Dry-type transformer

Abstract

The invention discloses a dry-type transformer which comprises a transformer body, the transformer body is provided with an n point for grounding, the n point is directly connected with a metal structural part on the transformer body through a connecting piece, and reliable grounding of the transformer body is completed through the metal structural part. The device has the advantages of simple structure, low cost, more convenience and simplicity in installation and debugging and the like.

Description

Technical Field

[0001] The invention mainly relates to the technical field of transformers, in particular to a dry-type transformer. Background Art

[0002] At present, transformers are widely used in various electrical equipment. There are still some areas that need to be improved in the use of traditional transformers, especially in working environments with narrow installation space, small heat dissipation space and high heat generation, such as the cabin of a wind turbine.

[0003] The above-mentioned traditional transformers have the following disadvantages:

[0004] 1. In the field of transformers, in order to stabilize the potential, most three-phase transformers balance the phases by n-point grounding (for transformers with Dyn connection group numbers, the terminals after short-circuiting the a / b / or x / y / z ends of the three-phase transformer on the y-connection side). The current n-point grounding is achieved by reserving an electrical interface point for customers to connect to the ground using cables or copper bars. This method increases labor costs and manufacturing costs to a certain extent. Especially for high-voltage products, the routing of the grounding wire and the guarantee of insulation distance will increase the requirements for the secondary line structure and size space of the product. For example, based on the special installation environment of the wind turbine cabin transformer, it is not convenient to connect n points to the low end separately according to the conventional transformer structure.

[0005] 2. The common cooling methods for traditional dry-type transformers are self-heating cooling and forced air cooling. The common air cooling methods are top-blowing and side-blowing. In response to the structural characteristics and capacity of the transformer, different projects should choose the best cooling conditions. For transformers with larger capacity, the winding radius is relatively thick, and the top-blowing method is generally used, but this will lead to poor air cooling effect. The problem often encountered is how to ensure that the cooling airflow evenly takes away the heat of the windings inside and outside the transformer, achieve the relative uniformity of the transformer temperature rise, and improve the heat dissipation efficiency. Summary of the invention

[0006] The technical problem to be solved by the present invention is: in view of the technical problems existing in the prior art, the present invention provides a dry-type transformer with a simple structure, low cost, and more convenient and concise installation and debugging.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0008] A dry-type transformer comprises a transformer body, wherein the transformer body is provided with n points for grounding, wherein the n points are directly connected to metal structural parts on the transformer body through connectors, and reliable grounding of the transformer body is achieved through the metal structural parts.

[0009] As a further improvement of the present invention: the connecting piece is a copper bar, and the copper bar is connected to the pull plate of the iron core on the transformer body.

[0010] As a further improvement of the present invention: the connecting piece is reliably connected to the pull plate via a first metal connecting column.

[0011] As a further improvement of the present invention: the pull plate is reliably connected to the lower clamp of the transformer body via a second metal connecting column, and the lower clamp has a grounding point.

[0012] As a further improvement of the present invention: the transformer body includes a heat dissipation component, the heat dissipation component includes a heat dissipation fan, the heat dissipation fan is bottom-mounted, and a guide cover is arranged on the top of the heat dissipation fan, and the air flow outlet direction of the guide cover is toward the position of the coil winding in the transformer body.

[0013] As a further improvement of the present invention: the coil winding in the transformer body includes an inner winding, an outer winding and a middle air duct, and the middle air duct is located between the inner winding and the outer winding; the air guide cover prevents the cold air blown out by the heat dissipation fan from passing through the middle air duct between the inner winding and the outer winding through the air guide effect.

[0014] As a further improvement of the present invention, the deflector cover is provided with more than one deflector plate, and the deflector plate is used to reasonably distribute the cooling gas.

[0015] As a further improvement of the present invention: a V-shaped structure is formed at the outlet of the air guide cover.

[0016] As a further improvement of the present invention: the guide plates in the guide cover all have a certain inclination angle, and the inclination angle is formed according to the distribution of the cooling gas.

