing element (301) comprises a protrusion (301b) adapted to extend through an opening (33) in the housing (32) to rest on the mounting rail (10).
6. The sensor device (30) according to any of the preceding claims,wherein the sensor device (30) further comprises a protective sheet (35) disposed adjacent to the acoustic sensor element (301).
7. The sensor device (30) according to any of the preceding claims, wherein the sensor device (30) further comprises a damping element (36) disposed in connection with the acoustic sensor element (301).
8. The sensor device (30) according to any of the preceding claims, wherein the sensor device (30) further comprises a pressure portion (37) arranged to apply pressure to the acoustic sensor element (301).
9. The sensor device (30) according to any of the preceding claims, wherein the sensor device (30) is configured such that the acoustic sensor element (301) rests against a flange section (14) of the mounting rail (10).
10. A system (1) for detecting electrical anomalies in association with electrical equipment,The system (1) comprising a sensor device (30) according to any of the preceding claims, and at least one processor (303, 803) operatively coupled to the acoustic sensor element (301) of the sensor device (30), wherein the processor (303, 803) is configured to detect the occurrence of electrical anomalies based on the acoustic signals recorded by the sensor device (30).
11. A method for detecting electrical anomalies in association with electrical equipment by means of a system (1) according to claim 10, the method comprising: i) recording (S1) acoustic signals reflecting the sound of the electrical equipment by means of the sensor device (30); and ii) detecting (S2) electrical anomalies based on the recorded acoustic signals.
12. A computer program comprising computer-readable instructions that, when executed by at least one processor (303,803) of the system (1) for detecting electrical anomalies in association with electrical equipment according to claim 10, causes the at least one processor (303, 803) to perform the steps of: - receiving acoustic signals reflecting sound from the electrical equipment, recorded by the sensor device (30) of the system (1); and - detecting electrical anomalies based on the acoustic signals received.