Assembling method of tank-type capacitor voltage transformer

Abstract

The invention relates to the technical field of assembly of tank-type capacitor voltage transformers, in particular to an assembly method of a tank-type capacitor voltage transformer, which comprises the following steps: S1, assembling a high-voltage capacitor module; s2, assembling an electromagnetic unit module; s3, assembling and packaging a low-voltage capacitor module; s4, the high-voltage capacitor module is in butt joint with the electromagnetic unit module and the low-voltage capacitor module; s5, vacuumizing and leak detection are carried out; and S6, testing. According to the utility model, the whole machine can be subjected to multi-cavity splitting and sub-module installation, so that the production time is shortened, the quality controllability is improved, and the error precision characteristic of a tank type capacitor voltage transformer product can be kept within a 0.2-level high-precision range.

Description

Technical Field

[0001] The invention relates to the technical field of tank type capacitor voltage transformer assembly, in particular to an assembly method of a tank type capacitor voltage transformer. Background Art

[0002] At present, the voltage transformer widely used in gas insulated switchgear (GIS) is the tank type electromagnetic voltage transformer. With the increase of voltage level, the manufacturing difficulty, process, cost, volume and weight of the tank type electromagnetic voltage transformer will increase exponentially, and the insulation characteristics are also very poor. In particular, the tank type electromagnetic voltage transformer is prone to ferromagnetic resonance with the power grid, and its ability to withstand lightning impulse overvoltage and operation impulse overvoltage is poor.

[0003] The capacitor voltage divider of the traditional column capacitor voltage transformer has a complex structure and a difficult manufacturing process. The capacitor voltage divider is composed of hundreds or thousands of capacitor units connected in series. The column capacitor voltage transformer is greatly affected by the high-voltage lead, adjacent objects and adjacent phase power supply. The ambient temperature and temperature gradient, the degree of contamination on the surface of the porcelain bushing and the relative humidity also have an impact on the error characteristics. Various factors such as high-voltage lead, temperature change (including the upper and lower temperature gradient of the column capacitor voltage divider) have an error influence of 0.3% on the 765kV voltage level column capacitor voltage transformer, and the combined influence is even greater.

[0004] With the construction and development of UHV power grid, the existing conventional 1000kV voltage level column capacitor voltage transformer adopts oil-paper composite voltage divider structure, which cannot be effectively connected with GIS station, and has problems of complex structure, difficult manufacturing process and poor error characteristic accuracy. The tank capacitor voltage transformer technology is proposed in the CN200610020003.7 patent, but it does not involve the manufacturing process of capacitors and tank capacitor voltage transformers. The cleanliness and assembly size between coaxial electrodes will directly affect the capacitance and error accuracy characteristics of the tank capacitor voltage transformer. At present, the tank capacitor voltage transformer only meets the voltage measurement level 0.5 requirements, and does not meet the measurement level 0.2 error requirements. Repeated disassembly and assembly of each component will also have a large impact on the cleanliness and electrode deformation inside the packaging shell. Summary of the invention

[0005] Aiming at the problem that the error accuracy characteristic of the current tank-type capacitor voltage transformer only meets the voltage measurement level 0.5 requirement and cannot achieve high accuracy, the present invention provides an assembly method of the tank-type capacitor voltage transformer.

[0006] In order to solve the above problems, the technical solution adopted by the present invention is: A method for assembling a tank-type capacitor voltage transformer includes the following steps: S1, assembling a high-voltage capacitor module; S2, assembling an electromagnetic unit module; S3, assembling and packaging a low-voltage capacitor module; S4, docking the high-voltage capacitor module with the electromagnetic unit module and the low-voltage capacitor module; S5, vacuuming and leak detection; S6, conducting a test. The whole machine can be split into multiple cavities and installed in modules, which shortens the production time, improves the quality controllability, and can keep the error accuracy characteristics of the tank-type capacitor voltage transformer product within the 0.2-level high-precision range.

