Method for measuring the internal pressure of vacuum interrupters, and measurement system

Abstract

The invention relates to a method for measuring the internal pressure of at least one vacuum interrupter (12), the method comprising the steps of: applying a voltage (U) between an anode and a cathode of the vacuum interrupter (12); applying a magnetic field (F) in order to deflect an electron trajectory; measuring a discharge current arising from gas particles which have been struck by electrons and thereby ionised, and which have discharged within a vacuum of the vacuum interrupter (12); and measuring the internal pressure by converting the discharge current (I), wherein the discharge current (I) is measured in a defined partial region (24) of the vacuum interrupter (12). The invention also relates to a measurement system (10) for operating such a method.

Description

[0001] 2023PF12500

[0002] 1

[0003] Methods for measuring the internal pressure of vacuum switching tubes and measuring systems

[0004] The invention relates to a method for measuring the internal pressure of vacuum switching tubes according to the preamble of claim 1. Furthermore, the invention relates to a measuring system for operating such a method.

[0005] Vacuum switching tubes are electrical components used to switch electrical currents within, for example, a gas-free glass, ceramic, or metal housing. The internal pressure and leakage rate of such a vacuum switching tube directly affect its function and lifespan. Vacuum switching tubes are sealed for the duration of their service life, and it is not possible to directly access the internal volume of the vacuum switching tubes to perform a pressure measurement.

[0006] By far the most common method for measuring the internal pressure of vacuum switching tubes is based on the magnetron principle.

[0007] This method involves electrons accelerated in an electric field being forced by a magnetic field onto spiral paths, thus requiring them to travel a significantly longer distance to the anode. Gas particles struck by these electrons can be ionized, allowing a discharge to build up in the vacuum. The measurable discharge current is proportional to the internal pressure of the vacuum tube.

[0008] The plan is to generate targeted discharges within the vacuum interrupter and measure the resulting discharge current. Since this current is proportional to the internal pressure, a previously determined calibration curve can be used to determine the internal pressure of the vacuum interrupter. Typically, a voltage is applied between the closed contact system and one or more electrodes surrounding the contact system. The switching chamber and / or a metal vapor shield and / or field control shields, if present, are usually used as electrodes. Simultaneously, a magnetic field perpendicular to the electric field is applied by a coil located outside the vacuum interrupter. Because the construction of a vacuum interrupter can vary considerably from model to model, the available electrodes also vary.Therefore, the method yields results of varying reliability for different vacuum interrupter models and is also more or less difficult to adapt to individual vacuum interrupter models. 2023PF12500.

[0009] 2

[0010] This process is therefore highly dependent on the corresponding geometry of the respective vacuum switching tubes. Previous vacuum switching tubes for medium- and low-voltage applications have small volumes and simple geometries, so the existing method for measuring internal pressure yields reliable results. Newer high-voltage vacuum switching tubes, however, are significantly larger and their structure can be more complex, so the existing method yields less reliable results.

[0011] The object of the invention is therefore to provide a method for measuring the internal pressure of vacuum interrupters and a measuring system by which a particularly reliable statement can be made for high-voltage vacuum interrupters.

[0012] This problem is solved by means of a method with the features of claim 1 and by means of a measuring system according to the invention. Advantageous embodiments of the measuring system according to the invention are to be regarded as advantageous embodiments of the method according to the invention, wherein the means of the measuring system are used to carry out the method steps. Furthermore, advantageous developments of the invention are described by the dependent claims, the following description, and the figures.

[0013] A first aspect of the invention relates to a method for measuring the internal pressure of at least one vacuum switching tube, or a method for measuring the internal pressure of the at least one vacuum switching tube, both by means of a corresponding measuring system. In particular, the method is also configured to measure the corresponding internal pressure of vacuum switching tubes of different sizes with different geometric parameters or geometries and thus sizes.

