ELECTRICAL ENERGY TRANSFER DEVICE

Description

[0001] The invention relates to a switching device with a switching point and a sensor for monitoring the condition of the switching device.

[0002] An electrical power transmission device is used to transmit electrical energy. Part of an electrical power transmission device is a switching device, which has at least one contact fitting for connecting the switching device. Furthermore, the electrical power transmission device has a sensor for monitoring the condition of the switching device.

[0003] In established systems, expensive sensors are used that employ algorithms to correct errors in the data they provide. This necessitates increased computing power, which in turn requires energy. In addition to increased energy consumption, more installation space is often required.

[0004] European patent application EP 3 001 204 A1 discloses a device for passing at least one electrical conductor through an opening. The device comprises a housing that surrounds a cavity for receiving the at least one electrical conductor. A current sensor is integrated into the housing. German patent application DE 10 2016 202 853 A1 discloses a high-voltage circuit breaker. For powering the high-voltage circuit breaker, it is provided that a device for generating electrical energy is arranged directly on the circuit breaker. For this purpose, it is proposed to arrange wind turbine generators or solar modules on a support frame of the circuit breaker, in addition to a control cabinet housing. European patent application EP 3 279 027 A1 discloses an arrangement with a network device for attachment to a contact wire of a current-carrying overhead line. Operating or condition parameters of the overhead line, or...Data from an associated railway line or road can be acquired and transmitted via the network device. A dedicated transceiver is connected to an inductive energy harvesting device. The Fraunhofer-Gesellschaft publication, "Sensor system with energy-autonomous sensor modules through energy harvesting for monitoring the operating parameters (condition monitoring) of high-voltage overhead lines," Duisburg, Germany, August 28, 2019, XP 055644739, describes the equipping of high-voltage overhead lines with sensor modules that are installed directly on the conductor cables at periodic intervals. The sensors are designed to operate autonomously, drawing energy from the current in the conductor cables via energy harvesting.

[0005] Therefore, the object of the invention is to provide a switching device with a sensor which, with a cost-effective design of the sensor, enables reliable and long-term operation of the sensor.

[0006] According to the invention, the problem is solved in a switching device of the type mentioned at the outset by the fact that the switching device has a contact fitting that enables access to the switching point of the switching device, the contact fitting is electrically contacted with the switching point and is part of a current path to be switched, and the sensor is supported by the contact fitting, wherein the sensor rests on a surface of the contact fitting and is in thermal contact with it.

[0007] Electrical energy is transmitted by means of an electrical power transmission device. For this purpose, the electrical power transmission device includes a switching device. The switching device serves to change the impedance of a switching point in a current path. For example, the switching device can have switching contacts that are movable relative to each other to form a switching point, and this relative movement of the switching contacts causes a change in impedance. However, it can also be provided that a potential change is effected, for example, using a semiconducting element. Electrical power transmission devices operate particularly in the medium and high voltage range, i.e., at rated voltages from several thousand volts up to several hundred thousand volts, e.g., over 1,000,000 volts. In order to integrate the switching device into a phase conductor, it is connected to at least a contact fitting.The contact fitting provides access to the variable-impedance current path (switching point) of the switching device. This allows the phase conductor, which is connected to the contact fitting, to be electrically connected to the switching device. Preferably, several contact fittings can be provided, particularly to allow the phase conductor to be connected to both sides of a switching point of the switching device. A contact fitting can also serve, for example, to electrically connect two switching points of a switching device (e.g., in series). A contact fitting can also be part of a supporting structure of the switching device. The contact fitting can also form a distribution housing or a gearbox housing, which serves both to transmit drive motion and to act as an electrically conductive contact fitting.A contact fitting is part of the electrical circuit to be switched. Switching devices include, for example, disconnect switches, circuit breakers, load switches, earthing switches, quick-action earthing switches, or surge arresters, which provide protection, e.g., against earth potential, based on a level-spark gap or a voltage-dependent resistor element. The contact fitting can be detachably connected to the switching device. It typically has high electrical conductivity to enable low-impedance integration of the switching device. The contact fitting can also serve to position a sensor, which can be supported by the contact fitting.Accordingly, the sensor is positioned near the switching point and thus typically near a critical area of ​​a switching device, but far enough away that its function is not affected by switching operations, such as those caused by mechanical vibrations. Furthermore, this type of sensor mounting offers the advantage of allowing for retrofitting. The sensor can, for example, rest on a surface of the contact fitting and be in thermal contact with it. This type of thermal contact between the sensor and the contact fitting is particularly advantageous when using sensors that measure the temperature of the contact fitting, as it reduces thermal transfer between the two.In addition to measuring temperature, the sensor can also measure other physical quantities, either additionally or alternatively. These can include, for example, electric current, electric voltage, force (e.g., from wind load), strain, other impulses, humidity, brightness, movements, changes in position, etc.