[0007] Preferably, the high-voltage capacitor module includes a shell; a core column, a high-voltage electrode and a low-voltage electrode are coaxially arranged in the shell; a four-way connector is connected to the outer wall of the shell; step S1 includes the following steps: S11, coaxially assembling the low-voltage electrode in the shell; the high-voltage electrode is fixed on the core column inside the shell; S12, with one end of the high-voltage electrode as the stationary end and the low-voltage electrode as the moving end, the low-voltage electrode is covered outside the high-voltage electrode; then the shell is packaged with bolts; S13, the four-way connector is connected to the outer wall of the shell.

[0008] Preferably, after step S13, step S14 is also included: the installed high-voltage capacitor module is evacuated and inflated for leak detection; evacuated to below 10Pa and maintained for at least 8 hours; filled with insulating gas to rated pressure, sealed and leak detected; S15, semi-finished product test; including capacitance, withstand voltage, partial discharge, and dielectric loss test.

[0009] Preferably, in step S13, the four-way connector includes a shell one; a conductive rod is arranged in the shell one; and the conductive rod is arranged in a T-shape or a cross shape as a whole.

[0010] Preferably, in step S4, one direction of the conductive rod is connected to the housing, one direction is connected to the electromagnetic unit module, and the other direction is connected to the low-voltage capacitor module.

[0011] Preferably, the electromagnetic unit module includes an iron core; a coil is wound around the iron core; a shielding cover is arranged outside the coil; an insulating layer is arranged outside the shielding cover; the iron core is arranged on a clamp; the clamp is arranged on the second shell; a fixing piece is arranged at the lower end of the clamp; and a compensating inductor is arranged on the fixing piece.

[0012] Preferably, step S2 includes the following steps: S21, fixing the iron core on the clamp; S22, sleeve the coil on the iron core; then assembling a shielding cover outside the coil; then assembling an insulating layer outside the shielding cover; S23, assembling a compensating inductor on the fixing member.

[0013] Preferably, after step S23, step S24 is also included: evacuating the electromagnetic unit module and inflating it for leak detection; evacuating it to below 10Pa and maintaining it for at least 4 hours, filling it with insulating gas to the rated pressure, and sealing it for leak detection; the sealing time is 24 hours; and then conducting a semi-finished product test of the electromagnetic unit module.

[0014] Preferably, the low-voltage capacitor module includes a third shell; the third shell is provided with a capacitor element; step S3 includes the following steps: S31, assembling the capacitor element in the third shell; S32, measuring the temperature coefficient of the low-voltage capacitor module; the temperature coefficient parameter is within the range of ±1×10-4 / K; S33, evacuating and filling the low-voltage capacitor module for leak detection; evacuating to below 10Pa and maintaining for at least 4 hours, filling with insulating gas to the rated pressure, and sealing for leak detection; the sealing time is 24 hours; S34, conducting semi-finished product tests, including capacitance, withstand voltage, partial discharge, and dielectric loss tests.

[0015] It can be seen from the above technical solutions that the advantages of the present invention are: 1. Provide an assembly method for tank-type capacitor voltage transformer, which simplifies the process of repeated disassembly and assembly to the greatest extent, and avoids the invasion of metal impurities and dust into the UHV cavity caused by repeated disassembly and assembly.

[0016] 2. The multi-cavity splitting of the whole machine, module installation and semi-finished product testing shortens the production time and improves the quality controllability. The module installation and testing can increase the probability of discovering and solving potential problems. Ensure that each component is qualified and reliable before the whole machine is assembled.

[0017] 3. The coaxial electrode is installed with the high voltage inside and the low voltage outside. The axial electric field is evenly distributed, which is beneficial to improving the insulation capacity of ultra-high voltage. The overall volume is small and the structure is compact, which is very suitable for closed power stations or places with limited space.