[0014] The method comprises a multitude of steps, which are described below. The sequence is merely exemplary and by no means mandatory; therefore, the order may vary, and further, unmentioned steps may be added. In the first step, a voltage is applied between an anode and a cathode, which act as electrodes or contacts of the vacuum switching tube, particularly by means of a voltage device within the measuring system. This voltage device is used, in particular, to generate a defined potential difference between the anode and the cathode in the vacuum switching tube. 2023PF12500

[0015] 3

[0016] The anode and cathode thus also establish the electric field within the vacuum tube, with the anode typically being positively charged and the cathode negatively charged. This causes the electrons to accelerate from the cathode to the anode along a path (particularly from a central region of the vacuum tube to an inner circumferential region). Furthermore, it would also be possible to reverse the polarity of the anode and cathode, thereby reversing the direction of the electric field and thus the direction of electron movement within the vacuum tube. This switching allows for different operating modes, which can be used depending on the application.

[0017] In a second process step, a magnetic field is applied by means of at least one magnetic field coil or at least one magnet or magnetic element, in particular a magnetic field device of the measuring system, to deflect the path of the electrons transferring from the cathode to the anode. The at least one magnetic field coil (or magnet or magnetic element) or the entire magnetic field device is positioned and operated such that the magnetic field is perpendicular to the electric field between the anode and cathode. This deflects the electrons, which are accelerated by the electric field, for example, onto spiral paths. This spiral motion significantly lengthens the path of the electrons within the vacuum tube before they finally reach the anode.The magnetic field device is preferably arranged around the outer circumference of the vacuum switching tube and / or is designed in a ring-shaped form according to the outer circumference geometry. It comprises several individual, ring-shaped modules stacked on top of each other, which can be switched independently of one another for different magnetic fields.

[0018] In other words, applying an electric voltage provides the necessary electric field, which acts on the electrons inside the vacuum tube and accelerates them. The magnetic field causes them to move along spiral or helical paths through the vacuum tube, forcing them to travel a longer distance before reaching the anode. This arrangement, and the specific application of the electric voltage between the anode and cathode, allows the electric field to be used to provide predefined discharge conditions within the vacuum tube. 2023PF12500

[0019] 4

[0020] In a third process step, a measurement of the discharge current of gas particles struck by electrons and discharged in the vacuum of the vacuum interrupter is provided. This measurement is carried out, in particular, by means of a measuring device of the measuring system. The measuring device is thus designed to measure or detect the electric current or discharge current that arises from the movement of the ionized gas particles when they are accelerated by the electric field within the vacuum interrupter. This discharge current is, in particular, a measure of the number of ionized gas particles and is therefore proportional to the internal pressure of the vacuum interrupter. By detecting and evaluating this discharge current, the process enables the determination of the internal pressure of the vacuum interrupter.

[0021] In a fourth process step, the internal pressure measurement is performed by a conversion, in particular a proportional conversion, for example, by applying a calibration curve of the discharge current. This conversion is carried out, in particular, by means of an electronic computing unit of the measuring system. Furthermore, this conversion can also be performed, in particular, by means of a previously created calibration curve that takes into account specific geometric parameters such as the size and shape of the respective vacuum interrupter. The electronic computing unit is designed to acquire and process all measured data from the measuring system or from the discharge current measurement and to output data, in particular the internal pressure of the respective vacuum interrupters. It uses the information from the calibration curve to derive the current internal pressure of the vacuum interrupter.

[0022] The calibration curve is designed, for example, to have as little scatter band as possible in order to produce the most accurate values. A low scatter in the curve leads to increased reliability of the pressure measurement.

[0023] Finally, further algorithms, specialized software, trained models, and AI can be used to automate this process. These can support the electronic computing device in improving and accelerating the conversion of the discharge current into the internal pressure of the vacuum interrupter, thereby at least partially minimizing potential sources of human error. 2023PF12500

[0024] 5

[0025] To solve the problem of the invention and accordingly provide an internal pressure measurement of vacuum interrupters that can deliver particularly reliable information for high-voltage vacuum interrupters, the invention provides for virtually reducing the complexity of the vacuum interrupter by performing the measurement of the discharge current in a defined sub-region of the vacuum interrupter. This means that the discharge is only triggered in the defined sub-region of the vacuum interrupter, so as not to have to consider the complexity of the entire vacuum interrupter. Specifically, this means that the discharge is initiated only in a specific area or module (sub-region) of the vacuum interrupter. This area is defined in such a way that representative measurement results can be obtained that are correspondingly meaningful for the condition of the entire vacuum interrupter.Accordingly, a central section in front of the end sections along the elongated length of the vacuum switching tube would be preferable. This targeted measurement allows for the most accurate possible estimation of the internal pressure without requiring all information and / or details of the entire vacuum switching tube to be included in the measurement.

