Voltage transformer manufacturing method facilitating assembly and maintenance

Abstract

The application discloses a voltage transformer manufacturing method convenient for assembly and maintenance, and relates to the technical field of high-voltage measurement or relay protection of a power system; a secondary winding and a primary winding are concentrically wound on a resin insulation framework by winding equipment, and are then sleeved on a core column, and after insulation and buffer wrapping, a coil body is formed; after vacuum drying, the coil body is installed in a pouring mold, a low-voltage shielding net is fixed, the primary winding is connected with three primary high-voltage terminals through a primary lead, another primary lead is connected with a primary N terminal, and the low-voltage shielding net is bolted with the mold; the secondary terminal is connected with the secondary winding and is fixed through a mold secondary cover plate, the primary high-voltage terminal and the primary N terminal are fixed, the insulation distance between the low-voltage shielding net and the mold core mold is adjusted, and an insulator is formed by adopting epoxy resin vacuum pouring and solidification. The method is simple, easy and convenient to operate, and can save manpower and time cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of high-voltage measurement or relay protection technology of power system, and particularly relates to a voltage transformer manufacturing method facilitating assembly and maintenance. BACKGROUND

[0002] The voltage transformer mainly serves the functions of measurement and protection in the power system or electrical control system. In order to realize the function of power system harmonic elimination and miniaturization of the switch cabinet and facilitate maintenance, a voltage transformer with a harmonic eliminator is usually used, which mainly comprises a single-phase voltage transformer, a harmonic eliminator, an insulating support, an external fuse, a contact, etc. However, when installed in a new type of switch cabinet, the voltage transformer has problems such as too many components, complicated installation, cumbersome maintenance, too many quality control points, high cost, unreliable insulation, etc. On the other hand, in high-altitude areas, the primary high-voltage line sometimes has problems such as creeping, flashover, leakage, tracking, and discharge. When the primary high-voltage connection line is replaced, the primary line and the voltage transformer need to be disassembled for maintenance, which is cumbersome and wastes manpower and time. SUMMARY

[0003] The present application aims to provide a voltage transformer manufacturing method facilitating assembly and maintenance. The transformer obtained by the method has the advantages of small size, novel structure, complete functions, easy installation, stable insulation, small partial discharge, safe operation, easy maintenance, etc., and can be adapted to a new type of switch cabinet.

[0004] To achieve the above-mentioned purpose, the technical solution of the present application is as follows: a voltage transformer manufacturing method facilitating assembly and maintenance, comprising:

[0005] The secondary winding and the primary winding are concentrically wound on the resin insulation framework by winding equipment, so as to ensure uniform insulation distance between the primary and the secondary, and then the coil body is formed by being sleeved on the core column and being insulated and cushioned and banded.

[0006] After vacuum drying, the coil body is installed in a pouring mold, the low-voltage shielding net is fixed, the primary winding is connected to three primary high-voltage terminals through a primary lead, another primary lead is connected to the primary N terminal, and the low-voltage shielding net is bolted with the mold to shield the primary high voltage from the low-voltage electric field, and the low-voltage electric field is at the same low potential, so that the high and low voltage electric fields are uniformly distributed.

[0007] The secondary terminal and the secondary winding are connected and fixed through the mold secondary cover plate, the primary high-voltage terminal and the primary N terminal are fixed, the insulation distance between the low-voltage shielding net and the mold core mold is adjusted, and the insulation body is formed by vacuum pouring and curing of epoxy resin.

[0008] Further, the mutual inductor obtained by the above method comprises an insulator with a coil body built-in, three primary insulation columns are horizontally and equidistantly arranged on the front face of the insulator, a primary high-voltage terminal is arranged in each primary insulation column, the primary high-voltage terminal is connected with a corresponding coil body primary lead wire through a primary conductive rod, a low-voltage shielding net is arranged at the end of the primary insulation column and is concentric with the primary conductive rod, and the outer surface of the lower part of the insulator is uniformly sandblasted and then sprayed with a layer of metal conductive paint.

