A high-voltage three-phase common gas chamber current transformer structure with a large capacity

Abstract

The present invention provides a large-capacity high-voltage three-phase common-gas-chamber current transformer structure, which includes a three-phase common box housing, a support inner cylinder, a current transformer coil, a pot-type insulator, a contact base, a conductor, a wiring panel, a protective cover, and a first fastener. The support inner cylinder is located inside the three-phase common box housing, the current transformer coil is located in the middle of the support inner cylinder, the pot-type insulator is located inside the three-phase common box housing, the contact base is located inside the three-phase common box housing, the contact base and the pot-type insulator are connected by a third fastener, and the three-phase common box housings are connected by a second fastener. For the large-capacity high-voltage three-phase common-gas-chamber current transformer structure of the present invention, after the current transformer is assembled and formed with this structure, only two current transformers need to be assembled into the structure of the entire combined switch, which is very simple and convenient, and the product quality is well guaranteed.

Description

Technical Field

[0001] The present invention belongs to the technical field of high-voltage switches, and particularly relates to a large-capacity high-voltage three-phase common-gas-chamber current transformer structure. Background Art

[0002] Based on the requirements for the rated current of products in the "Technical Characteristics Requirements for Substation Engineering Goods of State Grid Corporation of China", the rated current has been expanded from the original 3150A / 4000A to 5000A. Due to the increasing variety of market demands, for this requirement, the rated current of the current transformer structures currently used in the market is 3150A / 4000A, and the maximum rated current of the original structure is 4000A, which no longer meets the requirements of the rated current increase project required by the State Grid Corporation. Therefore, our company designs a 5000A current transformer, which has the characteristics of small resistance, reducing energy loss during the power conduction process, reducing product heating, fast product heat dissipation, and being safer and more reliable during product operation, and is used for the GIS configuration with a rated current of 5000A of the State Grid Corporation. This type of design has a reasonable structure, stable performance, low production and manufacturing costs, low procurement management costs, low material management costs, convenient installation and use during the production and manufacturing process, and safe and reliable operation. Summary of the Invention

[0003] In view of this, the present invention aims to provide a large-capacity high-voltage three-phase common-gas-chamber current transformer structure, and the main technical problem to be solved is to provide a large-capacity high-voltage three-phase common-gas-chamber current transformer structure with a reasonable structure, stable performance, low production and manufacturing costs, high production efficiency during the production and manufacturing process, and convenient maintenance and repair use - a three-phase coaxial current transformer with a rated voltage of 252kV and a rated current of 5000A.

[0004] To achieve the above object, the technical solution of the present invention is realized as follows:

[0005] A high-voltage three-phase common-gas-chamber current transformer structure with a large capacity, comprising a three-phase common-box housing, a support inner cylinder, a current transformer coil, a pot insulator, a contact base, a conductor, a wiring panel, a protective cover and a first fastener. The support inner cylinder is located inside the three-phase common-box housing, the current transformer coil is located at the center of the support inner cylinder, the pot insulator is located at the inner bottom of the three-phase common-box housing, the contact base is located around the inner bottom of the three-phase common-box housing, the conductor is inserted at the middle position of the three-phase common-box housing, the wiring panel is located on one side of the three-phase common-box housing, the contact base with spring fingers is fastened to the pot insulator by the first fastener, the contact base and the pot insulator are connected by a third fastener, and the three-phase common-box housings are connected by a second fastener. The housing adopts a three-phase common-box structure, and the size of the distance between the three phases is very important, which is directly ensured by the machining process. This process increases the accuracy of the housing size and reduces the workload of product assembly. It ensures the centering of the phase spacing of the product and provides a good size basis for the docking of the next structure. The structure has been simulated and calculated in terms of electric field, strength and water pressure. The height of the current transformer coil reserves the requirements of various parameter combinations of current transformers of the State Grid. The size of the three-phase common-box housing is ensured by the housing machining process, and a protective cover is provided to protect the wiring panel. The current transformer coil and the inner cylinder housing are integrally cast, canceling the assembly forms of various components in the traditional structure, greatly reducing the types of existing components, improving the product quality and the production efficiency.