[0017] Compared with the prior art, the advantages of the present invention are:

[0018] 1. The dry-type transformer of the present invention has a simple structure, low cost, and is more convenient and concise to install and debug. By optimizing the structure after design, the present invention can greatly simplify the transformer n-point grounding structure, reduce the grounding cost, and reduce the assembly workload. Taking an actual project as an example, if the conventional grounding design is used, the transformer needs to set fixed points for the n-point grounding cables when installed in the cabinet, and increase the cable connection, which greatly increases the grounding operation time.

[0019] 2. The dry-type transformer of the present invention utilizes the design of the heat dissipation fan and the air guide cover to accurately control the flow distribution of cooling air between the inner and outer windings, thereby improving the distribution of cooling effect, greatly improving the thermal management efficiency of the transformer, and ultimately ensuring the relative balance of the temperature rise of the inner and outer windings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structural principle of the dry-type transformer of the present invention.

[0021] Figure 2 It is a schematic diagram of the implementation principle of n-point grounding in a specific application example of the present invention.

[0022] Figure 3 It is a schematic diagram of the structural principle of the connection between n points and the upper end of the transformer body in a specific application example of the present invention.

[0023] Figure 4 It is a schematic diagram of the structural principle of the connection between point n and the lower end of the transformer body in a specific application example of the present invention.

[0024] Figure 5 It is a schematic diagram of the structural principle of the heat dissipation component in a specific application example of the present invention.

[0025] Figure 6 It is a schematic diagram of fluid simulation of cooling gas formed by the heat dissipation component in actual operation in a specific application example of the present invention.

[0026] Legend:

[0027] 1. Transformer body; 2. Connector; 3. Pull plate; 4. First metal connecting column; 5. Second metal connecting column; 101. Cooling fan; 102. Air guide cover; 103. Inner winding; 104. Outer winding; 105. Middle air duct.

[0028] Yx Specific implementation method

[0029] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] In the description of the present application, it should be understood that the terms "length", "width", "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.

[0031] In addition, the terms "first" and "second" 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, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0032] In this application, unless otherwise clearly specified and limited, the terms "assemble", "connect", "connect", "fix" and the like 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.

[0033] like Figure 1-Figure 4 As shown, a dry-type transformer of the present invention comprises a transformer body 1, and the transformer body 1 is provided with n points for grounding. The n points in the present invention are directly connected to the metal structure on the transformer body 1 through the connector 2, and the transformer body 1 is reliably grounded through the metal structure. Through this structural form, the present invention omits the interface requirements of the n points and the additional wiring work, which not only meets the installation requirements of the narrow environment when the transformer is used, greatly reduces the cumbersomeness of wiring, but also can optimize the layout of the entire space.

[0034] In a specific application example, the connecting member 2 may be a copper bar according to actual needs, and the copper bar is connected to the pull plate 3 of the iron core on the transformer body 1 .

[0035] Further, as a preferred embodiment, the connector 2 is reliably connected to the pull plate 3 through a first metal connecting column 4 (such as a stainless steel connecting column), and finally reliably connected to the transformer body 1.

[0036] In a specific application example, the pull plate 3 is reliably connected to the lower clamp of the transformer body 1 via a second metal connecting column 5 (such as a stainless steel connecting column).

[0037] By adopting the above solution of the present invention, only the grounding point on the lower clamp of the transformer body 1 is connected, so that the transformer body 1 can be reliably grounded, that is, n points on the transformer body 1 can also be reliably grounded.

[0038] In the present invention, the n-point grounding is directly connected to the metal structure grounding of the transformer, thereby omitting the interface requirements and additional wiring work of the n-point. The N-point is connected to the stainless steel pull plate of the core through the copper bar, and is reliably connected through the stainless steel. The pull plate and the lower clamp of the transformer are also reliably connected through the stainless steel.

[0039] See also Figure 5In a specific application example, the transformer body 1 includes a heat dissipation component, and the heat dissipation component includes a heat dissipation fan 101. The heat dissipation fan 101 is bottom-mounted, and a guide cover 102 is arranged on the top of the heat dissipation fan 101. The airflow outlet direction of the guide cover 102 is toward the position of the coil winding in the transformer body 1.