[0018] 4. The assembly method of the tank-type capacitor voltage transformer can effectively avoid the introduction of impurities between electrodes, confirm the assembly dimensions, avoid the introduction of metal impurities and electrode deformation during secondary disassembly and assembly, ensure the accuracy of the capacitance of the voltage-dividing capacitor, and keep the error accuracy characteristics of the tank-type capacitor voltage transformer within the high-precision range of 0.2. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solution of the present invention, the accompanying drawings required for use in the description will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0020] Figure 1 It is a structural schematic diagram of the present invention.

[0021] Figure 2 This is a schematic diagram of assembling the high-voltage capacitor module of the present invention.

[0022] Figure 3 It is a structural schematic diagram of the low-voltage capacitor module of the present invention.

[0023] Figure 4 It is a structural schematic diagram of the electromagnetic unit module of the present invention.

[0024] Description of main reference numerals 1-shell, 2-low-voltage electrode, 3-high-voltage electrode, 4-core column, 5-four-way connector, 6-low-voltage capacitor module, 7-electromagnetic unit module; 501 - shell one, 502 - conductive rod; 601 - shell three, 602 - capacitor element; 701 - coil, 702 - compensation reactor, 703 - iron core, 704 - shielding cover, 705 - fixing part, 706 - clamp, 707 - shell two. DETAILED DESCRIPTION

[0025] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical scheme of the present invention will be clearly and completely described below in conjunction with the drawings in this specific embodiment. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of them. Based on the embodiments in this patent, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this patent.

[0026] like Figure 1 , 2 As shown, a method for assembling a tank-type capacitor voltage transformer, first assembling a high-voltage capacitor module; the high-voltage capacitor module includes a housing 1; a core column 4, a high-voltage electrode 3 and a low-voltage electrode 2 are coaxially arranged in the housing 1; a four-way connector 5 is connected to the outer wall of the housing 1; the following steps are included: the low-voltage electrode 2 is coaxially assembled in the housing 1; the high-voltage electrode 3 is fixed on the core column 4 inside the housing 1; one end of the high-voltage electrode 3 is used as a stationary end, and the low-voltage electrode 2 is used as a moving end, and the low-voltage electrode 2 is covered outside the high-voltage electrode 3; then the housing 1 is packaged with bolts. The four-way connector 5 includes a housing 1 501; a conductive rod 502 is arranged in the housing 1 501; the conductive rod 502 is arranged in a T-shaped or cross-shaped manner as a whole; the four-way connector 5 is connected to the outer wall of the housing 1; the electromagnetic unit module 7 and the low-voltage capacitor module 6 are connected to the four-way connector 5 to form a closed cavity. The installed high-voltage capacitor module is evacuated and filled with gas for leak detection; evacuated to below 10Pa and maintained for at least 8 hours; filled with insulating gas to the rated pressure, sealed for leak detection; semi-finished product tests are carried out, including capacitance, withstand voltage, partial discharge, and dielectric loss tests. The gap between the high-voltage electrode 3 and the low-voltage electrode 2 is tested at four points in the circumferential direction using a tooling gauge block. The installation deviation between the electrodes is controlled within ±5mm.

[0027] Next, assemble the electromagnetic unit module 7, such as Figure 4As shown, the electromagnetic unit module 7 includes an iron core 703; a coil 701 is wound around the iron core 703; a shielding cover 704 is provided outside the coil 701; an insulating layer is provided outside the shielding cover 704; the iron core 703 is arranged on a clamp 706; the clamp 706 is arranged on a second housing 707; a fixing member 705 is provided at the lower end of the clamp 706; a compensating inductor 702 is provided on the fixing member 705; the steps include fixing the iron core 703 on the clamp 706; sleeve the coil 701 on the iron core 703; then assemble the shielding cover 704 outside the coil 701; then assemble the insulating layer outside the shielding cover 704; assemble the compensating inductor 702 on the fixing member 705. The electromagnetic unit module 7 is evacuated and inflated for leak detection; evacuated to below 10Pa for at least 4 hours, inflated with insulating gas to the rated pressure, and sealed for leak detection; the sealing time is 24 hours; and then the semi-finished product test of the electromagnetic unit module 7 is carried out. Among them, the coil 701 is assembled by coaxial winding. From the inside to the outside, they are: low-voltage coil, regulating winding, and high-voltage coil. The low-voltage coil is equipped with multiple sets of turn adjustment taps, and the coil 701 is assembled by coaxial winding. This arrangement can realize the fully automatic equipment winding of the high-voltage coil, improve the winding efficiency and the precise control of the outer diameter of the winding.

