Shielding assembly of voltage transformer
By designing shielding assembly in the voltage transformer, including an annular and cylindrical shielding network, the corona discharge problem caused by uneven electric fields in the voltage transformer is solved, and the local discharge volume and the improvement of the insulating strength of the medium is achieved. Effect.
Patent Information
- Application Number
- CN202420482586.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-12
- Publication Date
- 2025-02-11
- Estimated Expiration
- 2034-03-12
AI Technical Summary
In the voltage transformer, the radius of curvature between the primary conductive rod and the low-voltage winding is less than the distance between the two electrodes, resulting in an uneven electric field, causing corona discharge, and the local discharge is too large, affecting the insulation strength of the medium and causing dielectric breakdown.
A shielding assembly of a voltage transformer is designed, including a first shielding net and a second shielding net pre-buried in the epoxy resin. The first shielding net forms an additional shielding layer on the primary conductive rod through an annular structure, and the second shielding net provides an annular shielding structure for the entire primary conductive rod through a cylindrical structure, reducing the distortion of the electric field and the local electric field strength.
By setting up a shielding assembly, the corona starting voltage of the high-voltage electric field is reduced, the possibility of corona discharge is reduced, the local discharge volume is effectively reduced, the insulation strength of the medium is improved, and the dielectric breakdown is avoided.
Smart Images
Figure CN222462576U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of voltage transformers, and in particular relates to a shielding assembly of a voltage transformer. Background Art
[0002] As we all know, the Potential Transformer (PT) is similar to the Voltage Transformer (VT) and is an instrument used to transform voltage. The purpose of voltage transformer transformation is mainly to supply power to measuring instruments and relay protection devices, to measure the voltage, power and electric energy of the line, or to protect the valuable equipment, motors and transformers in the line when a line fault occurs. Therefore, the capacity of voltage transformers ranges from volt-amperes to kilovolt-amperes.
[0003] The voltage transformer used in conjunction with the SF6 gas filling cabinet has been widely promoted and applied in recent years. The voltage transformer is required to have the characteristics of small size, safe operation, high altitude, and small partial discharge. According to the special structural design requirements, the primary terminal part of the transformer must be electrically connected to the equipment in the cabinet. The problem in traditional technology is that due to product structural limitations, the curvature radius of the two electrodes of the primary conductive rod and the low-voltage winding of the voltage transformer is smaller than the distance between the two electrodes, and there is an uneven electric field between the two electrodes. The uneven electric field causes corona discharge in the dielectric, and the partial discharge is too large. Long-term discharge affects the insulation strength of the dielectric and causes dielectric breakdown. Utility Model Content
[0004] The utility model aims to provide a shielding assembly of a voltage transformer to solve the technical problem of excessive partial discharge of the voltage transformer proposed in the above background technology.
[0005] In order to achieve the above purpose, the utility model provides the following technical solutions:
[0006] A shielding assembly for a voltage transformer, comprising:
[0007] a first shielding net, the first shielding net comprising a first main body of an annular structure, used to form an additional shielding device on the primary conductive rod, further improving the shielding effect through the principle of uniform electric field, and reducing the risk of corona discharge; a mounting terminal is arranged outside the first main body, the mounting terminal is connected to the first main body through a connecting rod, and a first mounting insert for fixing the primary terminal of the voltage transformer is arranged inside the mounting terminal;
[0008] The second shielding net includes a cylindrical second main body, which is used to provide an annular shielding structure for the primary conductive rod as a whole. When the voltage passes through, it can effectively shield the capacitance distribution formed between the primary terminal and the transformer body, improve the field strength, and thus achieve the purpose of reducing the amount of partial discharge; a second mounting insert is provided at one end of the second main body; wherein:
[0009] The first body is sleeved on the outer side of the second body, so as to more effectively prevent the electric field distortion and reduce the local electric field intensity between the first body and the second body.
[0010] Preferably, the voltage transformer comprises two primary terminals, a connecting rod and a primary conductive rod.
[0011] Preferably, the length of the first body is smaller than that of the second body, so as to ensure that the first body is completely sleeved on the outside of the second body to form a compact structure.
[0012] Preferably, the length of the second body is greater than the length of the primary conductive rod, so as to fully cover the primary conductive rod and achieve a more effective electric field shielding effect.
