Winding temperature measurement system of oil-immersed transformer

Abstract

The invention discloses a winding temperature measurement system of an oil-immersed transformer, which belongs to the technical field of temperature measurement, and comprises a low-voltage side temperature measurement assembly, and the low-voltage side winding of the winding is provided with an oil groove; a plurality of inner supporting strips are arranged on the oil groove at intervals, the low-voltage side temperature measuring assembly is installed on one inner supporting strip, the lower portion of the low-voltage side temperature measuring assembly is lower than the upper end face of the low-voltage side winding, and the upper portion of the low-voltage side temperature measuring assembly is higher than the upper end face of the low-voltage side winding. The pressure side temperature measurement assembly is pressed into the oil groove, the lower portion of the pressure side temperature measurement assembly is attached to the oil groove and the low-voltage side winding to form good temperature conduction and temperature measurement results, the upper portion of the pressure side temperature measurement assembly protrudes out of the low-voltage side winding, the detection results can be transmitted to the outside of the oil groove in a wireless mode, and wireless signals are prevented from being shielded or weakened. And the temperature measurement of the oil-immersed transformer is realized.

Description

Technical Field

[0001] The invention relates to the technical field of temperature measurement, and in particular to a winding temperature measurement system for an oil-immersed transformer. Background Art

[0002] Transformers are important power equipment in power systems, and their temperature changes directly affect the performance and safe operation of power equipment. Traditional transformer temperature measurement methods have problems such as limited measurement points and slow response speed. There is a strong demand for real-time, multi-point, continuous monitoring of the internal temperature of the transformer with a full range of temperature portraits. DL / T 572-1995 "Power Transformer Operation Regulations" stipulates that the upper oil temperature of the transformer shall generally not exceed 95°C. If the upper oil temperature exceeds 95°C, the temperature of the transformer winding will exceed the heat resistance strength of the winding insulation, thereby accelerating the aging of the insulation. Therefore, during the operation of the transformer, the upper oil temperature limit of 85°C is generally stipulated.

[0003] At present, the main methods for measuring the hot spot temperature of transformer windings are direct measurement and indirect calculation measurement. The direct measurement method is to bury sensors directly in the transformer windings and use a temperature measuring instrument to measure and display the winding temperature. It is usually used to compare with the thermal simulation measurement method to calibrate the error of the thermal simulation measurement. The main technology is optical fiber temperature measurement. The disadvantages of optical fiber temperature measurement are high cost, difficulty in construction and easy damage during installation. The indirect calculation measurement method is based on the hot spot calculation formula for oil-immersed power transformer windings recommended by the International Electrotechnical Commission. The hot spot temperature of the winding is calculated by calculating various key parameters and the load current value of the transformer. The main technology is to use thermal resistors to monitor the oil temperature around the windings and calculate the winding temperature through a formula. The disadvantage is that this temperature measurement method has low accuracy and a short life of thermal resistors.

[0004] Therefore, it is necessary to design a method for measuring the temperature of oil-immersed transformer windings through wireless monitoring. Summary of the invention

[0005] In view of the above technical problems existing in the prior art, the present invention provides a winding temperature measurement system for an oil-immersed transformer, which measures the temperature of the winding by wireless monitoring and has the characteristics of low cost and long service life.

[0006] The present invention discloses a winding temperature measurement system for an oil-immersed transformer, comprising a low-voltage side temperature measurement component, wherein the low-voltage side winding of the winding is provided with an oil groove; a plurality of inner support bars are arranged at intervals on the oil groove, and the low-voltage side temperature measurement component is installed on an inner support bar, and the lower part of the low-voltage side temperature measurement component is lower than the upper end surface of the low-voltage side winding, and the upper part is higher than the upper end surface of the low-voltage side winding.

[0007] Preferably, the low-pressure side temperature measurement assembly includes a mounting member and a low-pressure side temperature measurement tag.