[0008] Another advantageous embodiment can provide that the sensor is at least partially shaded by the contact fitting.

[0009] The sensor is supported by the contact fitting. It is advantageously possible for the contact fitting to at least partially shade the sensor. This means that, at least temporarily or in sections, direct access to the sensor is prevented by the contact fitting, at least from one direction. It is advantageous to provide for the sensor to be completely shaded by the contact fitting. The contact fitting can provide mechanical protection for the sensor. Alternatively or additionally, the contact fitting can provide at least partial dielectric shading of the sensor. For example, a sensor can be arranged on the contact fitting in areas that are at least partially shielded by the contact fitting. For this purpose, the contact fitting can, for example, have recesses, enclosed angles, etc.

[0010] Another advantageous embodiment can provide that the sensor rests with a contact surface on the contact fitting and projects with a surface facing away from the contact surface in the direction of an earth potential.

[0011] Contacting the contacting fitting with a contact surface enables suitable temperature transfer between the contacting fitting and the sensor, particularly its contact surface, especially when measuring temperature. Furthermore, orienting the sensor's surface facing away from the contacting fitting towards ground potential can reduce the sensor's dielectric effects on the contacting fitting. This can be advantageously achieved in conjunction with dielectric shading of the sensor by the contacting fitting. Ground potential represents a neutral potential at an electrical power transmission device. In particular, electric fields, or rather the direction of electric fields towards ground potential, can be considered less critical with regard to the sensor's orientation than when oriented towards a high-voltage potential.A sensor oriented in this way prevents interference with the field distribution at an electrical power transmission facility. An earth potential can also be created, for example, by a pylon.

[0012] It is possible to retrofit a sensor to existing contact fittings by attaching it, for example, using an adhesive or screw connection, so that the contact fitting supports it. The sensor, which typically has a dielectric effect, can then conduct current away from the contact fitting towards ground potential.

[0013] Another advantageous embodiment can provide that the sensor is an energy-autonomous sensor.

[0014] The contact fitting can carry different electrical potentials depending on the switching state of the switching device. Depending on the magnitude of the electrical potential, it can therefore be difficult or even impossible to supply electrical energy to the sensor, for example, via a wired connection. With an energy-autonomous sensor, a separate external power supply is not necessary. Instead, the sensor incorporates an energy storage device, such as a rechargeable battery or a standard battery. Furthermore, the sensor can include a generator which, driven by energy present in the environment, provides the energy required for the sensor's operation. In particular, an energy-autonomous sensor can extract energy from the currents and voltages present in an electrical power transmission device. Alternatively, other sources in the sensor's vicinity can also be used.For example, the sensor can have a contact surface to which the physical quantity to be monitored, in this case temperature, is coupled into the sensor; alternatively, the sensor can have a cooling surface that serves to dissipate thermal energy. A generator can produce electrical energy from the temperature difference between the contact surface and the cooling surface to operate the sensor.

[0015] Another advantageous embodiment may provide that the sensor has a wireless radiating unit whose beam direction points towards an earth potential.

[0016] By using a wireless transmitter, especially when combined with the sensor's design as an energy-autonomous sensor, it can also be used and operate at high voltage potentials. For information transmission, the sensor has a wireless transmitter that sends information from the sensor to a receiving device in the direction of the beam. The beam direction should preferably point towards ground potential, allowing a receiving device to be located there, preferably at ground potential. This makes it possible to extract information about the sensor across potential differences at the electrical switching device and transmit it to a receiving device. The receiving device can, for example, be located on a mast. Information received there can be forwarded, if necessary. A microwave link can be used for this purpose.

