CN216119863U

CN216119863U - High-voltage winding of dry type transformer

Info

Publication number: CN216119863U
Application number: CN202122574150.1U
Authority: CN
Inventors: 刘远; 张升; 贺之渊; 刘延卓; 王晓晖
Original assignee: State Grid Corp of China SGCC; Global Energy Interconnection Research Institute; State Grid Shanghai Electric Power Co Ltd
Current assignee: State Grid Corp of China SGCC; Global Energy Interconnection Research Institute; State Grid Shanghai Electric Power Co Ltd
Priority date: 2021-10-25
Filing date: 2021-10-25
Publication date: 2022-03-22
Anticipated expiration: 2031-10-25

Abstract

The utility model discloses a high-voltage winding of a dry-type transformer, which comprises two tail end module units and a plurality of winding module units arranged between the two tail end module units in parallel; the winding module unit comprises a conductor coil and an insulating layer poured and formed outside the conductor coil, wherein a first slot is formed in the insulating layer, and a plug-in terminal electrically connected with the conductor coil is connected to the first slot; two plug terminals on two adjacent winding module units are electrically connected through the insulating connecting terminal. The high-voltage winding is divided into two basic structures of winding module units and tail end module units, the structure of each winding module unit is the same, the voltage grade is fixed, and according to the difference of rated voltage of the high-voltage winding, winding module units with reasonable quantity are selected to be connected, so that the flexible extension of different voltages can be realized. And compared with integral casting, each module unit has the advantages that the structure volume is greatly reduced, the internal defects during molding are easier to control, and the quality of the high-voltage winding after molding is facilitated.

Description

High-voltage winding of dry type transformer

Technical Field

The utility model relates to the technical field of high-voltage power transmission and distribution, in particular to a high-voltage winding of a dry-type transformer.

Background

The dry type transformer is a transformer with an iron core and a winding which are not immersed in insulating oil, realizes cooling through air convection and the like, has the characteristics of flame retardance, fire prevention, explosion prevention, environmental protection and the like, is safe and reliable to use, simple and convenient to install and maintain, can be deeply inserted into a load center, and is widely applied to occasions such as high-rise buildings, subways, railway stations, airports, hospitals, petrochemical enterprises, mines and the like. With the development of power technology, dry-type transformers are also rapidly popularized in the fields of underground substations and wind-power step-up transformers, and the performance of the dry-type transformers is accepted by the industry.

At present, a core component high-voltage winding of a dry-type insulation high-voltage transformer generally adopts an epoxy resin casting structure, and a basic design method comprises the following steps: the copper conductor with the enameled wire is adopted, insulating paper and a thin film are wound outside the copper conductor, then, after the copper conductor is wound into a coil, epoxy resin is integrally poured, and the copper conductor is cured and formed. The design of the high-voltage winding of the transformer has the following problems:

1. epoxy resin is a thermosetting material, so that the molding difficulty is high, and defects are easily generated. Because the thermal expansion coefficients of the epoxy resin and the lead are different, if the buffer layer is improperly arranged, the cast layer is easy to crack under the impact of cold and hot temperatures, the partial discharge capacity is increased, and products of part of enterprises have the quality problems of being exposed in the operation, which is a problem commonly existing in the existing epoxy cast dry-type transformer and a core problem restricting the popularization and the application of dry transformers.

2. The design freedom is not large, and each winding can be flexible-injected by using a mould. The high-voltage winding is long in structural size and needs to be molded at one time, air bubble extraction, interface defects and the like in the epoxy casting process are difficult to control, and a large number of interface defects and air bubbles are formed inside the molded high-voltage winding, so that the insulation strength is reduced, and the reliability is reduced;

3. the one-time molding of the high-voltage winding increases the molding period and the manufacturing difficulty, and for the design of the dry-type transformer with higher voltage level, the manufacturing difficulty of the winding is further increased and is difficult to realize, so that the voltage level and the capacity of the dry-type transformer are limited to be improved.

Due to the above factors, the current epoxy cast dry-type transformer is basically applied to the voltage class of 35kV and below, but cannot be applied to the voltage class of 35kV and above.

