Method and test device for checking the state of a vacuum interrupter unit on the basis of x-ray diagnostics, and test system

Abstract

The invention relates to a method for checking the state of a vacuum interrupter unit (1), having the steps of: - detecting X-ray radiation (9) emitted by the vacuum interrupter unit (1), - generating an image (12) of at least one radiation source (R1, R2, R3, R11, R12, R13) of the vacuum interrupter unit (1) on a projection plane on the basis of the detected X-ray radiation (9), at least one radiation source being represented by at least one image point (B1, B2, B3, B11, B12, B13) in the image (12), - detecting an X-ray spectrum (19, 20, 21, 22, 23) of the X-ray radiation (9) in the at least one image point (B1, B2, B3, B11, B12, B13), and - checking the state of the vacuum interrupter unit (1) on the basis of the detected X-ray spectrum (19, 20, 21, 22, 23). The invention also relates to a test device (7) and a test system (8).

Description

[0001] 2023PF12496

[0002] Description

[0003] Method and test device for checking the condition of a vacuum interrupter unit based on X-ray diagnostics, as well as test system

[0004] Regardless of the grammatical gender of a particular term, persons with male, female or other gender identities are included.

[0005] The present invention relates to a method for checking the condition of a vacuum interrupter unit.

[0006] Furthermore, the invention relates to a test device for checking the condition of a vacuum interrupter unit.

[0007] The invention also relates to a test system comprising at least one vacuum interrupter unit and at least one test device.

[0008] Vacuum interrupter units are used, for example, in high-voltage circuit breakers. High voltage, as defined by the standard, corresponds to an alternating voltage greater than 1000 V, or a direct voltage greater than 1500 V.

[0009] Specifically, multiple vacuum interrupter units can be used in a vacuum switchgear system.

[0010] Vacuum switching tubes are electrical components for switching electric currents in, for example, a gas-free glass, ceramic or metal housing.

[0011] During the development and operation of the vacuum interrupter unit, the emission of electrons is unavoidable due to the switching processes and the applied voltages when the contacts of the vacuum interrupter unit or other components of the vacuum interrupter unit are closed. 2023PF12496

[0012] 2. A potential difference exists as a voltage difference. When the emitted electrons encounter an obstacle and are thereby decelerated, bremsstrahlung can be emitted. This bremsstrahlung can be X-ray radiation. Furthermore, the intensity of otherwise identical vacuum interrupter units is subject to considerable variation between individual units. In particular, vacuum interrupter units can act as sources of interference when emitting electrons. The intensity of X-ray radiation can also change over the lifetime of a vacuum interrupter unit.

[0013] Generally, the intensity of the interference radiation is measured and recorded integrally. If necessary, the radiation emanating from the vacuum interrupter unit is measured in different directions. However, this information does not allow us to determine the source of the X-rays or other radiation, and consequently, it does not reveal the cause or the problem with the vacuum interrupter.

[0014] In particular, a vacuum interrupter typically consists of two electrodes to which a defined voltage is applied. Additionally, there are further, floating electrodes whose voltage (referred to, for example, as intermediate voltage) drifts slowly, on the order of minutes, in one direction or the other due to the very good insulation, thus deviating from the design value (which can be determined, for example, by means of a capacitive voltage divider). This drift is difficult to predict and depends on the history of the individual vacuum interrupter. The resulting voltage of the floating potentials is a key factor in determining whether the vacuum interrupter achieves its required voltage withstand capability and can therefore fulfill its function. 2023PF12496

[0015] 3

[0016] Previous voltage measurements of the intermediate potentials involved capacitive coupling of a measuring system, such as a capacitive voltage divider. This influences the voltage being measured.

[0017] Therefore, one object of the present invention is to be able to efficiently check the condition of a vacuum interrupter unit by performing a non-contact analysis of the vacuum interrupter unit.

[0018] This task is solved by a method, a testing device, and a test system according to the independent patent claims. Meaningful further developments arise from the dependent patent claims.

[0019] One aspect of the invention relates to a method for checking the condition of a vacuum interrupter unit, comprising:

[0020] - Detection of X-ray radiation emitted by the vacuum interrupter unit,

[0021] - Generating an image of at least one radiation source of the vacuum interrupter unit on a projection plane based on the detected X-ray radiation, wherein at least one pixel in the image represents the at least one radiation source in and / or on the vacuum interrupter unit, wherein the X-ray radiation is emitted from the at least one radiation source,

[0022] - Capturing an X-ray spectrum of the X-ray radiation in which at least one pixel and

[0023] - Checking the condition of the vacuum interrupter unit based on the X-ray spectrum.

[0024] The proposed method allows for an efficient inspection and assessment of the condition of the vacuum interrupter unit or a vacuum switching tube. In particular, the inspection of the vacuum interrupter unit's condition can be carried out in such a way that no direct intervention, i.e., no direct contact and therefore no direct 2023PF12496

[0025] 4

[0026] Contacting the vacuum interrupter unit is required. This allows for a simpler, more space-saving, and more cost-effective setup for checking or measuring the condition of the vacuum interrupter unit.

[0027] For example, a potential difference may exist between two electrical components of the vacuum interrupter unit. Such a potential difference can lead to a locally increased electric field strength. This locally increased electric field strength may also occur at a defect in the vacuum interrupter unit. The increased electric field strength can lead to electron emission. If the emitted electrons encounter obstacles and are thereby slowed down, bremsstrahlung can be emitted. This emitted bremsstrahlung is then X-ray radiation.

[0028] Following a trajectory determined by the electric field, these electrons collide with a point in the vacuum interrupter unit, which in turn can lead to the emission of X-rays from that point. Thus, potential radiation sources can exist at such points or areas with a potential difference. By capturing and analyzing this X-ray radiation using image processing, the radiation sources can be detected or identified.

[0029] For example, reasons for changes in the functionality of the vacuum interrupter unit can be better determined by using X-ray diagnostics and, in particular, by pinpointing the location of the changes.

