HIGH-VOLTAGE DEVICE WITH TEMPERATURE SENSORING AND METHOD FOR TEMPERATURE SENSORING OF A HIGH-VOLTAGE DEVICE

Description

[0001] High-voltage device with temperature detection and method for temperature detection of a high-voltage device The invention relates to a high-voltage device with an inner conductor and an insulating body surrounding the inner conductor along its longitudinal direction.

[0002] Such a high-voltage device is known, for example, from WO 2015 / 172806 A1. The known high-voltage bushing is a high-voltage bushing that is typically used to guide the inner conductor, which is at high-voltage potential, through a wall at ground potential. For example, in the case of a transformer bushing, the wall forms a transformer housing. The high-voltage device is typically part of a high-voltage system with multiple high-voltage components such as transformers or switchgear.

[0003] The condition of the high-voltage device is therefore relevant both for the reliability of the high-voltage device and the reliability of the entire high-voltage system associated with the high-voltage device.

[0004] A temperature measurement at a feedthrough using an optical fiber inserted into the inner conductor is known from JPH 04296409 A.

[0005] The object of the invention is to propose a high-voltage device of the type which is as reliable as possible in operation.

[0006] The object is achieved by a high-voltage device according to claim 1. Further embodiments of the invention are part of the dependent claims.

[0007] During operation of the high-voltage device, relatively high currents flow through the inner conductor. This causes the temperature of the inner conductor to rise. The high-voltage device according to the invention provides a means of accurately and reliably measuring and evaluating the temperature of the inner conductor or of the insulating body close to the inner conductor. Methods for measuring temperature using light are already known to those skilled in the art. For example, using a light signal fed into the optical fiber, the temperature can be determined with spatial resolution using Raman scattering. This method utilizes temperature-dependent light scattering in the light-guiding optical fiber. The evaluation of the measured values ​​then includes an examination of the light wavelength of a light signal passing through the optical fiber.Furthermore, those skilled in the art are familiar with relatively inexpensive measurement methods that allow temperature measurement at only one point on the optical fiber, for example, at its end. Temperature measurement at the high-voltage device offers the advantageous possibility of monitoring the condition of the high-voltage device. This can be advantageously used to increase the reliability of the high-voltage device during its operation.

[0008] With the high-voltage device according to the invention, the temperature can be measured particularly accurately because the optical fiber is routed directly to the inner conductor. This is particularly advantageous compared to external temperature measurements, for example, on an outer housing of the high-voltage device. According to the invention, the optical fiber is routed directly to the inner conductor when the optical fiber and the inner conductor are located at a short distance from each other, no more than two centimeters. For example, the optical fiber can touch the inner conductor.

[0009] Depending on the design of the high-voltage device, the optical fiber can also be guided on a winding support, for example, made of a thin metal tube, surrounding the inner conductor. According to the invention, the optical fiber is guided in an insulating layer surrounding the inner conductor.

[0010] Temperature measurement in the high-voltage device according to the invention is particularly reliable because the means required for measurement, in particular the optical fiber, are already integrated into the high-voltage device during its manufacture. Therefore, systematic measurement errors cannot arise from the subsequent installation of a measuring device.

[0011] Furthermore, temperature measurement is also possible during operation of the high-voltage device according to the invention. In particular, temperature monitoring is not limited to laboratory tests. When using the optical fiber to transmit the measurement signal, the use of electrically conductive materials can advantageously be dispensed with. In this way, the measurement signal can be transmitted directly from the inner conductor, which is at high-voltage potential, to the evaluation unit, which is at ground potential.

[0012] In addition to the advantageous condition monitoring of the high-voltage bushing itself, the high-voltage device according to the invention offers advantages with respect to a high-voltage system in which the high-voltage device is used. If the high-voltage system is, for example, a power transmission system, the temperature detection at the high-voltage device can be used to optimize any load settings and / or load forecasts based on the measured temperatures. This enables improved load flow control of the entire power transmission system (for example, a high-voltage direct current transmission system).

[0013] The evaluation unit is suitably configured to generate a light signal that can be fed into the optical fiber. The evaluation unit can also extract the light signal from the optical fiber and evaluate it. As already mentioned, the evaluation of the light signal includes, for example, an examination of the wavelength of the light signal that has passed through the optical fiber.

[0014] The high-voltage device and / or the evaluation unit are expediently equipped with suitable means for coupling and decoupling the light signal.

[0015] The optical fiber is routed in sections along the inner conductor's length. The optical fiber can be routed directly adjacent to the inner conductor. The optical fiber is routed at a short distance of less than two centimeters from the inner conductor in one of the electrical insulation layers surrounding the inner conductor.

[0016] In this way, an arrangement for particularly accurate temperature measurement of the inner conductor is provided.