[0026] In other words, this means a modular internal pressure measurement of a vacuum interrupter tube. This allows for easier measurement of the internal pressure of vacuum interrupters with different tube geometries and geometric parameters. The targeted spatial limitation of the discharge offers advantages; for example, the discharge becomes insensitive to the specific vacuum interrupter tube geometry (especially in larger vacuum interrupters). The reproducibility of the discharges can also be increased, as unwanted discharges in unsuitable areas can be prevented, and multiple ignitions become less likely. Finally, it is advantageous that adapting the method to new tube geometries is simplified.

[0027] In an advantageous embodiment of the invention, the measurement is performed in a plurality of defined sub-areas, and at least one mean value for the internal pressure measurement is calculated based on these measurements. Measuring in multiple sub-areas allows for a more accurate and reliable determination of the internal pressure. This approach makes it possible, for example, to compensate for any local variations or irregularities in the discharge within the vacuum switching tube. Furthermore, a mean value of the measured values ​​reduces potential measurement errors and improves the overall accuracy of the internal pressure measurement. 2023PF12500

[0028] 6

[0029] In a further advantageous embodiment of the invention, the discharge takes place spatially in the area between the applied contacts. This precise spatial focus on the measurement between these defined contacts enables high accuracy of the internal pressure measurement, since, for example, interfering influences are not detected or are minimized, and the reproducibility of the measurement results is increased.

[0030] In a further advantageous embodiment of the invention, it is provided that the magnetic field is increased by the use of different magnetic field coils (or magnets, respectively).

[0031] The magnetic field is segmented, particularly to enable more complex magnetic field topologies. Segmentation of the magnetic field means that the magnetic field in the vacuum interrupter is not generated by a single magnetic field coil (or magnet or magnetic element), but by several positioned according to specifications. This allows for targeted control and adjustment of the magnetic field topology, which is especially advantageous in complex vacuum interrupter geometries. An example of this could be a vacuum interrupter with an irregular shape or multiple internal components that could influence the magnetic field differently. By using multiple magnetic field coils (or magnets or magnetic elements), different areas of the vacuum interrupter can be individually magnetically influenced.This allows for improved conditions to better control the electron trajectory and to increase or suppress the probability of gas particle ionization. In summary, segmenting the magnetic field using different magnetic field coils (or magnets or magnetic elements) enables precise adaptation to the specific requirements and conditions of various vacuum switching tubes.

[0032] In a further advantageous embodiment of the invention, it is provided that the distribution and / or current (magnet strength) of individual magnetic field coils (or magnets or magnetic elements) is adapted depending on the geometric parameters of the vacuum switching tube. This means that the positioning and current (magnet strength) of the individual magnetic field coils (or magnets or magnetic elements) can be adapted to the specific geometric properties of the vacuum switching tube.

[0033] In a further advantageous embodiment of the invention, it is provided that at least one electrically conductive element or component of the vacuum switching tube (e.g., a shielding body) is subjected to a voltage or grounded depending on the geometric parameters of the vacuum switching tube, so that the area in which discharges can occur is limited to the partial area or space between the 2023PF12500

[0034] The discharge activity is limited to the 7 contacts, and unwanted discharges are prevented in other areas or in a rear space. The predetermined or targeted application or grounding of an electrically conductive element of the vacuum interrupter (e.g., a shield) is therefore based in particular on the specific geometric parameters of the vacuum interrupter. This can mean that the specific shields or electrodes within the vacuum interrupter are designed in such a way that electric fields can be influenced or blocked in order to control the discharge activity.

[0035] This measure concentrates the discharge in a defined area, resulting in a more accurate measurement of the discharge current. At the same time, it prevents unwanted discharges from occurring in other parts of the vacuum interrupter, thereby improving, for example, the quality and / or stability of the measurement and / or the reproducibility of the results.

[0036] In a further advantageous embodiment of the invention, it is provided that a plurality of internal pressure measurements, shielded by electrically conductive elements (e.g., shielding elements), are carried out simultaneously. This means that several measurements of the internal pressure within the vacuum switching tube can be performed simultaneously and independently of one another. Each area or sub-area of ​​the tube is protected by electrically conductive elements or by special shielding elements or shields in order to isolate the measurements from one another and to prevent potential interference or crossover of the measurement results.