[0008] A mounting groove is provided on one side of the mounting member, and the low-pressure side temperature measuring label is installed in the mounting groove;

[0009] The metal surface of the lower part of the low-voltage side temperature measuring label is lower than the upper end surface of the low-voltage side winding, and the upper part is higher than the upper end surface of the low-voltage side winding;

[0010] The metal surface at the bottom of the low-voltage side temperature measuring label is in close contact with the coil of the low-voltage side winding.

[0011] Preferably, the mounting member is an insulating member;

[0012] The mounting piece is made of insulating paperboard of the low-voltage side winding;

[0013] The oil tank is arranged between the inner low-voltage side winding and the inner fixing frame.

[0014] Preferably, the thickness of the low-pressure side temperature measurement label is 1 mm;

[0015] The height of one inner support bar is lower than that of an adjacent inner support bar.

[0016] Preferably, it also includes a high-voltage side temperature measuring label, which is installed on the high-voltage side coil of the winding.

[0017] Preferably, the high-voltage side temperature measuring label is installed on the 5th to 10th turns of the high-voltage side coil.

[0018] Preferably, a ceramic tube shell is provided outside the high-voltage side temperature measurement label; the width of the high-voltage side temperature measurement label is 5-10 mm; and the dielectric constant of the ceramic tube shell is 60-120.

[0019] Preferably, it also includes a transceiver antenna, a plurality of the windings are installed in the box, and a mounting plate is installed on the upper side of the windings.

[0020] The transceiver antenna matched with the low-voltage side temperature measuring tag is installed inside the box and / or on the lower side of the mounting plate.

[0021] Preferably, a through-hole is sealed on the side wall of the box body, and radio frequency interfaces are respectively provided on the inner and outer sides of the through-hole;

[0022] A signal processing device is arranged on the outside of the box;

[0023] The signal processing device is connected to the transceiver antenna through a via.

[0024] Preferably, the signal processing device is connected to a host computer.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows: the pressure-side temperature measuring component is pressed into the oil tank, the lower part fits with the oil tank and the low-voltage side winding, forming good temperature conduction and temperature measurement results, and the upper part protrudes from the low-voltage side winding, and the detection results can be transmitted wirelessly to the outside of the oil tank, avoiding the wireless signal from being shielded or weakened; the temperature measurement of the oil-immersed transformer is realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is the installation diagram of the winding temperature measurement system of the oil-immersed transformer;

[0027] Figure 2 It is the installation diagram of the winding;

[0028] Figure 3 This is a schematic diagram of the installation of the temperature measurement label;

[0029] Figure 4 This is the installation diagram of the low-pressure side temperature measurement component;

[0030] Figure 5 It is a structural schematic diagram of the low-pressure side temperature measurement component;

[0031] Figure 6 It is the logic block diagram of the winding temperature measurement system.

[0032] Markings in the figure: 1 RF temperature measuring device, 11 high-voltage side temperature measuring label,

[0033] 12 low-pressure side temperature measurement component, 13 low-pressure side temperature measurement label, 15 installation parts,

[0034] 2 transceiver antenna, 3 penetrator, 4 signal processing device, 5 host computer;

[0035] 6 oil-immersed transformer, 61 winding, 62 high-voltage side winding, 621 high-voltage side coil, 63 low-voltage side winding, 631 inner support bar, 635 inner fixing frame, 637 oil tank, 65 box, 66 mounting plate. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0038] A winding temperature measurement system for an oil-immersed transformer 6, such as Figure 1-Figure 6As shown, it includes a radio frequency (RFID) temperature measuring device 1, which includes a low-voltage side temperature measuring component 12, and the low-voltage side winding 63 of the winding 61 is provided with an oil groove 637; a plurality of inner support bars 631 are arranged at intervals on the oil groove 637, and the low-voltage side temperature measuring component 12 is installed on an inner support bar 631, and the lower part of the low-voltage side temperature measuring component 12 is lower than the upper end surface of the low-voltage side winding 63, and the upper part is higher than the upper end surface of the low-voltage side winding 63.

[0039] The low-voltage side temperature measuring component 12 can be pressed into the oil tank, with the lower part fitting with the oil tank and the low-voltage side winding to form good temperature conduction and temperature measurement results, and the upper part protruding from the low-voltage side winding to transmit the detection results wirelessly to the outside of the oil tank to avoid shielding or weakening of the wireless signal, thereby realizing temperature measurement of the oil-immersed transformer.

