Dry-type transformer and wind power plant

Abstract

This application relates to a dry-type transformer and wind power equipment. The dry-type transformer includes a high-voltage winding, comprising an A-phase winding, a B-phase winding, and a C-phase winding. The dry-type transformer can be controllably switched between a first state and a second state. By controlling the dry-type transformer to be in the first state, the upper and lower parts of the high-voltage winding are connected in series, making it suitable for 69kV lines in offshore wind power projects. By controlling the dry-type transformer to be in the second state, the upper and lower parts of the high-voltage winding are connected in series, making it suitable for 34.5kV lines in onshore wind power projects. Thus, the aforementioned dry-type transformer can adapt to two scenarios with a single device, effectively reducing the R&D, production, and inventory costs of wind power projects, and effectively adapting to the current large-scale expansion of wind power production.

Description

Technical Field

[0001] This application relates to the field of transformer technology, and in particular to a dry-type transformer and wind power equipment. Background Technology

[0002] Currently, the transformers installed inside wind turbine nacelles are typically designed for a single voltage level. This configuration means that the 34.5kV lines in onshore wind power projects and the 69kV lines in offshore wind power projects cannot share the same type of transformer equipment. Therefore, wind power projects currently need to separately develop, produce, and stockpile transformers for both 34.5kV and 69kV voltage levels, resulting in a significant increase in project costs, nearly doubling them, making it difficult to meet the current large-scale expansion needs of wind power. Summary of the Invention

[0003] Therefore, it is necessary to provide a dry-type transformer and wind power equipment to address the issue that the 34.5KV lines in onshore wind power projects and the 69KV lines in offshore wind power projects cannot share the same type of transformer equipment.

[0004] A dry-type transformer, the dry-type transformer comprising:

[0005] The high-voltage winding includes an A-phase winding, a B-phase winding, and a C-phase winding. The A-phase winding includes a first upper section winding and a first lower section winding with equal turns. The B-phase winding includes a second upper section winding and a second lower section winding with equal turns. The C-phase winding includes a third upper section winding and a third lower section winding with equal turns.

[0006] The dry-type transformer can be switched between a first state and a second state in a controlled manner. When the dry-type transformer is in the first state, the first upper winding and the first lower winding are connected in series, the second upper winding and the second lower winding are connected in series, and the third upper winding and the third lower winding are connected in series.

[0007] When the dry-type transformer is in the second state, the first upper winding and the first lower winding are connected in parallel, the second upper winding and the second lower winding are connected in parallel, and the third upper winding and the third lower winding are connected in parallel.

[0008] In one embodiment, the first upper winding includes terminal A, terminal A1, terminal X1, and terminal X. Terminal A is located at the top of the first upper winding, terminal X is located at the bottom of the first upper winding, terminal A1 and terminal X1 are located between terminal A and terminal X, and the number of turns between terminal A1 and terminal A accounts for 3% of the number of turns between terminal A1 and terminal X1, and the number of turns between terminal X1 and terminal X accounts for 3% of the number of turns between terminal A1 and terminal X1.

[0009] The second upper winding includes terminal B, terminal B1, terminal Y1, and terminal Y. Terminal B is located at the top of the second upper winding, terminal Y is located at the bottom of the second upper winding, and terminal B1 and terminal Y1 are located between terminal B and terminal Y. The number of turns between terminal B1 and terminal B accounts for 3% of the number of turns between terminal B1 and terminal Y1, and the number of turns between terminal Y1 and terminal Y accounts for 3% of the number of turns between terminal B1 and terminal Y1.

[0010] The third upper winding includes terminal C, terminal C1, terminal Z1, and terminal Z. Terminal C is located at the top of the third upper winding, terminal Z is located at the bottom of the third upper winding, and terminal C1 and terminal Z1 are located between terminal C and terminal Z. The number of turns between terminal C1 and terminal C accounts for 3% of the number of turns between terminal C1 and terminal Z1, and the number of turns between terminal Z1 and terminal Z accounts for 3% of the number of turns between terminal C1 and terminal Z1.

[0011] In one embodiment, the first lower winding includes terminal A', terminal A1', terminal X1', and terminal X', with terminal A located at the top of the first lower winding, terminal X' located at the bottom of the first lower winding, and terminal A1' and terminal X1' located between terminal A' and terminal X'. The number of turns between terminal A1' and terminal A' accounts for 3% of the number of turns between terminal A1' and terminal X1', and the number of turns between terminal X1' and terminal X' accounts for 3% of the number of turns between terminal A1' and terminal X1'.