[0037] In a further advantageous embodiment of the invention, at least one geometric parameter is at least semi-automatically retrieved from a database by entering a vacuum interrupter identification number. This means that relevant geometric parameters can be automatically retrieved from a pre-existing database using a specific marking or identification of a vacuum interrupter. These geometric parameters could include information such as the size, shape, position, and other specific characteristics of the tube that are relevant for performing the internal pressure measurement. The automatic acquisition of these parameters simplifies and accelerates the process of configuring and adjusting the measuring system. The database used for this purpose can also be stored externally, and the required data can be acquired wirelessly, for example, via transmission modules over the internet.In other words, this data can also be downloaded from third-party databases. 2023PF12500.

[0038] 8

[0039] In a further advantageous embodiment of the invention, at least one adjustment for the internal pressure measurement is suggested, at least semi-automatically, depending on the geometric parameters. This means that the specific geometric parameters of a vacuum switching tube are used to automatically or semi-automatically suggest suitable settings or configurations for the measuring system. These adjustments can relate to various parameters, such as the placement and configuration of the magnetic field coils (or magnets or magnetic elements), the selection of the shielding bodies or shields, or the optimal measuring points within the tube. Finally, these adjustments can also be supported by training models and / or AI.

[0040] A further aspect of the invention relates to a measuring system for operating a method for measuring the internal pressure of at least one vacuum interrupter tube. The measuring system comprises a voltage device for applying a voltage between an anode and a cathode of the vacuum interrupter tube, a magnetic field device that generates a magnetic field by means of at least one magnetic field coil (or a magnet or magnetic element) to guide the electron path, a measuring device for detecting the discharge current of gas particles that have been struck by electrons and discharged in the vacuum of the vacuum interrupter tube, and an electronic computing device for converting the measured discharge current into the internal pressure of the vacuum interrupter tube. The measuring device is configured to measure the discharge current in a defined sub-region of the vacuum interrupter tube in order to enable improved internal pressure measurement.

[0041] In summary, the invention proposes a geometry-insensitive internal pressure measurement of vacuum switching tubes.

[0042] Further advantages, features, and details of the invention will become apparent from the following description of a preferred embodiment and from the drawing. The features and combinations of features mentioned above in the description, as well as those mentioned below in the figure description and / or shown in the single figure alone, can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention.

[0043] This shows: 2023PF12500

[0044] 9

[0045] Fig. 1 shows a schematic view of a possible embodiment of a measuring system for operating a method for measuring the internal pressure of at least one vacuum switching tube.

[0046] In the figure, identical or functionally equivalent elements are provided with the same reference symbols.

[0047] Fig. 1 shows an embodiment of a measuring system 10 for measuring or determining an internal pressure P in at least one vacuum switching tube 12. This measuring system 10 comprises a voltage device 14 that applies a voltage U between an anode 16 and a cathode 18 in the vacuum switching tube 12.

[0048] A magnetic field device 20 of the measuring system 10, which comprises at least one magnetic field coil or a magnet or magnetic element, generates a magnetic field F that deflects the electron paths B of the respective electrons e in the voltage field or in the electric field, as is also shown. The deflection of the electron paths is necessary for detecting the discharge current I of gas particles that are struck by electrons and discharged in the vacuum of the vacuum switching tube 12.

[0049] This process is monitored and measured by a measuring device 22 of the measuring system 10, which is designed to measure the discharge current I in a defined sub-area 24 of the vacuum interrupter 12. The data obtained are processed by an electronic computing unit 25 to calculate the internal pressure P of this vacuum interrupter 12. The technical design makes it possible to perform the measurement of the discharge current spatially between the energized anode 16 and cathode 18. In addition, the magnetic field F is segmented by the application of various magnetic field coils (or magnets or magnetic elements), whereby the distribution and / or current (or magnet strength) of these coils (or magnets or magnetic elements) is adapted according to the geometric parameters of the vacuum interrupter 12.

