System for monitoring a device

Abstract

The invention relates to a system for monitoring a device, the system comprising: at least one temperature sensor; a processing unit; and an output unit; wherein the at least one temperature sensor is configured to acquire at least one temperature measurement at a first location of the device under operation, and wherein the first location is in thermal contact with a second location of the device under operation; wherein the at least one temperature sensor is configured to provide the at least one temperature measurement to the processing unit; wherein the processing unit is configured to select a simulated temperature profile of the first location of the device from a plurality of simulated temperature profiles simulating the first location of the device; wherein the processing unit is configured to determine a presence or development of a hot spot at the second location of the device under operation, wherein the determination comprises: using a correlation between the simulated temperature profile of the first location and the second location for the selected simulated temperature profile of the first location of the device; and wherein the output unit is configured to output a fault indication at the second location of the device under operation.

Description

TECHNICAL FIELD

[0001] The present invention relates to a system for monitoring an apparatus and a method for monitoring an apparatus. BACKGROUND

[0002] The temperature of a power apparatus, e.g. a low-, medium- or high-voltage switching apparatus, needs to be kept within apparatus-specific limits to avoid damage due to thermal stress.

[0003] Temperature monitoring, e.g. measurement using infrared (IR) sensors, is used to control whether these limits are adhered to.

[0004] Temperature can be monitored using sensors but only at locations accessible to the sensors, the meas- urable points meas-pt. Other locations or positions can be important points of interest important-pt in that they can have higher temperatures and are more likely to cause an apparatus failure but are usually not accessible, i.e. hidden from the sensors.

[0005] Therefore, the temperature at these most important points, locations or positions cannot be directly monitored by the sensors alone.

[0006] This problem has to be solved. SUMMARY

[0007] It can therefore be advantageous to have an improved technology for monitoring an apparatus.

[0008] The object of the present invention is solved by the subject-matter of the independent claims, wherein further embodiments are incorporated in the dependent claims.

[0009] In a first aspect, a system for monitoring an apparatus is provided, the system comprising:

[0010] at least one temperature sensor;

[0011] a processing unit; and

[0012] an output unit.

[0013] The at least one temperature sensor is configured to acquire at least one temperature measurement at a first location of the operating device, and the first location is in thermal contact with a second location of the operating device. The at least one temperature sensor is configured to provide the at least one temperature measurement to the processing unit. The processing unit is configured to select a simulated temperature distribution of the first location of the simulated device from a plurality of simulated temperature distributions simulating the first location of the simulated device. The selection comprises comparing the at least one temperature measurement with the plurality of simulated temperature distributions of the first location. The plurality of simulated temperature distributions of the first location each relate to a different scenario with respect to a simulated operation of the simulated device. For each of the different scenarios, there is a correlation between the simulated temperature distribution of the first location of the simulated device and a simulated temperature of the second location. The processing unit is configured to determine that there is or is developing a hot spot at the second location of the operating device, comprising using the correlation between the simulated temperature distribution of the first location and the second location for the selected simulated temperature distribution of the first location of the simulated device. The output unit is configured to output an indication of a malfunction at the second location of the operating device.

[0014] In an example, the temperature measurement can be at one location or at a plurality of different locations. Thus, the temperature measurement at one location can be used to select a simulated correlation between that location where the measurement can be made and a second location where it is difficult to make measurements that can be used to determine whether there is a hot spot. However, a plurality of temperature measurements at different locations can be used to determine a plurality of simulated temperature distributions of the same locations and a simulated correlation between these first locations and a simulated temperature of a second location where it is physically difficult to make measurements that can be used to determine whether there is a problem with this difficult to measure location.

[0015] According to an example, the at least one temperature sensor comprises one or more infrared cameras, one or more surface acoustic wave sensors, or one or more RFID sensors.

[0016] According to an example, the at least one temperature measurement comprises a plurality of temperature measurements, and wherein the plurality of temperature measurements are acquired simultaneously.

[0017] According to an example, the at least one temperature sensor is an infrared camera, and wherein the at least one temperature measurement comprises an infrared image of the first location.

[0018] According to an example, the plurality of simulated temperature distributions are simulated in a process comprising utilising finite element analysis.