[0009] Further, the low-voltage shielding net comprises an embedded nut, a metal wire net and metal wires, the metal wire net is in a cylindrical shape and the upper edge is outwardly folded, the lower edge is tin soldered with the embedded nut through the metal wires to form a symmetrical structure, and the exposed end face of the embedded nut is connected with the metal conductive paint.

[0010] Further, the insulator at the root of the three primary insulation columns is in a square flange plate structure, and secondary terminals are symmetrically arranged on both sides of the square flange plate.

[0011] Further, the top face of the square flange plate is rearwardly transitioned to a square rear face through a cylindrical face, and installation through holes are formed around the square flange plate.

[0012] Still further, an insulation distance is arranged between the low-voltage shielding net and the primary conductive rod.

[0013] Still further, the primary insulation column is a round table shape terminal, and the primary high-voltage terminal is recessed in the end face of the primary insulation column, and the recessed part is in a cylindrical cavity.

[0014] Still further, one side of the square flange plate is provided with a semi-cylindrical structure, a cylindrical cavity is arranged in the structure, the cylindrical cavity is transitioned from a straight face of the square flange plate to a cylindrical face, a primary N terminal is arranged at the bottom of the cylindrical cavity, and the primary N terminal is connected with a coil body primary N terminal lead wire.

[0015] Still further, ground terminals are symmetrically arranged on both sides of the square flange plate, and the end face of the ground terminal is connected with the metal conductive paint.

[0016] Still further, secondary wiring platforms are symmetrically arranged on both sides of the square flange plate, secondary terminals are arranged on the secondary wiring platforms, and ground terminals are arranged below the secondary terminals.

[0017] The above technical scheme can achieve the following technical effects:

[0018] 1. The primary high voltage terminal can be switched arbitrarily without disassembling the primary circuit, making the product structure more compact and small; the primary terminal is arranged in front and back with a primary insulating column and a cylindrical cavity, the secondary terminal is symmetrically arranged on both sides of the flange plate, the product surface is sprayed with a metal conductive layer to effectively shield the internal and external interference electric field, the structure is more novel and unique, the function is more complete, and the product is integrated with measurement, protection and harmonic elimination, has the advantages of small size, novel structure, complete function, easy installation, stable insulation, large creepage distance, small partial discharge, safe operation, reliable sealing and easy maintenance, and is more suitable for use with new switch cabinets in high altitude areas;

[0019] 2. The primary insulating column obtained by the above method is lengthened and the primary terminal is recessed to increase the insulation creepage distance, preventing the primary conductive rod from discharging to the rectangular flange plate when used in high altitude areas, which can further enhance the overall mechanical strength of the product; during installation and use, only the three primary insulating columns of the transformer are inserted into the switch cabinet and connected to the primary circuit, and the primary terminal is tightly sealed by bolts, thereby ensuring the use requirements in high altitude areas, and the through hole fixing bolt of the flange plate can be used, the primary high voltage terminal can be switched arbitrarily, without disassembling or adding other numerous electrical accessories, effectively saving the assembly and maintenance time of the switch cabinet, and no special maintenance work is needed;

[0020] 3. The low-voltage shielding net is added, and the whole is poured with epoxy resin, and the shielding effect of the surface sprayed metal conductive layer, so that the transformer insulation is reliable, the high and low voltage electric field distribution is uniform, the shielding effect is good, the partial discharge is small, and the safe operation of the product is ensured, and the occurrence of voltage transformer ferromagnetic resonance fault is avoided from the structure.

[0021] 4. The method is simple, easy to operate, and can save labor and time cost. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 The internal structure diagram of the voltage transformer manufacturing method for easy assembly and maintenance;

[0023] Figure 2 The main view of the external structure of the voltage transformer manufacturing method for easy assembly and maintenance;

[0024] Figure 3 The right view of the external structure of the voltage transformer manufacturing method for easy assembly and maintenance;

[0025] Figure 4 The top view of the external structure of the voltage transformer manufacturing method for easy assembly and maintenance;

[0026] Figure 5 The structure diagram of the low-voltage shielding net;

[0027] The components are: 1. Iron core; 2. Secondary winding; 3. Primary winding; 4. Primary conductive rod; 5. Primary high-voltage terminal; 6. Low-voltage shielding mesh; 7. Primary insulating column; 8. Insulator; 9. Secondary terminal; 10. Grounding terminal; 11. Embedded nut; 12. Square flange; 13. Cylindrical cavity; 14. Primary N terminal; 15. Secondary terminal block; 16. Through hole; 17. Metal wire; 18. Metal wire mesh; 19. Metal conductive paint; 20. Resin insulating skeleton. Detailed Implementation

[0028] The embodiments of the present invention are implemented under the premise of the technical solution of the present invention, and detailed implementation methods and specific operation processes are given. However, the protection scope of the present invention is not limited to the following embodiments.