[0050] All components are electronically interconnected and feature data transmission modules that enable communication and data transfer between the individual components. The measuring system 10 is designed to perform the internal pressure measurement procedure in a specific sequence, but also offers flexibility for alternative procedure steps and the inclusion of further procedure steps as needed. 2023PF12500

[0051] 10

[0052] Another aspect of the measuring system 10 is the integration of at least one electrically conductive element 26 (e.g., a shielding body, in particular an annular shielding body, which is arranged on the inner and / or outer circumference around the vacuum switching tube) or, in particular, two electrically conductive elements 26 (e.g., two shielding bodies) for providing sub-areas 24 (in the elongated vertical direction of the vacuum switching tube 12, top and bottom), which, depending on the geometric parameters of the vacuum switching tube 12 to be dimensioned, is / are either additionally supplied with power or grounded. This allows a large number of shielded internal pressure measurements to be carried out simultaneously.

[0053] Finally, measuring system 10 offers the possibility of automatically retrieving geometric parameters from a database by entering an identification or identification number of the vacuum switching tube 12. Based on these geometric parameters, an adjustment of the measuring system or the components for the internal pressure measurement is automatically suggested in order to make the procedure as easy to handle as possible while still obtaining good values ​​and / or data.

[0054] 2023PF12500

[0055] 11

[0056] Reference symbol list

[0057] 10 measuring system

[0058] 12 Vacuum switching tube 14 Voltage device

[0059] 16 Anode

[0060] 18 Cathode

[0061] 20 Magnetic field device

[0062] 22 Measuring device 24 Sub-area

[0063] 25 Electronic computing equipment

[0064] 26 electrically conductive element (shielding body)

[0065] B Electron orbit

[0066] I Discharge current F Magnetic field

[0067] P Internal pressure

[0068] Voltage e electrons

Claims

1. 2023PF12500 12 Patent claims 1. Method for measuring the internal pressure of at least one vacuum switching tube (12), comprising the following method steps: - Applying a voltage (U) between an anode and a cathode of at least one vacuum switching tube (12), - Applying a magnetic field (F) to deflect an electron path, - Measurement of a discharge current (I) of gas particles that were struck by electrons and thereby ionized, discharged in a vacuum of at least one vacuum switching tube (12), and - Internal pressure measurement by conversion of the discharge current (I), characterized in that the measurement of the discharge current (I) is carried out in a defined sub-area (24) of the at least one vacuum switching tube (12).

2. Method according to claim 1, characterized in that the measurement is carried out in a plurality of defined sub-areas (24) and at least one mean value for the internal pressure measurement is calculated depending on this.

3. Method according to claim 1 or 2, characterized in that a discharge is carried out spatially in an area between the assembled contacts.

4. Method according to one of the preceding claims, characterized in that the magnetic field (F) is segmented by applying different magnetic field coils and / or magnets and / or magnetic elements.

5. Method according to claim 4, characterized in that a distribution and / or current and / or strength of the magnet of individual magnetic field coils and / or magnets and / or magnetic elements) is adapted depending on geometric parameters of the at least one vacuum switching tube (12). 2023PF12500 13 6. Method according to one of the preceding claims, characterized in that at least one electrically conductive element (26) of the at least one vacuum switching tube (12) is subjected to a further voltage or grounded depending on geometric parameters of the at least one vacuum switching tube (12).

7. Method according to claim 6, characterized in that a plurality of internal pressure measurements shielded with electrically conductive elements (26) are carried out simultaneously.

8. Method according to one of the preceding claims, characterized in that at least one geometric parameter is recorded at least semi-automatically from a database by entering a vacuum switching tube identification.

9. Method according to one of the preceding claims, characterized in that, depending on the geometry parameters, at least one adjustment for the internal pressure measurement is proposed, at least semi-automatically.

10. Measuring system (10) for operating a method for measuring the internal pressure of at least one vacuum switching tube (12), comprising at least one voltage device (14) for applying a voltage (U) between an anode (16) and a cathode (18) of the at least one vacuum switching tube (12) and a magnetic field device (20) for applying a magnetic field (F) by means of at least one magnetic field coil (or a magnet ora magnetic element) for deflecting an electron path (B), with at least one measuring device (22) for measuring a discharge current (I) of gas particles that have been struck by electrons and thereby ionized, have discharged in a vacuum of the vacuum switching tube (12), and with at least one electronic computing device (25) for converting the discharge current into an internal pressure (P) in the at least one vacuum switching tube (12), wherein the measuring device (22) is configured to perform the measurement of the discharge current in a defined partial area (24) of the at least one vacuum switching tube (12).

Images