[0017] According to the invention, the high-voltage device comprises a mounting flange for fastening the insulating body, wherein the optical fiber is guided through the mounting flange and is provided with a connecting element that is designed for connection to the evaluation unit. Due to its mechanical strength, the mounting flange offers a particularly suitable option for attaching the connecting element. The optical fiber can, for example, be guided through secondary insulation between a resin-impregnated insulating body and a housing of the high-voltage device. The secondary insulation can, for example, comprise a gas or a plastic foam that surrounds the optical fiber during manufacture of the high-voltage device. To connect the optical fiber to the connecting element, the optical fiber can be guided through a suitable bore in the mounting flange.

[0018] According to the invention, the high-voltage device is a high-voltage bushing. The insulating body comprises an active part with electrically conductive control inserts arranged concentrically around the inner conductor and separated from each other by insulating layers. The insulating layers can, for example, comprise suitable paper or synthetic material impregnated with a resin. The control inserts serve to control the field and are arranged concentrically around the inner conductor and spaced from each other by the insulating layers.

[0019] According to one embodiment of the invention, the optical fiber is guided in sections around the active part. For example, the optical fiber can be guided spirally around the active part.

[0020] The active part is at least partially surrounded by a secondary insulation, wherein the secondary insulation is gaseous, pasty or foam-like and the optical fiber is guided at least partially in the secondary insulation.

[0021] According to one embodiment of the invention, the optical waveguide is guided in the secondary insulation at least in sections along guide elements.

[0022] As an alternative or in combination with this, the optical fiber of the secondary insulation can be freely suspended, at least in sections.

[0023] It should be noted that, in the context of the invention, it may be advantageous if the high-voltage device according to the invention comprises multiple optical fibers. The temperature measurement of the inner conductor can be performed more accurately in this way. Therefore, all of the features described above can be applied to additional optical fibers provided with the high-voltage device according to the invention.

[0024] As already stated above, the high-voltage device according to the invention is particularly suitable for use in a high-voltage system.

[0025] In this context, the object of the invention is to propose a high-voltage system that is as reliable as possible in operation.

[0026] The object is achieved by a high-voltage system having at least one high-voltage component at high-voltage potential, in which the at least one high-voltage component is electrically separated from the earth potential by means of the high-voltage device according to the invention.

[0027] The advantages of the high-voltage system according to the invention result from the corresponding advantages of the high-voltage device according to the invention.

[0028] The high-voltage components of the high-voltage system can in particular be transformers, switchgear, converters or the like.

[0029] During operation of the system, a light signal is fed into an optical fiber, which is guided at least in sections along the inner conductor, led out of the insulating body and connected to an evaluation unit for recording temperature measurement values, a measurement signal dependent on the light signal is taken from the optical fiber and the measurement signal is evaluated by the evaluation unit according to its temperature dependence.

[0030] The unclaimed method allows for particularly precise temperature measurements because the optical fiber is routed directly to the inner conductor. This is particularly advantageous compared to external temperature measurements, for example, on an outer housing of the high-voltage device.

[0031] As previously discussed, the method is particularly reliable because the measurement equipment, in particular the optical fiber, is integrated into the high-voltage device during its manufacture. Subsequent systematic measurement errors due to the subsequent installation of a measuring device cannot arise.

[0032] Furthermore, the method enables temperature measurement even during operation of the high-voltage device according to the invention. In particular, temperature monitoring is not limited to laboratory tests. Only electrically insulating components can be used to transmit the measured values ​​to the evaluation unit.

[0033] The temperature dependence of the measurement signal can be analyzed, for example, by evaluating a wavelength shift relative to the light signal fed into the optical fiber. By exploiting physical effects known to those skilled in the art, the method can be used to perform a point-based or spatially resolved measurement of the temperature of the inner conductor.

[0034] The invention will be further explained below with reference to an embodiment shown in the figure.

[0035] The figure shows an embodiment of a high-voltage device according to the invention in a schematic representation.

[0036] In detail, the figure shows a high-voltage device 1 according to the invention, which is a high-voltage bushing. The figure shows the high-voltage device 1 in a partial cross-sectional view. The high-voltage device 1 has a cylindrically symmetrical design. The axis of symmetry of the high-voltage device 1 is shown as a dot-dashed line 2.

[0037] The high-voltage device 1 comprises a hollow, cylindrical inner conductor 3 made of aluminum, which is surrounded by an insulating body 4 in a longitudinal direction along line 2. A thin layer of a cushioning material (not shown) can be arranged between the inner conductor 3 and the insulating body 4 to reduce mechanical stresses in the high-voltage device 1. Within the scope of the invention, the inner conductor is not necessarily a hollow conductor. The inner conductor can also be a solid conductor. Copper, for example, can also be used as a further working material for the inner conductor.

[0038] The insulating body 4 comprises an active part 5, which comprises insulating layers made of paper and separated by electrically conductive control inserts 6. The insulating layers are impregnated with an epoxy resin, so that the active part 5 forms a compact block. A secondary insulation 7 made of dry foam is arranged on the outside of the active part 5. According to other examples, the secondary insulation can comprise an insulating gas or a combination of several such substances.