[0017] Another advantageous embodiment can provide that the sensor is arranged laterally on a contact fitting.

[0018] A contact fitting can have a receptacle for the sensor in a vertical direction, against which, for example, the sensor's contact surface rests. The sensor is thus arranged laterally on the contact fitting, with contact bolts, for example, being located essentially perpendicular or parallel to the surface on which the sensor is laterally mounted. Particularly when a switching point of a switching device is oriented horizontally, a contact fitting can be arranged at the end face, and the sensor can also be positioned at the end face. If the sensor protrudes beyond the contact fitting, it may be shaded.

[0019] Another advantageous embodiment can provide that the switching device is an outdoor switching device.

[0020] An outdoor switching device is a switching device whose design allows it to withstand the elements. For example, the switching device may be equipped with an electrically insulating housing, which may feature ribbing to prevent the formation of leakage current paths. An outdoor switching device can be oriented horizontally or vertically in a columnar configuration. The horizontal or vertical orientation refers primarily to the relative position of the contact fittings. Particularly in columnar vertical configurations, the sensor may be spanned by a contact fitting and positioned below it. In this case, the connecting pins used to contact the contact fitting are preferably oriented vertically.An outdoor switching device in a horizontal orientation preferably positions the sensor at the front or between several switching points.

[0021] Another advantageous embodiment can provide that the sensor is spanned by an overhead line which is attached to the contact fitting.

[0022] When using outdoor switching devices, overhead lines can be used, which are attached to the contact fitting. The overhead lines are connected to the contact fitting, for example, by means of bolts, which are preferably oriented substantially perpendicular to the surface on which the sensor is attached to the contact fitting. Preferably, the sensor can be spanned by the overhead lines, and in particular, the sensor can be spanned by the contact fitting itself. This spanning can be achieved, for example, by covering the sensor with the overhead line and / or the contact fitting. This provides at least partial mechanical protection for the sensor. Furthermore, this can protect the sensor from weathering.However, it is also possible for the outdoor switching device to have, for example, an inclined orientation of the contact fitting located between a vertical and a horizontal. This is possible, for instance, when using switching devices in a so-called dead-tank design, where a switching point is located inside an electrically conductive encapsulated housing. Outdoor feedthroughs are used to integrate the electrical switching device into a phase conductor run; these feedthroughs are, for example, attached at an angle to the electrically conductive housing. The sensor may be partially or sectionally spanned by the overhead lines and / or by the contact fitting.

[0023] Another advantageous embodiment can provide that the sensor is at least partially spanned by the contact fitting.

[0024] Alternatively or in addition to overvoltage of the sensor by an overhead power line, the sensor may also be at least partially covered / shielded by the contact fitting itself. In this case, the contact fitting can provide mechanical protection for the sensor in addition to its electrical function.

[0025] Advantageously, the sensor can also be provided with a thermally reflective surface shape.

[0026] When a sensor or electrical power transmission device is installed outdoors, it is exposed to various external influences, particularly weathering. Using a reflective surface on the sensor reduces dynamic stresses caused by external factors such as sunlight. The sensor can be appropriately colored for this purpose. It can also have a coating, such as paint. This coating should have a high coefficient of thermal radiation to reduce measurement errors and minimize heat buildup. Alternatively, the sensor can have a structured surface. For example, it can be equipped with ribs that provide cooling and can also shade each other.

[0027] Furthermore, it can be advantageous to arrange the sensor on the front side of a switching device.

[0028] An end-face positioning utilizes a housing end to accommodate the contact fitting and sensor. This allows for easy alignment of the sensor towards ground potential. As a result, the electrical fields around the electrical switching device are only minimally affected. Furthermore, no modifications to the housing structure of the electrical switching device are necessary.

