Device for measuring the contact pressure of a winding press element in an output transformer

专利摘要:
The present invention relates to a device for measuring the contact pressure exerted by the winding compression element (2) on the winding (1) in a power transformer or other high power installation, wherein at least one having a sensor element (40) in response to pressure or stretching. Sensor 4 is inserted into the winding compression element 2, which is set up to correspond with the checking electronics 7 via a wireless link.
公开号:KR20020011434A
申请号:KR1020017015717
申请日:2000-07-14
公开日:2002-02-08
发明作者:판타나니콜라이라우렌티우；가쉬아르민；포겔알브레히트
申请人:루프레흐트 클라우/프리취 클라우스；아베베 파텐트 게엠베하；
IPC主号:

专利说明:

DEVICE FOR MEASURING THE CONTACT PRESSURE OF A WINDING PRESS ELEMENT IN AN OUTPUT TRANSFORMER}
[2] In particular, windings in power transformers consist of a combination of conductors and insulating materials. These basically represent a composite structure having a cylindrical shape. After manufacture / winding, the windings are arranged to be surrounded by the iron core of the transformer.
[3] Transformer windings should be designed to have sufficient mechanical strength and robustness to withstand short-circuit and other mechanical forces in the circuit throughout the transformer's entire life. One particularly important aspect is the compression of the windings which produces good mechanical robustness.
[4] The pressure on the windings of the transformer due to compression decreases over time as a result of a number of effects. This then increases the mechanical strength often becomes insufficient in the case of a short circuit, increasing the probability of breakdown of the transformer. No device is known that can be installed in a transformer to detect a change in contact pressure.
[5] For example, FIG. 6 shows a typical contour of decreasing contact pressure, which was determined off-line in each case after a short circuit. 7 shows the contour recorded offline at predetermined time intervals.
[6] Transformer windings are normally compressed during fabrication. It lacks the capability to detect any change during operation. Recompression for calibration can only be carried out during large repairs, for example when one of the windings needs to be replaced.
[7] Although batches where compression is re-adjusted to some extent by the mechanical elastic element during the working period are used, there is in principle no objective information about the actual compression state of the windings and thus no information on the state of the transformer. .
[1] The present invention relates to a device for measuring the contact pressure exerted by a winding compression element on a winding in a power transformer or other high power installation.
[12] 1 illustrates an overview of a measuring device arranged in a power transformer.
[13] 2 shows one possible arrangement for the pressure sensor between the compression element and the antenna arrangement.
[14] 3 shows a first embodiment variant of the arrangement of the sensor elements arranged in the elastic deformation body;
[15] 4 shows a second embodiment variant of the arrangement of sensor elements arranged in a spring element;
[16] 5 is a diagram illustrating an antenna arrangement;
[17] 6 shows a typical contour of the contact pressure of a winding compression element recorded off-line at an individual point after a circuit short.
[18] FIG. 7 shows a typical profile of contact pressures recorded at regular time intervals.
[19] 8 shows the contour of contact pressure recorded online using the device according to the invention.
[20] 9 shows a pressure contour that can be dynamically recorded in the case of a circuit short.
[8] The present invention is therefore based on the purpose of specifying a device for measuring the contact pressure of a winding compression element in a power transformer.
[9] This object is achieved by an apparatus for measuring contact pressure having the features of claim 1. Advantageous improvements are described in further claims.
[10] The apparatus ensures that the final contact pressure can always be detected by measurement, so that the residual contact pressure still present after a relatively long working period can also be detected by measurement at all times.
[11] The following text contains further description of the present invention with reference to the exemplary embodiments shown in the drawings.
[21] 1 shows a schematic illustration of the arrangement of a device according to the invention in a power transformer. This shows the winding 1 of one of the multiple windings. The edge of the iron core 5, which is not visible in the figure, is located in the winding 1. The winding compression element 2 is in each case inserted between the upper and lower yokes of the shim 5 and the winding 1.
[22] In the example shown, the sensor 4 is arranged in the region of the upper compression element 2. Also a number of sensors 4 can be arranged there. This sensor 4 is preferably arranged on one side of the compression element 2 facing the shim yoke 5. Sensors 4 responsive to pressure or strain may be suitable for use, depending on their configuration and placement.
[23] At least one sensor 4 is in the form of a wire-free miniature sensor, ie a miniature sensor that can be checked wirelessly. The sensor elements included in the sensor 4 are thus electrically connected to at least one radio-frequency or microwave antenna, which is called the sensor antenna 3.
[24] Together with the winding 1, the shim 5 is located in the tank 6 in the power transformer. Checking electronics 7 are located outside this tank 6, and the checking antenna 9 is via a radio-frequency bushing 8 passing through the wall of the tank 6. Connected with the device (7). The checking antenna 9 and the sensor antenna 3 are arranged to enable a radio link. The checking electronic device 7 comprises a transmitter and a receiver as well as a control device and a monitoring device.
[25] The measuring device formed of the checking electronics 7 together with the sensors 4 and the antennas 3, 9 can be advantageously designed and operated using SAW technology, which is described in document DE-A1, for example. -44 13 211 and DE-A1-195 35 543.
[26] The abbreviation SAW stands for Surface Acoustic Waves. Wireless transmission occurs at frequencies in the range of 30 MHz to 3 GHz. The SAW sensor includes a thin platelet made of piezoelectric crystal as a sensor element. The radio frequency signal emitted from the checking facility 7 is received by the antenna 3 of the sensor 4 and converted into a mechanical SAW by a (interdigital) transducer and propagated. The propagating SAW is reflected back to the transducer in the sensor 4 via a suitable reflective structure, in which the SAW is converted back to electromagnetic waves and transmitted by the antenna 3. For SAW sensors, the physical parameters to be measured should affect the characteristics of the surface acoustic wave. In principle, the propagation speed and path distance change. Mechanical forces such as bending and pressure change both the acoustic path length and the elastic constant of the crystal, thus changing the SAW velocity. The checking electronics 7 evaluates the delay time or phase shift, the signal amplitude and the signal shape as well as the movement at the intermediate frequency in the case of the resonant sensor. Since the SAW sensor is a passive element, i.e. there is no battery or any active electronics on the substrate, the SAW sensor is particularly suitable for long-term use in severe environmental conditions.
[27] 2 shows one possible arrangement of the sensor 4 and two sensor antennas 3 connected to the sensor. The sensor 4 comprises a sensor element 40 in the form of a chip in a hermetically sealed and elastic encapsulation 10. This capsule 10 protects the sensor element 40 from chemical effects that can cause aging effects and signal corruption.
[28] Since the SAW sensor is also sensitive to expansion / compression, it is advantageous to install the device so that the housing shape converts the compressive force into expansion / compression. 3 and 4 show an example of the elastically deformable sensor 4.
[29] 3 shows one embodiment of a sensor 4 in which the element 40 is placed within the elastic deformable body 100. 4 shows a combination of the spring element 11 and the sensor 4.
[30] 5 shows one possible antenna arrangement with multiple sensor antennas 3 interacting with a common checking antenna 9.
[31] FIG. 8 shows the contour of the contact pressure as a function of time, in a manner similar to that of FIGS. 6 and 7 already mentioned, but in this case of the contact pressure recorded online continuously over the years by the arrangement according to the invention. Show the outline.
[32] However, the same arrangement can also be used in the case of a short circuit to record the dynamic change in contact pressure over a very short period of time, for example 100 kPa shown in FIG.
[33] The invention is applicable to an apparatus for measuring the contact pressure exerted by a winding compression element on a winding in a power transformer or other high power installation.

