Transformer system and wind turbine generator system

Abstract

The application provides a transformer system and a wind turbine generator set. The transformer system comprises a transformer and a cooling system. The transformer comprises a shell, a core arranged in the shell, and a coil wound on the core. The shell can be filled with a first cooling medium. The first cooling medium is a phase change cooling medium. The cooling system is used to condense the phase change cooling medium evaporated in the shell into liquid and then return to the shell, forming a closed loop circulation of the phase change cooling medium, realizing effective cooling circulation, improving the cooling performance of the transformer system, and maintaining the continuous and reliable operation of the transformer system.

Description

Technical Field

[0001] This utility model relates to the field of wind power generation, specifically to a transformer system and a wind turbine generator set. Background Technology

[0002] Transformers are core equipment in power systems, responsible for voltage transformation, power distribution, and transmission. During operation, they generate significant heat due to winding resistance losses and core eddy current losses, causing the equipment temperature to rise. If this heat cannot be dissipated promptly, it accelerates the aging of insulation materials, reduces insulation performance, and can even lead to equipment failure, severely impacting the safe and stable operation of the power grid. Therefore, the transformer's cooling system is crucial for its reliable operation.

[0003] Currently, common transformer cooling methods mainly include oil-immersed self-cooling, oil-immersed air cooling, and forced oil circulation cooling. In these traditional solutions, mineral oil or silicone oil is often used as the cooling medium. Heat generated by the transformer windings and core is carried away by convection, and then dissipated into the environment through heat sinks or air / water-cooled heat exchangers. However, the specific heat capacity and thermal conductivity of the cooling medium in these methods are limited. Relying on convection for heat dissipation results in low heat exchange efficiency and slow response speed. Their cooling efficiency is increasingly unable to meet the heat dissipation requirements of modern high-power-density transformers. Furthermore, to ensure effective heat dissipation, a large amount of oil needs to be injected, leading to a large transformer size and weight, difficulty in hoisting, and making it difficult to install transformers in the nacelle of wind turbine generators under site constraints. Utility Model Content

[0004] In order to solve the above-mentioned problems in the prior art, the purpose of this utility model is to provide a transformer system and a wind turbine generator set.

[0005] A first aspect of this utility model provides a transformer system, which includes a transformer and a cooling system. The transformer includes a housing, an iron core disposed in the housing, and a coil wound on the iron core. A first cooling medium, which is a phase change cooling medium, can be injected into the housing. The cooling system is used to condense the phase change cooling medium that has evaporated in the housing into a liquid and then return it to the housing.

[0006] According to one aspect of the embodiments of this application, the transformer system further includes a conductivity sensor disposed in the housing for detecting the conductivity of the first cooling medium.

[0007] According to one aspect of the embodiments of this application, the transformer system further includes a controller configured to receive a detection signal from a conductivity sensor and output prompt information regarding the operating status of a first cooling medium based on the detection signal.

[0008] According to one aspect of the embodiments of this application, the cooling system includes a condenser, a radiator, and a first pipe and a second pipe connected between the condenser and the radiator. A second cooling medium is capable of circulating in the cooling system. The first pipe is used to deliver the second cooling medium, after being cooled by the radiator, to the condenser. The second pipe is used to deliver the second cooling medium, after being heated in the condenser, to the radiator.

[0009] According to one aspect of the embodiments of this application, the condenser is disposed in the housing and located above the iron core, so that the phase change cooling medium, after evaporation, can be condensed into liquid by the condenser and drip downwards.

[0010] According to one aspect of the embodiments of this application, the projected area of ​​the condenser on the iron core covers at least 80% of the cross-sectional area of ​​the iron core.

[0011] According to one aspect of the embodiments of this application, the housing includes a bottom wall and a top wall disposed opposite to each other, and a side wall connecting the bottom wall and the top wall. At least a portion of the inner surface of the side wall is adapted to the outer contour of the coil and has a predetermined interval with the outer contour of the coil. The iron core includes three iron core units, and the coil includes three coil units respectively wound on the three iron core units. The side wall of the housing includes a plurality of outwardly convex arcuate portions corresponding to the outer peripheral surfaces of the respective coil units.

[0012] According to one aspect of the embodiments of this application, the transformer system further includes a level gauge and a heater disposed in the housing, the level gauge being used to detect the level height of a first cooling medium, the heater being used to heat the first cooling medium, and the controller being configured to control the operation of the heater based on the detection result of the level gauge.