[0012] The second lower winding includes terminal B', terminal B1', terminal Y1', and terminal Y'. Terminal B' is located at the top of the second lower winding, terminal Y' is located at the bottom of the second lower winding, and terminal B1' and terminal Y1' are located between terminal B' and terminal Y'. The number of turns between terminal B1' and terminal B' accounts for 3% of the number of turns between terminal B1' and terminal Y1', and the number of turns between terminal Y1' and terminal Y' accounts for 3% of the number of turns between terminal B1' and terminal Y1'.

[0013] The third lower winding includes terminal C', terminal C1', terminal Z1', and terminal Z'. Terminal C' is located at the top of the third lower winding, terminal Z' is located at the bottom of the third lower winding, and terminal C1' and terminal Z1' are located between terminal C' and terminal Z'. The number of turns between terminal C1' and terminal C' accounts for 3% of the number of turns between terminal C1' and terminal Z1', and the number of turns between terminal Z1' and terminal Z' accounts for 3% of the number of turns between terminal C1' and terminal Z1'.

[0014] In one embodiment, the wires winding the high-voltage winding include, from the inside out, bare wires, an inner shielding layer, a main insulation layer, and an outer shielding layer, wherein both the inner shielding layer and the outer shielding layer are semiconductors.

[0015] In one embodiment, both the inner and outer shielding layers are polypropylene films.

[0016] In one embodiment, the wires winding the high-voltage winding include, from the inside out, bare wires, a semiconductor shielding layer, and an insulating layer. The outer surface of the insulating layer is coated with a main insulating material. The substrate material of the semiconductor shielding layer, the insulating layer, and the main insulating material are the same medium.

[0017] In one embodiment, the wires winding the high-voltage winding comprise, from the inside out, bare wires, a polyimide layer, an aromatic polyamide fiber paper layer, and a glass fiber layer.

[0018] In one embodiment, the fillet radius of the bare conductor is greater than r > 6 mm.

[0019] In one embodiment, an ultra-high frequency partial discharge sensor is provided inside the dry-type transformer;

[0020] And / or the dry-type transformer is equipped with an optical fiber temperature sensor;

[0021] And / or, a vibration sensor is installed inside the dry-type transformer.

[0022] A wind power device comprising a dry-type transformer as described in any of the preceding claims.

[0023] The aforementioned dry-type transformer, by controlling it in its first state (connecting the upper and lower sections of the high-voltage winding in series), is suitable for 69kV lines in offshore wind power projects. By controlling it in its second state (connecting the upper and lower sections of the high-voltage winding in series), it is suitable for 34.5kV lines in onshore wind power projects. Thus, this dry-type transformer can be adapted to two scenarios with a single device, effectively reducing the R&D, production, and inventory costs of wind power projects, and effectively adapting to the current large-scale expansion of wind power production. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of a dry-type transformer in some embodiments of this application.

[0025] Figure 2 for Figure 1 A top view of the dry-type transformer in the embodiment.

[0026] Figure 3 for Figure 1 A schematic diagram of the high-voltage winding of the dry-type transformer in the embodiment.

[0027] Figure 4 for Figure 1 The embodiment shows a schematic diagram of the structure of the high-voltage winding of the dry-type transformer when used on a 69KV line.

[0028] Figure 5 for Figure 1 The embodiment shows a schematic diagram of the structure of the high-voltage winding of the dry-type transformer when used in a 34.5KV line.

[0029] Figure 6 for Figure 1 The embodiment shows a schematic diagram of the structure of the high-voltage winding of the dry-type transformer when used in a 36.5KV line.

[0030] Figure 7 This is a schematic diagram of the structure of a wire used in traditional high-voltage winding.

[0031] Figure 8 for Figure 7 A schematic diagram of the microstructure of the middle conductor.

[0032] Figure 9 This is a schematic diagram of the structure of the wires used to wind high-voltage windings in some embodiments of this application.

[0033] Figure 10 for Figure 9 A schematic diagram of the microstructure of the wire in the embodiment.

[0034] Explanation of reference numerals in the attached figures:

[0035] High-voltage winding 10; low-voltage winding 11; iron core 12; air duct 13; switching device 14;

[0036] First upper section winding 20; First lower section winding 21; Second upper section winding 22; Second lower section winding 23; Third upper section winding 24; Third lower section winding 25;

[0037] Bare conductor 30; semiconductor shielding layer 31; insulating layer 32; main insulating material 33. Detailed Implementation

[0038] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0039] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0040] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0041] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0042] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0043] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0044] See Figure 1 , Figure 1 The diagram shows a structural schematic of a dry-type transformer according to an embodiment of this application. The dry-type transformer provided in this embodiment can adapt to both land and sea voltages through dual voltage switching. Specifically, the dry-type transformer includes an iron core 12, and a high-voltage winding 10 and a low-voltage winding 11 wound on the iron core 12. Through the electromagnetic induction between the high-voltage winding 10 and the low-voltage winding 11, the transmission of electrical energy and the transformation of voltage are realized.