权利要求:
Claims (7)
[1" claim-type="Currently amended] A device for measuring the contact pressure exerted by the winding compression element 2 on the winding 1 in a power transformer or other high power installation,
a) at least one sensor 4 having a sensor element responsive to pressure or strain is inserted into the winding compression element 2,
b) The sensor (4) is set up to correspond with the checking electronics (7) via a wireless link.
[2" claim-type="Currently amended] Device according to claim 1, characterized in that the sensor (4) is electrically connected to at least one sensor antenna (3).
[3" claim-type="Currently amended] The radio according to claim 1 or 2, wherein the checking electronics (7) is arranged outside of the transformer tank (6) comprising the windings (1) and passes through a wall of the tank (6). Contact pressure measuring device, characterized in that it is connected to the checking antenna (9) via a frequency bushing (8).
[4" claim-type="Currently amended] 4. A combination according to claim 3, wherein the combination of the checking electronics (7) and the sensor (4) receives a radio-frequency signal transmitted by the checking electronics (7) to the sensor (4). It is set up to convert a frequency signal into a mechanical surface acoustic wave, the surface acoustic wave propagates into the sensor 4, is reflected, converted back to electromagnetic waves, and then transmitted to the checking electronic device 7, and the checking electronic device 7 Contact pressure measuring device, characterized in that it is received and evaluated.
[5" claim-type="Currently amended] 5. Device according to any of the preceding claims, characterized in that the sensor (4) comprises a Surface Acoustic Wave (SAW) sensor element (40).
[6" claim-type="Currently amended] 6. The sensor (4) according to any one of the preceding claims, wherein the sensor (4) is constituted by a sensor element (40) arranged in a hermetically sealed encapsulation (100) in the form of an elastic deformation body. Contact pressure measuring device, characterized in that.
[7" claim-type="Currently amended] Device according to one of the preceding claims, wherein the sensor (4) is inserted into a spring element (11).

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同族专利:

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公开号 | 公开日

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EP1200809A1|2002-05-02|

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JP2003506674A|2003-02-18|

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CN1365442A|2002-08-21|

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AT409852T|2008-10-15|

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US6718268B2|2004-04-06|

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ZA200109825B|2002-09-25|

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CN1157596C|2004-07-14|

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EP1200809B1|2008-10-01|

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BR0012760A|2002-04-02|

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DE19935515A1|2001-02-01|

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WO2001009582A1|2001-02-08|

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CA2380233A1|2001-02-08|

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US20020107657A1|2002-08-08|

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DE50015380D1|2008-11-13|

引用文献:

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公开号 | 申请日 | 公开日 | 申请人 | 专利标题

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法律状态:
1999-07-28|Priority to DE19935515A

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1999-07-28|Priority to DE19935515.0

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2000-07-14|Application filed by 루프레흐트 클라우/프리취 클라우스, 아베베 파텐트 게엠베하

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2000-07-14|Priority to PCT/EP2000/006742

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2002-02-08|Publication of KR20020011434A

优先权:

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申请号 | 申请日 | 专利标题

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DE19935515A|DE19935515A1|1999-07-28|1999-07-28|Device for measuring the contact pressure of a winding press element in a power transformer|

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DE19935515.0|1999-07-28|

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PCT/EP2000/006742|WO2001009582A1|1999-07-28|2000-07-14|Device for measuring the contact pressure of a winding press element in an output transformer|