A special tool for transformer bushing test

Abstract

The application provides a special tool for transformer bushing test, which comprises a closed oil tank, a bushing mounting seat, a temperature sensing probe, a heating component and a temperature monitoring device; the top surface of the closed oil tank is provided with an inlet, an oil injection port and a first through hole, and the side wall is provided with a second through hole and an oil outlet; the bushing mounting seat is in a hollow columnar shape, and a cover is arranged on the top surface inlet and is provided with a flange plate; the temperature sensing probe is sealingly arranged on the first through hole, one end of which is arranged in the oil in the tank, and the other end is connected with the temperature monitoring device outside the tank; the heating component is sealingly arranged on the second through hole, one end of which is arranged in the oil in the tank, and the other end is provided with a voltage terminal outside the tank; the temperature monitoring device is arranged on the side wall; after the transformer bushing to be tested is fixed and extended into the closed oil tank, transformer oil is injected to immerse the heating component, the temperature sensing probe and the equalizing ring of the transformer bushing to be tested, and the heating component continuously heats the oil to a preset oil temperature, so that the required temperature in the actual operation environment is simulated. By implementing the application, the test accuracy of the transformer bushing can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the mechanical technical field, and particularly to a special tool for transformer bushing test. BACKGROUND

[0002] According to DL / T596-2021 "Preventive Test Regulations for Power Equipment", the preventive test items of the bushing include AC withstand voltage test and partial discharge measurement of 66kV and above capacitive bushing. Among them, the test voltage requirement of transformer bushing partial discharge measurement is (U m The partial discharge value of oil-paper capacitive bushing under test voltage should be less than 10pC, and the partial discharge value of rubber-paper capacitive bushing should be less than 250pC.

[0003] Currently, in GB / T4109-2008 "Insulating Bushing with AC Voltage Higher than 1000V", the power frequency withstand voltage test and partial discharge measurement of different bushings are also clearly required.

[0004] However, there is a lack of special tool in the prior art to simulate the actual operating environment of the transformer bushing in the transformer oil, which is easy to cause the test result of the transformer bushing to be affected by the internal structure defects of the transformer body (such as transformer winding, core clamp, etc.), causing the measured value of the partial discharge to exceed the standard value. Therefore, there is an urgent need for a special tool for transformer bushing test, which can simulate the actual operating environment of the transformer bushing in the transformer oil, thereby improving the test accuracy of the transformer bushing. SUMMARY

[0005] The technical problem to be solved by the embodiments of the present application is to provide a special tool for transformer bushing test, which can simulate the actual operating environment of the transformer bushing in the transformer oil, thereby improving the test accuracy of the transformer bushing.

[0006] In order to solve the above technical problems, the embodiments of the present application provide a special tool for transformer bushing test, which comprises a closed oil tank, a bushing mounting seat, a temperature sensing probe, a heating component and a temperature monitoring device; wherein,

[0007] The closed oil tank comprises a top surface, a bottom surface and a side wall between the top surface and the bottom surface; the top surface is provided with an inlet for the tested transformer bushing to extend into, an oil injection port for injecting transformer oil and a first through hole for mounting the temperature sensing probe; the side wall is provided with a second through hole for mounting the heating component and an oil outlet for discharging transformer oil on the side close to the bottom surface;

[0008] The sleeve mounting seat is a hollow column, one end of which is capped and fixed to the entrance of the top surface of the closed oil tank, and the other end is formed with a flange plate for fixing the transformer sleeve to be tested;

[0009] The temperature sensing probe is sealingly mounted on the first through hole, one end of which extends into the closed oil tank and is immersed in the transformer oil, and the other end is located outside the closed oil tank and is connected to the temperature monitoring device through a lead wire;

[0010] The heating component is sealingly mounted on the second through hole, one end of which extends into the closed oil tank and is immersed in the transformer oil, and the other end is located outside the closed oil tank and is formed with a voltage terminal connected to an external power source;