[0040] like Figure 4 and Figure 5 The low-voltage side temperature measurement component 12 includes a mounting member 15 and a low-voltage side temperature measurement label 13. A mounting groove is provided on one side of the mounting member 15, and the low-voltage side temperature measurement label 13 is installed in the mounting groove; the metal surface of the lower part of the low-voltage side temperature measurement label 13 is lower than the upper end surface of the low-voltage side winding 63, and the upper part is higher than the upper end surface of the low-voltage side winding 63; the metal surface of the lower part of the low-voltage side temperature measurement label 13 is close to the coil of the low-voltage side winding 63, ensuring the accuracy of temperature monitoring, while keeping the entire sensor and the low-voltage coil at the same potential, preventing the generation of floating potential and causing insulation problems. More specifically, the mounting member 15 is an insulating member, which is arc-shaped and fits the oil groove; the mounting member 15 is made of the insulating cardboard of the low-voltage side winding 63; the oil groove 637 is arranged between the inner low-voltage side winding 63 and the inner fixing frame 635. No extra fixing structure is required so that the low-voltage side temperature measuring label can be effectively fixed on the low-voltage side winding, and the temperature measuring label can have a certain arc to fit the low-voltage coil. Figure 4 The high voltage side winding has been removed.

[0041] The thickness of the low-voltage side temperature measurement label 13 is 1mm, which is suitable for various oil channels / slideways of oil-immersed transformers; the height of one inner support bar 631 is lower than the height of the adjacent inner support bar, which can be achieved by shortening. The cut support bar is replaced by the outer shell of the low-voltage side temperature measurement label 13 to ensure the original structural performance of the low-voltage side. The low-voltage side temperature measurement label consists of a specially designed temperature sensor and an outer shell cover. In a specific test, the size of the low-voltage side temperature measurement label is: 40*20*0.8mm. After installation, the upper part is 10mm higher than the low-voltage coil.

[0042] The radio frequency temperature measuring device is based on the UHF frequency band and has the characteristics of small thickness and strong signal.

[0043] like Figure 3 and Figure 6The radio frequency temperature measuring device 1 further includes a high-voltage side temperature measuring tag 11, which is installed on the high-voltage side coil 621 of the high-voltage side winding 62 of the winding 61, and is used to detect the temperature of the high-voltage side winding 62. The high-voltage side temperature measuring tag 11 is installed on the 5th to 10th turns of the high-voltage side coil 621, where the temperature is usually higher, to reflect the highest temperature of the high-voltage side winding.

[0044] The high-voltage side temperature measurement label 11 is provided with a ceramic shell on the outside; the width of the high-voltage side temperature measurement label 11 is 5-10mm, which is suitable for the width of the high-voltage side coil of most existing oil-immersed transformers; the dielectric constant of the ceramic shell is 60-120, which ensures the miniaturization design of the label. The high-voltage side temperature measurement label 11 can be wrapped and fixed with the original insulating paper on the high-voltage side, which ensures the accuracy of temperature monitoring without destroying the insulation of the coil.

[0045] Figure 2 and Figure 6 A box 65 and a transceiver antenna 2 are shown, and multiple windings 61 are installed in the box 65, specifically 2 or 3 windings. A mounting plate 66 is installed on the upper side of the winding 61, and the transceiver antenna 2 cooperating with the low-voltage side temperature measurement tag 13 is installed on the inner side of the box 64 and / or on the lower side of the mounting plate 66.

[0046] The side wall of the box 65 is sealed with a through-hole 3, and the inner and outer sides of the through-hole are respectively provided with radio frequency interfaces; the signal processing device 4 is connected to the transceiver antenna 2 through the through-hole 3. It ensures that the radio frequency (RFID) signals of the transceiver antenna 2 and the signal processing device 4 can be connected, and the lubricating oil inside the transformer will not leak; the signal processing device 4 is provided on the outer side of the box 65.