[0013] According to one aspect of the embodiments of this application, the condenser is disposed on the outside of the housing and is connected to the inside of the housing through a pipeline, so that the phase change cooling medium can be condensed into liquid by the condenser after evaporation and transported back to the housing.

[0014] According to one aspect of the embodiments of this application, the transformer system further includes a pressure regulating unit, which includes a breather valve disposed on the upper part of the condenser.

[0015] According to one aspect of the embodiments of this application, the transformer system further includes a pressure regulating unit, which includes a storage tank, a breather valve disposed on the storage tank, and a pressure sensor. The storage tank is filled with gas and communicates with the interior of the housing through a connecting pipe.

[0016] According to one aspect of the embodiments of this application, a diaphragm is provided inside the storage tank, which divides the interior of the storage tank into a first chamber and a second chamber. A breather valve is installed on the first chamber, and a connecting pipe connects the second chamber to the interior of the shell.

[0017] According to one aspect of the embodiments of this application, the transformer system further includes a pressure regulating unit, which is in communication with the interior of the housing and is used to regulate the pressure inside the housing. The pressure regulating unit includes a breather valve, which is disposed on the upper part of the housing.

[0018] According to one aspect of the embodiments of this application, the transformer system further includes a pressure regulating unit, which is connected to the interior of the housing and is used to regulate the pressure inside the housing. The pressure regulating unit includes a storage tank, a third connecting pipe, an exhaust pump, and an intake pump. The third connecting pipe connects the interior of the housing with the interior of the storage tank. The exhaust pump and the intake pump are arranged in parallel on the third connecting pipe. The exhaust pump is used to transport gas inside the housing to the storage tank, and the intake pump is used to transport gas in the storage tank to the housing.

[0019] According to one aspect of the embodiments of this application, the pressure regulating unit further includes a fourth connecting pipe, an inlet pump, and a drain pump. The fourth connecting pipe connects the bottom of the storage tank to the lower part of the shell. The inlet pump and the drain pump are arranged in parallel on the fourth connecting pipe. The storage tank can also store a first cooling medium. The inlet pump is used to transport the liquid in the storage tank to the shell, and the drain pump is used to transport the liquid in the shell to the storage tank.

[0020] Another embodiment of the present invention provides a wind turbine generator set, which includes the above-described transformer system.

[0021] According to the embodiments of this application, a transformer system and a wind turbine generator set are provided. By adopting a phase change cooling medium and a cooling system, the phase change cooling medium can efficiently absorb the latent heat generated by the transformer during operation by utilizing the evaporative heat absorption characteristics of the phase change cooling medium. The phase change cooling medium is converted into gas, condensed by the cooling system, and flows back into the transformer shell, forming a closed-loop circulation of the phase change cooling medium. This achieves an effective cooling cycle, which not only improves the cooling performance of the transformer system and reduces its volume, but also avoids the reduction in cooling performance and the risk of transformer operation due to poor cooling circulation, thereby maintaining the continuous and reliable operation of the transformer system. Attached Figure Description

[0022] The above and other objects and features of this utility model will become clearer from the following description of embodiments in conjunction with the accompanying drawings, in which: Figure 1 A schematic diagram of the transformer system according to the first embodiment of this application is shown; Figure 2 A front view of an example transformer according to an embodiment of this application is shown; Figure 3 A side view of an example transformer according to an embodiment of this application is shown. Figure 4 A top view of an example transformer according to the first embodiment of this application is shown. Figure 5 A schematic diagram of the pressure control unit of the transformer system according to an embodiment of this application is shown; Figure 6 A schematic diagram of the pressure and liquid level control unit of the transformer system according to an embodiment of this application is shown; Figure 7 This is a schematic diagram of the structure of a transformer system according to the second embodiment of this application; Figure 8 This is a front view schematic diagram of another example of a transformer according to an embodiment of this application; Figure 9 This is a front view structural schematic diagram of another example of a transformer according to an embodiment of this application.

