Modularized low-partial-discharge combined mutual inductor

Abstract

The utility model relates to a modularized low-partial-discharge combined mutual inductor which comprises an epoxy resin pouring body, a plurality of line banks and a coil assembly. The coil assembly comprises a voltage iron core, a voltage secondary winding, two hoisting pieces, two insulation supporting pieces, a plurality of voltage primary windings, three current iron cores, three current primary windings, three current secondary windings and a current supporting frame, and the two insulation supporting pieces are respectively provided with a plurality of supporting arms connected with the voltage primary windings. The current support frame is respectively provided with support plates connected with the three current secondary windings; the utility model has the advantages of simple structure, stable and reliable performance, high production efficiency, modularization and low partial discharge.

Description

Technical Field

[0001] The utility model relates to the technical field of instrument transformers, in particular to a modular low partial discharge combined instrument transformer. Background Art

[0002] A combined instrument transformer is an instrument transformer formed by combining a three-phase voltage transformer and three single-phase (or two single-phase) current transformers into one for use in a three-phase power system. It is mainly used for three-phase electric energy metering and measurement in the power system. The design and use of the combined instrument transformer aim to meet the requirements of the power system for high precision and high reliability, while ensuring the safety of personnel and equipment. The combined instrument transformer includes an epoxy resin casting body, an iron core, a primary voltage winding, a secondary voltage winding, a primary current winding, and a secondary current winding. The iron core, primary voltage winding, secondary voltage winding, primary current winding, and secondary current winding of the existing combined instrument transformer cannot be integrated modularly, resulting in a cumbersome mold loading process for the combined instrument transformer, greatly affecting production efficiency, and unable to ensure the insulation distance between the primary voltage winding and the secondary voltage winding, and between the primary current winding and the secondary current winding. When using epoxy resin casting, it is easy to cause uneven thickness of the epoxy resin layer, and bubbles are likely to be generated between the epoxy resin casting layers, causing the epoxy resin layer to be prone to cracking. Therefore, the combined instrument transformer has defects such as poor insulation performance, unstable performance, and high partial discharge. Summary of the Invention

[0003] The purpose of the utility model is to overcome the defects of the prior art and provide a modular low partial discharge combined instrument transformer with a simple structure, stable and reliable performance, and good insulation performance.

[0004] To achieve the above purpose, the utility model adopts a modular low partial discharge combined instrument transformer, which includes an epoxy resin casting body, a plurality of terminal blocks arranged on the epoxy resin casting body, and a coil assembly arranged in the epoxy resin casting body. The coil assembly includes a voltage iron core, a secondary voltage winding wound around the voltage iron core, two lifting members symmetrically arranged on one side of the secondary voltage winding, two insulation supports symmetrically arranged on the other side of the secondary voltage winding, a plurality of primary voltage windings sleeved on the secondary voltage winding, three current iron cores, three primary current windings respectively wound around the three current iron cores and connected to the plurality of terminal blocks, three secondary current windings respectively sleeved on the three primary current windings, and a current support frame arranged on the two insulation supports. A plurality of support arms connected to the plurality of primary voltage windings are respectively arranged on the two insulation supports, and support plates connected to the three secondary current windings are respectively arranged on the current support frame.

[0005] The beneficial effects of the above structure are as follows: The coil assembly adopts a modular structure design. The iron core, the primary voltage winding, the secondary voltage winding, the primary current winding, and the secondary current winding are integrated modularly through the lifting parts, the insulating support parts, and the current support frame, so that the modular assembly of the coil assembly and the casting mold can be realized, and the mold loading efficiency is higher. The two lifting parts can be fixed on the bottom plate of the casting mold, so as to facilitate the lifting of the coil assembly and the bottom plate. The two insulating support parts can ensure the insulation distance between the secondary voltage winding and the primary voltage winding, and the current support frame can ensure the insulation distance between the primary current winding and the secondary current winding. When epoxy resin is cast, the casting thickness of the epoxy resin between the primary voltage winding and the secondary voltage winding, and between the primary current winding and the secondary current winding can be ensured. The thickness of the epoxy resin layer is uniform, and it is not easy to generate bubbles between the epoxy resin casting layers, and it will not cause cracking of the epoxy resin layer, with better insulation performance and lower partial discharge. Therefore, the combined transformer has the advantages of simple structure, stable and reliable performance, high production efficiency, modularization, and low partial discharge.

