Single-phase grounding type combined mutual inductor

Abstract

The utility model discloses a single-phase grounding type combined mutual inductor, and relates to the technical field of power system high-voltage measurement or relay protection equipment. Comprising a main insulator which is formed by pouring a current transformer body, a voltage transformer body, a primary high-voltage current wiring terminal and a secondary wiring terminal into a whole by adopting epoxy resin; the upper part of the primary high-voltage current wiring terminal extends out of the main insulator, and the lower part is positioned in the main insulator and connected with the current transformer body and the voltage transformer body; a plurality of first arc-shaped umbrella skirts are distributed on the outer wall of the upper part of the main insulator, and the plurality of first arc-shaped umbrella skirts are distributed around the periphery of the lower part of the primary high-voltage current wiring terminal; the current transformer body and the voltage transformer body are arranged in the middle of the main insulator side by side, a secondary wiring platform is processed at the lower part of the main insulator, a secondary wiring terminal is arranged in the secondary wiring platform, and the secondary wiring terminal is respectively connected with the current transformer body and the voltage transformer body. The product has the advantages of small volume, strong interference resistance, high metering precision, convenient installation, easy maintenance, stable insulation and safe operation.

Description

Technical Field

[0001] The utility model relates to the technical field of high-voltage measurement or relay protection equipment of an electric power system, in particular to a single-phase grounding type combined mutual inductor. Background Art

[0002] The combined instrument transformer is a device for measuring current, voltage and electric energy in the power system or electrical control system. In order to realize the miniaturization of the switch cabinet and facilitate the overhaul and maintenance, a semi-insulated voltage transformer and a split current transformer are usually used. The existing split combined instrument transformer is mainly: the primary A terminal of the semi-insulated voltage transformer is connected to the high voltage, the N terminal is grounded, and the current transformer is connected in series. The size and insulation quality requirements are very low. The installation and overhaul are relatively complicated, and there are many quality control points. Otherwise, it will affect the overall performance of the current transformer and the voltage transformer, and bury hidden dangers to the actual operation safety of the combined instrument transformer. The split structure makes the assembly of the whole machine very troublesome, and the volume is too bulky, especially in outdoor high-altitude areas. The installation is more difficult, and there are many high-voltage terminals and the electrical connection is more dispersed, which makes the high-voltage field strength distribution extremely uneven, directly affecting the product's service life. Utility Model Content

[0003] The purpose of the utility model is to provide a single-phase grounding combined transformer, which changes the current situation that the existing transformer is more difficult to install, has more high-voltage terminals, has greater electrical connection dispersion, and has extremely uneven high-voltage field strength distribution.

[0004] To achieve the above-mentioned purpose, the present application proposes a single-phase grounding combined transformer, including a main insulator in which a current body, a voltage body, a primary high-voltage current terminal, and a secondary terminal are cast as one body using epoxy resin; the upper part of the primary high-voltage current terminal extends out of the main insulator, and the lower part is located in the main insulator and connected to the current body and the voltage body; a plurality of first arc-shaped sheds are distributed on the outer wall of the upper part of the main insulator, and the plurality of first arc-shaped sheds are distributed around the outer periphery of the lower part of the primary high-voltage current terminal; the current body and the voltage body are arranged side by side in the middle part of the main insulator, and a secondary wiring board is cast at the lower part of the main insulator, and the secondary wiring board has secondary wiring terminals built in, and the secondary wiring terminals are respectively connected to the current body and the voltage body.

[0005] Furthermore, a plurality of second arc-shaped sheds are distributed on the outer wall of the middle portion of the main insulator, and the plurality of second arc-shaped sheds are distributed around the outer circumference of the current transformer body and transition to a portion of the outer circumference of the voltage transformer body.

[0006] Furthermore, a third arc-shaped umbrella skirt is distributed on the outer wall of the middle part of the main insulator. The third arc-shaped umbrella skirt is located above the second arc-shaped umbrella skirt, and the third arc-shaped umbrella skirt crosses the top of the current body and the voltage body.