[0030] By checking the condition based on the detected X-ray radiation, the radiation source and thus the area with regard to potential difference can be identified early on. Accordingly, appropriate repair measures or 2023PF12496

[0031] 5

[0032] Replacement measures will be carried out on the vacuum interrupter unit.

[0033] The proposed method allows for the highly accurate localization of X-ray source points, i.e., the radiation sources within the vacuum interrupter unit. For example, localization can be achieved with an accuracy of 1 mm. Furthermore, spectral properties of the X-rays can be used to obtain further information about their origin. Additionally, temporal intensity fluctuations can be averaged for all X-ray source points by capturing them simultaneously, i.e., in a single shot. Slow scanning would lead to inaccurate results. Therefore, a scanning mechanism is unnecessary.

[0034] The proposed method can be used or carried out especially during development, testing, laboratory tests or in the field.

[0035] The image can be generated based on the detected X-ray radiation. From this image, relevant information regarding the radiation source in and / or on the vacuum interrupter unit can then be determined or ascertained using image processing or other processing steps.

[0036] Based on the detected X-ray radiation, a partial area of ​​the vacuum interrupter unit, where electrons strike due to the potential difference, can be imaged. In other words, a complete image of the vacuum interrupter unit is not generated; rather, the "luminous" or "radiating" points, i.e., radiation points, are made visible in the image.

[0037] The generated image is not a "shadow", a contour, or a 2023PF12496

[0038] Figure 6 shows the outline of the vacuum interrupter unit, which is created using an external X-ray source. The resulting image is actually a photograph of a body that itself emits light. Therefore, no external radiation source is required to create the image, as the vacuum interrupter unit itself serves as the light source to generate the corresponding image.

[0039] For example, the proposed method could be a computer-implemented method.

[0040] It is intended that an X-ray spectrum, particularly of a portion of the X-ray radiation, be recorded in order to take it into account when checking the condition. This can be achieved by placing a suitable detector, for example an energy-sensitive detector, in the area of ​​the pixel, with which the X-ray spectrum can be recorded. The condition of the vacuum interrupter unit can then be determined using the X-ray spectrum.

[0041] For example, a detector that does not resolve spatially but does resolve spectrally, or a detector that resolves spatially and spectrally, can be used.

[0042] The part of the X-ray radiation being analyzed could be the portion that created the single pixel. It is also conceivable that the entire X-ray radiation is being analyzed.

[0043] In one embodiment, it is provided that a voltage difference is determined based on the X-ray spectrum with respect to the electrical component and one of the two contact elements, or with respect to both electrical contact elements, or with respect to two electrical components of the vacuum interrupter unit. Thus, the detected radiation source, which is located in the area of ​​2023PF12496

[0044] The electrical component located at point 7 will be further analyzed. Using appropriate calculation methods, a voltage can be determined from the X-ray spectrum. Thus, based on the acquired spectrum, a non-contact voltage measurement of electrodes with a floating potential on a vacuum interrupter unit can be performed.

[0045] Above all, this means that, based on the evaluated X-ray spectrum and especially the evaluated image, a voltage measurement, in particular a voltage determination, can be carried out with regard to the vacuum interrupter unit without direct contact and especially without touching the vacuum interrupter unit.

[0046] The proposed method can be used for both DC-operated and AC-operated vacuum interrupter units. In the latter case, due to the highly non-linear field emission, the peak voltage is always measured. That is, all statements relating to the voltage apply to DC or the peak voltage value.

[0047] For example, the vacuum interrupter unit can be operated with alternating current, which is the normal case. Due to the strongly nonlinear increase in electron emission with the voltage difference and the extremely short time that the entire process (electron emission, electron flight time, photon emission) takes, essentially only electrons emitted at the time of the voltage peak contribute to the spectrum.

[0048] In one embodiment, it is provided that a photon energy is determined from the X-ray spectrum, whereby the voltage difference is determined based on the determined photon energy. An energetically upper end of the photon spectrum, and thus in particular the photon energy, corresponds to the maximum electron energy, which is calculated from the potential difference multiplied by the electron charge. 2023PF12496

[0049] 8. The affected electrons and the source electrode of the electrons that caused the X-ray radiation are seen. Based on the photon energy, which can be determined from the X-ray spectrum, a difference voltage can in turn be determined.

[0050] In one embodiment, it is provided that, based on a first voltage applied to the first electrical contact element and a second voltage applied to the second electrical contact element, it is determined whether the voltage difference determined from the X-ray spectrum represents a voltage difference between the electrical component and one of the two electrical contact elements. In other words, it can be verified whether the voltage difference determined from the X-ray spectrum corresponds to a voltage difference between the two known, and in particular measurable, voltages of the contact elements. Should a discrepancy be detected, it can be assumed that the voltage difference occurs between the component and one of the two contact elements.

[0051] In one embodiment, it is provided that, based on information about the at least one radiation source and the voltage difference between the electrical component and one of the two electrical contact elements determined from the X-ray spectrum, it is determined whether one of the two electrical contact elements or the electrical component is the source of electrons that strike the at least one radiation source and thus generate the X-rays. This allows for a more precise inspection of the vacuum interrupter unit.

[0052] In one embodiment, it is provided that the information about the at least one radiation source is used to represent the position of the at least one radiation source, based on a tracing of the electron flight path 2023PF12496

[0053] 9 starting from the position of at least one radiation source, the origin of the electrons is determined.

[0054] To determine whether the radiation source is such a radiation source, i.e., for example an electrode, which is formed in the area of ​​the electrical component, two approaches can be used.

[0055] These approaches make it possible to definitively identify the electrode from which the electrons were originally emitted.

[0056] In a first approach, taking into account a measured voltage, a self-consistent backward calculation, i.e., for example, a backward tracking, of the electron trajectory can be carried out from the location of the mapped, hit area.