[0029] A switching device can have an end face on which the sensor is arranged. For this purpose, the end face of the switching device is provided with a contact fitting by which the sensor is supported on the switching device. Preferably, an end face can be arranged on an insulating housing or electrically insulating housing section of the switching device. For example, the housing can be a substantially rotationally symmetrical hollow housing such as a hollow cylinder, a hollow cone, a truncated hollow cone, etc. A mounting point, in particular provided by the contact fitting, can be arranged on the end face to integrate the switching device into a phase conductor. Depending on the mounting position, an end face of the switching device can be positioned horizontally, vertically, or at an angle.To form an end face, the switching device can have a single-sided, electrically insulating section that projects freely towards the end face. The housing projecting freely towards the end face is preferably electrically insulating. For example, an end face can be formed on an outdoor bushing with an electrically insulating housing, on a switching point with an electrically insulating housing, etc., which is oriented essentially perpendicular to the longitudinal axis of the element forming the end face, for example, an insulating housing. The insulating housing can form part of an electrically insulating barrier. The electrically insulating barrier can delimit a fluid receiving chamber. An electrically insulating fluid (especially gaseous) can be enclosed in the fluid receiving chamber and surround and electrically insulate phase conductors arranged inside the fluid receiving chamber.The fluid receiving chamber can, in particular, house a switching point of the switching device. The fluid can be pressurized to improve its electrically insulating properties. The switching device can be a pressure-fluid-insulated, or in particular, a pressure-gas-insulated, switching device.

[0030] An embodiment of the invention is shown schematically in a drawing below and described in more detail thereafter. The drawing shows... Figure 1: an electrical power transmission device with a vertical switching device, Figure 2: an electrical power transmission device with a horizontal switching device, Figure 3: an electrical power transmission device with a switching device in dead-tank design, Figure 4: a contacting fitting, in a first perspective view, Figure 5: the one from the Figure 4known contact fitting in a second perspective view, Figure 6: a contact fitting in a first modification, Figure 7: a contact fitting in a second modification, and Figures 8, 9 and 10: a contact fitting in a third modification.

[0031] In the Figure 1 , 2 and 3 The diagram shows the mounting options for a sensor on a switching device. Figures 4 and 5 They also show a mounting option for arranging a sensor on a contact fitting.

[0032] The Figures 1 to 3The figures show switching devices that have switching contacts movable relative to each other and can perform a switching operation (impedance change of a current path) by means of a relative movement of the switching contacts. Furthermore, the invention can also be used with other switching devices that, for example, operate using a semiconductor to change the impedance. A so-called surge arrester, which has a voltage-dependent resistive element and which performs a switching operation, i.e., an impedance change of the voltage-dependent resistive element, can also be understood as a switching device.

[0033] The one in Figure 1The vertical switching device shown has a support frame 1. The vertical switching device is positioned above the support frame 1. The vertical switching device has a support insulator 2, on which a switching point 3 of the vertical switching device is electrically insulated. The support insulator 2 is essentially hollow and cylindrical and is connected at one end to the support frame 1 and at the other end to the switching point 3. The switching point 3 has an insulating housing, inside of which switching contacts of the vertical switching device are positioned that are movable relative to each other. The insulating housing is fluid-tight at the ends of the switching point 3, allowing electrical contact between the switching contacts located inside the insulating housing to be made through the fluid-tight seal. The hollow axis of the insulating housing is essentially vertically oriented. Accordingly, in the Figure 1A single-line diagram is indicated. A first contact fitting 4 and a second contact fitting 5 are arranged on the end faces of the insulating housing of the switching point 3. The two contact fittings 4 and 5 are spaced apart from each other along a vertical line. The two contact fittings 4 and 5 are essentially identical in construction. The contact fittings 4 and 5 serve to connect overhead lines 6 and 7. The vertical switching device is connected to the overhead lines 6 and 7. Figure 1The system can be integrated into an electrical power transmission network, with the switching point 3 of the vertical switching device being arranged between the overhead lines 6, 7. In this case, the overhead lines 6, 7 are each designed with two conductors, so that a current flow via the overhead lines 6, 7 is divided between two conductors of the respective overhead line 6, 7. Bolts 8 are provided for contacting the overhead lines 6, 7 with the respective contact fittings 4, 5, to which the overhead lines 6, 7 can be connected, for example, by means of cable lugs (see illustrations of the Figure 4 ).

[0034] During operation of a switching device, heating occurs due to current flow through the closed switching point 3 or via the overhead lines 6, 7 and the contact fittings 4, 5. Furthermore, thermal energy can also be introduced into the system from the outside. Depending on the ambient temperature, especially when a [missing information] is provided as in the [missing information] Figure 1In the free-air version of a switching device shown, varying intensities of thermal energy can be emitted into or out of the switching device.