[0019] According to an example, for each of the different scenarios, the correlation between the simulated temperature distribution of the first location of the simulated device and a simulated temperature of the second location is determined by utilising finite element analysis.

[0020] According to an example, the comparison of the at least one temperature measurement value with the plurality of simulated temperature distributions comprises utilizing a matrix norm or a machine learning algorithm implemented by the processing unit.

[0021] In a second aspect, a method for monitoring a device is provided, comprising:

[0022] a) acquiring, by at least one temperature sensor, at least one temperature measurement value at a first location of the operating device, and wherein the first location is in thermal contact with a second location of the operating device;

[0023] b) providing the at least one temperature sensor to a processing unit;

[0024] c) selecting, by the processing unit, a simulated temperature distribution of the first location of the simulated device from a plurality of simulated temperature distributions of the first location of the simulated device, wherein the selecting comprises comparing the at least one temperature measurement value with the plurality of simulated temperature distributions of the first location, wherein the plurality of simulated temperature distributions of the first location each relate to a different case with respect to a simulated operation of the simulated device, and wherein for each of the different cases there is a correlation between the simulated temperature distribution of the first location of the simulated device and a simulated temperature of the second location; and

[0025] d) determining, by the processing unit, that a hot spot exists or is developing at the second location of the operating device, and wherein the determining comprises using the correlation between the simulated temperature distribution of the first location and the second location for the selected simulated temperature distribution of the first location of the simulated device; and

[0026] e) outputting, by an output unit, a fault indication at the second location of the operating device.

[0027] According to an example, the at least one temperature sensor comprises one or more infrared cameras, one or more surface acoustic wave sensors, or one or more RFID sensors.

[0028] According to an example, the at least one temperature measurement value comprises a plurality of temperature measurement values, and wherein the plurality of temperature measurement values are acquired simultaneously.

[0029] According to an example, the at least one temperature sensor is an infrared camera, and wherein the at least one temperature measurement value comprises an infrared image of the first location.

[0030] According to an example, the plurality of simulated temperature distributions are simulated in a process comprising utilizing finite element analysis.

[0031] According to an example, for each of the different cases, the correlation between the simulated temperature distribution of the first location of the simulated device and the simulated temperature of the second location is determined by utilizing finite element analysis.

[0032] According to examples, comparing the at least one temperature measurement value to the plurality of simulated temperature distributions comprises utilizing a matrix norm or a machine learning algorithm implemented by the processing unit.

[0033] The above aspects and examples will become apparent and elucidated from the embodiments described hereinafter with reference to the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0034] Exemplary embodiments are described below with reference to the following drawings:

[0035] Fig. 1 A representation of device monitoring is shown; and

[0036] Fig. 2 A representation of selecting a measured temperature distribution of simulated temperature distributions is shown. DETAILED DESCRIPTION

[0037] Figs. 1-2 A system for monitoring a device and a method for monitoring a device are described.

[0038] In examples, the system for monitoring a device comprises at least one temperature sensor, a processing unit, and an output unit. The at least one temperature sensor is configured to acquire at least one temperature measurement value at a first location of the operating device, and the first location is in thermal contact with a second location of the operating device. The at least one temperature sensor is configured to provide the at least one temperature measurement value to the processing unit. The processing unit is configured to select a simulated temperature distribution of the first location of the operating device from a plurality of simulated temperature distributions simulating the first location of the operating device. The selection comprises comparing the at least one temperature measurement value to the plurality of simulated temperature distributions of the first location. The plurality of simulated temperature distributions of the first location each relate to a different scenario with respect to a simulated operation of the operating device, and for each of the different scenarios there is a correlation between the simulated temperature distribution of the first location of the operating device and a simulated temperature of the second location. The processing unit is configured to determine that there is or is developing a hot spot at the second location of the operating device. The determination comprises using the correlation between the simulated temperature distribution of the first location and the second location for the selected simulated temperature distribution of the first location of the operating device (selecting the simulated temperature distribution using the at least one temperature measurement value acquired at the first location). The output unit is configured to output a fault indication at the second location of the operating device.