[0057] A second approach involves first determining the number of floating potentials, i.e., electrical components, present in the vacuum interrupter unit. If, for example, there is only one such floating potential, this potential can be determined directly. From a measured voltage difference, and with the aid of theoretical calculations, a single possible electrode can be identified.

[0058] Above all, the image point and the geometry of the vacuum interrupter unit allow the origin of the image point, and thus the radiation source, to be determined. For example, this allows conclusions to be drawn about the regions between which the potential difference exists.

[0059] In one embodiment, it is provided that if the first electrical contact element is the origin of the electrons, a voltage applied to the electrical component is determined based on the first voltage and the voltage difference. If the second electrical contact element is the origin of the electrons, the voltage is determined based on the first voltage and the voltage difference. 2023PF12496

[0060] 10. The voltage applied to the electrical component is determined based on the second voltage and the voltage difference. If the electrical component is the origin of the electrons, the voltage applied to the electrical component is determined based on the first or second voltage and the voltage difference. Whether the first or second voltage is considered can be determined by checking whether the X-rays were emitted from the first or second electrical contact element.

[0061] Based on information from the radiation source, and in particular the position of the radiation source on a component, the origin of the electrons can be determined by computer-aided electron tracing or other methods. This optionally allows the absolute voltage applied to the component to be uniquely determined.

[0062] In one embodiment, it is provided that, based on the at least one pixel, a position of the at least one radiation source in and / or on the vacuum interrupter unit is determined.

[0063] For example, based on an imaging property of an image-generating unit, the radiation source can be deduced from the image point, i.e., a location on a projection surface or image plane. Thus, it is possible to trace back to the electrode or the area of ​​the vacuum interrupter unit that emitted the X-rays.

[0064] During image acquisition and generation, the image is created based on pixels derived from the captured X-rays. At least one pixel is generated on the image based on the radiation source that emitted the X-rays. Thus, the position of the image can be determined based on the pixel, specifically on 2023PF12496.

[0065] 11. The location of the radiation source can be determined. For example, for each radiation source located in and / or on the vacuum interrupter unit, a pixel or image area can be present in the image. Thus, an analysis regarding the radiation sources can be performed based on the pixel or multiple pixels.

[0066] In one embodiment, the image is generated using a photographic element or a flat-panel detector, whereby the X-ray radiation at least partially strikes the photographic element or the flat-panel detector. In particular, the X-ray radiation can be detected such that it at least partially strikes the photographic element or the flat-panel detector. The image can then be generated with the aid of the photographic element or the flat-panel detector. Specifically, the principal plane of extension of the photographic element or the flat-panel detector contains an image plane or projection plane of the generated image. The photographic element can, for example, be a photosensitive material such as X-ray film. The flat-panel detector can be referred to simply as a flat-panel detector.

[0067] With the aid of a flat-panel detector, images can be generated in digital form. In other words, the flat-panel detector can be a solid-state detector or a flat X-ray detector. This allows the image to be generated digitally for evaluation and analysis. The X-rays are primarily detected when they strike the photographic element or the flat-panel detector.

[0068] In one embodiment, it is provided that an aperture is arranged between the vacuum interrupter unit and the photographic element or between the vacuum interrupter unit and the flat panel detector, which is directed at the 2023PF12496

[0069] 12. The photographic element or X-ray radiation incident on the flat-panel detector is affected. The aperture can be an optical aperture, in particular a pinhole aperture. The aperture can be designed, for example, particularly in its shape and size, to provide a required resolution with regard to the image.

[0070] The aperture and the photographic element or the flat-panel detector capture the X-rays and generate the image, similar to a pinhole camera or based on the same principle. Thus, the X-rays can be captured or recorded according to a simple principle, allowing a desired image with a corresponding resolution to be produced.

[0071] Another aspect of the invention relates to a test device for checking the condition of a vacuum interrupter unit, comprising:

[0072] - a detection unit for detecting X-rays emitted by the vacuum interrupter unit and for generating an image of at least one radiation source of the vacuum interrupter unit on a projection plane based on the detected X-rays, wherein at least one image point in the image represents at least one radiation source in and / or on the vacuum interrupter unit, wherein the X-rays are emitted from the at least one radiation source,

[0073] - a detector for capturing an X-ray spectrum of the X-ray radiation in at least one pixel, and

[0074] - an electronic evaluation unit which is designed to check the condition of the vacuum interrupter unit based on the X-ray spectrum.

[0075] With the aid of the testing device, which may at least partially be an image processing system, 2023PF12496

[0076] 13. The condition of the vacuum interrupter unit is automatically checked or assessed.

[0077] With the aid of the proposed test device, the procedure of the aforementioned aspect can be carried out. In particular, the previously described procedure or an advantageous further development of the previously described procedure can be carried out with the test device just described.

[0078] The test device can be designed as an electrical, electromechanical and / or electronic system.

[0079] With the aid of the acquisition unit, the X-ray radiation can be captured in such a way that it can optionally be provided to an image generation unit in a targeted or processed manner to generate the image. The image generation unit can then generate the image or an X-ray image based on the captured X-ray radiation. The generated image can then be transmitted to or provided to the electronic evaluation unit, which may be a processing unit. The evaluation unit can then perform image processing on the generated image.

[0080] For this purpose, the image is evaluated accordingly, so that radiation sources in particular can be identified.

[0081] The respective radiation source can be located spatially close to or further away from a defect in and / or on the vacuum interrupter unit.

[0082] With the help of the test device, a system-side evaluation or analysis of the vacuum interrupter unit can be carried out.

[0083] In one embodiment of this further aspect, the detection unit is provided to have a photographic element or a flat-panel detector. X-rays, 2023PF12496

[0084] 14. The object detected by the detection unit can be located on the photographic element or on the flat-panel detector. The photographic element can be a photosensitive material. Thus, the image can be generated with the help of the photographic element or the flat-panel detector. The image plane or projection plane of the generated image is located in the area of ​​the flat-panel detector or in the area of ​​the photographic element.