[0035] To monitor the state of the switching device, a sensor 9 is attached to the first contact fitting 4. The first contact fitting 4 supports the sensor 9. The contact fitting 4 is, in turn, supported by the switching point 3, the support insulator 2, and the support frame 1. The sensor 9 is arranged such that it is spanned by the first contact fitting 4 and also by the overhead line 6, which is contacted with the first contact fitting 4. This provides mechanical protection or a mechanical structure for the sensor 9 by both the overhead line 6 and the first contact fitting 4, with the sensor 9 itself being supported by this mechanical structure. The sensor 9 faces the first contact fitting 4, which supports the sensor 9, with a contact surface and is preferably rigidly connected to the first contact fitting 4.A surface of the sensor 9 facing away from the first contact fitting 4 and the mounting surface projects towards earth potential, i.e., towards the force-bearing support frame 1. This ensures not only mechanical shielding of the sensor 9 by the first contact fitting 4 and the overhead line 6 attached to it, but also dielectric shielding. Furthermore, this allows the orientation of the sensor 9 to only have a limited influence on the electric field that develops around the switching point 3. Alternatively or additionally, a sensor 9 can also be arranged on the second contact fitting 5.

[0036] Sensor 9 is an energy-autonomous sensor, meaning that it obtains the electrical energy necessary for its operation from its surroundings. Preferably, this sensor converts thermal energy present in its environment into electrical energy, thus providing its own power supply. For this purpose, the contact surface of sensor 9, which rests against the first contact fitting 4, can be used, allowing thermal energy to be introduced and converted into the sensor 9, particularly at this point. However, other energy-autonomous sensors can also be used. For example, energy can be wirelessly coupled to the sensor 9 by means of incident light, such as atmospheric light, or by illuminating the sensor 9 with laser light.The energy generated in sensor 9 is used to operate sensor 9. The sensor has sensing means for detecting a physical quantity, preferably temperature, but also humidity, air pressure, wind speed, electrical and / or mechanical voltage, current, acceleration, change in position (e.g., inclination), etc. The information determined by the sensing means is transmitted via a wireless transmission unit of sensor 9. The transmission of information by the transmission unit preferably occurs in a direction 16 towards ground potential, preferably in the direction of the support frame 1. Alternatively, transmission can also occur towards a mast.

[0037] The Figure 2Figure 1 shows a switching device in a horizontal configuration. This horizontal switching device has a support frame 1a on which a support insulator 2a is arranged. A distribution housing 10 is arranged on the support insulator 2a, facing away from the support frame 1a. A first switching point 11 and a second switching point 12 extend from this housing in opposite directions. The two switching points 11 and 12 each have an electrically insulating housing, which is essentially hollow. The hollow axes are oriented horizontally and are essentially perpendicular to the vertically oriented support insulator 2a of the horizontal switching device. The two switching points 11 and 12 are electrically connected in series. This series connection is preferably made via the electrically conductive distribution housing 10.As such, the distribution housing 10 forms a contacting assembly 10 to connect the switching points 11, 12 to each other. The distribution housing 10 can also serve to accommodate the sensor 9a. Contacting assemblies 4a, 5a are arranged at the free ends, i.e., on the end faces of the insulating housings of the switching points 11, 12. The contacting assemblies 4a, 5a serve in an analogous manner to the embodiment shown in the figure. Figure 1 a connection of the series-connected switching points 11, 12 with overhead lines 6, 7. The overhead lines 6, 7 are analogous to the design of the Figure 1 The system is constructed with multiple conductors, allowing the distribution of electrical current across several conductors of the overhead lines 6, 7. Bolts 8 are provided for electrical contact. One example of such contact is shown in the Figure 4shown in more detail. A sensor 9a is arranged on the first contact fitting 4a at one end face of the insulating housing of the first switching point 11. The sensor 9a is spanned by the overhead line 6, which is electrically contacted with the first contact fitting 4a. Furthermore, the sensor 9a is shaded from the first contact fitting 4a by being located substantially within the envelope of the first contact fitting 4a, and in particular within the envelope of the first switching point 11. Regarding the use of the sensor 9a, reference is made to the descriptions of the vertical switching device according to [reference to relevant section]. Figure 1 referred.