[0011] The temperature monitoring device is mounted on the side wall of the closed oil tank;

[0012] Wherein, after the transformer sleeve to be tested is fixed on the flange plate of the sleeve mounting seat and extends into the closed oil tank through the entrance, transformer oil is injected through the oil injection port, so that the transformer oil immerses the heating component, the temperature sensing probe and the pre-set equalizing ring on the base of the transformer sleeve to be tested, and the external power source is connected to the heating component for continuous heating until the oil temperature monitored by the temperature monitoring device through the temperature sensing probe is equal to the pre-set oil temperature, so as to simulate the required temperature of the transformer sleeve to be tested in the actual running environment of the transformer oil.

[0013] Further comprising: a UHF sensor;

[0014] Further comprising: a UHF sensor;

[0015] The UHF sensor is sealingly mounted on the third through hole, one end of which extends into the closed oil tank and is immersed in the transformer oil, and the other end is located outside the closed oil tank and is formed with a signal terminal connected to an external partial discharge signal detection device; wherein the partial discharge signal detection device is used to detect the partial discharge signal existing on the transformer sleeve to be tested.

[0016] Further comprising: a transparent observation window;

[0017] Further comprising: a transparent observation window;

[0018] The transparent observation window is sealingly mounted on the fourth through hole.

[0019] Further comprising: a grounding column;

[0020] Further comprising: a grounding column;

[0021] Wherein, the lifting ring is further included.

[0022] Wherein, the four lifting rings are respectively fixed on the four corners of the top surface of the closed oil tank.

[0023] Wherein, the sleeve mounting seat cover is arranged at the entrance of the top surface of the closed oil tank and is fixed by welding.

[0024] Wherein, the transformer sleeve to be measured is a 110kV transformer sleeve or a 220kV transformer sleeve; the flange plate of the sleeve mounting seat is formed with a first mounting hole for mounting the 110kV transformer sleeve and a second mounting hole for mounting the 220kV transformer sleeve.

[0025] Wherein, the oil inlet and the oil outlet of the closed oil tank are both provided with a manual valve.

[0026] Wherein, the heating components are two and are both heating pipes.

[0027] Wherein, the transparent observation windows are four and are all made of glass; the fourth through holes are four; wherein,

[0028] The four transparent observation windows are all in sealing connection with the four fourth through holes through sealing rings and are all located in the middle part of the closed oil tank; two of the four transparent observation windows are located on one side wall and the other two are located on the other side wall.

[0029] The embodiment of the present application has the following beneficial effects:

[0030] 1. The temperature sensing probe, the heating component and the temperature monitoring device of the present application form a temperature control system, which can control the transformer oil in the closed oil tank in real time, simulate various actual operation conditions of the transformer sleeve to be measured in the transformer oil, and improve the test accuracy of the transformer sleeve.

[0031] 2. The present application can monitor the partial discharge of the transformer sleeve to be measured in real time through the ultra-high frequency sensor, observe the transformer oil in the closed oil tank and the pressure equalizing ring of the transformer sleeve to be measured immersed in the transformer oil through the transparent observation window, and assist in judging and analyzing the abnormal sleeve in the test, thereby further improving the test accuracy of the transformer sleeve. BRIEF DESCRIPTION OF DRAWINGS

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, obtaining other drawings based on these drawings without creative effort still falls within the scope of the present invention.

[0033] Figure 1 This is a left-view three-dimensional structural diagram of a special tooling for testing transformer bushings and the transformer bushing to be tested during assembly, as provided in an embodiment of the present invention.

[0034] Figure 2 This is a right-view three-dimensional structural diagram of a special tooling for testing transformer bushings and the transformer bushing to be tested during assembly, as provided in an embodiment of the present invention.

[0035] Figure 3 This is a top view of a special tooling for testing transformer bushings provided in an embodiment of the present invention, when assembled with the transformer bushing to be tested.