[0039] In an example, the temperature measurement can be at one location or at multiple different locations. Thus, the temperature measurement at one location can be used to select an analog correlation between that location where the measurement can be made and a second location where measurements that can be used to determine whether there is a hot spot are difficult to make. However, multiple temperature measurements at different locations can be used to determine multiple analog temperature distributions for the same locations and an analog correlation between those first locations and analog temperatures for a second location where measurements are physically difficult to make that can be used to determine whether there is a problem with this difficult to measure location.

[0040] According to an example, the at least one temperature sensor comprises one or more infrared cameras, one or more surface acoustic wave sensors, or one or more RFID sensors.

[0041] According to an example, the at least one temperature measurement comprises a plurality of temperature measurements, and wherein the plurality of temperature measurements are taken simultaneously.

[0042] According to an example, the at least one temperature sensor is an infrared camera, and wherein the at least one temperature measurement comprises an infrared image of the first location.

[0043] According to an example, the plurality of analog temperature distributions are simulated in a process comprising utilization of finite element analysis.

[0044] According to an example, for each of the different cases, the correlation between the analog temperature distribution for the first location of the simulated device and the analog temperature for the second location is determined by utilization of finite element analysis.

[0045] According to an example, the comparison of the at least one temperature measurement to the plurality of analog temperature distributions comprises utilization of a matrix norm or a machine learning algorithm implemented by the processing unit.

[0046] In an example, a method for monitoring a device comprises:

[0047] a) obtaining, by at least one temperature sensor, at least one temperature measurement at a first location of the device being operated, and wherein the first location is in thermal contact with a second location of the device being operated;

[0048] b) providing the at least one temperature sensor to a processing unit;

[0049] c) selecting, by the processing unit, an analog temperature distribution for the first location of the simulated device from a plurality of analog temperature distributions for the first location of the simulated device, wherein the selection comprises: comparing the at least one temperature measurement to the plurality of analog temperature distributions for the first location, wherein the plurality of analog temperature distributions for the first location each relate to a different case with respect to a simulated operation of the simulated device, and wherein for each of the different cases there is a correlation between the analog temperature distribution for the first location of the simulated device and an analog temperature for a second location; and

[0050] d) determining, by the processing unit, that a hot spot exists or is developing at the second location of the operating device, and wherein determining comprises using a correlation between the simulated temperature profile of the first location and the second location for simulating the selected simulated temperature profile of the first location of the device; and

[0051] e) outputting, by the output unit, a fault indication at the second location of the operating device.

[0052] According to an example, the at least one temperature sensor comprises one or more infrared cameras, one or more surface acoustic wave sensors, or one or more RFID sensors.

[0053] According to an example, the at least one temperature measurement comprises a plurality of temperature measurements, and wherein the plurality of temperature measurements are taken simultaneously.

[0054] According to an example, the at least one temperature sensor is an infrared camera, and wherein the at least one temperature measurement comprises an infrared image of the first location.

[0055] According to an example, the plurality of simulated temperature profiles are simulated in a process comprising utilization of finite element analysis.

[0056] According to an example, the correlation between the simulated temperature profile of the first location and the simulated temperature of the second location of the device is determined for each of the different cases by utilizing finite element analysis.

[0057] According to an example, comparing the at least one temperature measurement to the plurality of simulated temperature profiles comprises utilizing a matrix norm or a machine learning algorithm implemented by the processing unit.

[0058] Thus, the new device monitoring technique can draw conclusions about the temperature at an important, even possibly critical, but inaccessible point of a power device: the temperature is measured at an accessible point by a sensor (e.g. by an infrared camera or other sensing method like SAW, RFID). This measurement is then compared to simulations of a plurality of cases. If the measurement corresponds to one of the pre-simulated cases, the temperature at the important / critical point can be determined from the simulation of this case.

[0059] It has been determined that a correlation between the temperature measured by a sensor at a measurement point (meas-Pt) and the temperature of another, non-measurable location (important-Pt) is able to overcome this problem. Once this correlation is known, the temperature at important-Pt can be drawn from the measurement at meas-Pt.

[0060] It has been established that this correlation can sometimes be derived from dedicated experiments during the product design phase. However, this correlation is only valid for the measured situation (e.g. for the specific current applied in the experiment and for the specific situation, such as a loose connection or a connection that is not perfect in a very specific way) and cannot be generalized to other situations or other devices. Moreover, experiments require a lot of time and are costly. Furthermore, measurements at important or critical points or locations (important-Pt) are not always possible, since the location is not accessible, and this can even apply to the design phase in the laboratory.

