Built-in high-voltage shielding net of pillar type current transformer
By designing a built-in high-voltage shielding network in the current transformer, the local discharge problem caused by uneven electric field is solved, and the electric field is uniformly distributed, which improves product qualification rate and reduces production costs.
Patent Information
- Application Number
- CN202422048383.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-22
- Publication Date
- 2025-07-04
- Estimated Expiration
- 2034-08-22
AI Technical Summary
The internal electric field segments of the current transformer are uneven, especially the uneven electric field below the primary terminal, which leads to local discharge, affecting the product qualification rate and production efficiency and increasing costs.
Design a built-in high-voltage shielding net of a pillar current transformer, including a frame, a shielding net and a brush wire. The shielding net is located below the primary terminal. The frame is connected to the primary winding. The brush wire is connected to the primary winding and covers the shielding paper to achieve uniform field strength. Reinforcement ribs are provided on the front side of the frame to enhance structural strength.
The electric field distribution of the current transformer is improved, the pass rate of local discharge tests is improved, the production cost is reduced, and the quality of the current transformer is ensured.
Smart Images
Figure CN223065990U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of partial discharge shielding of transformers, and particularly relates to a built-in high-voltage shielding net for a post-type current transformer. Background Art
[0002] A current transformer is an electrical device that uses the principle of electromagnetic induction to convert high current into low current through the transformer principle for current measurement. When the current transformer inductively measures the current in a high-voltage line, the electric field intensity in the high-voltage line is very large. Due to the complex internal structure of the current transformer, it will cause uneven distribution of the electric field inside the current transformer, resulting in partial discharge phenomena, especially the electric field under the primary terminal. Whether the partial discharge of the current transformer is qualified directly affects the manufacturing cost and the reliable operation of the product on the grid. If the partial discharge is unqualified or seriously exceeds the standard, it will lead to a shortened life of the insulating medium, and ultimately cause the entire insulation breakdown, triggering a power grid accident. Therefore, there are unqualified phenomena in the partial discharge test during product factory, the qualified rate of the product is not high, which affects the quality of the product, resulting in low production efficiency of the enterprise and increasing the enterprise cost. Summary of the Invention
[0003] An improvement aiming at at least one defect of the prior art, the utility model provides a built-in high-voltage shielding net for a post-type current transformer, which solves the problem of uneven distribution of the electric field inside the current transformer, especially the uneven electric field under the primary terminal, resulting in partial discharge phenomena.
[0004] The technical solution adopted by the utility model is a built-in high-voltage shielding net for a post-type current transformer, including a frame, a shielding net and a brush wire. The frame is a special-shaped contour line formed by bending galvanized iron wire. The front side of the frame is a rectangular contour, and the rear side of the frame is two parallel protruding ends. There is a folded line transition between the front side and the rear side of the frame. The shielding net is welded on the front side of the frame. One of the protruding ends on the rear side of the frame is welded with a brush wire. The shielding net is located under the primary terminal. The protruding end of the frame is fixed on the primary winding. The brush wire is connected to the primary winding. A shielding paper is covered on the shielding net. One shielding net is installed under each of the two primary terminals of the transformer. The two shielding nets do not contact each other and the distance between them is greater than 10 mm.
[0005] Preferably, the shielding net is a brass net.
[0006] Preferably, reinforcing ribs are arranged on the front side of the frame, and both ends of the reinforcing ribs are welded and fixed at the centers of two opposite sides of the frame.
[0007] Preferably, the width of the shielding net is 5-10 mm greater than the width of the wiring board of the primary terminal.
[0008] The beneficial effects of the present utility model are as follows: The structure of the present utility model is simple. The high-voltage shielding net effectively improves the electric field distribution of the current transformer, especially the electric field under the primary terminal, making the field strength distribution of the current transformer uniform, improving the qualified rate of the partial discharge test of the product, reducing the production cost, and ensuring the quality of the current transformer. Brief Description of the Drawings
[0009] Figure 1 It is a schematic diagram of the high-voltage shielding net structure.