[0023] Explanation of reference numerals in the attached figures: 100. Transformer; 101. Shell; 1011. Bottom wall; 1012. Top wall; 1013. Side wall; 102. Coil; 103. Iron core; 201. Conductivity sensor; 202. Condenser; 203. Radiator; 204. Storage tank; 205. Pressure sensor; 206. Breather valve; 207. First filter; 208. Safety valve; 209. Level gauge; 210. Heater; 211. Pressure regulating unit; 212. Diaphragm; 301. First pipeline; 302. First temperature sensor; 303. First pressure sensor; 304. Second filter; 305. Exhaust valve; 306. Second pipeline; 307. Second temperature sensor; 308. Second pressure sensor; 309. Pressure regulating device; 310. Pump; 311. Pressure gauge; 312. Connecting pipe; 401. Third connecting pipe; 402. Exhaust pump; 403. Intake pump; 404. First valve; 501. Fourth connecting pipeline; 502. Drain pump; 503. Inlet pump; 504. Second valve; 600, Cabin. Detailed Implementation

[0024] The following detailed embodiments are provided to aid the reader in gaining a comprehensive understanding of the methods, apparatus, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatus, and / or systems described herein will become apparent upon understanding this disclosure. For example, the order of operations described herein is merely illustrative and is not limited to those orders set forth herein, but may be changed as will become clear upon understanding this disclosure, except for operations that must occur in a specific order. Furthermore, for clarity and conciseness, descriptions of features known in the art may be omitted.

[0025] The features described herein may be implemented in different forms and should not be construed as limited to the examples described herein. Rather, the examples described herein are provided only to illustrate some of the many feasible ways of implementing the methods, apparatus, and / or systems described herein, which will become clear upon understanding the disclosure of this application.

[0026] As used herein, the term “and / or” includes any one of the associated listed items and any combination of any two or more.

[0027] Although terms such as “first,” “second,” and “third” may be used herein to describe various components, assemblies, regions, layers, or parts, these components, assemblies, regions, layers, or parts should not be limited by these terms. Rather, these terms are used only to distinguish one component, assembly, region, layer, or part from another. Thus, without departing from the teaching of the examples described herein, the first component, first assembly, first region, first layer, or first part referred to as the first component, first assembly, first region, first layer, or first part may also be referred to as the second component, second assembly, second region, second layer, or second part.

[0028] In the specification, when an element such as a layer, region, or substrate is described as being "on" another element, "connected to," or "bonded to" another element, the element may be directly "on" another element, directly "connected to," or "bonded to" the other element, or one or more other elements may be present in between. Conversely, when an element is described as being "directly on" another element, "directly connected to," or "directly bonded to" another element, no other elements may be present in between.

[0029] The terminology used herein is for the purpose of describing various examples only and is not intended to limit disclosure. Unless the context clearly indicates otherwise, the singular form is intended to include the plural form as well. The terms “comprising,” “including,” and “having” indicate the presence of the described features, quantities, operations, components, elements, and / or combinations thereof, but do not preclude the presence or addition of one or more other features, quantities, operations, components, elements, and / or combinations thereof. The term “a plurality” represents any quantity of two or more.

[0030] The directional terms “above,” “below,” “top,” and “bottom” used in this application, unless otherwise specified, are based on the orientation of the product when it is in normal use.

[0031] Unless otherwise defined, all terms used herein, including technical and scientific terms, shall have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains after understanding the invention. Unless expressly defined herein, terms such as those defined in a general dictionary shall be interpreted as having a meaning consistent with their meaning in the context of the relevant field and in this invention, and shall not be interpreted in an idealized or overly formalistic manner.

[0032] In order to improve the cooling efficiency of the transformer system and ensure the stable and reliable operation of the transformer system while reducing the size of the transformer 100, an embodiment of the present application provides a transformer system. Figure 1 A schematic diagram of the structure of a transformer system according to the first embodiment of this application is shown. Figure 2 , Figure 3 and Figure 4 The diagram shows a structural schematic of an example transformer. Figure 5 A schematic diagram of the pressure control unit of the transformer system is shown. Figure 6 A schematic diagram of the pressure and liquid level control unit of a transformer system is shown. The following will be combined with... Figures 1 to 6 This invention introduces a transformer system provided by an embodiment of the present invention.

[0033] like Figure 1 As shown, the transformer system includes a transformer 100 and a cooling system, which is used to cool the transformer 100.