[0038] The Figure 3Figure 1 shows an electrical switching device in a dead-tank design. The electrical switching device has a switching point 13, which is surrounded by an electrically conductive housing 14. The electrically conductive housing 14 of the switching point 13 is connected to earth potential. Moving switching contacts of the switching point 13 are arranged within the electrically conductive housing of the switching point 13. To enable electrically isolated contacting and integration of the switching device in a dead-tank design, free-air penetrations 14a, 14b are provided via flange connections. The free-air penetrations 14a, 14b provide electrically insulating housings, each of which is connected at one end to a flange connection. A first and a second contact fitting 4b, 5b are connected to the free ends of the free-air penetrations 14a, 14b.Inside the outdoor penetrations 14a and 14b, phase conductors are arranged, which lead electrically insulated from the switching point 13 into the environment of the switching device in a dead-tank design. The first and second contact fittings 4b and 5b are arranged at the free ends of the outdoor penetrations 14a and 14b. Overhead lines 6 and 7 can be connected to the switching point 13 via the contact fittings 4b and 5b. The overhead lines 6 and 7 are electrically connected to the first and second contact fittings 4b and 5b via bolts 8. A sensor 9b is arranged on the first contact fitting 4b. The sensor 9b is positioned below the first contact fitting 4b, so that the sensor 9b is essentially spanned by the first contact fitting 4b and also by the outdoor line 6. The first contact fitting 4b shields the sensor 9b.

[0039] To ensure sufficient distance between the free ends of the open-air bushings 14a, 14b, the bushings 14a, 14b are tilted in opposite directions from a vertical on the electrically conductive housing of the switching point 13. This tilting enhances the protective function provided by the first contact fitting 4b and the overhead line 6. The emission direction 16 of the sensor 9b is again oriented towards earth potential, thus simplifying the placement of a receiving device there. Regarding the design, use, and function of the sensor 9b, reference is made to the embodiments according to sensors 9, 9a in the exemplary embodiments shown in [reference to relevant section]. Figure 1 and 2 referred.

[0040] In the exemplary embodiments according to Figure 1 , 2 and 3The contact fittings 4, 4a, 4b, 5, 5a, 5b are shown. The contact fittings 4, 4a, 4b, 5, 5a, 5b are in the Figures 4 and 5 Shown in perspective. A contact fitting 4, 4a, 4b, 5, 5a, 5b is to be electrically connected to the respective switching point 3, 11, 12, 13 of the respective switching device. For dielectric stabilization, the contact fitting 4, 4a, 4b, 5, 5a, 5b has four recesses arranged on a circular path. Through these recesses, electrical contact and mechanical retention of the contact fitting 4, 4a, 4b, 5, 5a, 5b on a switching device are achieved by means of bolts. A suitable position of the contact fitting 4, 4a, 4b, 5, 5a, 5b can be adjusted by rotating it on the circular path.

[0041] Furthermore, the contact fittings 4, 4a, 4b, 5, 5a, 5b form a tab in which several openings are arranged. Bolts 8 can be passed through these openings, to which, for example, an overhead line 6 can be electrically connected by means of cable lugs 15. Depending on the design of the overhead line 6, several conductors of the overhead line 6 can be connected to the multiple openings and the multiple bolts 8 arranged therein. A sensor 9, 9a, 9b is arranged on each of the first contact fittings 4, 4a, 4b. The radiation pattern of a radiation unit of the sensor 9, 9a, 9b is oriented such that it preferably radiates substantially towards ground potential.

[0042] In the Figure 4 For example, the use of a bolt 8 and a cable lug 15 for a conductor of an overhead line 6 is shown.