[0007] Furthermore, the primary high-voltage current connection terminals are symmetrically distributed on both sides of a fourth arc-shaped shed, and the fourth arc-shaped shed is located on the top of the main insulator.

[0008] Furthermore, the current body includes a current core and a current primary winding and a current secondary winding. The current core is made of amorphous alloy. The current core is wrapped with an insulating cardboard corner ring, a twill tape insulating layer, a polyurethane board buffer layer, a half-layer of self-adhesive tape from the inside to the outside, and then after winding the enameled round copper wire, a half-layer of polyester film, copper foil or aluminum foil, and a half-layer of semi-conductive crepe paper shielding layer are stacked; after passing through the current core to wind the current primary winding, a half-layer of glass fiber cloth tape, a half-layer of crepe paper, and another half-layer of semi-conductive crepe paper are stacked.

[0009] Furthermore, the voltage device body includes a voltage core, a voltage primary winding, and a voltage secondary winding. After being wrapped with two half-fold layers of self-adhesive tape to the middle position on both sides of the voltage core, the primary winding and the secondary winding are installed. The exposed part of the voltage core is wrapped from inside to outside in the following order: half-folded layer of self-adhesive tape insulation layer, polyurethane board buffer layer, half-folded layer of self-adhesive tape insulation layer, copper foil, and half-folded layer of semi-conductive crepe paper shielding layer.

[0010] Furthermore, the primary high-voltage lead of the primary voltage winding is connected to the primary high-voltage current terminal, the exposed part of the connection is sealed with a semi-conductive rubber tape, and the primary low-voltage lead of the primary voltage winding is connected to the primary N terminal, and the primary N terminal is located at the bottom of the main insulator and at the rear end.

[0011] Furthermore, the voltage secondary lead of the voltage secondary winding and the current secondary lead of the current secondary winding are both connected to the secondary wiring terminals in the secondary wiring station.

[0012] As a further step, the secondary connection station is located at the front end of the main insulator, and a secondary cover plate is installed through a secondary rubber pad.

[0013] As a further step, the main insulator is installed on the base plate, the grounding terminal is located at the lower part of the main insulator and at the rear end of the base plate, and the grounding terminal is connected to the primary N terminal through a connecting piece.

[0014] Compared with the prior art, the above technical solution adopted by the utility model has the following advantages:

[0015] 1. Small size, strong anti-interference, high measurement accuracy: The product adopts the contoured optimized structural design. The voltage core of the product adopts the rolled core, and the current core adopts the amorphous alloy. The structure is more compact, small in size, and large in capacity. The coil is made of shielding materials such as copper foil or non-magnetic aluminum foil and semi-conductive crepe paper to avoid the mutual influence of electromagnetic fields between current and voltage and between adjacent phases. It has strong anti-interference and high measurement accuracy, and is more suitable for the use of the new grounding combination transformer supporting the switch cabinet;

[0016] 2. Easy installation and maintenance: When installing and using the product, you only need to fix the transformer and wire it according to the phase sequence, which effectively saves the assembly time of the switch cabinet; the product maintenance is simpler and no special maintenance work is required;

[0017] 3. Stable insulation and safe operation: It is integrally cast with epoxy resin material, with reliable insulation; the primary terminal is designed with isolation umbrella skirts on both sides to increase the primary creepage distance, effectively reduce the size of the switch cabinet, and effectively avoid many quality risks from the design to ensure safer operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the internal structure of a single-phase grounding combined transformer;

[0019] Figure 2 This is the right view of the single-phase grounding combined transformer;

[0020] Figure 3 This is the main view of the single-phase grounding combined transformer;

[0021] Figure 4 This is the left view of the single-phase grounding combined transformer;

[0022] Figure 5 It is a top view of a single-phase grounding combined transformer;