[0034] like Figures 1 to 2As shown, the transformer 100 includes a housing 101, an iron core 103, and a coil 102. The housing 101 has an internal cavity, within which the iron core 103 and the coil 102 wound around the iron core 103 are located. To reduce the weight and volume of the transformer 100 and improve its heat dissipation efficiency, the transformer system according to an embodiment of this application employs a phase-change cooling method. A phase-change cooling medium (hereinafter referred to as the first cooling medium) is injected into the housing 101, immersing the heat-generating elements such as the iron core 103 and the coil 102 in the liquid. During operation, the iron core 103 and the coil 102, as the main heat sources of the transformer 100, generate a large amount of heat. The first cooling medium contacts the iron core 103 and the coil 102, absorbs heat, boils and evaporates into a gas, and is transported to the cooling system. The cooling system condenses the gaseous first cooling medium into a liquid, which then flows back into the housing 101 for the next cooling cycle, forming a highly efficient closed-loop circulation circuit.

[0035] Existing oil-immersed transformers primarily use mineral oil to immerse the heating components, and the heat is carried away through the circulation of the oil. This method mainly relies on sensible heat absorption. Since the heat absorbed by sensible heat is much less than the heat absorbed by the latent heat of vaporization, the amount of medium circulation required for phase change cooling is much less than that for oil immersion cooling, while removing the same amount of heat. Therefore, this application adopts two-phase boiling heat transfer of phase change coolant, utilizing the latent heat absorbed during liquid vaporization. This not only significantly improves the cooling efficiency of transformer 100 but also greatly reduces the amount of liquid required for cooling medium, thereby significantly reducing the size and weight of transformer 100 and simplifying installation and maintenance.

[0036] According to embodiments of this application, the first cooling medium can be an insulating cooling medium with a low boiling point at atmospheric pressure. For example, the first cooling medium can be a fluorinated liquid, a low-boiling-point hydrocarbon, or an ether. Fluorinated liquids have a high latent heat of vaporization, enabling them to efficiently absorb heat and improve cooling performance. Furthermore, fluorinated liquids possess extremely high chemical and thermal stability, are not easily flammable or explosive, and do not readily react with other materials within the transformer 100, thus maintaining the stable and safe operation of the transformer system. Therefore, preferably, a fluorinated liquid is used as the phase change cooling medium. As an example, a fluorinated liquid with a boiling point of 45°C-80°C at atmospheric pressure can be selected, but it is not limited to this. Types of fluorinated liquids include fluorinated ketones, fluoronitriles, perfluorocarbons, and perfluoropolyethers, and a suitable type can be selected according to actual application requirements.

[0037] According to embodiments of this application, such as Figure 1 and Figure 2 As shown, the cooling system includes a condenser 202 for condensing the first cooling medium, which evaporates into a gas, into a liquid. The condenser 202 can be located outside or inside the transformer 100. (See attached diagram.) Figures 1 to 6 In the first embodiment shown, the condenser 202 is disposed inside the housing 101 of the transformer 100 and located above the core 103 and the coil 102. Additionally, the transformer typically includes electrical components such as high-voltage bushings and low-voltage bushings. The positions of these electrical components can be adjusted depending on the configuration of the condenser; for example, they can be disposed on the top or side of the transformer housing.

[0038] During the operation of the transformer system, the first cooling medium absorbs heat from the iron core 103 and coil 102, evaporates into gas, and due to its low density, rises naturally to the condenser 202 under the pressure difference caused by the density difference. The evaporated gas can directly contact the low-temperature surface of the condenser 202 with the shortest path and least flow resistance. After condensation in the condenser 202, it becomes liquid, and the resulting droplets fall back onto the coil 102 and iron core 103 below by gravity, completing one cooling cycle. By shortening the circulation path of the first cooling medium, the operating efficiency of the cooling system is improved. Compared with a structure where the condenser 202 is located outside the transformer 100, the pipes used for circulating the first cooling medium can be eliminated, simplifying the system structure, reducing manufacturing costs, and reducing seals and leakage points. In addition, utilizing the natural dripping of droplets by gravity eliminates the need for delivery pipelines and drive pumps, simplifying the equipment structure and reducing manufacturing costs.