[0045] For the high-voltage winding 10, in order to enable the high-voltage winding 10 to adapt to the 34.5KV onshore line and the 69KV offshore line, the high-voltage winding 10 of the dry-type transformer in this embodiment includes an A-phase winding, a B-phase winding and a C-phase winding. The A-phase winding includes a first upper section winding 20 and a first lower section winding 21 with equal number of turns. The B-phase winding includes a second upper section winding 22 and a second lower section winding 23 with equal number of turns. The C-phase winding includes a third upper section winding 24 and a third lower section winding 25 with equal number of turns. The first upper winding 20, the second upper winding 22, and the third upper winding 24 are arranged side by side and are located above the first lower winding 21, the second lower winding 23, and the third lower winding 25, respectively. Thus, the first upper winding 20, the second upper winding 22, and the third upper winding 24 together form the upper part of the high-voltage winding 10, while the first lower winding 21, the second lower winding 23, and the third lower winding 25 together form the lower part of the high-voltage winding 10.

[0046] The dry-type transformer can also be controlled to switch between a first state and a second state. When the dry-type transformer is in the first state, the high-voltage winding 10... Figure 4 As shown, the first upper winding 20 and the first lower winding 21 are connected in series, the second upper winding 22 and the second lower winding 23 are connected in series, and the third upper winding 24 and the third lower winding 25 are connected in series. That is, the upper and lower parts of the high-voltage winding 10 are connected in series, thus realizing the 69KV operation scenario under series connection, enabling the high-voltage winding 10 to adapt to the 69KV lines of offshore wind power projects.

[0047] When the dry-type transformer is in the second state, the high-voltage winding 10 is as follows: Figure 5 As shown, the first upper winding 20 and the first lower winding 21 are connected in parallel, the second upper winding 22 and the second lower winding 23 are connected in parallel, and the third upper winding 24 and the third lower winding 25 are connected in parallel. That is, the upper and lower parts of the high-voltage winding 10 are connected in parallel, thus achieving a 34.5KV operation scenario under parallel connection, enabling the high-voltage winding 10 to adapt to 34.5KV lines in onshore wind power projects.

[0048] The aforementioned dry-type transformer, by controlling it in its first state, connects the upper and lower parts of its high-voltage winding 10 in series, making it suitable for 69kV lines in offshore wind power projects. By controlling it in its second state, connecting the upper and lower parts of the high-voltage winding 10 in series, it becomes suitable for 34.5kV lines in onshore wind power projects. Thus, this dry-type transformer can adapt to two scenarios with a single set of equipment, effectively reducing the R&D, production, and inventory costs of wind power projects, and effectively adapting to the current large-scale expansion of wind power production.

[0049] Furthermore, the aforementioned dry-type transformer can also be applied to a towing test platform. Through its voltage switching function, it is compatible with the matching development requirements of 34.5kV, 36.5kV and 69kV nacelle power systems. It is deeply adapted to the test platform, with reserved dedicated test interfaces and multi-parameter acquisition modules. It can be directly connected to the towing test platform to realistically simulate all working conditions such as nacelle load, vibration, and temperature change without the need for additional test system construction.

[0050] In some embodiments of this application, the dry-type transformer is further provided with a switching device 14. The switching device 14 can control the dry-type transformer to switch between a first state and a second state. That is, the switching device 14 controls the first upper winding 20 and the first lower winding 21 to switch between series and parallel connection, controls the second upper winding 22 and the second lower winding 23 to switch between series and parallel connection, and controls the third upper winding 24 and the third lower winding 25 to switch between series and parallel connection.

[0051] It is understood that the switching device 14 can be used by switching switches or external terminal blocks, as long as the switching device 14 can switch the upper and lower parts of the high voltage winding 10 between series and parallel connections. In some other embodiments, the high voltage winding 10 can also be connected manually to achieve series and parallel connections between the upper and lower parts of the high voltage winding 10, which is not limited here.