[0023] Among them: 1. voltage core; 2. voltage primary winding; 3. voltage secondary winding; 4. secondary terminal; 5. secondary terminal; 6. bottom plate; 7. primary high-voltage lead; 8. primary N terminal; 9. current core; 10. current secondary winding; 11. current primary winding; 12. primary high-voltage current terminal; 13. grounding terminal; 14. main insulator; 15. first arc shed; 16. second arc shed; 17. third arc shed; 18. secondary cover; 19. secondary rubber pad; 20. fourth arc shed; 21. waterproof joint cover; 22. current body; 23. voltage body; 24. connecting piece; 25. voltage primary low-voltage lead; 26. current secondary lead; 27. voltage secondary lead; 28. current secondary bracket. DETAILED DESCRIPTION

[0024] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0025] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0026] In addition, the terms "first", "second", "third", and "fourth" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "multiple" means two or more, unless otherwise clearly and specifically defined. "Several" means one or more, unless otherwise clearly and specifically defined.

[0027] In the description of the present application, it should be understood that the terms "center", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply 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 understood as a limitation on the present application.

[0028] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0029] The present embodiment provides a method for manufacturing a single-phase grounding combined mutual inductor, comprising: fixing a current body 22 in a casting mold through a current secondary bracket 28, fixing a voltage body 23 in a casting mold through a voltage body bracket, and then connecting a primary high-voltage lead 7 to a primary high-voltage current terminal 12, and sealing the exposed portion of the connection with a semi-conductive rubber tape to shield the primary high-voltage electric field; connecting a primary low-voltage lead 25 of the voltage body to a primary N terminal 8, connecting a current secondary lead 26 of the current body and a voltage secondary lead 27 of the voltage body 23 to a secondary terminal 5 in a secondary wiring station, adjusting the insulation distance, and using imported outdoor high-quality high-performance brand epoxy resin to form a main insulator 14 by vacuum casting and curing, so as to improve the mechanical strength and electrical strength, and to resist corrosion to adapt to harsh outdoor weather conditions, and finally installing the entire body on a base plate 6.

[0030] like Figure 1 As shown, the voltage body is manufactured in the following manner: the voltage secondary winding 3 and the voltage primary winding 2 are concentrically wound on an insulating frame and then mounted on a voltage core 1 column. After being wrapped with two layers of self-adhesive tape half-stacked to the middle position on both sides of the voltage core, the primary winding and the secondary winding are mounted. The exposed portion of the voltage core is wrapped from the inside to the outside in the following order: a half-stacked layer of self-adhesive tape insulation layer, a polyurethane board buffer layer, a half-stacked layer of self-adhesive tape insulation layer, copper foil, and a half-stacked layer of semi-conductive crepe paper shielding layer; a layer of semi-conductive paint of appropriate width is brushed along both sides of the voltage core to form the voltage body 23; the current body is manufactured in the following manner: the current secondary winding 10 is wound on the current core 9, the current core is made of amorphous alloy, and the current core is wrapped from the inside to the outside in accordance with The first wrapping is an insulating cardboard corner ring, a twill tape insulating layer, a polyurethane board buffer layer, a half-layer of self-adhesive tape, and then after winding the enameled round copper wire, a half-layer of polyester film, copper foil or aluminum foil, and a half-layer of semi-conductive crepe paper shielding layer are stacked; after passing through the current core 9 to wind the current primary winding 11, a half-layer of glass fiber cloth tape, a half-layer of crepe paper, and a half-layer of semi-conductive crepe paper are stacked to form the current body 22. The purpose of using semi-conductive crepe paper and semi-conductive paint is to shield or balance the electric field, thereby reducing the local discharge of the combined mutual inductor. The use of copper foil or aluminum foil fully considers the mutual influence of the electromagnetic field between the current and voltage of the mutual inductor during operation, ensuring that the stability, reliability and accuracy of product measurement are higher.