[0039] During the operation of transformer 100, the heat dissipated by core 103 is less than that of coil 102. Therefore, the first cooling medium does not need to completely submerge core 103. Instead, the cooling effect of core 103 is ensured by the droplets dripping from condenser 202, thereby reducing the amount of coolant used and lowering manufacturing costs. To ensure the cooling effect of core 103, the projected area of ​​condenser 202 on core 103 covers at least 80% of the cross-sectional area of ​​core 103, ensuring that most of the area of ​​core 103 can receive the dripping droplets, rather than being completely exposed to the gas phase. With the liquid cooling medium condensed by condenser 202 continuously dripping onto core 103, the portion of core 103 not directly submerged by the liquid first cooling medium is simultaneously enveloped by both the gaseous cooling medium and the liquid cooling medium dripping from condenser 202, thus ensuring insulation performance.

[0040] In addition, the condenser 202 can also be installed on the inner top wall 1012 of the transformer 100 housing 101 by means of mounting brackets, etc., which makes full use of the gas phase space in the upper part of the transformer 100 housing 101, reduces the volume of the transformer system, and makes the equipment more compact.

[0041] According to the first embodiment of this application, as Figure 1As shown, the cooling system also includes an external cooling circulation loop located outside the transformer 100. This loop removes heat from the condenser 202 via a second cooling medium, causing the gaseous first cooling medium to condense into a liquid. The external cooling circulation loop includes a radiator 203 and a first pipe 301 and a second pipe 306 located between the condenser 202 and the radiator 203. This transfers the heat absorbed by the condenser 202 to the external environment, allowing the condenser 202 to maintain a consistently low temperature. The second cooling medium fills the radiator 203, the condenser 202, and the first and second pipes 301 and 306, circulating continuously to absorb heat from the condenser 202 and transfer it to the external environment. The cooling circulation of the second cooling medium, combined with the cooling circulation of the first cooling medium, forms a closed loop for thermal management.

[0042] To improve the efficiency of the external cooling cycle, the second cooling medium can be a liquid cooling medium. For example, the second cooling medium can be an ethylene glycol-water solution, deionized water, or a propylene glycol-water solution. Because ethylene glycol solution has low cost, high specific heat capacity, and low freezing point, it has good heat exchange performance and antifreeze properties. Therefore, ethylene glycol-water solution is preferably used as the second cooling medium.

[0043] Furthermore, the external cooling circulation loop also includes a first temperature sensor 302, a first pressure sensor 303, a second filter 304, and an exhaust valve 305 installed on the first pipe 301; a second temperature sensor 307, a second pressure sensor 308, a pressure regulating device 309, a pump 310, and a pressure gauge 311 installed on the second pipe 306. The first temperature sensor 302, the first pressure sensor 303, the second temperature sensor 307, and the second pressure sensor 308 are used to detect the temperature and pressure information at the inlet and outlet in real time. The second filter 304 can filter impurities generated in the pipe. The exhaust valve 305 is used to expel gas from the pipe. The pressure regulating device 309 (e.g., an expansion tank or a high-level water tank) is used to stabilize the pressure in the pipe. The pump 310 provides power for the flow of the second cooling medium in the pipe. The pressure gauge 311 is used to detect the total pressure in the pipe. The radiator 203 can use either air cooling or liquid cooling to cool the second cooling medium. When the radiator 203 is air-cooled, the external cooling circulation system may also include a fan for forced cooling of the radiator 203.

[0044] During the operation of the external cooling circulation loop, temperature and pressure sensors detect temperature and pressure information at the inlet and outlet, respectively, and transmit this information to the controller. The controller calculates the temperature and pressure differences and controls the pump 310 and fan to operate at variable frequency, achieving on-demand cooling. Furthermore, the pressure gauge 311, pressure regulating device 309, and exhaust valve 305 work together to eliminate pressure fluctuations and pressure build-up within the pipeline. The second filter 304 removes impurities from the pipeline, collectively ensuring the stable and reliable operation of the second cooling medium circulation loop. These components form a closed-loop loop for the second cooling medium, providing continuous, stable, and controllable cooling performance for the condenser 202 inside the housing 101, thereby ensuring the efficient and stable cooling circulation of the first cooling medium in the transformer system.