[0085] In one embodiment of this further aspect, the detection unit is provided with an aperture located between the vacuum interrupter unit and the photographic element, or between the vacuum interrupter unit and the flat-panel detector. The aperture allows the X-ray radiation incident on the photographic element or the flat-panel detector to be influenced. In particular, the resolution of the generated image can be influenced by means of the aperture. The aperture can be designed in different shapes and sizes, depending on the required resolution of the generated image. Above all, the aperture can be selected or designed depending on the required resolution and the available radiation intensity of the X-ray radiation.

[0086] For example, the aperture can be designed as a pinhole aperture or a slit aperture.

[0087] Since the aperture is used for X-rays, it can be made of metals with a high atomic number, such as lead or wolfram. When using a slit aperture, spatial resolution in one direction can be completely dispensed with, depending on the circumstances. In this case, the slit aperture is positioned in the corresponding direction. Thus, image generation can be carried out as needed. 2023PF12496

[0088] 15

[0089] Other designs or configurations of apertures are also conceivable or usable.

[0090] For example, a detector that does not resolve spatially but does resolve spectrally, or a detector that resolves both spatially and spectrally, can be used.

[0091] Another aspect of the invention relates to a test system with at least one vacuum interrupter unit and at least one test device according to the previous aspect. Thus, the test device described earlier can be used for the test system. With the aid of the test system or test arrangement, the at least one vacuum interrupter unit or several vacuum interrupter units can be tested. In particular, with the aid of the test system, an automated check of the condition of a vacuum interrupter unit can be carried out.

[0092] For example, the test system can have appropriate mechanical devices so that the vacuum interrupter unit can be positioned at a suitable distance from the test device, in order to be able to analyze the X-ray radiation in the direction of the test device.

[0093] The test system can optionally be referred to as a test setup.

[0094] For example, the test system can be used for laboratory testing of vacuum interrupter units. The test system can be used not only in a testing laboratory but also in the field.

[0095] For use cases or application situations that may arise during the procedure and are not explicitly described here, it may be necessary to issue an error message and / or a request for user feedback and / or to set a default setting and / or a predetermined initial state according to the procedure. 2023PF12496

[0096] 16

[0097] Advantageous embodiments of one aspect are to be regarded as advantageous embodiments of all other aspects. The reverse is also true.

[0098] The invention also includes further developments of the inventive testing device and the inventive test system, which have features already described in connection with the further developments of the inventive method. For this reason, the corresponding further developments of the inventive testing device and the inventive test system are not described again here.

[0099] The invention also includes combinations of the features of the described embodiments.

[0100] The exemplary embodiments described below are preferred embodiments of the invention. In these embodiments, the described components each represent individual features of the invention, which can be considered independently of one another and further develop the invention independently. Each of these features can therefore be considered part of the invention, either individually or in a combination other than that shown. Furthermore, the described embodiments can also be supplemented by other features of the invention already described.

[0101] In the figures, functionally identical elements are each provided with the same reference symbols.

[0102] The following figures illustrate this in:

[0103] FIG 1 shows a schematic representation of a test system comprising a vacuum interrupter unit and a test device, wherein the 2023PF12496

[0104] 17

[0105] The test device can be used to check the condition of the vacuum interrupter unit;

[0106] FIG 2 shows a schematic representation of a further embodiment of a test system comprising a vacuum interrupter unit and a test device, wherein the test device can be used to check the condition of the vacuum interrupter unit; and

[0107] FIG 3 shows a schematic sequence of a verification process of the vacuum interrupter unit from FIG 1 and FIG 2, where spatially resolved X-ray diagnostics are used.

[0108] FIG. 1 schematically shows a vacuum interrupter unit 1. For example, the vacuum interrupter unit 1 is a component of a vacuum switchgear, which may have several vacuum interrupter units.

[0109] The vacuum interrupter unit 1 can, for example, be used as a circuit breaker. It can be used in high-voltage applications with voltages greater than 72 kV.

[0110] Optionally, a first voltage terminal 2 can be electrically connected to a second voltage terminal 3 using the vacuum interrupter unit 1. These voltage terminals 2 and 3 can be high-voltage terminals. To establish or break an electrical connection between the voltage terminals 2 and 3, the vacuum interrupter unit 1 has a first electrical contact element 4 and a second electrical contact element 5 spaced apart from it. The two electrical contact elements 4 and 5 can be moved towards each other by a mechanical switching movement to establish an electrical connection or at least to create a 2023PF12496

[0111] 18 of these electrical contact elements 4 , 5 can in turn be moved away from the other to create an electrical separation .

[0112] Due to the application areas of the vacuum interrupter unit 1, and especially the high voltages that can be safely switched with the vacuum interrupter unit 1, significant potential differences can occur between components of the vacuum interrupter unit 1. A voltage difference can occur between individual components or between an electrical component 6 and one of the two contact elements 4, 5. This potential difference can cause or result in field emission, i.e., the emission of electrons.

[0113] Excessive field strengths can occur due to a potential difference or multiple potential differences in and / or at the vacuum interrupter unit 1. These can be problematic with regard to flashover probability and / or dielectric strength. The proposed method can be used to achieve a high probability of detection in this respect.

[0114] For this purpose, a test device 7 can be used, for example. With this test device 7, the condition and thus the functionality of the vacuum interrupter unit 1 can be checked.

[0115] In a test system 8, which includes the vacuum interrupter unit 1 and the test device 7, a corresponding inspection can take place. The vacuum interrupter unit 1 and the test device 7 can be arranged or positioned relative to each other such that the condition of the vacuum interrupter unit 1 can be specifically checked using the test device 7. This allows for a non-destructive and, in particular, non-influencing inspection, because no direct contact with the vacuum interrupter unit 1 is necessary. To this end, see 2023PF12496

[0116] In order to realize 19, the condition of the vacuum interrupter unit 1 is checked on the basis of X-ray radiation 9 emitted by the vacuum interrupter unit 1.