[0052] Specifically, see Figure 3 , Figure 3 A schematic diagram of the winding of phase A of the high-voltage winding 10 is shown. The first upper section winding 20 of phase A includes terminal A1 and terminal X1, and the lower section winding includes terminal A1' and terminal X1'. When the switching device 14 controls the first upper section winding 20 and the first lower section winding 21 to be connected in series, terminal X1 and terminal X1' are connected to each other. At this time, the high-voltage winding 10... Figure 4 As shown, when the switching device 14 controls the first upper winding 20 and the first lower winding 21 to be connected in parallel, terminals A1 and A1' are connected, and terminals X1 and X1' are connected. At this time, the high-voltage winding 10 is as follows: Figure 5 As shown.

[0053] It is understandable that the B-phase and C-phase windings of the high-voltage winding 10 have the same number of turns as the A-phase winding, the same terminal positions, and the same switching process, so they will not be described in detail here.

[0054] In some embodiments of this application, the first upper winding 20 further includes terminal A and terminal X, with terminal A located at the top of the first upper winding 20 and terminal X located at the bottom of the first upper winding 20. Terminal A1 and terminal X1 are located between terminal A and terminal X, and the number of turns between terminal A1 and terminal A accounts for 3% of the number of turns between terminal A1 and terminal X1, and the number of turns between terminal X1 and terminal X accounts for 3% of the number of turns between terminal A1 and terminal X1.

[0055] Furthermore, the first lower winding 21 also includes terminal A' and terminal X'. Terminal A is located at the top of the first lower winding 21, and terminal X' is located at the bottom of the first lower winding 21. Terminal A1' and terminal X1' are located between terminal A' and terminal X', and the number of turns between terminal A1' and terminal A' accounts for 3% of the number of turns between terminal A1' and terminal X1', and the number of turns between terminal X1' and terminal X' accounts for 3% of the number of turns between terminal A1' and terminal X1'.

[0056] Thus, based on the number of turns of terminals A1 and X1, 3% more turns are added to both the beginning and end of the first upper winding 20, and simultaneously, based on the number of turns of terminals A1' and X1', 3% more turns are added to both the beginning and end of the first lower winding 21. In this way, by selecting different terminals according to the A-phase winding, different input voltages can be accommodated, resulting in a more stable output voltage.

[0057] In this winding, the A-phase winding, the B-phase winding, and the C-phase winding need to maintain the same number of turns. For this purpose, the second upper winding 22 includes terminal B, terminal B1, terminal Y1, and terminal Y. Terminal B is located at the top of the second upper winding 22, terminal Y is located at the bottom of the second upper winding 22, and terminal B1 and terminal Y1 are located between terminal B and terminal Y. The number of turns between terminal B1 and terminal B accounts for 3% of the number of turns between terminal B1 and terminal Y1, and the number of turns between terminal Y1 and terminal Y accounts for 3% of the number of turns between terminal B1 and terminal Y1. The second lower winding 23 includes terminals B', B1', Y1', and Y'. Terminal B' is located at the top of the second lower winding 23, and terminal Y' is located at the bottom of the second lower winding 23. Terminals B1' and Y1' are located between terminals B' and Y', and the number of turns between terminals B1' and B' accounts for 3% of the number of turns between terminals B1' and Y1', and the number of turns between terminals Y1' and Y' accounts for 3% of the number of turns between terminals B1' and Y1'. Thus, the B-phase winding is the same as the A-phase winding. Additionally, 3% more windings are added to the first and second ends of the second upper winding 22 and the second lower winding 23 to ensure that the B-phase winding has the same number of turns as the A-phase winding.

[0058] More specifically, the third upper winding 24 includes terminals C, C1, Z1, and Z. Terminal C is located at the top of the third upper winding 24, and terminal Z is located at the bottom of the third upper winding 24. Terminals C1 and Z1 are located between terminals C and Z, and the number of turns between terminals C1 and C accounts for 3% of the number of turns between terminals C1 and Z1, and the number of turns between terminals Z1 and Z accounts for 3% of the number of turns between terminals C1 and Z1. The third lower winding 25 includes terminals C', C1', Z1', and Z'. Terminal C' is located at the top of the third lower winding 25, and terminal Z' is located at the bottom of the third lower winding 25. Terminals C1' and Z1' are located between terminals C' and Z', and the number of turns between terminals C1' and C' accounts for 3% of the number of turns between terminals C1' and Z1', and the number of turns between terminals Z1' and Z' accounts for 3% of the number of turns between terminals C1' and Z1'.

[0059] Thus, the C-phase winding, B-phase winding, and A-phase winding are kept consistent. The first and second ends of the third upper winding 24 and the third lower winding 25 are also increased by 3% to ensure that the C-phase winding, B-phase winding, and A-phase winding have the same number of turns. Depending on the connection terminals of the high-voltage winding 10, the transformer can operate in the first state at 69KV±2KV×2.5%, while in the second state, the high-voltage winding 10 can operate in two tap scenarios: 34.5KV±2KV×2.5% and 36.5KV±2KV×2.5%.