[0006] Further, the three-phase common-box housing is provided with reinforcing ribs, and heat dissipation fins are provided on the inner wall of the three-phase common-box housing. The design adopts an integral casting structure.

[0007] Further, the support inner cylinder of the housing is designed as a welded structure, with a common processing technology and a low manufacturing cost.

[0008] Further, the material of the pot insulator is pure copper. The diameter of the pot insulator is 130 mm. Without changing the outer diameter and the surface arc of the resin part, the diameter of the insert is increased. By finely adjusting and modifying the pot mold, the material of the insert is changed from the original aluminum alloy material to pure copper material. From the cross-section of the insert, the conductor cross-sectional area is increased, the material is changed, and the conductivity is reduced, greatly reducing the contact resistance of the product.

[0009] Further, polyurethane is provided between the current transformer coil and the support inner cylinder, and the current transformer coil and the support inner cylinder are filled and fixed with polyurethane, and the compactness of the structure is good.

[0010] Further, a groove is provided at the bottom of the contact base, and the spring finger is fixed in the groove. The number of turns of the spring finger is 5 turns, and the number of turns of the spring is 11 turns. The spring finger structure has changed from the original 2-turn spring finger structure to the current 5-turn structure, and the structure of the spring finger itself has also been changed. The spring has changed from the original 85 turns to the current 110 turns, and the number of contact points has increased to 1.3 times the original. The contact points are increased from both axial and radial dimensions, greatly reducing the contact resistance of the product. The resistance of the product is greatly reduced, that is, the resistance of the product is decreased, and at the same time, the design of the product heat dissipation is added. When the product is installed and put into operation on site, it can meet the requirements of the rated current of the product and operate safely and reliably.

[0011] Further, the material of the conductor is a copper conductor, the diameter of the conductor is 130 mm, and heat dissipation holes are provided on the conductor. The material selection of the conductor has been changed from the original aluminum conductor to a copper conductor, and the resistivity has been reduced from the original 5.5 to 2.6. In terms of structural design, the diameter of the conductor has been increased from the original 100 mm to 130 mm. The cross-sectional area of the conductor increases, and the resistance decreases accordingly. The round holes specially provided in the structure of the conductor itself increase the contact area between the conducting rod and the air, thereby increasing the carrier of heat exchange and playing a good role in heat dissipation.

[0012] Further, current transformer terminal blocks are provided on the wiring panel. The current transformer terminal blocks are provided with 27 terminal posts. The current transformer terminal blocks have increased from the original 18 terminal posts to 27 terminal posts, which can meet all the wiring combination methods of the current transformer coils of the State Grid Corporation users.

[0013] Compared with the prior art, the structure of a large-capacity high-voltage three-phase common gas chamber current transformer described in the present invention has the following advantages:

[0014] After the current transformer is assembled and formed with this structure, only two current transformers need to be assembled into the structure of the entire combined switch, which is very simple and convenient. Since the dimensional and flatness requirements between the three phases of the product have been ensured during the machining process of the housing. The product quality is well guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0016] Figure 1 is a schematic diagram of the structure of a large-capacity high-voltage three-phase common gas chamber current transformer according to an embodiment of the present invention;

[0017] Figure 2 is a schematic diagram of the support inner cylinder;

[0018] Figure 3 It is a drawing for supporting the inner cylinder fitting;

[0019] Figure 4 It is a schematic diagram of a pot-type insulator;

[0020] Figure 5 It is a schematic diagram of a spring finger indicator;

[0021] Figure 6 It is a schematic diagram of a conductor;

[0022] Figure 7 It is a schematic diagram of the wiring terminal of a current transformer;

[0023] Figure 8 It is a schematic diagram of the overall structure;

[0024] Figure 9 It is a schematic diagram of the overall coaxial housing;