[0036] Figure 4 for Figures 1 to 3 Installation structure diagram of the medium-frequency sensor;

[0037] Figure 5 for Figures 1 to 3 A three-dimensional structural diagram of the bushing of the transformer under test. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings.

[0039] like Figures 1 to 5 As shown in the figure, a special tooling for testing transformer bushings according to an embodiment of the present invention includes a closed oil tank 1 made of metal, a bushing mounting base 2 made of metal, a temperature sensing probe 3, a heating element 4, and a temperature monitoring device 5; wherein,

[0040] The enclosed oil tank 1 includes a top surface 11, a bottom surface 12, and a side wall 13 located between the top surface 11 and the bottom surface 12. The top surface 1 is provided with an inlet (not shown) for the bushing T of the transformer under test to extend into, an oil inlet 14 for injecting transformer oil (not shown), and a first through hole (not shown) for installing a temperature sensor probe. The side wall 13 is provided with a second through hole (not shown) for installing a heating element 4 and an oil outlet 15 for discharging transformer oil on the side near the bottom surface 12. It should be noted that both the oil inlet 14 and the oil outlet 15 are provided with manual valves to control the injection and discharge of transformer oil.

[0041] The sleeve mounting seat 2 is in a hollow columnar shape, one end of which is capped and fixed at the entrance of the top surface 11 of the closed oil tank 1, and the other end is formed with a flange plate 21 for fixing the transformer sleeve T; at this time, the sleeve mounting seat 2 is capped and fixed at the entrance of the top surface 11 of the closed oil tank 1 by welding, so that the sleeve mounting seat 2 is fixed with the closed oil tank 1 and is in communication with the entrance of the top surface 11; considering that the transformer sleeve T to be tested is usually a 110kV transformer sleeve or a 220kV transformer sleeve, the flange plate 21 of the sleeve mounting seat 2 needs to be matched with transformer sleeves of different specifications, and the flange plate 21 is formed with a first mounting hole 211 for mounting a 110kV transformer sleeve and a second mounting hole 212 for mounting a 220kV transformer sleeve;

[0042] The temperature sensing probe 3 is sealed and mounted on the first through hole by a sealing ring, one end of which extends into the closed oil tank 1 and is immersed in the transformer oil, and the other end is located outside the closed oil tank 1 and is connected to the temperature monitoring device 5 by a wire (not shown);

[0043] The heating component 4 (such as a heating pipe or a heating wire) is sealed and mounted on the second through hole by a sealing ring, one end of which extends into the closed oil tank 1 and is immersed in the transformer oil, and the other end is located outside the closed oil tank 1 and is formed with a voltage terminal 41 connected to an external power source (not shown, such as an alternating current power source); in one example, the heating component 4 has two and is a heating pipe;

[0044] The temperature monitoring device 5 (such as an electronic temperature meter) is mounted on the side wall 13 of the closed oil tank 1 by screws or the like;

[0045] After the transformer sleeve T to be tested is fixed on the flange plate 21 of the sleeve mounting seat 2 and extends into the closed oil tank 1 from the entrance, the transformer oil is injected through the oil injection port 14, so that the transformer oil immerses the heating component 4, the temperature sensing probe 3 and the pre-set equalizing ring T1 on the base of the transformer sleeve T to be tested, and the external power source is connected to the heating component 4 for continuous heating until the oil temperature monitored by the temperature sensing probe 3 is equal to the pre-set oil temperature, so as to simulate the required temperature of the transformer sleeve T to be tested in the actual operating environment of the transformer oil.

[0046] It should be noted that the transformer oil has insulation and heat dissipation properties, and the capacity filled in the closed oil tank 1 should meet the detection of the temperature sensing probe 3, the immersion of the transformer sleeve T to be tested and the heating requirement of the heating component 4. In addition, the pre-set oil temperature can be flexibly adjusted according to the required temperature of different specifications of the transformer sleeve T to be tested in various actual operating conditions of the transformer oil, and the actual operating conditions are the required conditions of transformer sleeve withstand voltage test, partial discharge test or other tests.