[0029] Example 1

[0030] like Figures 1-5 As shown, the voltage transformer obtained by the above method includes an insulator with a built-in coil body. Three primary insulating columns are evenly spaced horizontally on the front of the insulator, and each primary insulating column contains a primary high-voltage terminal. The primary high-voltage terminals are all connected to the primary leads of the coil body through primary conductive rods. The primary high-voltage terminals can be switched arbitrarily without disassembling the primary circuit, which facilitates the sequential arrangement of high-voltage lines in the switchgear, ensures a uniform electric field around it, and has sufficient mechanical strength. The lower outer surface of the insulator is uniformly sandblasted and then coated with a layer of metallic conductive paint to increase the surface creepage distance while ensuring that the outer surface of the insulator is at the same potential as the ground. Together with the low-voltage shielding mesh, it effectively shields the low-voltage electric field.

[0031] An insulating distance is provided between the low-voltage shielding mesh and the primary conductive rod to ensure complete isolation between the high and low voltage. The low-voltage shielding mesh includes an embedded nut, a metal mesh, and metal wires. The metal mesh is cylindrical with an outward-folded upper edge, and one side of the lower edge is soldered to the embedded nut via metal wires to form an angled symmetrical structure. The exposed end face of the embedded nut is connected to the conductive metal paint to ensure good shielding effect of the low-voltage electric field.

[0032] The insulators at the base of the three primary insulating columns are square flange structures. Secondary terminals are symmetrically arranged on both sides of the square flange, further improving the electrical insulation distance between phases and the insulation distance to ground, resulting in a better insulation level and facilitating secondary wiring for users. The top surface of the square flange transitions from a cylindrical surface to a square rear surface. The square flange has symmetrical through holes around its perimeter, effectively preventing the epoxy resin from cracking due to uneven stress during installation, ensuring safer and more reliable product installation.

[0033] The primary insulation column is a circular truncated cone shaped terminal, the primary high voltage terminal is recessed in the end face of the insulation column, the recessed part is a cylindrical cavity, which is a primary conductive connection mode different from the American elbow head, realizes flexible electrical contact with the high voltage bus of the switch cabinet, ensures effective electrical contact with the primary high voltage terminal, and makes the whole have sufficient mechanical strength. At the same time, the lengthening of the primary insulation column and the increase of the recessed primary terminal increase the insulation creepage distance, prevent the primary conductive rod from creeping flashover discharge to the square flange plate in high altitude area, and can further enhance the overall mechanical strength of the product. The primary terminal is tightly sealed by bolts, thereby ensuring the use requirements in high altitude area.

[0034] The square flange plate is provided with a semi-cylindrical structure on one side, the structure is provided with a cylindrical cavity, the cylindrical cavity is directly from the middle of the square flange plate to the cylindrical surface, and a primary N terminal is arranged at the bottom of the cylindrical cavity, the primary N terminal is connected with the coil body primary N terminal lead wire, and the insulation distance to ground during test is effectively increased.

[0035] The square flange plate is provided with a semi-cylindrical structure on one side, the structure is provided with a cylindrical cavity, the cylindrical cavity is directly from the middle of the square flange plate to the cylindrical surface, and a primary N terminal is arranged at the bottom of the cylindrical cavity, the primary N terminal is connected with the coil body primary N terminal lead wire, and the insulation distance to ground during test is effectively increased.

[0036] When used, only the three primary insulation columns of the mutual inductor are inserted in the switch cabinet, the primary fixing bolts are tightened, the flange plate through hole fixing bolts are tightened, and finally the secondary line cable connection is performed, without the need for special installation of other numerous electrical accessories, so that the function of eliminating harmonic protection is realized, the assembly time of the switch cabinet and the assembly work completion time of the voltage mutual inductor are effectively saved; the product maintenance is simpler, and no special maintenance work is needed.