[0025] Figure 10 It is an overall drawing of the application of this solution;

[0026] Figure 11 It is a schematic diagram of the overall in the prior art;

[0027] Figure 12 It is a top view of the prior art;

[0028] Figure 13 It is a schematic diagram of the overall of this solution;

[0029] Figure 14 It is a top view of this solution;

[0030] Explanation of reference numerals:

[0031] 1 - Coaxial housing; 1 - 1 - Reinforcing rib; 1 - 2 - Heat sink; 2 - Supporting inner cylinder; 3 - Current transformer coil; 4 - Pot-type insulator; 4 - 1 - Insert; 4 - 2 - Resin part; 5 - Contact base; 5 - 1 - Spring finger; 6 - Conductor; 7 - Wiring plate; 8 - Protective cover; 9 - First fastener; 10 - Second fastener; 11 - Third fastener; 12 - Protective cover plate. Detailed implementation manners

[0032] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0033] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention 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 should not be construed as a limitation to the present invention. 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 specifying the quantity of the indicated technical features. Thus, features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise stated, the meaning of "a plurality of" is two or more.

[0034] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "mounted", "connected", "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific circumstances.

[0035] The present invention will be described in detail below with reference to the drawings and in conjunction with embodiments.

[0036] Such as Figures 1-14As shown in the figure, a large-capacity and high-voltage three-phase common gas chamber current transformer structure includes a three-phase common box housing 1, a support inner cylinder 2, a current transformer coil 3, a pot insulator 4, a contact base 5, a conductor 6, a wiring plate 7, a protective cover 8, and a first fastener 9. The support inner cylinder 2 is located inside the three-phase common box housing 1. The current transformer coil 3 is located around the support inner cylinder 2. The pot insulator 4 is located at the inner bottom of the three-phase common box housing 1. The contact base 5 is located at the center of the inner bottom of the three-phase common box housing 1. The conductor 6 is inserted at the middle position of the three-phase common box housing 1. The wiring plate 7 is located on one side of the three-phase common box housing 1. The contact base 5 with spring fingers 5-1 is fastened to the pot insulator 4 by the first fastener 9. The contact base 5 and the pot insulator 4 are connected by a third fastener 11. The protective cover plate 12 and the protective cover 8 are connected by a second fastener 10. The housing adopts a three-phase common box structure. The distance between the three phases is very important and is directly ensured by the machining process. This process increases the accuracy of the housing size and reduces the product assembly workload. It ensures the centering of the phase distance of the product and provides a good dimensional basis for the docking of the next structure. The structure has been simulated and calculated in terms of electric field, strength, and water pressure. The height of the current transformer coil reserves the requirements of various parameter combinations of current transformers of the State Grid. The three-phase common box housing 1 ensures the size through the housing machining process and is provided with a protective cover 8 to protect the wiring plate 7. The current transformer coil and the inner cylinder housing are integrally cast, canceling the assembly forms of various parts in the traditional structure. The types of existing parts are greatly reduced, improving the product quality and production efficiency.

[0037] The three-phase common box housing 1 is provided with reinforcing ribs 1-1, and heat sinks 1-2 are provided on the inner wall of the three-phase common box housing 1. The design adopts an integral casting structure.

[0038] The support inner cylinder 2 of the housing is designed as a welded structure, with a common machining process and low manufacturing cost.

[0039] The material of the pot insulator 4 is pure copper. The diameter of the pot insulator 4 is 130 mm. On the premise of not changing the outer diameter and the surface arc of the resin part 4-2, the diameter of the insert 4-1 is increased. By slightly adjusting and modifying the pot mold, the material of the insert is changed from the original aluminum alloy material to pure copper material. From the cross-section of the insert, the conductor cross-sectional area is increased, the material is changed, and the conductivity is reduced, greatly reducing the contact resistance of the product.