[0060] Specifically, see Figure 4 At this time, the dry-type transformer is in the first state. Terminal X1 of phase A winding is connected to terminal A1', terminal Y1 of phase B winding is connected to B1', and terminal Z1 of phase C winding is connected to C1'. Terminals A1 and X1' of phase A winding serve as the start and end points, terminals B1 and Y1' of phase B winding serve as the start and end points, and terminals C1 and Z1' of phase C winding serve as the start and end points. At this time, the entire high-voltage winding 10 can operate in a 69KV scenario.

[0061] See Figure 5 At this time, the dry-type transformer is in the second state, and the terminals A1 and A1' of the A-phase winding are connected, the terminals X1 and X1' of the B-phase winding are connected, the terminals B1 and B1' of the B-phase winding are connected, the terminals Y1 and Y1' of the C-phase winding are connected, the terminals C1 and C1' of the C-phase winding are connected, and the terminals Z1 and Z1' of the C-phase winding are connected. At this time, the entire high-voltage winding 10 can operate in a 34.5KV scenario.

[0062] See Figure 6At this time, the dry-type transformer is in the second state. Terminal A of the A-phase winding is connected to terminal A', terminal X is connected to terminal X', terminal B of the B-phase winding is connected to terminal B', terminal Y is connected to terminal Y', terminal C of the C-phase winding is connected to terminal C', and terminal Z is connected to terminal Z'. At this time, the entire high-voltage winding 10 can operate in a 36.5KV scenario.

[0063] Currently, during the casting process of existing epoxy resin cast dry-type transformers, micro-air gaps and resin-conductor separation defects are prone to occur on the inner and outer surfaces of the high-voltage winding 10 and at the interface of the air passage 13. This leads to a decrease in the partial discharge initiation voltage, especially at 69kV high voltage, where the partial discharge is prone to exceed the standard, seriously affecting the service life. At the same time, traditional conductor insulation is prone to inter-turn breakdown under lightning impulse overvoltage. Epoxy resin cast winding interface defects, conductor-epoxy interface, and air passage 13 interface are prone to residual bubbles / gaps, which in turn cause partial discharge to exceed the standard, seriously shortening the service life of dry-type transformers under marine high humidity salt spray and onshore sandstorm vibration conditions.

[0064] During their research, the inventors discovered that in the traditional structure of high-voltage winding conductors, an irregular interface forms between the conductor's insulation layer and the epoxy resin, such as... Figure 7 and Figure 8 As shown, irregular interfaces can lead to defects such as microcracks, air gaps, and bubble aggregation. Furthermore, under applied voltage, defects in high-field-strength regions can cause partial discharge, deteriorating the epoxy resin insulation and ultimately leading to insulation breakdown. This results in losses and increased high-voltage winding temperature during long-term transformer operation. Moreover, the thermal expansion coefficients of the bare conductor, insulation layer, and epoxy resin in the conductor structure differ significantly. These different expansion parameters under the same temperature rise exacerbate the expansion of defects at irregular interfaces, making it easier for epoxy resin to peel off from the conductor under voltage and thermal excitation, increasing partial discharge, accelerating insulation aging, and ultimately leading to insulation breakdown.

[0065] Therefore, in some embodiments of this application, the conductor of the high-voltage winding 10 includes, from the inside out, a bare conductor 30, an inner shielding layer, a main insulation layer, and an outer shielding layer, both of which are semiconductors. Each layer achieves interface-free molecular-level fusion through a multilayer co-extrusion process, and the interface characteristics between the inner shielding layer, the outer shielding layer, and the main insulation layer are effectively controlled through this process. This eliminates interlayer air gaps in traditional processes, and eliminating interface defects is equivalent to increasing the radius of curvature of the conductor, thereby reducing the electric field strength and the risk of partial discharge.

[0066] Specifically, the inner and outer shielding layers are made of modified polypropylene-based semiconductor materials with a volume resistivity of 10³~10⁻⁶. 5Ω·cm; The main insulation layer uses modified epoxy resin / nanocomposite insulation material, with added nano-silica, montmorillonite, and benzoyl voltage stabilizers. The multilayer co-extrusion process refers to the use of the same dielectric material as the main insulation layer for the base materials of the inner and outer shielding layers. This ensures full compatibility between the inner and outer shielding layers and the main insulation layer, forming a regular interface. This reduces interface defects, lowers the electric field strength, and decreases the risk of partial discharge.