[0061] It should be realized that for a range of different situations of current flow, in fact a range of different theoretical situations, such as different degrees of imperfect connection, etc., the correlation between the measured temperature at the meas-Pt and the temperature at the important-Pt can be determined using simulations (e.g. by finite element FEM) instead of measurements, by simulating the temperature at the meas-Pt and the difficult-to-measure location (important-Pt) for a range of different situations.

[0062] FEM simulations allow for an analysis of the entire device and are not limited to accessible locations. The situation can easily change. Therefore, the correlation required for a larger number of different situations can be determined compared to experiments. These devices can also be easily replaced in the simulation. Therefore, once the simulation method has been established, it is cheaper, more flexible and more general than experiments to determine the desired correlation.

[0063] Fig. 1 An example is shown that illustrates an overview of the new technology.

[0064] The new monitoring system consists of the following elements:

[0065] 1. Temperature measurement by a sensor

[0066] 2. Finite element simulation of a range of different situations, pre-simulated

[0067] 3. An algorithm to compare the measured temperature at the measurement point (meas-pt) with the pre-simulated FEM simulation and to determine which of the situations corresponds to the measurement

[0068] The measurement by the sensor results in a temperature distribution at the meas-Pt. In the case of an infrared camera, this comprises a temperature array corresponding to the number of pixels of the infrared camera optics.

[0069] Alternatively, the temperature distribution meas-Pt can be generated by several sensors placed at different locations (e.g. compartments) in the switchgear, instead of only by one IR camera.

[0070] Alternatively, the temperature distribution can consist of point temperature measurements, e.g. from distributed wireless sensors.

[0071] The FEM simulation is a coupled electro-thermal simulation. Ohmic losses are calculated by solving Maxwell's equations. There are several options to calculate the temperature in the thermal part of the simulation:

[0072] Alternatively, the simple heat conduction equation is solved. The heat exchange with the environment can be estimated via heat transfer coefficients at the surface of the device.

[0073] Alternatively, a full CFD calculation can be made. This requires more effort, but is only necessary when convection and radiation cannot be estimated accurately enough via heat transfer coefficients.

[0074] Several cases can be simulated that correspond to possible fault situations. Then, the simulated temperature distribution at the meas-PT is compared to the temperature distribution measured by the sensors, see Fig. 2 This comparison can be done by e.g. a matrix norm or a machine learning algorithm. Then, the best match of the pre-simulated cases to the measured is taken as the current state of the device. Then, the temperature at the important-PT can be looked up in that simulation.

[0075] Fig. 2 The measured and simulated temperature distributions are plotted. Each simulated case is compared to the measured and the best match is identified.

[0076] While the application has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. The application is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practising the claimed application, from a study of the drawings, the disclosure, and the dependent claims.

Claims

1. A system for monitoring equipment, the system comprising: - at least one temperature sensor; - a processing unit; and - an output unit; wherein the at least one temperature sensor is configured to acquire at least one temperature measurement at a first location of an operating equipment, and wherein the first location is in thermal contact with a second location of the operating equipment; wherein the at least one temperature sensor is configured to provide the at least one temperature measurement to the processing unit; wherein the processing unit is configured to select a simulated temperature distribution of the first location of a simulated equipment from a plurality of simulated temperature distributions simulating the first location of the simulated equipment, wherein the selection comprises a comparison of the at least one temperature measurement with the plurality of simulated temperature distributions of the first location, wherein the plurality of simulated temperature distributions of the first location each relate to a different scenario with respect to a simulated operation of the simulated equipment, and wherein for each of the different scenarios there is a correlation between the simulated temperature distribution of the first location of the simulated equipment and a simulated temperature at the second location; wherein the processing unit is configured to determine that there is or is developing a hot spot at the second location of the operating equipment, wherein the determination comprises using the correlation between the simulated temperature distribution of the first location and the second location for the selected simulated temperature distribution of the first location of the simulated equipment; and wherein upon determining that there is or is developing a hot spot at the second location of the operating equipment, the output unit is configured to output a fault indication at the second location of the operating equipment.