[0117] Based on the detected X-ray radiation 9, an image 12, or a photograph, can be generated by an image generation unit 11 of the test device 7. The image is not, in particular, a silhouette of the vacuum interrupter unit 1, which is exposed or irradiated by means of an external X-ray source. Rather, the image 12 corresponds to a photograph of a body that itself emits light. In other words, image generation can be performed here, whereby the light source or radiation source is the object to be imaged, i.e., in this case, the vacuum interrupter unit 1 itself. Based on this generated image 12, image processing, image evaluation, and / or image analysis can be performed, for example, by means of an electronic evaluation unit 13 of the test device 7.This allows information, in particular location information, to be determined for at least one radiation source RI, R2, R3. The radiation source RI, R2, R3 can be an X-ray source point or an X-ray source area from which the X-ray radiation 9 is emitted. The radiation source RI, R2, R3 is specifically represented in Figure 12 by a pixel B1, B2, B3.

[0118] As illustrated in FIG. 1, and as is known in imaging technology and camera technology, image 12 is initially upside down. Therefore, taking this into account, the location or position of the radiation source R2 can be determined based on pixel B2.

[0119] Optionally, the test device 7 can be used to determine the local location of the X-ray points, for example, at least 2023PF12496.

[0120] 20. A radiation source RI, R2, R3 can be located on or within the vacuum interrupter unit 1 with high accuracy. Furthermore, spectral properties of the X-rays 9 can be used to obtain further information about the origin of the X-rays. Temporal intensity fluctuations are averaged equally for all X-ray points, since these are acquired simultaneously "in one shot". Thus, information for condition monitoring can be obtained from 2-dimensional images. In other words, by means of intensity-dependent projection of the source points, i.e., the position of at least one radiation source RI, R2, R3 within the vacuum interrupter unit 1, it is possible to deduce their position.

[0121] Optionally, spatially resolved X-ray diagnostics for vacuum interrupter units and corresponding vacuum switchgear can be provided, in particular carried out, with the aid of the test device 7.

[0122] Since reflecting or refracting X-rays is essentially only possible with very great effort, lens and mirror systems are not available for the image processing described here. Instead, an aperture 16 is used. This can be part of the image generation unit 11. By using the aperture 16, image generation can be analogous to image generation using a pinhole camera. The shape of the aperture 16 can be designed differently. In particular, it can be selected depending on the required resolution with respect to Figure 12 and the available radiation intensity of the X-rays 9. For example, the aperture 16 can be selected such that different resolutions result for different directions, especially the spatial direction. In particular, the aperture 16 serves to detect the X-rays 9.

[0123] For example, an aperture of f / 16 could be a pinhole or slit aperture. 2023PF12496

[0124] 21

[0125] Furthermore, the image-generating unit 11 can include a photographic element 17. This photographic element 17 can be, for example, an X-ray film or another photosensitive material. A flat-panel detector can also be used instead of the photographic element 17. In particular, the photographic element 17 can be designed as a photosensitive screen. As shown by way of example in FIG. 1, the aperture 16 is arranged between the vacuum interrupter unit 1 and the photographic element 17. An image plane or projection plane of Figure 12 is located in the principal extension plane of the photographic element 17. An aperture plane can, in turn, be located in the principal extension plane of the aperture 16.

[0126] In particular, the distance 18 between the aperture plane or aperture 16 and the image plane or photographic element 17 can be changed. For this purpose, the test device 7 can have one or more adjustment devices. Different magnifications, and thus also different resolutions with respect to Figure 12, can be achieved by changing the distance 18 or the ratio of the distances of the aperture 16 and the photographic element 17 to the vacuum interrupter unit 1.

[0127] For example, when using a slit aperture as aperture 16, the spatial resolution during image generation can be adjusted.

[0128] Alternatively, the aperture of f / 16 can have a circular aperture.

[0129] Furthermore, the test device 7 can be configured to generate multiple images of the vacuum interrupter unit 1 from different directions or perspectives, thereby achieving spatial resolution of the X-ray source points. 2023PF12496

[0130] 22

[0131] In particular, electron emission can occur in areas with increased surface field strength. In FIG. 1, such areas are represented, for example, by the electron emission points El, E2, and E3. For example, El is the cause of the radiation source RI, E2 is the cause of the radiation source R2, and E3 is the cause of the radiation source R3. For better understanding, an electron path 24 is shown between El and RI, E2 and R2, and E3 and R3, where RI, R2, and R3 can be referred to as impact points. Due to physical constraints, these impact points also represent the respective radiation sources RI, R2, and R3, which correspond to the electronic emission points El, E2, and E3.Due to the electron emission occurring in regions El, E2, and E3, the radiation sources RI, R2, and R3 can arise at any position in and / or on the vacuum interrupter unit 1, provided the electric and magnetic fields at the time of electron emission permit. Since field emission is a highly nonlinear effect, it can be approximated that, when an alternating voltage is applied to the vacuum interrupter unit 1, the emissions occur essentially at the voltage peaks. Therefore, the permissible paths that the electrons take from the electron emission points El, E2, and E3 to their points of impact are determined by the fields at the time of the voltage peaks. In Figure 12, for example, pixel Bl represents the radiation source RI, pixel B2 represents the radiation source R2, and pixel B3 represents the radiation source R3.

[0132] For example, the detection unit 10 and the image generation unit 11 can together form an X-ray pinhole camera.

[0133] Furthermore, based on the analyzed X-ray radiation 9 and the generated figure 12, further information for checking the condition of the vacuum interrupter unit 1 can be determined. In particular, a touch- 2023PF12496

[0134] 23. Voltage measurements without a voltage test are performed with regard to potential differences. The X-ray spectrum is taken into account for this purpose.