[0028] Assemble and package the low-voltage capacitor module 6 again; Figure 3 As shown, the low-voltage capacitor module 6 includes a housing 3 601; the housing 3 601 is provided with a capacitor element 602; and the following steps are included: assembling the capacitor element 602 in the housing 3 601; measuring the temperature coefficient of the low-voltage capacitor module 6; the temperature coefficient parameter is within ±1×10 -4 / K range; low-voltage capacitor module 6 is evacuated and filled with gas for leak detection; evacuated to below 10Pa and maintained for at least 4 hours, filled with insulating gas to the rated pressure, and sealed for leak detection; the sealing time is 24 hours; semi-finished product tests are carried out, including capacitance, withstand voltage, partial discharge, and dielectric loss tests. Capacitor element 602 is a ceramic capacitor or a thin film capacitor element, arranged in a cylinder, and the whole is docked with the housing three 601, and is coaxially assembled and fixed by plugging.

[0029] Then, the high-voltage capacitor module is docked with the electromagnetic unit module 7 and the low-voltage capacitor module 6; the conductive rod 502 is used to perform a three-way connection by plugging the static and dynamic contacts, with one direction of the conductive rod 502 connected to the housing 1, one direction connected to the electromagnetic unit module 7, and the other direction connected to the low-voltage capacitor module 6. After the docking is completed, the whole machine is leak-checked, especially the sealing surfaces between the modules are partially wrapped for leak-checking and testing. Routine tests of the whole machine and gas composition tests are performed.

[0030] The above insulating gas is SF6 gas.

[0031] By using the assembly method of the tank-type capacitor voltage transformer, the process of repeated disassembly and assembly is simplified to the greatest extent, and the repeated disassembly and assembly can avoid the invasion of metal impurities and dust into the UHV cavity. The whole machine can be split into multiple cavities, installed in modules and tested in semi-finished products, which shortens the production time and improves the quality controllability. The installation and testing of modules can increase the probability of discovering and solving potential problems. Ensure that each component is qualified and reliable before the whole machine is assembled. The arrangement and installation method of the coaxial electrode with the high voltage inside and the low voltage outside is adopted, and the axial electric field is evenly distributed, which is conducive to improving the insulation capacity of the UHV voltage. The overall volume is small and the structure is compact, which is very suitable for closed power stations or places with limited space. It can effectively avoid the introduction of impurities between electrodes, confirm the assembly size, avoid the introduction of metal impurities and electrode deformation during secondary disassembly and assembly, ensure the accuracy of the capacitance of the voltage divider capacitor, and keep the error accuracy characteristics of the tank-type capacitor voltage transformer product within the high-precision range of 0.2.

[0032] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for assembling a tank-type capacitor voltage transformer, characterized in that: The following steps are involved: S1, assemble high voltage capacitor module; S2, assembling the electromagnetic unit module (7); S3, assembling and packaging the low voltage capacitor module (6); S4, docking the high-voltage capacitor module with the electromagnetic unit module (7) and the low-voltage capacitor module (6); S5, vacuum leak detection; S6. Conduct the test.