[0067] In some other embodiments, such as Figure 9 and Figure 10 As shown, the conductors used to wind the high-voltage winding 10, from the inside out, include bare conductors 30, a semiconductor shielding layer 31, and an insulating layer 32. A main insulating material 33 is cast onto the outside of the insulating layer 32. The substrate material of the semiconductor shielding layer 31, the insulating layer 32, and the main insulating material 33 are all made of the same medium. In actual use, the conductors used to wind the high-voltage winding are first wrapped with a semi-conductive shielding layer, then with an insulating layer 32, and finally with the main insulating material 33. The substrate material of the semi-conductive shielding layer, the conductor insulating layer 32, and the main insulation are all made of the same medium. Irregular interfaces between the semi-conductive shielding layer and the conductor are shielded by the semi-conductive shielding layer, and the electric field strength within the semi-conductive shielding layer is close to zero. Even if defects are caused by irregular interfaces, partial discharge will not occur. Since the semi-conductive shielding layer, the conductor insulating layer 32, and the conductor insulating layer 32 are all made of the same medium, they are fully compatible, forming a regular interface, thereby significantly reducing interface defects.

[0068] Among these, the base materials of the inner and outer shielding layers are the same medium as the main insulation layer, and the base material of the semi-conductive shielding layer and the conductor insulation layer 32 are the same medium as the main insulation. This medium refers to silicone rubber. In practical applications, modified silicone rubber materials are widely used in high-voltage AC / DC insulators and high-voltage cable accessories. Silicone rubber has excellent electrical insulation properties, good mechanical elasticity, and good high and low temperature performance. It also has a certain self-recovery ability in insulation. Moreover, this material has good processing and molding characteristics, making it suitable for extrusion molding design of high-voltage winding conductors. Furthermore, by doping silicone rubber with conductive or semi-conductive materials, it can be modified into a semi-conductive material, which can be used as a shielding layer material for conductors.

[0069] In some other embodiments, the high-voltage winding 10 conductor can also be made of multi-layer composite insulation co-extrusion. The high-voltage winding 10 includes, from the inside out, bare conductor 30, polyimide layer, aromatic polyamide fiber paper layer and glass fiber layer. The polyimide layer is a polyimide film layer. The high-voltage winding 10 is vacuum impregnated and then epoxy resin cast, so that the entire dry-type transformer can withstand lightning impulse voltage ≥350kV.

[0070] Furthermore, the radius of the rounded corner of the bare conductor 30 is increased to R≥6mm, thereby eliminating the electric field distortion caused by the sharp edge of the conductor. Combined with the aforementioned shielding and insulation structure, the insulation stability of the dry-type transformer is further improved. Even in the complex and ever-changing operating environment of wind power scenarios, the equipment can be guaranteed to operate stably for a long time, which is suitable for the stringent requirements of wind power equipment on transformer reliability.

[0071] The aforementioned transformer, through optimized design for uniform field strength across the entire winding, combined with series-parallel switching scenarios and a 69kV high voltage level, achieves comprehensive optimization of the end electric field. The upper and lower ends of the high-voltage winding 10, the corners of the air duct 13, and the edges of the conductors are all covered with large-curvature rounded-corner insulation with a curvature radius ≥6mm, integrally molded using flexible epoxy insulation material. This eliminates electric field concentration at the sharp points. Electromagnetic field simulation is used to optimize the axial / radial dimensions of the winding, ensuring that the maximum field strength inside the winding is controlled below 3.0kV / mm, far below the epoxy breakdown field strength.

[0072] In some embodiments, the dry-type transformer is equipped with an ultra-high frequency partial discharge sensor, a fiber optic temperature sensor, and a vibration sensor to achieve online monitoring of the insulation status. The ultra-high frequency partial discharge sensor is a sensing device used to monitor the partial discharge signal of the dry-type transformer. It can sensitively capture the ultra-high frequency discharge signal generated by local defects inside the insulation, effectively filter out background interference in the field operating environment, and accurately identify weak partial discharge anomalies. In conjunction with the fiber optic temperature sensor to collect temperature data at different locations of the high-voltage winding 10 and the low-voltage winding 11 in real time, and the vibration sensor to capture the vibration state changes during transformer operation, the three types of sensors work together to comprehensively and in real time grasp the insulation status and operational health level inside the transformer. This helps maintenance personnel to discover potential insulation fault hazards in advance, perform timely maintenance, and avoid the fault from escalating and affecting the stable operation of wind power equipment.