[0135] Of particular importance is the potential difference between the electrical component 6 and one of the contact elements 4, 5. Since multiple radiation sources may be present, additional pixels may appear in Figure 12. Therefore, a selection must first be made to determine the respective potential difference. Specifically, a check is performed to identify the radiation source R2, which extends into the area of ​​the electrical component 6. For this purpose, information concerning the vacuum interrupter unit 1 could be considered, for example. Furthermore, imaging properties of the X-ray pinhole camera can be taken into account.

[0136] As shown in FIG 1, an X-ray spectrum 19 is recorded with respect to the image point B2 and thus the radiation source R2.

[0137] To detect or measure the X-ray spectrum 19, a detector 15 can be positioned at pixel B2. This detector 15 can be a spatially and spectrally resolving detector or a non-spatially resolving but spectrally resolving detector. It is placed at the location of the film or flat-panel detector to measure the X-ray spectrum 19. The X-ray spectrum 19 can then be evaluated accordingly for potential difference determination.

[0138] An energetically upper end of the photon spectrum, and in particular of the photon energy, corresponds to the maximum electron energy Emax, which is calculated from the potential difference between the electrode containing the X-ray emission site and the 2023PF12496 multiplied by the electron charge e.

[0139] 24

[0140] The source electrode of the electrons is determined. Based on the photon energy, which can be determined from the X-ray spectrum 19, a differential voltage can in turn be calculated. For example, this can be illustrated with the following equation:

[0141] AU = Emax / e

[0142] For potential determination, the differential voltage can therefore be determined on the basis of the X-ray spectrum 19.

[0143] A detector 15 can also be used to record an X-ray spectrum 20 with respect to pixel Bl. This allows a differential voltage to be determined from the X-ray spectrum 20. In this example, based on the voltage difference, it can be determined that this is a voltage difference with respect to the two electrical contact elements 4 and 5. Due to the known and measurable voltages of the contact elements 4 and 5, a simple assignment is possible.

[0144] Based on a first voltage Ul applied to the first electrical contact element 4 and a second voltage U2 applied to the second electrical contact element 5, it can be determined whether the specified voltage difference is a voltage difference that exists between the electrical component 6 and one of the two electrical contact elements 4 or 5. The two voltages or potentials Ul and U2 are either already known or can be easily measured.

[0145] Specifically, based on at least one piece of information (e.g., location information) from at least one radiation source RI, R2, R3 and the voltage difference determined from the spectrum between the electrical component 6 and one of the two electrical contact elements 4, 5, it can be determined which of the two electrical contact elements 4, 5 is the origin of electrons which are in the at least one radiation source RI, 2023PF12496

[0146] 25

[0147] R2 strikes and thus generates the X-rays 9. If the origin of the electrons is the first electrical contact element 4, a voltage UO of component 6 is determined based on the first voltage Ul and the voltage difference, or if the origin of the electrons is the second electrical contact element 5, the voltage UO of component 6 is determined based on the second voltage U2 and the voltage difference. If the origin of the electrons is the electrical component 6, the voltage UO of the electrical component 6 is determined based on the voltage difference and either the first voltage Ul or the second voltage U2. For this purpose, it is checked whether the X-rays were emitted by the first or second electrical contact element 4, 5. This allows it to be determined whether the first voltage Ul or the second voltage U2 is to be used.

[0148] The voltage UO is, in particular, the voltage to be determined with respect to the floating potential of component 6. Component 6 can be a shield, a contact, or a part of the switching chamber of the vacuum interrupter unit 1.

[0149] Above all, such a measurement is advantageous because the voltage UO of component 6 is usually not measurable without influence, since generally very small capacitances determine the floating potential.

[0150] For example, component 6 could be a part formed between two insulators of the switching chamber of the vacuum interrupter unit 1. X-ray spectrum 19 could be a bremsstrahlung spectrum.

[0151] In particular, FIG. 1 shows a method for the non-contact measurement of high voltages, especially differential voltages and absolute voltages, for three electrodes of a vacuum interrupter unit 1. 2023PF12496

[0152] 26

[0153] The following explains in other words how the voltage measurement can be carried out on the vacuum interrupter unit 1.

[0154] First, image 12 can be acquired. Subsequently, at points Bl, B2, and B3 with sufficiently high intensity on the image plane, the spectrum can be determined, for example, using an energy-sensitive detector 15. If point Bl is selected and the spectrum analysis yields a voltage difference corresponding to the voltage between U2 and Ul, then it can be concluded that the corresponding electrons were accelerated between contact elements 4 and 5. From the additional spatial information of Bl, it follows that the corresponding X-ray source RI is located on contact element 5, which is why the defect El must then be located on contact element 4.

[0155] However, if the spectrum analysis yields a voltage difference that differs from the voltage difference between U2 and Ul, in the present example when analyzing pixels B2 and B3, then the determined voltage difference cannot initially be uniquely assigned and further analysis is required. This can be done as follows:

[0156] - Determining the electron energy, where the voltage difference is smaller than the voltage difference between U2 and Ul;

[0157] - Determining the location of the X-ray emission on the vacuum interrupter unit 1 ;

[0158] - Determining the origin of the electrons based on the location of the X-ray emission, which allows the definition of which of the two reference voltages, Ul or U2, is involved;

[0159] -If the X-ray source is located on one of the contact elements 4, 5, for example in the configuration B3, R3 and E3, the voltage UO can be directly determined. Similarly, 2023PF12496

[0160] 27. The voltage determination can also be carried out for other constellations.

[0161] Figure 2 shows a further example based on Figure 1. The difference here is that there is an additional potential difference between another electrical component 14 and one of the two contact elements 4, 5. The explanations already described with regard to Figure 1 also apply to Figure 2.