[0047] Therefore, the temperature sensing probe 3, the heating component 4 and the temperature monitoring device 5 form a coordinated temperature control system, which can simulate various actual operation conditions of the transformer bushing T in the transformer oil, thereby improving the testing accuracy of the transformer bushing.

[0048] It can be understood that, after the testing of the transformer bushing T is completed, the transformer oil in the closed oil tank 1 can be discharged through the oil inlet 15.

[0049] In the embodiment of the present application, in order to monitor the partial discharge of the transformer bushing T in real time during the testing, the special tool further comprises a UHF sensor 6; the side wall 13 of the closed oil tank 1 is further provided with a third through hole (not shown) for mounting the UHF sensor 6; the UHF sensor 6 is mounted on the third through hole, one end of which extends into the closed oil tank 1 and is immersed in the transformer oil, and the other end is located outside the closed oil tank 1 and is provided with a signal terminal 61 connected to an external partial discharge signal detection device (not shown); at this time, the partial discharge signal detection device is used to detect the partial discharge signal existing on the transformer bushing T.

[0050] In the embodiment of the present application, in order to ensure electrical safety, the special tool needs to be designed as a whole for grounding, and therefore the special tool further comprises a grounding column 7 made of metal; one end of the grounding column 7 is mounted on the side wall of the closed oil tank 1 by welding, and the other end is grounded. In addition, in order to facilitate hoisting and moving, the special tool further comprises a lifting ring 8 made of metal; the lifting ring 8 has four, which are respectively fixed on the four corners of the top surface 11 of the closed oil tank 1 by welding.

[0051] In the embodiment of the present application, in order to observe the condition of the transformer oil in the closed oil tank 1 and the condition of the grading ring T1 of the transformer bushing T immersed in the transformer oil in real time, thereby assisting in the judgment and analysis of the abnormal bushing during the testing. Therefore, the special tool further comprises a transparent observation window 9; the side wall 13 of the closed oil tank 1 is further provided with a fourth through hole (not shown) for mounting the transparent observation window 9; the transparent observation window 9 is sealingly mounted on the fourth through hole. In one example, the transparent observation window 9 has four and is made of glass; the fourth through hole has four; wherein the four transparent observation windows 9 are sealingly connected with the four fourth through holes through sealing rings (such as annular sealing rings with notches on the inner ring), and are located in the middle of the closed oil tank 1 for observation; two of the four transparent observation windows are located on one side wall, and the other two are located on the other side wall.

[0052] The embodiment of the present application has the following beneficial effects:

[0053] 1、The temperature control system formed by the temperature sensing probe, the heating component and the temperature monitoring device is adopted to perform real-time temperature control on the transformer oil in the closed oil tank, various actual operation conditions of the measured transformer bushing in the transformer oil can be simulated, thus the test accuracy of the transformer bushing is improved;

[0054] 2、The partial discharge condition of the measured transformer bushing during the test is monitored in real time by the ultrahigh frequency sensor, the condition of the transformer oil in the closed oil tank and the equalizing ring of the measured transformer bushing immersed in the transformer oil are observed in real time through the transparent observation window, the abnormal bushing during the test can be judged and analyzed, thus the test accuracy of the transformer bushing is further improved.

[0055] The above only discloses the preferred embodiments of the present application, of course, cannot be limited by the scope of the present application, therefore, the equivalent changes made according to the claims of the present application still belong to the scope covered by the present application.