[0010] Figure 2 It is a schematic diagram of the structure of a current transformer with a built-in high-voltage shielding net.
[0011] Markings in the figure: 1 - primary terminal, 2 - high-voltage shielding net, 3 - primary winding, 201 - frame, 202 - brush wire, 203 - shielding net, 204 - reinforcing rib. Detailed Embodiment
[0012] To make the objectives, technical solutions, and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. Generally, the components of the embodiments of the present utility model described and shown in the accompanying drawings here can be arranged and designed in various different configurations.
[0013] As Figure 1 and Figure 2 shown, a built-in high-voltage shielding net of a post-type current transformer includes a frame 201, a shielding net 203, and a brush wire 202. The frame 201 is a special-shaped contour line formed by bending a galvanized iron wire with a diameter of 2 mm. The front side of the frame 201 is a rectangular contour, and the rear side of the frame 201 is two parallel protruding ends. There is a broken-line transition between the front side and the rear side of the frame 201. A shielding net 203 is welded to the front side of the frame 201. The shielding net 203 is a brass net. A brush wire 202 is welded to one of the protruding ends on the rear side of the frame 201. The diameter of the brush wire 202 is 1 mm, and the material of the brush wire 202 is copper. The shielding net 203 is located below the primary terminal 1. The protruding ends of the frame 201 are fixed to the primary winding 3, and the brush wire 202 is connected to the primary winding 3, which can better achieve the effect of field strength shielding. Since there will be welding bumps during the welding connection of the shielding net 203, and the electric field strength is relatively high at the places with bumps, the shielding paper can play a role in buffering, shielding, and uniforming the field strength. Therefore, a shielding paper is covered on the shielding net 203. A high-voltage shielding net is installed under each of the two primary terminals 1 of the current transformer. The two shielding nets 203 do not contact each other and the distance between them is greater than 10 mm. The width of the shielding net 203 is 5 - 10 mm greater than the width of the wiring board of the primary terminal 1.
[0014] For a high-voltage shielding net structure with a relatively large area, reinforcing ribs 204 are arranged on the front side of the frame 201, and both ends of the reinforcing ribs 204 are welded and fixed at the centers of two opposite sides of the frame 201 to improve the overall frame strength at the welded shielding net 203.
[0015] When the body of the pillar-type current transformer is being bandaged, according to the size of the primary terminal 1, a high-voltage shielding net with an appropriate size is installed below the primary terminal 1, and it is ensured that the shielding nets 203 below the two primary terminals 1 do not come into contact. The brush wire 202 on the high-voltage shielding net frame 201 is connected to the primary winding 3, and then the shielding bandaging process is carried out on the body of the product. The processed body of the product is installed in the product mold and the epoxy resin mixture is poured.
[0016] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.
Claims
1. An internal high-voltage shielding net of a pillar-type current transformer, characterized in that: It includes a frame, a shielding net and a brush wire. The frame is a special-shaped contour line formed by bending galvanized iron wire. The front side of the frame is a rectangular contour, and the rear side of the frame is two parallel protruding ends. There is a broken-line transition between the front side and the rear side of the frame. The shielding net is welded to the front side of the frame, and the brush wire is welded to one of the protruding ends on the rear side of the frame. The shielding net is located below the primary terminal. The protruding end of the frame is fixed to the primary winding, and the brush wire is connected to the primary winding. A shielding paper is covered on the shielding net. One shielding net is installed below each of the two primary terminals of the mutual inductor. The two shielding nets do not contact each other and the distance between them is greater than 10 mm.
2. The built-in high-voltage shielding net of the pillar type current transformer according to claim 1, characterized in that: The shielding net is a brass net.
3. The built-in high-voltage shielding net of the pillar-type current transformer according to claim 1, characterized in that: Reinforcing ribs are arranged on the front side of the frame, and both ends of the reinforcing ribs are welded and fixed at the centers of two opposite sides of the frame.
4. The built-in high-voltage shielding net of the post-type current transformer according to claim 1, wherein: The width of the shielding net is 5-10 mm greater than the width of the wiring board of the primary terminal.