[0073] Furthermore, the dry-type transformer is also equipped with multiple air ducts 13 that run through the high-voltage winding 10 along its own axis. The air ducts 13 improve the heat dissipation of the high-voltage winding 10, reduce the temperature rise during winding operation, reduce the impact of temperature changes on the performance of insulation materials, slow down the aging of insulation, improve the reliability of the dry-type transformer under long-term high-load operation in wind power scenarios, adapt to the working conditions of large load fluctuations during wind power grid connection, ensure that the dry-type transformer can stably supply power to all systems of the wind turbine, and support the continuous and stable output of power by wind power equipment.

[0074] This application also provides a wind power device, which includes the dry-type transformer as described above. Since the wind power device includes all the technical features of the dry-type transformer, it possesses all the technical effects of the dry-type transformer, which will not be repeated here.

[0075] The above-mentioned dry-type transformers have at least the following advantages:

[0076] 1. Voltage Adaptive: The above-mentioned dry-type transformer can cover both 34.5kV onshore and 69kV offshore scenarios, reducing the number of spare parts and costs for OEMs.

[0077] 2. Interface defect suppression: By setting a semiconductor shielding layer 31 to eliminate the concentration of the interface air gap electric field, combined with surface treatment and process optimization, the partial discharge extinction voltage of the inner and outer surfaces of the high voltage winding 10 and the wall of the air passage 13 is increased by more than 50%, and the partial discharge is ≤10pC at 69kV.

[0078] 3. Improved insulation reliability: Through the multi-layer composite insulated wire and the large rounded corner design of the wire, the inter-turn withstand voltage level is increased by more than 2 times, enabling the high voltage winding 10 to withstand vibration, temperature cycling and operating overvoltage in the nacelle.

[0079] 4. Strong environmental adaptability: Fully sealed dry structure, no risk of oil leakage, meeting the requirements for fire prevention, explosion protection and maintenance-free operation in the engine room.

[0080] 5. The aforementioned transformer can serve as the core equipment of the towed test platform, realistically simulating the electrical characteristics, temperature rise characteristics, and insulation aging characteristics of the transformer inside the wind turbine nacelle. It is designed to be compatible with the towed test platform, with pre-reserved test-specific interface modules at the transformer ends, including high-voltage and low-voltage input terminals, and multi-parameter acquisition interfaces for temperature, vibration, partial discharge, current, and voltage. These can be directly plugged into the towed test platform. In test mode, the series and parallel connection states of the aforementioned dry-type transformer can be flexibly switched to simulate full-condition testing, such as low-wind-speed / high-load onshore and high-wind-speed / low-load offshore conditions. The application value of the towed test platform lies in achieving consistency between the towed test platform and on-site operating conditions, shortening the development cycle of the nacelle power system, and reducing testing costs. Combined with the load simulator of the test platform, it can reproduce the dynamic load curve of the actual nacelle operation, accurately test the transformer's temperature rise characteristics, insulation aging patterns, and vibration coupling response, providing real data support for the matching development of the nacelle power system, with test data errors ≤3%.

[0081] 6. The dry-type transformer's built-in online monitoring system can collect characteristic parameters such as partial discharge and temperature in real time, providing data support for the matching and optimization of the wind turbine nacelle's power system. It features intelligent operation and maintenance integration, ensuring worry-free operation throughout the entire life cycle: It has a built-in multi-parameter monitoring and wireless communication module to realize remote real-time monitoring and fault early warning. In offshore scenarios, no manual operation is required, reducing operation and maintenance costs by 70% and improving operational reliability by 90%, adapting to the needs of wind power's entire life cycle management.

[0082] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0083] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A dry-type transformer, characterized by, The dry-type transformer includes: The high-voltage winding (10) includes an A-phase winding, a B-phase winding and a C-phase winding. The A-phase winding includes a first upper section winding (20) and a first lower section winding (21) with equal number of turns. The B-phase winding includes a second upper section winding (22) and a second lower section winding (23) with equal number of turns. The C-phase winding includes a third upper section winding (24) and a third lower section winding (25) with equal number of turns. The dry-type transformer can be switched between a first state and a second state in a controlled manner. When the dry-type transformer is in the first state, the first upper winding (20) and the first lower winding (21) are connected in series, the second upper winding (22) and the second lower winding (23) are connected in series, and the third upper winding (24) and the third lower winding (25) are connected in series. When the dry-type transformer is in the second state, the first upper winding (20) and the first lower winding (21) are connected in parallel, the second upper winding (22) and the second lower winding (23) are connected in parallel, and the third upper winding (24) and the third lower winding (25) are connected in parallel.