[0047] The signal processing device 4 can be connected to the host computer 5 via a RS232 / 485 serial communication line, thereby achieving background monitoring.

[0048] The present invention combines RFID radio frequency identification technology, an RFID temperature measuring device, and the internal structure and electromagnetic environment of the oil-immersed transformer winding to solve the problem of wireless monitoring of the oil-immersed transformer winding temperature. The temperature of the high and low voltage sides of the winding can be monitored in real time. The wireless monitoring method does not require additional wiring inside the winding. The installation is simple and efficient, and it plays an important role in the stable operation of the transformer. In actual tests, it will not cause interference or significant attenuation of the RFID signal. The radio frequency temperature measuring device is based on the UHF frequency band and has the characteristics of small thickness and strong signal. The installation structure of the low-voltage side temperature measurement component well balances and solves the problems of accuracy of low-voltage side temperature monitoring and wireless transmission.

[0049] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A winding temperature measurement system for an oil-immersed transformer, characterized in that: It includes a low-pressure side temperature measuring component (12), The low-voltage side winding (63) of the winding (61) is provided with an oil groove (637); A plurality of inner support bars (631) are arranged at intervals on the oil groove (637), and the low-voltage side temperature measuring component (12) is installed on one of the inner support bars (631). The lower portion of the low-voltage side temperature measuring component (12) is lower than the upper end surface of the low-voltage side winding (63), and the upper portion is higher than the upper end surface of the low-voltage side winding (63).

2. The winding temperature measurement system according to claim 1, characterized in that: The low-pressure side temperature measurement component (12) comprises a mounting member (15) and a low-pressure side temperature measurement label (13). A mounting groove is provided on one side of the mounting member (15), and the low-pressure side temperature measuring label (13) is mounted in the mounting groove; The metal surface of the lower part of the low-voltage side temperature measurement label (13) is lower than the upper end surface of the low-voltage side winding (63), and the upper part is higher than the upper end surface of the low-voltage side winding (63); The metal surface at the bottom of the low-voltage side temperature measurement label (13) is in close contact with the coil of the low-voltage side winding (63).

3. The winding temperature measurement system according to claim 2, characterized in that: The mounting member (15) is an insulating member; The mounting member (15) is made of insulating paperboard of the low-voltage side winding (63); The oil groove (637) is arranged between the inner low-voltage side winding (63) and the inner fixing frame (635).

4. The winding temperature measurement system according to claim 3, characterized in that: The thickness of the low-pressure side temperature measurement label (13) is 1 mm; The height of one inner support bar (631) is lower than the height of an adjacent inner support bar.

5. The winding temperature measurement system according to claim 1, characterized in that: It also includes a high-voltage side temperature measurement label (11), wherein the high-voltage side temperature measurement label (11) is installed on the high-voltage side coil (621) of the winding (61).

6. The winding temperature measurement system according to claim 5, characterized in that: The high-voltage side temperature measurement label (11) is installed on the 5th to 10th turns of the high-voltage side coil (621).

7. The winding temperature measurement system according to claim 5, characterized in that: A ceramic tube shell is provided outside the high-voltage side temperature measurement label (11); the width of the high-voltage side temperature measurement label (11) is 5-10 mm; and the dielectric constant of the ceramic tube shell is 60-120.

8. The winding temperature measurement system according to claim 1, characterized in that: It also includes a transceiver antenna (2), a plurality of windings (61) are installed in a box (65), and a mounting plate (66) is installed on the upper side of the windings (61). The transceiver antenna (2) matched with the low-pressure side temperature measurement tag (13) is installed on the inner side of the box (64) and / or on the lower side of the installation plate (66).

9. The winding temperature measurement system according to claim 7, characterized in that: A through-hole (3) is sealed on the side wall of the box body (65), and radio frequency interfaces are respectively provided on the inner and outer sides of the through-hole (3); A signal processing device (4) is arranged outside the box (65); The signal processing device (4) is connected to the transceiver antenna (2) via a via (3).

10. The winding temperature measurement system according to claim 7, characterized in that: The signal processing device (4) is connected to a host computer (5).

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