[0162] In FIG. 2, for example, potential electron emission points E1, E12, and E13 are shown. The explanations from FIG. 1 can be considered analogously here. For example, E1 is the cause of the radiation source R11, E12 is the cause of the radiation source R12, and E13 is the cause of the radiation source R13. The exemplary electron path 24 illustrates how the electrons can move from one electrode to the other. Due to the electron emission occurring in regions of E11, E12, and E13, the radiation sources R11, R12, and R13 can arise at any position in and / or on the vacuum interrupter unit 1. In FIG. 12, for example, pixel B1 represents the radiation source R11, pixel B12 represents the radiation source R12, and pixel B13 represents the radiation source R13.

[0163] As shown in FIG 2, a respective X-ray spectrum 21, 22, 23 is recorded with respect to the image points B11, B12, B13 and thus the radiation sources R11, R12, R13.

[0164] By tracing the respective electron path, the electrodes involved are determined. The corresponding voltage differences are obtained directly by evaluating the X-ray spectra 21, 22, 23. 2023PF12496

[0165] 28

[0166] For example, the X-ray spectrum 21 corresponds to a stress difference between the contact element 4 and the component 6. The X-ray spectrum 22 can correspond to a stress difference between the two components 6 and 14. The X-ray spectrum 23 can correspond to a stress difference between the contact element 5 and the component 14.

[0167] For an absolute voltage measurement with respect to one of the suspended electrodes 6, 14, at least one of the two absolute voltages of the electrodes involved must be known. These would be, for example, the voltage UO of component 6 and a third voltage U3 of the other component 14. Further evaluation with respect to the still unknown absolute voltage can now be carried out analogously to what has already been explained for FIG. 1.

[0168] If UO and U3 are unknown, the absolute voltage UO or U3 can be determined by one or more evaluations according to the procedure described above in FIG. 1 for three electrodes or for more than three electrodes, depending on the known absolute voltage of the electrodes involved. In the example of FIG. 2, determining the absolute voltage U3 would also be possible if the configuration E13, R13, and B13 is unknown. Here, UO would first be determined, and subsequent calculations could then be performed based on E12, R12, and B12.

[0169] U3 = Ul + (t70 - Ul) + (t / 3 - UO

[0170] Figure 3 below illustrates an exemplary procedure for checking the condition of the vacuum interrupter unit 1 and thus provides an example of a spatially resolved X-ray diagnosis of the vacuum interrupter unit 1. In particular, a non-contact voltage measurement of the vacuum interrupter unit 1 can be performed here.

[0171] In a first step S 1, the vacuum interrupter unit can

[0172] 1 and the test device 7 positioned accordingly relative to each other- 2023PF12496

[0173] 29 are performed so that test system 8 is available. This can be done, for example, in the testing laboratory or in the field.

[0174] In a subsequent step S2, a voltage can be applied to the vacuum interrupter unit 1 and, in particular, to the voltage terminals 2 and 3. In other words, the first voltage Ul and the second voltage U2 can be applied accordingly.

[0175] In a subsequent exemplary step S3, the X-ray radiation 9 can then be detected using the test device 7. For this purpose, the detection unit 10, an X-ray pinhole camera, or another X-ray-detecting unit can be used.

[0176] In a subsequent step S4, the figure 12 can be generated based on the detected X-ray radiation 9.

[0177] In an exemplary subsequent step S5, the generated image 12 can be analyzed, in particular evaluated, using image processing or image processing software, so that, based on the captured or determined pixels Bl, B2, B3, Bll, B12, B13, conclusions can be drawn about the location of the radiation sources RI, R2, R3, Rll, R12, R13. Furthermore, the respective voltage can be measured without touching or contacting the vacuum interrupter unit 1.

[0178] In a subsequent step S6, the potential differences can be determined on the basis of the X-ray spectra 19, 20, 21, 22, 23 without direct measurement at the vacuum interrupter unit 1.

[0179] For example, to determine the X-ray spectra 19, 20, 21, 22, 23, the detector 15 can be placed in the areas where the pixels Bl, B2, B3, B11, B12, B13 are formed in order to measure the respective X-ray spectrum. In this case, a detector with non-spatial but spectral resolution (2023PF12496) can be used.

[0180] 30

[0181] A detector can be placed. Alternatively, a spatially and spectrally resolved detector can be used instead of a film or a conventional flat-panel detector. An energetically high end of the photon spectrum, and in particular the photon energy, corresponds to the maximum electron energy E. max, which results from the potential difference between the electrodes involved, multiplied by the electron charge. The source electrode can be determined, for example, from field calculations. Thus, a non-contact measurement of the voltage difference is possible. Influence of the potential by the measurement due to connected measuring devices is excluded. Previous measurements have a lower limit frequency; therefore, the DC voltage value cannot be measured with the existing methods, but can be with the presented measurement method. The electrode to be evaluated can be measured externally without opening the vacuum interrupter unit 1 or placing measuring elements inside it.

[0182] 2023PF12496

[0183] 31

[0184] Reference character list

[0185] 1 vacuum interrupter unit

[0186] 2 first voltage connection

[0187] 3 second voltage connection

[0188] 4 first electrical contact element

[0189] 5 second electrical contact element

[0190] 6 electrical components

[0191] 7 Test device

[0192] 8 Test system

[0193] 9 X-rays

[0194] 10 recording units

[0195] 11 Image generation unit

[0196] Figure 12

[0197] 13 electronic evaluation unit

[0198] 14 other electrical components

[0199] 15 Detector

[0200] 16 aperture

[0201] 17 photographic elements

[0202] 18 distance

[0203] 19 X-ray spectrum

[0204] 20 X-ray spectrum

[0205] 21 X-ray spectrum

[0206] 22 X-ray spectrum

[0207] 23 X-ray spectrum

[0208] 24 Emission movement

[0209] Bl - B13 pixels

[0210] El - E13 electron emission points

[0211] RI - R13 radiation sources

[0212] U0 voltage

[0213] Ul first tension

[0214] U2 second voltage

[0215] U3 third voltage

[0216] S1-S 6 steps

Claims

2023PF12496 32 Patent claims 1. Method for checking the condition of a vacuum interrupter unit (1) , characterized by, - Detection of X-ray radiation (9) emitted by the vacuum interrupter unit (1) , - Generating an image (12) of at least one radiation source in and / or on the vacuum interrupter unit (1) on a projection plane based on the detected X-ray radiation (9) , wherein at least one image point (B1, B2, B3, B11, B12, B13) of the image (12) represents the at least one radiation source (RI, R2, R3, R11, R12, R13) , wherein the X-ray radiation (9) is emitted from the at least one radiation source (RI, R2, R3, R11, R12, R13) - Acquisition of an X-ray spectrum (19, 20, 21, 22, 23) of the X-ray radiation (9) in which at least one pixel (B1, B2, B3, B11, B12, B13) , and - Checking the condition of the vacuum interrupter unit (1) based on the captured X-ray spectrum (19, 20, 21, 22, 23) .