2. The method for assembling a tank-type capacitor voltage transformer according to claim 1, characterized in that: The high-voltage capacitor module comprises a shell (1); a core column (4), a high-voltage electrode (3) and a low-voltage electrode (2) are coaxially arranged inside the shell (1); a four-way connector (5) is connected to the outer wall of the shell (1); step S1 comprises the following steps: S11, coaxially assembling a low-voltage electrode (2) in the housing (1); the high-voltage electrode (3) is fixed on a core column (4) inside the housing (1); S12, with one end of the high-voltage electrode (3) as the stationary end and the low-voltage electrode (2) as the moving end, the low-voltage electrode (2) is covered outside the high-voltage electrode (3); and then the housing (1) is sealed with bolts; S13, a four-way connector (5) is connected to the outer wall of the shell (1).

3. The method for assembling a tank-type capacitor voltage transformer according to claim 2, characterized in that: After step S13, the method further includes step S14: evacuating and filling the installed high-voltage capacitor module to detect leaks; evacuating the module to below 10 Pa and maintaining the pressure for at least 8 hours; filling the module with insulating gas to the rated pressure, and sealing the module for leak detection; S15. Conduct semi-finished product tests, including capacitance, withstand voltage, partial discharge, and dielectric loss tests.

4. The method for assembling a tank-type capacitor voltage transformer according to claim 2, characterized in that: In step S13, the four-way connector (5) comprises a housing 1 (501); a conductive rod (502) is arranged inside the housing 1 (501); and the conductive rod (502) is arranged in a T-shape or a cross shape as a whole.

5. The method for assembling a tank-type capacitor voltage transformer according to claim 4, characterized in that: The conductive rod (502) is connected to the housing (1) in one direction, connected to the electromagnetic unit module (7) in one direction, and connected to the low-voltage capacitor module (6) in the other direction.

6. The method for assembling a tank-type capacitor voltage transformer according to claim 1, characterized in that: The electromagnetic unit module (7) comprises an iron core (703); a coil (701) is wound around the iron core (703); a shielding cover (704) is provided on the outer shell of the coil (701); an insulating layer is provided on the outer shell (704); the iron core (703) is arranged on a clamp (706); the clamp (706) is arranged on a second housing (707); a fixing part (705) is arranged at the lower end of the clamp (706); and a compensating reactor (702) is arranged on the fixing part (705).

7. The method for assembling a tank-type capacitor voltage transformer according to claim 6, characterized in that: Step S2 includes the following steps: S21, fixing the iron core (703) on the clamp (706); S22, sleeve the coil (701) onto the iron core (703); then assemble a shielding cover (704) outside the coil (701); and then assemble an insulating layer outside the shielding cover (704); S23. Assemble the compensating reactor (702) on the fixing member (705).

8. The method for assembling a tank-type capacitor voltage transformer according to claim 7, characterized in that: After step S23, the method further comprises step S24: evacuating the electromagnetic unit module (7) and inflating it for leak detection; evacuating it to below 10 Pa and maintaining it for at least 4 hours, inflating it with insulating gas to the rated pressure, and sealing it for leak detection; the sealing time is 24 hours; and then conducting a semi-finished product test of the electromagnetic unit module (7).

9. The method for assembling a tank-type capacitor voltage transformer according to claim 1, characterized in that: The low-voltage capacitor module (6) comprises a housing three (601); the housing three (601) is provided with a capacitor element (602); step S3 comprises the following steps: S31, assembling a capacitor element (602) in the housing three (601); S32, measure the temperature coefficient of the low voltage capacitor module (6); the temperature coefficient parameter is within ±1×10 -4 / K range; S33, the low-voltage capacitor module (6) is evacuated and filled with gas for leak detection; the evacuation is maintained below 10 Pa for at least 4 hours, and then filled with insulating gas to the rated pressure, and then sealed for leak detection; the sealing time is 24 hours; S34. Conduct semi-finished product tests, including capacitance, withstand voltage, partial discharge, and dielectric loss tests.

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