[0043] The Figure 5shows an alternative perspective view of the first contacting fitting 4, 4a, 4b, as shown in the Figure 4 The sensor 9, 9a, 9b rests with a contact surface on the first contact fitting 4, 4a, 4b. The contact surface of the sensor 9, 9a, 9b allows, for example, the emission or introduction, or generally the transfer of thermal energy between the sensor 9, 9a, 9b and the first contact fitting 4, 4a, 4b. Depending on the installation position of the first contact fitting 4, 4a, 4b, the sensor 9, 9a, 9b can be completely shaded, covered, or shielded by the first contact fitting 4, 4a, 4b. If required, the first contact fitting 4, 4a, 4b can also be configured such that the sensor is arranged laterally or end-faced on an insulating housing (see Figure 1). Figures 6, 7Regardless of the mounting position of the sensor 9, 9a, 9b or the first contact fitting 4, 4a, 4b, the first contact fitting 4, 4a, 4b should be electrically insulated from ground potential by means of an electrically insulating housing, for example, a switching point 3, 11, 12 or an outdoor feedthrough 14a, 14b. Information transmission from the sensor 9, 9a, 9b by a transmitting unit should preferably occur in the direction 16 of ground potential, from which the first contact fitting 4, 4a, 4b is electrically insulated.

[0044] The in the Figures 4 and 5The illustrated embodiment of a first contact fitting 4, 4a, 4b has a substantially flat, plate-like structure. However, it is also possible for the recesses through which the first contact fitting 4, 4a, 4b is mechanically connected to the switching device to be oriented at an angle, particularly perpendicular to the multiple openings for electrical contact with an overhead line. This can be achieved, for example, by joining two discrete plates at an angle, by bending or casting the contact fittings at an angle. The angled legs can be, for example, L-shaped or T-shaped relative to each other. Depending on the installation location, an angled design of the contact fitting allows for the desired effect, particularly with regard to dielectric shading of the sensor 9, 9a, 9b.

[0045] The in the Figures 6 and 7The contact fittings 4c and 4d shown in the first and second variations are plate-like. The contact fitting 4e in the third variation is angled, is a cast part, and has a circular base.

[0046] The contact fitting 4c of the first modification is plate-like, with one side of the plate having a concave shape. This allows for the arrangement of several recesses distributed along a circular path along the concave recess. The contact fitting 4c of the first modification can be brought into contact with, for example, a shoulder or collar on its outer surface, which is appropriately curved, via these recesses distributed along the circular path, and thus electrically contacted. This simplifies the process of, for example, utilizing existing sections of a switching device to make electrical contacts with a contact fitting 4c. Furthermore, several openings are provided in the plate-like surface of the contact fitting 4c of the first modification to allow for the insertion of bolts, analogous to the embodiment shown. Figures 4 and 5Overhead lines 6, 7, for example, can be electrically contacted via bolts 8 and corresponding cable lugs.

[0047] The contact fitting 4c of the first modification has an asymmetrical shape, the asymmetry relating to the circular path of the recesses on the convex section of the contact fitting 4c of the first modification. In the asymmetrical zone, i.e., laterally adjacent to the field with the openings for the bolts, a surface 17 is provided on which a sensor 9, 9a, 9b can be positioned. For example, the sensor 9, 9a, 9b can be screwed to the contact fitting 4c of the first modification.

[0048] The Figure 7 shows a contact fitting 4d in a second modification, which is a further development of the one from the Figure 6The contact fitting 4d is a known modification of the first version. To obtain a larger contact area for the recesses for mounting with a switching device, a convex edge is arranged asymmetrically along the edge of the essentially plate-shaped rectangular contact fitting 4d in the second version. Similarly, the field with the openings for the bolts for contacting the contact fitting 4d in the second version is also arranged asymmetrically. Compared to the contact fitting 4c of the first version, this allows for a larger number of recesses for mounting the contact fitting 4d in the second version. Analogous to the design of the contact fitting 4c of the first version, the contact fitting 4d in the second version also features a rectangular area 17, which is arranged in the asymmetrically widened area.