[0040] Polyurethane is provided between the current transformer coil 3 and the support inner cylinder 2. The current transformer coil 3 and the support inner cylinder 2 are filled and fixed with polyurethane, and the tightness of the structure is good.

[0041] A groove is provided at the bottom of the contact base 5, and the spring finger 5-1 is fixed in the groove. The number of turns of the spring finger 5-1 is 5 turns, and the number of turns of the spring is 110 turns. The spring finger 5-1 has changed from the original 2-turn spring finger structure to the current 5-turn structure, and the structure of the spring finger 5-1 itself has also been changed. The spring has changed from the original 85 turns to the current 110 turns, and the contact points have increased to 1.3 times the original. The contact points are increased from both axial and radial dimensions, greatly reducing the contact resistance of the product. The resistance of the product is greatly reduced, that is, the resistance of the product is decreased, and at the same time, the design of the product's heat dissipation is increased. When the product is installed and put into operation on site, it can meet the requirements of the rated current of the product and operate safely and reliably.

[0042] The material of the conductor 6 is a copper conductor. The diameter of the conductor 6 is 130 mm. Heat dissipation holes are provided on the conductor 6. The material selection of the conductor 6 has been changed from the original aluminum conductor to a copper conductor, and the resistivity has been reduced from the original 5.5 to 2.6. In terms of structural design, the diameter of the conductor 6 has been increased from the original 100 mm to 130 mm. The cross-sectional area of the conductor 6 is increased, and the resistance is correspondingly reduced. The round holes specially provided in the structure of the conductor 6 increase the contact area between the conducting rod and the air, thereby increasing the carrier of heat exchange and playing a good role in heat dissipation.

[0043] Current transformer terminals are provided on the wiring panel 7. The current transformer terminals are provided with 27 terminal posts. The current transformer terminals have increased from the original 18 terminal posts to 27 terminal posts, which can meet all the wiring combination methods of the current transformer coils of the State Grid Corporation's users.

[0044] The current transformer coil 3 and the inner cylinder 2 of the housing are integrally cast, canceling the assembly forms of various components in the traditional structure. The types of existing components are greatly reduced, improving the product quality and production efficiency. The contact base 5 is provided with a groove, and the spring finger 5-1 is stuck in the groove. The contact base 5 with the spring finger 5-1 is fastened on the pot-type insulator 4 through the first fastener 9. The contact base 5 and the spring finger 5-1 on the upper pot-type insulator 4 are fastened through the third fastener 11. The inner cylinder 2 of the housing and the current transformer coil 3 are integrally cast and connected to the lower part with the contact base 5 and the pot-type insulator 4 by the third fastener 11, with 3 sets in number. The three-phase coaxial housings 1 are connected together by the second fastener 10, and the connection part is the flange of the inner cylinder 2 of the housing. The conductor 6, as an independent component, is inserted into the contact base 5 and is held tightly by the spring finger 5-1. Similarly, the upper pot-type insulator 4 together with the lower contact base 5 of the same structure is connected to the current transformer by the third fastener 11 and connected to the flange of the three-phase coaxial housing 1. The lead wire of the current transformer coil 3 is connected to the terminal 7, and the terminal is fastened to the three-phase coaxial housing 1 by a fastener. Finally, the terminal is protected by a protective cover 8.

[0045] This design aims to solve the problem that after the rated current of the State Grid power transmission process is increased to 5000A, the original design with a rated current of 3150A / 4000A no longer meets the requirements. The newly designed structure meets the requirements of current capacity increase. During the manufacturing process, the selection and design of each component are all aimed at coping with a series of problems caused by the increase in heat generated after the current increases. That is, the selection of conductors, the change of conductor size, the improvement of the spring structure in the contact base, the adjustment of the size of the basin insert, and the increase of heat sinks inside the housing are all the countermeasures adopted. Through practice, it is proved that correct material selection can indeed solve the problem of increased heat energy after the resistance increases. On the one hand, the increase of heat energy is controlled by reducing the resistance, and on the other hand, the generated energy can be quickly dissipated. The relevant temperature rise test is successfully passed.