SUMMERY OF THE UTILITY MODEL

Therefore, the technical problem to be solved by the present invention is to overcome the defect that the high voltage winding of the dry type transformer in the prior art cannot realize the voltage level increase, so as to provide a high voltage winding of a dry type transformer.

In order to solve the technical problems, the technical scheme of the utility model is as follows:

the high-voltage winding of the dry-type transformer comprises two tail end module units positioned at the head end and the tail end, and a plurality of winding module units which are positioned between the two tail end module units and are sequentially arranged side by side along the connecting line direction of the two tail end module units; the winding module unit comprises a conductor coil and an insulating layer poured and formed outside the conductor coil, a first slot is formed in the insulating layer, and a plug-in terminal electrically connected with the conductor coil is connected to the first slot; two plug terminals on two adjacent winding module units are electrically connected through an insulating connecting terminal.

Furthermore, the winding module unit comprises at least two layers of winding layers which are sequentially sleeved, an air passage for air circulation is arranged between every two adjacent layers of windings, and winding insulation supporting bars which are supported between the two layers of windings are arranged on the air passage.

Furthermore, the winding layer comprises a plurality of turns of coils and winding insulation layers poured and molded outside the coils.

Furthermore, two first slots are formed in the winding insulating layer, one plugging terminal is connected to each first slot, and the two plugging terminals are connected with the ends of the incoming and outgoing lines at the head and the tail of the coil respectively.

Furthermore, the insulation connection terminal comprises a conductor positioned inside and a terminal insulation layer poured and molded outside the conductor, and the conductor is electrically connected with two plug terminals on two adjacent winding insulation layers.

Further, the conductor is in a cylindrical rod-shaped structure.

Furthermore, two embedded second slots are formed in the terminal insulating layer, and the plug terminals can be inserted into the second slots to achieve electrical connection between conductors in the insulating connecting terminals and the wire inlet and outlet ends of the coil.

Furthermore, the tail end module unit comprises at least two layers of insulating sleeves which are sequentially sleeved, and an interlayer air passage for air circulation is arranged between every two adjacent layers of insulating sleeves; and sleeve insulating support bars supported between the two layers of insulating sleeves are arranged on the interlayer air passages.

Furthermore, the interlayer air passage and the air passage between two adjacent winding layers are correspondingly arranged in the axial direction of the high-voltage winding.

Furthermore, an umbrella skirt structure is arranged on the periphery of the outermost insulating sleeve.

The technical scheme of the utility model has the following advantages:

1. according to the high-voltage winding of the dry-type transformer, the high-voltage winding is divided into two end module units and a plurality of winding module units according to the function of the high-voltage winding, the winding module units give consideration to the electrical performance and the insulation structure of the winding, and the end module units are only used for solving the problem that the high-voltage winding is insulated to the ground; and each winding module unit has the same structure and fixed voltage grade, and winding module units with reasonable quantity are selected to be connected according to different rated voltages of the high-voltage winding, so that flexible expansion of different voltages can be realized. The number of winding unit modules can be increased when the rated voltage of the high-voltage transformer is high, and can be decreased when the voltage is low. In addition, according to the design method, a large-size integral casting structure of the high-voltage winding is decomposed into module units with smaller sizes, and compared with integral casting, casting of each module unit greatly reduces the structure volume, internal defects during molding are easier to control, the molding difficulty of the high-voltage winding can be greatly reduced, and the molding efficiency and the molded quality of the high-voltage winding are improved.

2. According to the high-voltage winding of the dry-type transformer, the conductor coils in the two adjacent winding module units are connected through the plug terminals and the insulation connecting terminals, so that the electric connection is realized, the electric field distribution of the connecting part can be improved, and the corona discharge caused by the concentration of an electric field is avoided.

3. According to the high-voltage winding of the dry-type transformer, each winding module unit is designed with a standardized slot structure and is matched with the adaptive plug-in terminal and the adaptive insulating connecting terminal, so that flexible electrical connection among different winding module units is realized.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic diagram of a high voltage winding according to an embodiment of the present invention;

fig. 2 is a schematic structural view of a winding module unit according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of an end module unit according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of an insulated connection terminal according to an embodiment of the present invention.