Claims

1. A special tool for transformer bushing testing, characterized in that, The application relates to a transformer bushing oil temperature test device, which comprises a closed oil tank, a bushing mounting base, a temperature sensing probe, a heating component and a temperature monitoring device. The closed oil tank comprises a top surface, a bottom surface and a side wall between the top surface and the bottom surface; the top surface is provided with an inlet for the extension of a transformer bushing to be tested, an oil injection port for injecting transformer oil and a first through hole for mounting the temperature sensing probe; the side wall is provided, on a side close to the bottom surface, with a second through hole for mounting the heating component and an oil outlet for discharging transformer oil; The bushing mounting base is in a hollow columnar shape, one end of the bushing mounting base is provided with a flange plate for fixing the transformer bushing to be tested and the other end of the bushing mounting base is provided with an inlet on the top surface of the closed oil tank. The temperature sensing probe is sealingly mounted on the first through hole, one end of the temperature sensing probe extends into the closed oil tank and is immersed in the transformer oil, and the other end of the temperature sensing probe is located outside the closed oil tank and is connected to the temperature monitoring device through a lead wire. The heating component is sealingly mounted on the second through hole, one end of the heating component extends into the closed oil tank and is immersed in the transformer oil, and the other end of the heating component is located outside the closed oil tank and is provided with a voltage terminal connected to an external power supply. The temperature monitoring device is mounted on the side wall of the closed oil tank. After the transformer bushing to be tested is fixed on the flange plate of the bushing mounting base and extends into the closed oil tank through the inlet, transformer oil is injected through the oil injection port, so that the transformer oil immerses the heating component, the temperature sensing probe and a pre-set equalizing ring on the base of the transformer bushing to be tested, and the external power supply is connected to the heating component for continuous heating until the oil temperature monitored by the temperature monitoring device through the temperature sensing probe is equal to a pre-set oil temperature, so that the required temperature of the transformer bushing to be tested in the actual operation environment of the transformer oil is simulated.

2. The transformer bushing test specific tooling of claim 1, wherein, Further comprising: A UHF sensor; The side wall of the closed oil tank is further provided with a third through hole for mounting the UHF sensor; The UHF sensor is mounted on the third through hole, one end of the UHF sensor extends into the closed oil tank and is immersed in the transformer oil, and the other end of the UHF sensor is located outside the closed oil tank and is provided with a signal terminal connected to an external partial discharge signal detection device; wherein the partial discharge signal detection device is used for detecting the partial discharge signal existing on the transformer bushing to be tested.

3. The transformer bushing test specific tooling of claim 2, wherein, Further comprising: A transparent observation window; The side wall of the closed oil tank is further provided with a fourth through hole for mounting the transparent observation window; The transparent observation window is sealingly mounted on the fourth through hole.

4. The transformer bushing test specific tooling of claim 3, wherein, Further comprising: A grounding column; One end of the grounding column is mounted on the side wall of the closed oil tank, and the other end of the grounding column is grounded.

5. The transformer bushing test specific tooling of claim 4, wherein, Further comprising: A lifting ring; The four lifting rings are fixed on the four corners of the top surface of the closed oil tank.

6. The transformer bushing test specific tooling of claim 5, wherein, The bushing mounting base is provided on the inlet of the top surface of the closed oil tank and is fixed by welding.

7. The transformer bushing test specific tooling of claim 6, wherein, The transformer bushing to be tested is a 110kV transformer bushing or a 220kV transformer bushing; a flange plate of the bushing mounting base is formed with a first mounting hole for mounting the 110kV transformer bushing and a second mounting hole for mounting the 220kV transformer bushing.

8. The transformer bushing test specific tooling of claim 7, wherein, Manual valves are arranged on the oil inlet and the oil outlet of the closed oil tank.

9. The transformer bushing test specific tooling of claim 8, wherein, The heating components are two and are both heating pipes.

10. The transformer bushing test specific tooling of claim 9, wherein, The transparent observation windows are four and are all made of glass; the fourth through holes are four; wherein, The four transparent observation windows are in sealing connection with the four fourth through holes through sealing rings and are all located in the middle of the closed oil tank; two of the four transparent observation windows are located on one side wall and the other two are located on the other side wall.

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