[0046] The original structure shown is a single-phase current transformer structure. After the current transformer is assembled and formed into this structure, 6 separate current transformers need to be assembled into the structure of the entire combined switch respectively, and the process is cumbersome. During this process, the spatial position of each one needs to be considered, and the tolerances generated during the docking process are difficult to offset. Due to bolt connection, the level of precision control of the size is limited. The improved structure is a three-phase coaxial current transformer structure. After the current transformer is assembled and formed into this structure, only two sets of current transformers need to be assembled into the structure of the entire combined switch, which is very simple and convenient. Since the requirements for the size and flatness between the three phases of the product have been ensured during the machining process of the housing. The product quality is well guaranteed.

[0047] In terms of structure, the workload of assembling and adjusting single-phase current transformers one by one is reduced. For assembling a single-phase current transformer, for a high-voltage switch combined electrical appliance in one bay, it requires 2 people to work for 12 hours. For the current transformer with a three-phase coaxial structure, 2 people need to work for 4 hours. For a manufacturing enterprise with an annual output value of 400 million yuan, in 2020, 120 bays of 252 products are produced. Each bay saves 2 people for 8 hours, that is, 16 man-hours. The total man-hours saved in 2020 is 1920 hours. The human resource cost of this project is greatly reduced, and the human resource input is reduced. For the installed size, the three-phase coaxial structure is accurately guaranteed. It provides a precise size basis for the docking of the remaining product structures with the upper interfaces of the current transformers being the same three-phase coaxial.

[0048] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A structure of a large-capacity high-voltage three-phase common gas chamber current transformer, characterized in that: It includes a three-phase common enclosure housing (1), a support inner cylinder (2), a current transformer coil (3), a pot-type insulator (4), a contact base (5), a conductor (6), a wiring panel (7), a protective cover (8) and a first fastener (9). The support inner cylinder (2) is located inside the three-phase common enclosure housing (1), the current transformer coil (3) is located around the support inner cylinder (2), the pot-type insulator (4) is located at the inner bottom of the three-phase common enclosure housing (1), the contact base (5) is located at the center of the inner bottom of the three-phase common enclosure housing (1), the conductor (6) is inserted at the middle position of the three-phase common enclosure housing (1), the wiring panel (7) is located on one side of the three-phase common enclosure housing (1), the contact base (5) with spring fingers (5-1) is fastened to the pot-type insulator (4) by the first fastener (9), the contact base (5) and the pot-type insulator (4) are connected by a third fastener (11); the protective cover plate (12) and the protective cover (8) are connected by a second fastener (10); A groove is provided at the bottom of the contact base (5), the spring fingers (5-1) are fixed in the groove, the number of turns of the spring fingers (5-1) is 5 turns, and the number of turns of the spring is 110 turns; The pot-type insulator (4) is made of pure copper material, and the diameter of the pot-type insulator (4) is 130 mm; The conductor (6) is made of copper material, the diameter of the conductor (6) is 130 mm, and heat dissipation holes are provided on the conductor (6); The three-phase common enclosure housing (1) is provided with reinforcing ribs (1-1), heat dissipation fins (1-2) are provided on the inner wall of the three-phase common enclosure housing (1), the rated voltage of the three-phase common enclosure type current transformer is 252 kV, and the rated current is 5000 A.

2. The structure of a large-capacity high-voltage three-phase common gas chamber current transformer according to claim 1, characterized in that: The support inner cylinder (2) of the housing is of welded structure.

3. The structure of a large-capacity high-voltage three-phase common gas chamber current transformer according to claim 1, characterized in that: Polyurethane is provided between the current transformer coil (3) and the support inner cylinder (2).

4. A large-capacity high-voltage three-phase common gas chamber current transformer structure according to claim 1, characterized in that: Current transformer connection terminals are provided on the wiring panel (7), and the current transformer connection terminals are provided with 27 connection posts.

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