Description of reference numerals: 1. a high voltage winding; 2. a winding module unit; 3. an end module unit; 4. plugging and unplugging a terminal; 5. an insulated connection terminal; 6. layering windings; 7. an airway; 8. a first slot; 9. an insulating cylinder; 10. an interlayer air passage; 11. an umbrella skirt structure; 12. a terminal insulating layer; 13. a second slot.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

As shown in fig. 1, the high-voltage winding of the dry-type transformer includes two end module units 3 located at the head and tail ends, and 1-n winding module units 2 located between the two end module units 3 and sequentially arranged side by side along the connection direction of the two end module units 3. The winding module unit 2 comprises a conductor coil and an insulating layer poured and formed outside the conductor coil, a first slot 8 is formed in the insulating layer, and a plug-in terminal 4 electrically connected with the conductor coil is connected to the first slot 8; the two plug terminals 4 on two adjacent winding module units 2 are electrically connected by the insulating connection terminal 5.

As shown in fig. 2, the winding module unit 2 includes two layers of winding layers 6 sequentially sleeved, an air passage 7 for air circulation is provided between two adjacent layers of winding layers 6, and a winding insulation support bar (not shown) supported between the two layers of winding layers 6 is provided on the air passage 7. The provision of the air passages 7 improves the heat radiation performance of the winding module unit 2. The winding layer 6 specifically includes a coil with a plurality of turns and a winding insulation layer cast outside the coil. Two first slots 8 are formed in the winding insulating layer, each first slot 8 is connected with one plugging terminal 4, and the two plugging terminals 4 are connected with the wire inlet and outlet ends of the head end and the tail end of the coil respectively.

As shown in fig. 3, the end module unit 3 includes two layers of insulating sleeves sequentially sleeved, and an interlayer air passage 10 for air circulation is provided between two adjacent layers of insulating sleeves; the interlayer air duct 10 is provided with sleeve insulating support strips (not shown) supported between two layers of insulating sleeves. The insulating sleeve is used for realizing the insulation tolerance of the high-voltage winding conductor coil to the ground, and the height of the insulating cylinder 9 depends on the operating voltage of the high-voltage winding. The interlayer air passage 10 and the air passage 7 between the two adjacent layers of winding layers 6 are correspondingly arranged in the axial direction of the high-voltage winding, so that the heat dissipation of the high-voltage winding is facilitated. An umbrella skirt structure 11 is integrally formed on the periphery of the outermost insulating sleeve, and the umbrella skirt structure 11 is used for increasing the creepage distance requirement of the high-voltage winding along the surface under the long-term operation voltage.

As shown in fig. 1 and 4, the insulated connection terminal 5 includes a conductor located inside and a terminal insulation layer 12 cast outside the conductor, and the conductor is electrically connected to two plug terminals 4 on two adjacent winding insulation layers. The conductor is a cylindrical rod-shaped structure, the insulating connecting terminal 5 formed after the terminal insulating layer 12 is poured on the conductor is also a cylindrical rod-shaped structure, the design can improve the electric field distribution at the connecting position of the two winding module units 2 according to the requirement, and the corona discharge caused by electric field concentration is avoided.

The terminal insulating layer 12 is provided with two embedded second slots 13, and the second slots 13 have the same shape as the first slots 8 and are used for matching with the plug terminals to realize the series connection between the winding module units 2. The shape of the plug terminal depends on the interface of a lead in a winding and the through-current requirement, and the plug terminal is usually a cylindrical bar-shaped structure and is matched with a bolt structure and a contact to ensure that one end can be connected by a bolt and the other end can be plugged and clamped; the plug-in terminal can also be designed in a structure with both ends being contacts, and is fixedly connected with the first slot 8 on the winding module unit 2 and the second slot 13 on the insulating connection terminal 5 through a direct plug-in mode. Each winding module unit 2 is designed with a standardized slot structure, and is matched with a plug terminal and an insulation connecting terminal 5 which are adaptive to each other, so that flexible electrical connection between different winding module units 2 is realized.

In summary, the high-voltage winding of the dry-type transformer provided by the embodiment of the utility model has the following advantages:

1. according to the function of the high-voltage winding, the high-voltage winding is divided into two basic structures of a winding module unit 2 and an end module unit 3, the structures of the winding module unit 2 and the end module unit 3 are different, the winding module unit 2 gives consideration to the electrical performance and the insulation structure of the winding, and the end module unit 3 is only used for solving the problem that the high-voltage winding is insulated to the ground.