[0049] The Figures 8, 9 and 10Figure 4e shows a contact fitting in a third modification. The contact fitting 4e has a substantially rectangular terminal plate in which openings for contacting the contact fitting 4e in the third modification are provided. This terminal plate sits perpendicularly on a base which has several recesses distributed along a circular path for contacting the contact fitting 4e in the third modification. For example, such a contact fitting 4e in the third modification can be mounted on the end face of an outdoor feedthrough. This angled arrangement of the terminal plate and base enables improved shading of the surfaces 17 intended for receiving a sensor 9c.An angle is enclosed between the base and the connection plate, which, due to the electrically conductive properties of the contact fitting 4e in the third modification, at least partially enables dielectric shielding of the sensor 9c. An example is shown in the... Figure 8 It has been shown that a sensor can be positioned near the origin of the angle vertex. However, it can also be provided that a sensor 9c can be arranged at a distance from the angle vertex, for example at the level of the openings for receiving the bolts for contacting overhead lines. Recesses in the base for contacting or for fastening the contacting fitting 4e in the third modification 7 can be analogous to those in the Figures 4 and 5 The described circular path (there with four openings) lies. Thus, here too, there is the possibility of choosing the orientation of the contact fitting 4e in a third variation.

[0050] The in the Figures 4, 5 ,6, 7 , 8, 9 and 10 The contact fittings 4, 4a, 4b, 4c, 4d, 4e shown are interchangeable and can be used on various switching devices. In particular, it is possible to use the contact fittings shown in the Figures 8, 9 , 10 The contact fitting 4e shown in the third embodiment of the switching device in dead-tank design, as in the Figure 3 shown, to be applied. There, by a corresponding rotation of the base of the contact fitting 4e in the third modification, a suitable dielectric and mechanical shielding of the sensor 9b on the inclined free-air feedthroughs 14a, 14b is enabled.

Claims

1. Switching unit having a switching point (3, 11, 12, 13) and a sensor (9, 9a, 9b, 9c) for monitoring the state of the switching unit, characterized in that the switching unit has a contact fitting (4, 4a, 4b, 5, 5a, 5b, 10) that enables access to the switching point (3, 11, 12, 13) of the switching unit, the contact fitting (4, 4a, 4b, 5, 5a, 5b, 10) is electrically contact-connected to the switching point (3, 11, 12, 13) and is part of a current path to be switched, and the sensor (9, 9a, 9b, 9c) is carried by the contact fitting (4, 4a, 4b, 4c, 4d, 4e, 5, 5a, 5b, 10), wherein the sensor (9, 9a, 9b, 9c) bears on a surface of the contact fitting (4, 4a, 4b, 4c, 4d, 4e, 5, 5a, 5b, 10) and is thermally linked thereto.

2. Switching unit according to Claim 1, characterized in that the sensor (9, 9a, 9b, 9c) is at least partially masked by the contact fitting (4, 4a, 4b, 4c, 4d, 4e, 5, 5a, 5b, 10).

3. Switching unit according to Claim 1 or Claim 2, characterized in that the sensor (9, 9a, 9b, 9c) bears on the contact fitting (4, 4a, 4b, 4c, 4d, 4e, 10) with a bearing surface and protrudes in the direction of a ground potential with a surface facing away from the bearing surface.

4. Switching unit according to one of Claims 1 to 3, characterized in that the sensor (9, 9a, 9b, 9c) is an energy-self-sufficient sensor (9, 9a, 9b).

5. Switching unit according to one of Claims 1 to 4, characterized in that the sensor (9, 9a, 9b, 9c) has a wireless radiation unit whose radiation direction points in the direction of a ground potential.

6. Switching unit according to one of Claims 1 to 5, characterized in that the sensor (9, 9a, 9b, 9c) is arranged laterally on a contact fitting (4a, 4b, 4c, 4d, 4e, 5, 5a, 5b, 10).

7. Switching unit according to one of Claims 1 to 6, characterized in that the switching unit is an outdoor switching unit.

8. Switching unit according to one of Claims 1 to 7, characterized in that the sensor (9, 9a, 9b, 9c) is spanned by an overhead line (6, 7) that is fastened to the contact fitting (4, 4a, 4b, 4c, 4d, 4e, 5, 5a, 5b, 10).

9. Switching unit according to one of Claims 1 to 8, characterized in that the sensor (9, 9a, 9b, 9c) is at least partially spanned by the contact fitting (4, 4a, 4b, 4c, 4d, 4e, 5, 5a, 5b, 10).

10. Switching unit according to one of Claims 1 to 9, characterized in that the sensor (9, 9a, 9b, 9c) has a thermally reflective surface structure.

11. Switching unit according to one of Claims 1 to 10, characterized in that the sensor (9, 9a, 9b, 9c) is arranged on an end face on a switching unit.