[0006] Particularly, three support rods are respectively arranged on the support plate corresponding to the three secondary current windings. One end of the support rod has a screw part connected to the support plate, and one end of the support rod has an arc-shaped support piece attached to the secondary current winding. A binding band is wound between the arc-shaped support piece and the secondary current winding. The support rod is attached to the secondary current winding through the arc-shaped support piece, so as to ensure a more compact connection between the support rod and the secondary current winding. The binding band is used for fixation, so as to facilitate the assembly of the support rod and the secondary current winding, and the assembly efficiency is higher.

[0007] Particularly, fixing feet are respectively arranged at both ends of the two lifting parts, and the fixing feet of the two lifting parts are distributed in a rectangular array. Hoisting holes are respectively arranged on the fixing feet of the two lifting parts. The two lifting parts are fixed on the bottom plate of the casting mold through the fixing feet distributed in a rectangular array, so as to facilitate the assembly of the lifting parts and the casting mold, and is beneficial to improving the mold loading efficiency of the coil assembly.

[0008] Particularly, the secondary voltage winding and the two lifting parts, the secondary voltage winding and the two insulating support parts, the two insulating support parts and the multiple primary voltage windings, and the two insulating support parts and the current support frame are respectively connected by tie straps. The tie strap method is used for fixation, so as to facilitate the assembly of the secondary voltage winding and the two lifting parts, the secondary voltage winding and the two insulating support parts, the two insulating support parts and the multiple primary voltage windings, and the two insulating support parts and the current support frame, and the assembly efficiency is higher.

[0009] In particular, a backing plate is provided between the two insulating supports and the primary voltage winding. The backing plate is arranged between the insulating support and the primary voltage winding, and both sides of the backing plate can be attached to the insulating support and the primary voltage winding, thereby ensuring a more compact connection between the insulating support and the primary voltage winding. Description of the Drawings

[0010] Figure 1 It is the front view of the internal structure of the embodiment of the present utility model.

[0011] Figure 2 It is the left view of the internal structure of the embodiment of the present utility model.

[0012] Figure 3 It is the perspective view of the coil assembly of the embodiment of the present utility model. Detailed Embodiment

[0013] Such as Figures 1 to 3As shown in the figure, an embodiment of the utility model is a modular low partial discharge combined transformer, which includes an epoxy resin casting body 10, a plurality of wiring terminals 11 arranged on the epoxy resin casting body 10, and a coil assembly 20 arranged in the epoxy resin casting body 10. The coil assembly 20 includes a voltage iron core 21, a voltage secondary winding 22 wound around the voltage iron core 21, two lifting parts 23 symmetrically arranged on one side of the voltage secondary winding 22, two insulating supports 24 symmetrically arranged on the other side of the voltage secondary winding 22, a plurality of voltage primary windings 25 sleeved on the voltage secondary winding 22, three current iron cores 26, three current primary windings 27 respectively wound around the three current iron cores 26 and connected to the plurality of wiring terminals 11, three current secondary windings 28 respectively sleeved on the three current primary windings 27, and a current support frame 29 arranged on the two insulating supports 24. A plurality of support arms 241 connected to the plurality of voltage primary windings 25 are respectively arranged on the two insulating supports 24. Support plates 291 connected to the three current secondary windings 28 are respectively arranged on the current support frame 29. Three support rods 292 are respectively arranged on the support plates 291 corresponding to the three current secondary windings 28. One end of the support rod 292 has a screw part 2921 connected to the support plate 291, and one end of the support rod 292 has an arc-shaped support piece 2922 attached to the current secondary winding 28. A binding band 30 is wound between the arc-shaped support piece 2922 and the current secondary winding 28. The support rod is attached to the current secondary winding through the arc-shaped support piece, so as to ensure a more compact connection between the support rod and the current secondary winding. The binding band is used for fixation, so as to facilitate the assembly of the support rod and the current secondary winding, and the assembly efficiency is higher. Fixing feet 231 are respectively arranged at both ends of the two lifting parts 23, and the fixing feet 231 of the two lifting parts 23 are distributed in a rectangular array, and lifting holes 2311 are respectively arranged on the fixing feet 231 of the two lifting parts 23. The two lifting parts are fixed on the bottom plate of the casting mold through the fixing feet distributed in a rectangular array, so as to facilitate the assembly of the lifting parts and the casting mold, and is beneficial to improving the mold loading efficiency of the coil assembly. The voltage secondary winding 22 is respectively connected to the two lifting parts 23, the voltage secondary winding 22 is respectively connected to the two insulating supports 24, the two insulating supports 24 are respectively connected to the plurality of voltage primary windings 25, and the two insulating supports 24 are respectively connected to the current support frame 29 through tie straps 31. The tie strap method is used for fixation, so as to facilitate the assembly of the voltage secondary winding and the two lifting parts, the voltage secondary winding and the two insulating supports, the two insulating supports and the plurality of voltage primary windings, and the two insulating supports and the current support frame, and the assembly efficiency is higher. A cushion plate 32 is arranged between the two insulating supports 24 and the voltage primary winding 25. The cushion plate is arranged between the insulating support and the voltage primary winding, and both sides of the cushion plate can be attached to the insulating support and the voltage primary winding, so as to ensure a more compact connection between the insulating support and the voltage primary winding.