[0040] Further, as a preferred embodiment, the coil winding in the transformer body 1 includes an inner winding 103, an outer winding 104 and a middle airway 105, and the middle airway 105 is located between the inner winding 103 and the outer winding 104. In the traditional solution, most of the airflow will pass through the middle airway 105 and the outer winding 104, and will not pass through the inner winding 103. However, since the inner winding 103 is closer to the high-heat generating components, the temperature of the inner winding 103 is higher during operation and more effective heat dissipation is required. Therefore, in the present invention, the air guide 102 uses the air guide effect to avoid the cold air blown out by the heat dissipation fan 101 from passing through the middle airway 103 between the inner winding 103 and the outer winding 104 to the greatest extent.

[0041] As a preferred embodiment, the guide cover 102 of the present invention is provided with one or more guide plates (not shown in the figure), and the guide plates are used to reasonably distribute the cooling gas, so that the cooling gas can not only avoid the middle air duct 105 as much as possible, but also distribute more cooling gas to the inner winding 103 with a higher temperature, so as to ensure the normal operation of the transformer body 1 to the greatest extent possible.

[0042] Furthermore, a V-shaped structure is formed at the outlet of the air guide cover 102 to ensure a higher flow rate and more precise cooling airflow.

[0043] Furthermore, the guide plates in the guide cover 102 all have a certain inclination angle, and the inclination angle is designed according to the distribution of cooling gas. In actual use, the design of the inclination angle can be combined with the actual heat generation of the inner winding 103 and the outer winding 104 calculated by engineering, and the flow distribution of the cooling gas on the inner winding 103 and the outer winding 104 can be accurately controlled through simulation support to ensure the relative balance of the temperature rise of the inner winding 103 and the outer winding 104. By adopting the above structure and using the special guide structure such as the guide cover 102, the distribution of the cooling effect can be greatly improved, and the thermal management efficiency of the transformer can be greatly improved.

[0044] See also Figure 6 In the actual application process of the structure of the present invention, the temperature rise data before and after optimization are compared and verified.

[0045] Working conditions Inner winding temperature rise External winding temperature rise No deflector 112K 63.0K Add a deflector 71.1K 57.5K

[0046] The above are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should be regarded as the protection scope of the present invention.

Claims

1. A dry-type transformer, comprising a transformer body (1), characterized in that: The transformer body (1) is provided with n points for grounding, and the n points are directly connected to the metal structural parts on the transformer body (1) through the connecting parts (2), so that the transformer body (1) is reliably grounded through the metal structural parts.

2. The dry-type transformer according to claim 1, characterized in that: The connecting piece (2) is a copper bar, which is connected to a pull plate (3) of the iron core on the transformer body (1).

3. The dry-type transformer according to claim 2, characterized in that: The connecting piece (2) is reliably connected to the pull plate (3) via a first metal connecting column (4).

4. The dry-type transformer according to claim 2, characterized in that: The pull plate (3) and the lower clamp of the transformer body (1) are reliably connected via a second metal connection column (5), and a grounding point is provided on the lower clamp.

5. The dry-type transformer according to any one of claims 1 to 4, characterized in that: The transformer body (1) comprises a heat dissipation component, the heat dissipation component comprises a heat dissipation fan (101), the heat dissipation fan (101) is bottom-mounted, and a guide cover (102) is arranged at the top of the heat dissipation fan (101), the air flow outlet direction of the guide cover (102) is toward the position of the coil winding in the transformer body (1).

6. The dry-type transformer according to claim 5, characterized in that: The coil winding in the transformer body (1) comprises an inner winding (103), an outer winding (104) and a middle air duct (105); the middle air duct (105) is located between the inner winding (103) and the outer winding (104); the air guide cover (102) prevents the cold air blown out by the heat dissipation fan (101) from passing through the middle air duct (105) between the inner winding (103) and the outer winding (104) through the air guide effect.

7. The dry-type transformer according to claim 5, characterized in that: The guide cover (102) is provided with one or more guide plates, and the guide plates are used to reasonably distribute the cooling gas.

8. The dry-type transformer according to claim 5, characterized in that: The outlet of the air guide cover (102) forms a V-shaped structure.

9. The dry-type transformer according to any one of claims 6 to 8, characterized in that: The guide plates in the guide cover (102) all have a certain inclination angle, and the inclination angle is formed according to the distribution of cooling gas.

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