[0013] Preferably, the connecting rod is perpendicular to the primary conductive rod, which helps to reduce the influence of the primary electric field generated when the voltage transformer is working on the connecting rod.
[0014] Preferably, the central axis of the first main body is perpendicular to the connecting rod, so as to ensure that the overall structure of the shielding net has a more uniform and stable shielding effect on the electric field when a voltage passes through the primary conductive rod.
[0015] Preferably, the first shielding net and the second shielding net are made of semiconductor material to better shield the electric field and improve the performance of the entire assembly.
[0016] Compared with the prior art, the beneficial effects of the utility model are:
[0017] The utility model solves the problem that, during the operation of the voltage transformer, a relatively obvious discharge phenomenon is caused by uneven field strength between a primary terminal, a resin and an installation insert, resulting in a relatively large local discharge of the product for a long time, affecting the insulation strength of the medium and causing medium breakdown, leading to damage to the voltage transformer and related equipment by arranging a shielding assembly in the voltage transformer; a first shielding net is arranged, including a first main body with an annular structure, which is used to form an additional shielding layer on the primary conductive rod to help prevent the distortion of the electric field, further improve the shielding effect, and reduce the risk of corona discharge; a second shielding net is also arranged, including a cylindrical second main body, which is used to provide an annular shielding structure for the primary conductive rod as a whole, and provides an annular shielding structure for the primary conductive rod as a whole. When the voltage passes through, the capacitance distribution formed between the primary terminal and the transformer body can be effectively shielded, and the field strength can be improved, thereby achieving the purpose of reducing the amount of local discharge. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 This is a schematic diagram of the structure of the first shielding net in the preferred embodiment of the utility model;
[0019] Figure 2 This is a schematic diagram of the structure of the second shielding net in the preferred embodiment of the utility model;
[0020] Figure 3 This is a schematic diagram of the use status of a preferred embodiment of the utility model.
[0021] In the figure: 1, mounting terminal; 2, first mounting insert; 3, connecting rod; 4, first body; 5, second mounting insert; 6, second body. DETAILED DESCRIPTION
[0022] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0023] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.
[0024] In the description of the invention of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the invention of the utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the invention of the utility model. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the invention of the present utility model, unless otherwise specified, the meaning of "multiple" is two or more.
[0025] In the description of the invention of the utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the invention of the utility model can be understood according to specific circumstances.
[0026] like Figure 1-Figure 3 As shown:
[0027] First embodiment: A shielding assembly of a voltage transformer is pre-buried in epoxy resin to shield the electric field on a primary conductive rod. The specific structure includes:
[0028] A first shielding net, in order to form an additional shielding layer on the primary conductive rod, further improve the shielding effect through the principle of uniform electric field, and reduce the risk of corona discharge, the first shielding net comprises a first main body 4 of an annular structure, a mounting terminal 1 is arranged outside the first main body 4, the mounting terminal 1 is connected to the first main body 4 through a connecting rod 3, and a first mounting insert 2 for fixing the primary terminal of the voltage transformer is arranged inside the mounting terminal 1;
[0029] The second shielding net, in order to provide an annular shielding structure for the primary conductive rod as a whole, helps to offset the high-voltage electric field generated by the primary conductive rod, reduce the concentration of the electric field in the voltage transformer, and prevent the occurrence of corona discharge, the second shielding net includes a cylindrical second body 6, and a second mounting insert 5 is provided at one end of the second body 6; wherein:
[0030] In order to more effectively prevent uneven distribution of the electric field and reduce local electric field intensity between the first body 4 and the second body 6 , the first body 4 is sleeved on the outer side of the second body 6 .
[0031] In the above embodiment, the voltage transformer includes two primary terminals, a connecting rod 3 and a primary conductive rod.
[0032] On the basis of the above embodiment, in order to ensure that the first body 4 is completely sleeved on the outside of the second body 6, the inner diameter of the first body 4 is equal to or slightly larger than the outer diameter of the second body 6 to form a compact fitting relationship. At the same time, the length of the first body 4 is smaller than the length of the second body 6.
[0033] On the basis of the above embodiment, in order to fully cover the primary conductive rod and achieve a more effective electric field shielding effect, the length of the second body 6 is greater than the length of the primary conductive rod.