[0037] The foregoing description of specific exemplary embodiments of the application is intended for purposes of illustration and example only. These descriptions are not intended to limit the application to the precise form disclosed, and obviously many changes and modifications can be suggested to one skilled in the art without departing from the spirit or scope of the application. It is chosen and described in the hope that others skilled in the art will be able to make and use the application in its various embodiments and with various modifications as are enabled by the teachings set forth herein. The scope of the application is to be limited only by the claims and the equivalents thereof.

Claims

1. A method of manufacturing a voltage transformer that is easy to assemble and to overhaul, characterized in that, The application relates to a mutual inductor. The primary winding and the secondary winding are concentrically wound on a resin insulation framework by winding equipment, the insulation distance between the primary winding and the secondary winding is uniform, the winding body is formed by being sleeved on a core column after insulation and buffer wrapping, the winding body is installed in a pouring mold after vacuum drying, the primary winding is connected with three primary high-voltage terminals through a primary lead, another primary lead is connected with a primary N terminal, the low-voltage shielding net is fixed on the mold through a bolt, the primary high-voltage is shielded from the low-voltage electric field, the low-voltage electric field is at the same low potential, and the high-voltage and low-voltage electric fields are uniformly distributed. The secondary terminal is connected with the secondary winding and fixed through a mold secondary cover plate, the primary high-voltage terminal and the primary N terminal are fixed, the insulation distance between the low-voltage shielding net and the mold core mold is adjusted, and the insulation body is formed by adopting epoxy resin vacuum pouring and solidification. The mutual inductor obtained by the above method comprises an insulation body in which a winding body is arranged, three primary insulation columns are horizontally and equidistantly arranged on the front surface of the insulation body, a primary high-voltage terminal is arranged in each primary insulation column, the primary high-voltage terminal is connected with the primary lead of the corresponding winding body through a primary conductive rod, a low-voltage shielding net is arranged at the end of the primary insulation column and is concentric with the primary conductive rod, and the outer surface of the lower part of the insulation body is uniformly sandblasted and then sprayed with a layer of metal conductive paint. The low-voltage shielding net comprises a embedding nut, a metal wire net and metal wires, the metal wire net is in a cylindrical shape, the upper edge of the metal wire net is outwardly folded, the lower edge is tin soldered with the embedding nut through the metal wires to form a symmetrical structure, and the exposed end surface of the embedding nut is connected with the metal conductive paint. The insulation body at the root of the three primary insulation columns is in a square flange plate structure, the two sides of the square flange plate are symmetrically arranged with secondary terminals. One side of the square flange plate is provided with a semicylindrical structure, a cylindrical cavity is arranged in the structure, the cylindrical cavity is directly connected from the middle part of the square flange plate to a cylindrical surface, a primary N terminal is arranged at the bottom of the cylindrical cavity, and the primary N terminal is connected with the primary N terminal lead of the winding body. The top surface of the square flange plate is rearwardly connected from a cylindrical surface to a square rear surface, and installation through holes are formed in the periphery of the square flange plate.

2. The method of claim 1, wherein the voltage transformer is manufactured by the steps of: An insulation distance is arranged between the low-voltage shielding net and the primary conductive rod.

3. The method of claim 1, wherein the voltage transformer is manufactured by the steps of: The primary insulation column is a circular truncated cone shaped terminal, the primary high-voltage terminal is recessed in the end surface of the primary insulation column, and the recessed part is in a cylindrical cavity.

4. The method of claim 1, wherein the voltage transformer is manufactured by the steps of: Ground terminals are symmetrically arranged on the two sides of the square flange plate, the end surface of the ground terminal is connected with the metal conductive paint.

5. The method of claim 1, wherein the voltage transformer is manufactured by the steps of: Secondary terminals are arranged on the secondary wiring platforms which are symmetrically arranged on the two sides of the square flange plate, and ground terminals are arranged below the secondary terminals.

6. The method of claim 1, wherein the voltage transformer is manufactured by the steps of: ​

Images