2. Method according to claim 1, wherein a voltage difference with respect to a first and second electrical contact element is determined on the basis of the X-ray spectrum (19, 20, 21, 22, 23). (4, 5) of the vacuum interrupter unit (1) or with respect to an electrical component (6, 14) of the vacuum interrupter unit (1) that is different from the two electrical contact elements (4, 5) and one of the two electrical contact elements (4, 5) or with respect to two electrical components (6, 14) that are different from the two electrical contact elements (4, 5) of the vacuum interrupter unit (1).

3. Method according to claim 2, wherein a photon energy is determined from the X-ray spectrum (19, 20, 21, 22, 23), wherein- 2023PF12496 33 where the voltage difference is determined on the basis of the determined photon energy.

4. Method according to claim 2 or 3, wherein, based on a first voltage (U1) applied to the first electrical contact element (4) and a second voltage (U2) applied to the second electrical contact element (5), it is determined whether the voltage difference determined from the X-ray spectrum (19, 20, 21, 22, 23) is a voltage difference between the respective electrical component (6, 14) and one of the two electrical contact elements (4, 5).

5. Method according to claim 4, wherein, based on information about the at least one radiation source (RI, R2, R3, R11, R12, R13) and the voltage difference between the respective electrical component (6, 14) and one of the two electrical contact elements (4, 5) determined from the X-ray spectrum (19, 20, 21, 22, 23), it is determined whether one of the two electrical contact elements (4, 5) or the respective electrical component (6, 14) is the origin of electrons which strike the at least one radiation source (RI, R2, R3, R11, R12, R13) and thus generate the X-ray radiation (9).

6. Method according to claim 5, wherein the information about the at least one radiation source (RI, R2, R3, R11, R12, R13) represents a position of the at least one radiation source (RI, R2, R3, R11, R12, R13), wherein the origin of the electrons is determined on the basis of tracing the electron path starting from the position of the at least one radiation source (RI, R2, R3, R11, R12, R13).

7. Method according to claim 5 or 6, wherein, if the first electrical contact element (4) is the origin of the electrons, a voltage applied to the electrical component (6, 14) is determined on the basis of the first voltage (Ul) and the voltage difference, or, if the second electrical- 2023PF12496 34 see contact element (5) the origin of the electrons, the voltage which is applied to the electrical component (6, 14) is determined on the basis of the second voltage (U2) and the voltage difference, or, if the electrical component (6, 14) is the origin of the electrons, the voltage which is applied to the electrical component (6, 14) is determined on the basis of the first or second voltage (U1, U2) and the voltage difference.

8. Method according to claim 6 or 7, wherein the position of the at least one radiation source (RI, R2, R3, Rll, R12, R13) in and / or on the vacuum interrupter unit (1) is determined on the basis of the at least one pixel (Bl, B2, B3, Bll, B12, B13).

9. Method according to one of the preceding claims, wherein the image (12) is generated on the basis of a photographic element (17) or a flat-panel detector, wherein the X-ray radiation (9) at least partially hits the photographic element (17) or the flat-panel detector.

10. Method according to claim 9, wherein an aperture (16) which is arranged between the vacuum interrupter unit (1) and the photographic element (17) or between the vacuum interrupter unit (1) and the flat-panel detector influences the X-ray radiation (9) incident on the photographic element (17) or on the flat-panel detector.

11. Test device (7) for checking the condition of a vacuum interrupter unit (1) , characterized by, - a detection unit (10) for detecting X-ray radiation (9) emitted by the vacuum interrupter unit (1) and for generating an image (12) of at least one radiation source (RI, R2, R3, R11, R12, R13) of the vacuum interrupter unit (1) on a projection plane based on the detected X-ray radiation (9), wherein at least one image point (B1, B2, B3, B11, B12, B13) in the image (12) represents the 2023PF12496 35 at least one radiation source (RI, R2, R3, R11, R12, R13) is represented in and / or on the vacuum interrupter unit (1), wherein the X-ray radiation (9) is emitted from the at least one radiation source (RI, R2, R3, R11, R12, R13), - a detector (15) for detecting an X-ray spectrum (19, 20, 21, 22, 23) of the X-ray radiation (9) in which at least one pixel (B1, B2, B3, B11, B12, B13) , and - an electronic evaluation unit (13) which is designed to check the condition of the vacuum interrupter unit (1) on the basis of the X-ray spectrum (19, 20, 21, 22, 23).

12. Test device (7) according to claim 11, wherein the detection unit (10) comprises a photographic element (17) or a flat panel detector.

13. Test device (7) according to claim 12, wherein the detection unit (10) has an aperture (16) which is arranged between the vacuum interrupter unit (1) and the photographic element (17) or between the vacuum interrupter unit (1) and the flat panel detector, wherein the X-ray radiation (9) incident on the photographic element (17) or on the flat panel detector can be influenced by the aperture (16), and in particular the aperture (16) is designed as a pinhole aperture or slit aperture.

14. Test system (8) comprising at least one vacuum interrupter unit (1) and at least one test device (7) according to any one of the preceding claims 11 to 13.

Images