[0031] like Figure 1-5As shown, the primary high-voltage current terminal 12 of the present invention is symmetrically arranged and has an arc-shaped fourth arc-shaped shed 20 between them. Once dust and snow are accumulated on the surface, they can flow away quickly in rainy weather; the lower part of the primary high-voltage current terminal 12 of the primary current winding 11 is located in the main insulator 14, where the main insulator is elliptical, and a plurality of arc-shaped first arc-shaped sheds 15 are distributed on the outer wall to increase the primary creepage distance to the ground, and a third arc-shaped shed 17 is provided in the middle of the main insulator, which crosses the current body and the voltage body, to increase the creepage distance, and then a plurality of arc-shaped second arc-shaped sheds 16 are arranged in sequence downwards and located on the current body. 22 periphery, transition to the voltage body 23 periphery, increase the creepage distance to the ground, these shed layout makes the transformer structure more fitting and more compact, the product appearance along the surface structure is relatively smooth, so it has the self-cleaning function of natural flushing, the upper part of the voltage body 23 of the main insulator 14 is in an arc-shaped transition, and the four-corner arc-shaped depressions are symmetrically arranged front and back to form a rectangular parallelepiped shape. The overall contour design has a uniform insulation distance, a more fitting and compact structure, adapts to the shrinkage of epoxy resin insulation materials caused by rapid changes in outdoor temperature, prevents resin cracking, and is more stable and reliable when installed in harsh climate environments at high altitudes and severely polluted areas.

[0032] like Figure 1-5 As shown, the primary high-voltage lead 7 of the voltage primary winding 2 is connected to the primary high-voltage current terminal 12, and the primary low-voltage lead 25 of the voltage primary winding 2 is connected to the primary N terminal 8. The primary N terminal 8 is located at the center position of the current body 22 at the last end of the main insulator 14, which is biased downward, for easy grounding. The voltage secondary lead 26 of the voltage secondary winding 3 and the current secondary lead 27 of the current secondary winding 10 are respectively connected to the secondary terminal 5 in the secondary wiring station 4, which is convenient for users to make secondary wiring. The sealed secondary wiring station is located at the center position of the voltage body 23 at the front end of the main insulator 14, which is biased downward. The grounding terminal 13 is arranged at the rear end of the bottom plate 6, located at the bottom of the main insulator 14. The grounding terminal 13 is connected to the primary N terminal 12 through a connecting piece 24, which makes grounding more convenient.

[0033] When in use, first use the bottom plate of the combined mutual inductor to install the combined mutual inductor on the chassis of the switch cabinet according to the phase sequence according to the installation distance, then connect the primary high-voltage current terminal, and ground the primary N terminal and the grounding terminal together. Finally, connect the secondary line cable to the secondary terminal through the waterproof joint cover 21, and install the secondary rubber pad 19 and the secondary cover 18 to ensure that the secondary terminal 5 is completely sealed. Finally, install the primary high-voltage current terminal 12 and the external terminal block in place, and use heat shrink sleeves and internal potting environmentally friendly silicone to seal. The assembly of the single-phase grounded combined mutual inductor is completed. This product can be installed and used alone or in multiple units.

[0034] In this embodiment, the current core is made of amorphous alloy and the voltage core is made of rolled core. The electromagnetic conversion principle is used to enable the secondary current and voltage to accurately reflect the changes in the primary current and voltage, and is used for current and voltage measurement, electric energy metering, and relay protection.