[0034] On the basis of the above embodiment, in order to reduce the influence of the primary electric field generated by the voltage transformer during operation on the connecting rod 3, the connecting rod 3 is perpendicular to the primary conductive rod.
[0035] On the basis of the above embodiment, in order to ensure that the overall structure of the shielding net has a more uniform and stable shielding effect on the electric field when a voltage passes through the primary conductive rod, the central axis of the first body 4 is perpendicular to the connecting rod 3.
[0036] On the basis of the above embodiment, in order to better shield the electric field and improve the performance of the entire assembly, the first shielding net and the second shielding net are made of semiconductor materials.
[0037] In the utility model, in order to form an additional shielding layer on the primary conductive rod to help prevent the distortion of the electric field, further improve the shielding effect, and reduce the risk of corona discharge, a first shielding net is set, including a first main body 4 with an annular structure, and a mounting terminal 1 is arranged on the outside of the first main body 4, and the mounting terminal 1 is connected to the first main body 4 through a connecting rod 3, and a first mounting insert 2 for fixing the primary terminal of the voltage transformer is arranged in the mounting terminal 1; in order to provide an annular shielding structure for the primary conductive rod as a whole, when the voltage passes through, it can effectively shield the capacitance distribution formed between the primary terminal and the transformer body, improve the field strength, and thus achieve the purpose of reducing the amount of local discharge, a second shielding net is set, including a cylindrical second main body 6, and a second mounting insert 5 is arranged at one end of the second main body 6; in order to more effectively prevent the uneven distribution of the electric field and reduce the local electric field strength between the first main body 4 and the second main body 6, the first main body 4 is sleeved on the outside of the second main body 6.
[0038] Working principle:
[0039] During the operation of the voltage transformer, due to the limitation of the product structure, the radius of curvature of the two electrodes is smaller than the distance between the two electrodes, and there is an uneven electric field between the two electrodes (primary conductive rod and low-voltage winding); the shielding assembly reduces the corona starting voltage of the high-voltage electric field and reduces the possibility of corona discharge. The cylindrical second body 6 of the second shielding net provides an annular shielding structure for the primary conductive rod as a whole, which helps to offset the high-voltage electric field generated by the primary conductive rod and reduce the concentration of the electric field in the voltage transformer. The first body 4 is sleeved on the outside of the second body 6 to form an additional shielding layer to help prevent the distortion of the electric field, further improve the shielding effect, and reduce the risk of corona discharge; when the voltage transformer is working, the high-voltage electric field generated by the primary conductive rod is shielded and offset, and the phenomenon of corona discharge no longer occurs when the voltage transformer is working.
[0040] The above-mentioned embodiments of the present invention are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.
Claims
1. A shielding assembly for a voltage transformer, characterized in that: Includes embedded in epoxy resin: A first shielding net, the first shielding net comprising a first main body (4) of an annular structure, a mounting terminal (1) being arranged outside the first main body (4), the mounting terminal (1) being connected to the first main body (4) via a connecting rod (3), and a first mounting insert (2) for fixing a primary terminal of a voltage transformer being arranged inside the mounting terminal (1); A second shielding net, the second shielding net comprises a cylindrical second main body (6), a second mounting insert (5) being arranged at one end of the second main body (6); wherein: The first body (4) is sleeved on the outer side of the second body (6).
2. A shielding assembly for a voltage transformer according to claim 1, characterized in that: The voltage transformer comprises two primary terminals, a connecting rod (3) and a primary conductive rod.
3. The shielding assembly of a voltage transformer according to claim 1, characterized in that: The length of the first body (4) is smaller than the length of the second body (6).
4. The shielding assembly of a voltage transformer according to claim 1, characterized in that: The length of the second body (6) is greater than the length of the primary conductive rod.
5. The shielding assembly of a voltage transformer according to claim 1, characterized in that: The connecting rod (3) is perpendicular to the primary conductive rod.
6. A shielding assembly for a voltage transformer according to claim 5, characterized in that: The central axis of the first body (4) is perpendicular to the connecting rod (3).
7. The shielding assembly of a voltage transformer according to claim 1, characterized in that: The first shielding mesh and the second shielding mesh are made of semiconductor material.