[0039] The insulating body 4 is surrounded by a housing 8. Part of the housing 8 is a mounting flange 9, which is intended for attaching the high-voltage device 1 to a wall of a high-voltage component. A cover 10 forms the end of the high-voltage device 1 at the top.

[0040] The high-voltage device 1 further comprises an optical fiber 11, which is guided in sections along the inner conductor 3. There, in a detection area 12, the temperature of the inner conductor 3 is measured pointwise or with spatial resolution. The course of the optical fiber 11 is shown schematically in the figure and in several sections, with the sections being marked by curved lines 13a, 13b, and 13c. It should be noted that sections 13a-c are shown side by side in connection with an exemplary embodiment. However, it is also conceivable to interpret the routing of the optical fiber according to sections 13a-c as alternative possibilities for optical fiber routing. Accordingly, the optical fiber 11 is guided along the inner conductor 3, for example, through the cushioning material in the active part 5. It is not necessary for the optical fiber 11 to be in contact with the inner conductor 3.The optical fiber 11 then runs through the secondary insulation 7 back towards the fastening flange 9. In the intermediate section 13b-c, the optical fiber 11 is guided around the active part 5, which is figuratively indicated by a correspondingly bent section 11a of the optical fiber 11. In the section 13a-13b, suitable holders and guide elements 18 are provided for local fixing to the optical fiber. In the intermediate section above the line 13a, the optical fiber 11 is guided freely suspended through the secondary insulation 7. The optical fiber 11 is guided out of the housing 8 of the high-voltage device 1 through a hole in the fastening flange 9. There, the optical fiber 11 is connected to a connection element 14.

[0041] A connecting line 15 connects the connecting element 14 to an evaluation unit 16. The evaluation unit 16 is configured to convert light signals into electrical signals by means of a photoelectric unit 17 and to determine a temperature measurement value therefrom.

[0042] The temperature measuring method according to the invention will be explained step by step below using the embodiment shown in the figure.

[0043] First, a light signal is generated in the evaluation unit 16. The light signal is fed into the optical fiber 11 via the connecting cable 15 and the connection element 14. The light signal passes through the optical fiber 11, particularly also in the detection area 12. In the process, the light signal is modified according to the temperature of the inner conductor 3. The light signal then passes through the optical fiber 11 back to the connection element 14, where it is decoupled from the optical fiber as a measurement signal dependent on the light signal and fed to the evaluation unit 16. The light signal can be mirrored at one end of the optical fiber or fed back to the connection element by parallel routing of the optical fiber (not shown in the figure). The evaluation unit 16 converts the measurement signal into an electrical signal.The measurement signal is then converted into a temperature measurement value using a data processing unit integrated into the evaluation unit. This can also be performed during operation of the high-voltage device, i.e., when the inner conductor 3 is at a high-voltage potential, with the evaluation unit 16 being close to ground potential.

Claims

1. High-voltage device (1) having an inner conductor (3) and an insulation body (4) surrounding the inner conductor (3) along its lengthwise direction (2), wherein at least one optical waveguide (11) is guided at least in sections on the inner conductor (2), which is led out of the insulation body (4) and is connectable to an evaluating unit (16) for recording temperature measurement values, wherein the high-voltage device (1) comprises a mounting flange (9) for mounting the insulation body (4), wherein the optical waveguide (11) is guided through the mounting flange (9) and is provided with a connection element (14) that is set up for connection to the evaluating unit (16), wherein the optical waveguide is guided in sections on the inner conductor (3) along the lengthwise direction thereof at a distance of less than two centimeters from the inner conductor in one of the electrical insulating layers surrounding the inner conductor, wherein the high-voltage device (1) is a high-voltage bushing and the insulation body (4) comprises an active part (5) with electrically conductive control inserts (6) concentrically arranged around the inner conductor (3), which are separated from each other by insulating layers, the active part (4) being at least partially surrounded by a secondary insulation (7), the secondary insulation (7) being gaseous, pasty or foamy, and the optical waveguide (11) being guided at least in sections in the secondary insulation (7).

2. High-voltage device (1) according to claim 1, wherein the optical waveguide (11) is guided abutting the inner conductor (3) in sections.

3. High-voltage device (1) according to claim 1, wherein the optical waveguide (11) is guided in sections around the active part (5).

4. High-voltage device (1) according to claim 1, wherein the optical waveguide (11) is guided in the secondary insulation (7) at least in sections along guide elements (18).

5. High-voltage device (1) according to one of the preceding claims, in which the optical waveguide (11) of the secondary insulation (7) is guided in a freely suspended manner, at least in sections.

6. High-voltage system having at least one high-voltage component which is at high-voltage potential and is electrically isolated from the earth potential by means of the high-voltage device (1) according to one of claims 1 to 5.