[0035] The effect of this implementation is that the single-phase grounding combination transformer product is small in size, strong in anti-interference, high in measurement accuracy, easy to install, easy to maintain, stable in insulation, and safe in operation, which further improves the design and manufacturing level of the switch cabinet supporting the grounding combination transformer.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. Single-phase grounding combined transformer, characterized in that: The utility model comprises a main insulator in which a current body, a voltage body, a primary high-voltage current terminal and a secondary terminal are cast into one body by epoxy resin; the upper part of the primary high-voltage current terminal extends out of the main insulator, and the lower part is located in the main insulator and connected to the current body and the voltage body; a plurality of first arc-shaped sheds are distributed on the outer wall of the upper part of the main insulator, and the plurality of first arc-shaped sheds are distributed around the outer periphery of the lower part of the primary high-voltage current terminal; the current body and the voltage body are arranged side by side in the middle part of the main insulator, and a secondary wiring platform is cast at the lower part of the main insulator, and the secondary wiring terminal is built in the secondary wiring platform, and the secondary wiring terminal is respectively connected to the current body and the voltage body.

2. The single-phase grounding combined transformer according to claim 1, characterized in that: A plurality of second arc-shaped umbrella skirts are distributed on the outer wall of the middle part of the main insulator, and the plurality of second arc-shaped umbrella skirts are distributed around the outer periphery of the current device body and transition to a part of the outer periphery of the voltage device body.

3. The single-phase grounding combined transformer according to claim 2, characterized in that: A third arc-shaped umbrella skirt is also distributed on the outer wall of the middle part of the main insulator. The third arc-shaped umbrella skirt is located above the second arc-shaped umbrella skirt, and the third arc-shaped umbrella skirt crosses the top of the current device body and the voltage device body.

4. The single-phase grounding combined transformer according to claim 1, characterized in that: The primary high-voltage current connection terminals are symmetrically distributed on both sides of the fourth arc-shaped shed, and the fourth arc-shaped shed is located on the top of the main insulator.

5. The single-phase grounding combined transformer according to claim 1, characterized in that: The current device body comprises a current core, a current primary winding and a current secondary winding. The current core adopts an amorphous alloy. The current core is wrapped with an insulating cardboard corner ring, a twill tape insulating layer, a polyurethane board buffer layer, a half-layer of self-adhesive tape from the inside to the outside, and then a half-layer of polyester film, copper foil or aluminum foil, and a half-layer of semi-conductive crepe paper shielding layer are wrapped after the enameled round copper wire is wound. After the primary winding of the current is wound through the current core, a half-layer of glass fiber cloth tape, a half-layer of crepe paper, and a half-layer of semi-conductive crepe paper are wrapped.

6. The single-phase grounding combined transformer according to claim 1, characterized in that: The voltage device body includes a voltage core, a voltage primary winding and a voltage secondary winding. After being wrapped with two half-fold layers of self-adhesive tape to the middle position on both sides of the voltage core, the primary winding and the secondary winding are installed. The exposed part of the voltage core is wrapped from inside to outside in the following order: a half-fold layer of self-adhesive tape insulation layer, a polyurethane board buffer layer, a half-fold layer of self-adhesive tape insulation layer, copper foil, and a half-fold layer of semi-conductive crepe paper shielding layer.

7. The single-phase grounding combined transformer according to claim 6, characterized in that: The primary high voltage lead of the primary voltage winding is connected to the primary high voltage current terminal, and the exposed part of the connection is sealed with a semi-conductive rubber tape. The primary low voltage lead of the primary voltage winding is connected to the primary N terminal, and the primary N terminal is located at the bottom of the main insulator and at the rear end.

8. The single-phase grounding combined transformer according to claim 1, characterized in that: The voltage secondary lead wire of the voltage secondary winding and the current secondary lead wire of the current secondary winding are both connected to the secondary wiring terminals in the secondary wiring station.

9. The single-phase grounding combined transformer according to claim 1, characterized in that: The secondary connection platform is located at the front end of the main insulator, and a secondary cover plate is installed through a secondary rubber pad.

10. The single-phase grounding combined transformer according to claim 1, characterized in that: The main insulator is installed on the bottom plate, the grounding terminal is located at the lower part of the main insulator and at the rear end of the bottom plate, and the grounding terminal is connected to the primary N terminal through a connecting piece.

Images