2. The winding module units 2 are identical in structure and fixed in voltage grade, and according to the difference of rated voltage of the high-voltage winding, winding module units 2 with reasonable quantity are selected to be connected, so that flexible expansion of different voltages can be realized. The number of winding unit modules can be increased when the rated voltage of the high-voltage transformer is high, and can be decreased when the voltage is low.

3. According to the sectional type high-voltage winding, a large-size integral casting structure of the high-voltage winding is decomposed into module units with smaller sizes, and casting of each module unit is compared with integral casting, so that the structure volume is greatly reduced, internal defects during molding are easier to control, the molding difficulty of the high-voltage winding can be greatly reduced, and the molding efficiency and the molded quality of the high-voltage winding are improved.

4. Each winding module unit 2 is designed with a standardized slot structure, and is matched with a plug terminal and an insulation connecting terminal 5 which are adaptive to each other, so that flexible electrical connection between different winding module units 2 is realized.

5. In consideration of the fact that the connection among different module units has concentration of local field intensity, a special connecting joint is designed, electric field distribution of the connecting part can be improved while electric connection is achieved, and corona discharge caused by electric field concentration is avoided.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the utility model.

Claims

1. The high-voltage winding of the dry-type transformer is characterized by comprising two tail end module units (3) positioned at the head end and the tail end, and a plurality of winding module units (2) which are positioned between the two tail end module units (3) and are sequentially arranged side by side along the connecting line direction of the two tail end module units (3); the winding module unit (2) comprises a conductor coil and an insulating layer poured and formed outside the conductor coil, a first slot (8) is formed in the insulating layer, and a plug-in terminal (4) electrically connected with the conductor coil is connected to the first slot (8); two plug terminals (4) on two adjacent winding module units (2) are electrically connected through an insulating connecting terminal (5).

2. High-voltage winding of a dry-type transformer according to claim 1, characterized in that said winding module unit (2) comprises at least two layers of winding layers (6) sequentially sleeved, an air passage (7) for air circulation is arranged between two adjacent layers of winding layers (6), and a winding insulation support bar supported between two layers of winding layers (6) is arranged on said air passage (7).

3. High voltage winding of a dry transformer according to claim 2, characterized in that the winding layer (6) comprises a number of turns of coil and winding insulation cast on the outside of the coil.

4. The high-voltage winding of the dry-type transformer according to claim 3, wherein two first slots (8) are formed in the winding insulation layer, each first slot (8) is connected with one plug-in terminal (4), and the two plug-in terminals (4) are respectively connected with the wire inlet and outlet ends at the head and tail ends of the coil.

5. High-voltage winding of a dry-type transformer according to claim 4, characterized in that the insulation connection terminal (5) comprises a conductor located inside and a terminal insulation layer (12) cast outside the conductor, the conductor being electrically connected with two of the plug terminals (4) on two adjacent winding insulation layers.

6. A high voltage winding of a dry transformer according to claim 5, characterized in that the conductor is in the form of a cylindrical rod.

7. A high-voltage winding of a dry-type transformer according to claim 5, characterized in that the terminal insulation layer (12) is provided with two embedded second slots (13), and the plug-in terminal (4) can be inserted into the second slots (13) to electrically connect the conductor inside the insulation connection terminal (5) with the wire inlet and outlet ends of the coil.

8. A high-voltage winding of a dry-type transformer according to claim 3, characterized in that the end module unit (3) comprises at least two layers of insulating sleeves sleeved in sequence, and an interlayer air passage (10) for air circulation is arranged between two adjacent layers of the insulating sleeves; and sleeve insulating support bars supported between the two layers of insulating sleeves are arranged on the interlayer air passage (10).

9. High voltage winding of a dry transformer according to claim 8, characterized in that the inter-layer air ducts (10) are arranged in a position corresponding to the air ducts (7) between two adjacent winding layers (6) in the axial direction of the high voltage winding.

10. High voltage winding of a dry transformer according to claim 8, characterized in that the outermost insulation sleeve is provided with a shed structure (11) at its outer circumference.