2. The system according to claim 1, wherein the at least one temperature sensor comprises one or more infrared cameras, one or more surface acoustic wave sensors, or one or more RFID sensors.

3. The system according to any one of claims 1 to 2, wherein the at least one temperature measurement comprises a plurality of temperature measurements, and wherein the plurality of temperature measurements are acquired simultaneously.

4. The system according to any one of claims 2 to 3, wherein the at least one temperature sensor is an infrared camera, and wherein the at least one temperature measurement comprises an infrared image of the first location.

5. The system according to any one of claims 1 to 4, wherein the plurality of simulated temperature distributions are simulated in a process comprising utilization of finite element analysis.

6. The system according to any one of claims 1 to 5, wherein for each of the different scenarios the correlation between the simulated temperature distribution of the first location of the simulated equipment and the simulated temperature at the second location is determined by utilization of finite element analysis. utilization of matrix norms or machine learning algorithms implemented by the processing unit.

7. The system of any one of claims 1-6, wherein the comparison of the at least one temperature measurement to the plurality of simulated temperature distributions comprises:

8. A method for monitoring equipment, the method comprising: a) acquiring at least one temperature measurement at a first location of an operating equipment by at least one temperature sensor, and wherein the first location is in thermal contact with a second location of the operating equipment; b) providing the at least one temperature measurement to a processing unit; c) selecting a simulated temperature distribution of the first location of a simulated equipment from a plurality of simulated temperature distributions simulating the first location of the simulated equipment, wherein the selection comprises a comparison of the at least one temperature measurement with the plurality of simulated temperature distributions of the first location, wherein the plurality of simulated temperature distributions of the first location each relate to a different scenario with respect to a simulated operation of the simulated equipment, and wherein for each of the different scenarios there is a correlation between the simulated temperature distribution of the first location of the simulated equipment and a simulated temperature at the second location; d) determining that there is or is developing a hot spot at the second location of the operating equipment, wherein the determination comprises using the correlation between the simulated temperature distribution of the first location and the second location for the selected simulated temperature distribution of the first location of the simulated equipment; and e) upon determining that there is or is developing a hot spot at the second location of the operating equipment, outputting a fault indication at the second location of the operating equipment. c) selecting, by the processing unit, a simulated temperature profile of the first location of the simulated device from the plurality of simulated temperature profiles of the first location of the simulated device, wherein the selecting comprises: comparing the at least one temperature measurement to the plurality of simulated temperature profiles of the first location, wherein the plurality of simulated temperature profiles of the first location each relate to a different scenario with respect to simulated operation of the simulated device, and wherein for each of the different scenarios there is a correlation between a simulated temperature profile of the first location of the simulated device and a simulated temperature at the second location; and d) determining, by the processing unit, that there is or is developing a hot spot at the second location of the operating device, and wherein the determining comprises: using the correlation between the simulated temperature profile of the first location and the second location for the selected simulated temperature profile of the first location of the simulated device; and e) outputting, by an output unit, a fault indication at the second location of the operating device upon determining that there is or is developing a hot spot at the second location of the operating device.

9. The method of claim 8, wherein the at least one temperature sensor comprises one or more infrared cameras, one or more surface acoustic wave sensors, or one or more RFID sensors.

10. The method of any one of claims 8 to 9, wherein the at least one temperature measurement comprises a plurality of temperature measurements, and wherein the plurality of temperature measurements are taken simultaneously.

11. The method of any one of claims 8 to 10, wherein the at least one temperature sensor is an infrared camera, and wherein the at least one temperature measurement comprises an infrared image of the first location.

12. The method of any one of claims 8 to 11, wherein the plurality of simulated temperature profiles are simulated in a process comprising utilization of finite element analysis.

13. The method of any one of claims 8 to 12, wherein for each of the different scenarios the correlation between the simulated temperature profile of the first location of the simulated device and the simulated temperature at the second location is determined by utilization of finite element analysis.

14. The method of any one of claims 8-13, wherein comparing the at least one temperature measurement to the plurality of simulated temperature distributions comprises: utilizing a matrix norm or utilizing a machine learning algorithm implemented by the processing unit.

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