2. The dry-type transformer according to claim 1, characterized in that, The first upper winding (20) includes terminal A, terminal A1, terminal X1 and terminal X. Terminal A is located at the top of the first upper winding (20), terminal X is located at the bottom of the first upper winding (20), terminal A1 and terminal X1 are located between terminal A and terminal X, and the number of turns between terminal A1 and terminal A accounts for 3% of the number of turns between terminal A1 and terminal X1, and the number of turns between terminal X1 and terminal X accounts for 3% of the number of turns between terminal A1 and terminal X1. The second upper winding (22) includes terminal B, terminal B1, terminal Y1 and terminal Y. Terminal B is located at the top of the second upper winding (22), terminal Y is located at the bottom of the second upper winding (22), terminal B1 and terminal Y1 are located between terminal B and terminal Y, and the number of turns between terminal B1 and terminal B accounts for 3% of the number of turns between terminal B1 and terminal Y1, and the number of turns between terminal Y1 and terminal Y accounts for 3% of the number of turns between terminal B1 and terminal Y1. The third upper winding (24) includes terminal C, terminal C1, terminal Z1 and terminal Z. Terminal C is located at the top of the third upper winding (24), terminal Z is located at the bottom of the third upper winding (24), terminal C1 and terminal Z1 are located between terminal C and terminal Z, and the number of turns between terminal C1 and terminal C accounts for 3% of the number of turns between terminal C1 and terminal Z1, and the number of turns between terminal Z1 and terminal Z accounts for 3% of the number of turns between terminal C1 and terminal Z1.

3. The dry-type transformer according to claim 1, characterized in that, The first lower winding (21) includes terminal A', terminal A1', terminal X1' and terminal X'. Terminal A is located at the top of the first lower winding (21), terminal X' is located at the bottom of the first lower winding (21), terminal A1' and terminal X1' are located between terminal A' and terminal X', and the number of turns between terminal A1' and terminal A' accounts for 3% of the number of turns between terminal A1' and terminal X1', and the number of turns between terminal X1' and terminal X' accounts for 3% of the number of turns between terminal A1' and terminal X1'. The second lower winding (23) includes terminal B', terminal B1', terminal Y1' and terminal Y'. Terminal B' is located at the top of the second lower winding (23), terminal Y' is located at the bottom of the second lower winding (23), terminal B1' and terminal Y1' are located between terminal B' and terminal Y', and the number of turns between terminal B1' and terminal B' accounts for 3% of the number of turns between terminal B1' and terminal Y1', and the number of turns between terminal Y1' and terminal Y' accounts for 3% of the number of turns between terminal B1' and terminal Y1'. The third lower winding (25) includes terminal C', terminal C1', terminal Z1' and terminal Z'. Terminal C' is located at the top of the third lower winding (25), terminal Z' is located at the bottom of the third lower winding (25), terminal C1' and terminal Z1' are located between terminal C' and terminal Z', and the number of turns between terminal C1' and terminal C' accounts for 3% of the number of turns between terminal C1' and terminal Z1', and the number of turns between terminal Z1' and terminal Z' accounts for 3% of the number of turns between terminal C1' and terminal Z1'.

4. The dry-type transformer according to claim 1, characterized in that, The wires used to wind the high-voltage winding (10) include, from the inside out, bare wires (30), an inner shielding layer, a main insulation layer, and an outer shielding layer, both of which are semiconductors.

5. The dry-type transformer according to claim 4, characterized in that, Both the inner and outer shielding layers are polypropylene films.

6. The dry-type transformer according to claim 1, characterized in that, The wires that wind the high voltage winding (10) include, from the inside out, bare wires (30), semiconductor shielding layer (31), and insulation layer (32). The insulation layer (32) is coated with a main insulation material (33). The substrate material of the semiconductor shielding layer (31), the insulation layer (32), and the main insulation material (33) are the same medium.

7. The dry-type transformer according to claim 1, characterized in that, The conductors used to wind the high-voltage winding (10) consist of bare conductors (30), a polyimide layer, an aromatic polyamide fiber paper layer, and a glass fiber layer from the inside out.

8. The dry-type transformer according to claim 7, characterized in that, The fillet radius of the bare conductor (30) is greater than r > 6 mm.

9. The dry-type transformer according to claim 1, characterized in that, The dry-type transformer is equipped with an ultra-high frequency partial discharge sensor. And / or the dry-type transformer is equipped with an optical fiber temperature sensor; And / or, a vibration sensor is installed inside the dry-type transformer.

10. A wind power device, characterized in that, Including the dry-type transformer as described in any one of claims 1-9.

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