[0014] The coil assembly adopts a modular structure design. The iron core, primary voltage winding, secondary voltage winding, primary current winding, and secondary current winding are integrated modularly through hoisting parts, insulating supports, and current support frames, so that the modular assembly of the coil assembly and the casting mold can be realized, and the mold loading efficiency is higher. The two hoisting parts can be fixed on the bottom plate of the casting mold, facilitating the hoisting of the coil assembly and the bottom plate. The two insulating supports can ensure the insulation distance between the secondary voltage winding and the primary voltage winding, and the current support frame can ensure the insulation distance between the primary current winding and the secondary current winding. When epoxy resin casting is adopted, the casting thickness of epoxy resin between the primary voltage winding and the secondary voltage winding, and between the primary current winding and the secondary current winding can be ensured. The thickness of the epoxy resin layer is uniform, and bubbles are not easily generated between the epoxy resin casting layers, which will not cause cracking of the epoxy resin layer, and the insulation performance is better, and the partial discharge is lower. Therefore, the combined transformer has the advantages of simple structure, stable and reliable performance, high production efficiency, modularization, and low partial discharge.

Claims

1. A modular low partial discharge combined instrument transformer, characterized in that: It includes an epoxy resin casting body, a plurality of wiring terminals arranged on the epoxy resin casting body, and a coil assembly arranged in the epoxy resin casting body. The coil assembly includes a voltage iron core, a voltage secondary winding wound around the voltage iron core, two lifting members symmetrically arranged on one side of the voltage secondary winding, two insulating supports symmetrically arranged on the other side of the voltage secondary winding, a plurality of voltage primary windings sleeved on the voltage secondary winding, three current iron cores, three current primary windings respectively wound around the three current iron cores and connected to the plurality of wiring terminals, three current secondary windings respectively sleeved on the three current primary windings, and a current support frame arranged on the two insulating supports. A plurality of support arms connected to the plurality of voltage primary windings are respectively arranged on the two insulating supports, and support plates connected to the three current secondary windings are respectively arranged on the current support frame.

2. The modular low partial discharge combined instrument transformer according to claim 1, wherein: Three support rods are respectively arranged on the support plate corresponding to the three current secondary windings. One end of the support rod has a screw part connected to the support plate, and one end of the support rod has an arc-shaped support piece attached to the current secondary winding. A binding band is wound between the arc-shaped support piece and the current secondary winding.

3. The modular low partial discharge combined mutual inductor according to claim 1 or 2, characterized in that: Fixing feet are respectively arranged at both ends of the two lifting members, and the fixing feet of the two lifting members are distributed in a rectangular array, and lifting holes are respectively arranged on the fixing feet of the two lifting members.

4. The modular low partial discharge combined mutual inductor according to claim 1 or 2, characterized in that: The voltage secondary winding and the two lifting members, the voltage secondary winding and the two insulating supports, the two insulating supports and the plurality of voltage primary windings, and the two insulating supports and the current support frame are respectively connected by tie straps.

5. The modular low partial discharge combined mutual inductor according to claim 1 or 2, characterized in that: A backing plate is arranged between the two insulating supports and the voltage primary winding.

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