[0045] According to embodiments of this application, such as Figure 2 and Figure 3 As shown, the housing 101 includes a bottom wall 1011 and a top wall 1012 disposed opposite to each other, and a side wall 1013 connecting the bottom wall 1011 and the top wall 1012. The inner surface of the side wall 1013 is adapted to the outer contour of the coil 102 disposed inside the housing 101, and a preset interval distance is maintained between them. By adapting the side wall 1013 of the housing 101 to the outer contour of the coil 102, the overall gap between the side wall 1013 and the coil 102 is reduced, thereby reducing the volume of the transformer 100, and thus reducing the total weight and amount of cooling medium. While achieving miniaturization and lightweight design, it can also reduce the amount of coolant used and the material of the housing 101, thereby reducing manufacturing costs. In addition, by setting the preset interval distance, a smooth and uniform flow channel can be provided for the evaporation, rising and reflux of cooling medium and condensate droplets, avoiding the formation of flow dead zones, which would affect the uniform distribution and circulation efficiency of the cooling medium, and improve the overall operational stability of the cooling system.

[0046] According to an embodiment of this application, at least a portion of the inner surface of the sidewall 1013 of the housing 101 substantially conforms to the outer contour of the coil 102. For example... Figure 4As shown, the inner surface of the side wall 1013 of the housing 101 maintains a basically the same shape as the outer contour of the coil 102. Circumferentially, the shape of the inner surface of the side wall 1013 of the housing 101 varies with the overall shape of the outer contour of the coil 102. For example, the distance between the inner surface of the side wall 1013 of the housing 101 and the outer arc surface of the coil 102 is 50mm-100mm, but is not limited to this. This distance ensures efficient heat exchange between the coil 102 and the housing 101 without causing installation difficulties or the risk of localized overheating due to excessively small gaps. The distance between the inner surface of the side wall 1013 of the housing 101 and the outer contour of the coil 102 can be adjusted according to the manufacturing process, strength requirements, and heat dissipation needs of the housing 101.

[0047] According to the transformer of the present application embodiment, the coil 102 is wound on the iron core 103, and its outer contour is generally circular or elliptical. Therefore, the side wall 1013 of the housing has an outwardly convex arcuate portion that is adapted to the outer contour of the coil 102.

[0048] According to embodiments of this application, such as Figure 4 As shown, transformer 100 is a three-phase transformer. The core 103 includes three core units arranged in parallel along the height of the housing 101. The coil 102 includes three coil units wound around the three core units, forming three cylinders with circular or elliptical cross-sections. Correspondingly, the housing 101 has three interconnected and communicative cylindrical housing portions. Circumferentially, the distance between the inner surface of the sidewall 1013 and the outer contour of the three coil units remains consistent. Figure 4 As shown in the top view, the sidewall 1013 of the housing 101 includes three interconnected circular or elliptical housing segments.

[0049] Furthermore, without affecting the circulation path of the first cooling medium, insulating components (e.g., insulating particles) can be filled into the first cooling medium to occupy part of the volume of the first cooling medium, thereby reducing the amount of the first cooling medium used and thus reducing the operating cost of the transformer system.

[0050] According to an embodiment of this application, the transformer system further includes a conductivity sensor 201 disposed in the housing 101 and located in the first cooling medium, for detecting the conductivity of the first cooling medium. The transformer system also includes a controller configured to receive a detection signal from the conductivity sensor 201 and output prompt information regarding the operating status of the first cooling medium based on the detection signal.

[0051] As an example, the conductivity sensor 201 is an electrode-type sensor or an inductive sensor, installed in the liquid phase region of the housing sidewall 1013 to ensure accurate measurement of the conductivity of the liquid cooling medium. Multiple conductivity sensors 201 can be configured and disposed in multiple regions of the housing 101 to detect the conductivity of different regions respectively.

[0052] Under normal circumstances, the primary cooling medium is a poor conductor of electricity in its pure state, with very low conductivity. When the primary cooling medium ages, becomes damp, or becomes contaminated, it introduces or generates a large number of conductive ions (such as acidic substances, metal particles, and H+ ions from the decomposition of water). and OH (Ions, etc.). These ions move directionally under the influence of an electric field, thereby forming an electric current. According to an embodiment of this application, the conductivity sensor 201 can measure the conductivity of a liquid by measuring the current or resistance of the first cooling medium under a specific electric field, and indirectly calculate the conductivity. The conductivity value can reflect the total concentration of conductive ion contaminants in the first cooling medium, thereby reflecting the operating state of the first cooling medium.

[0053] Furthermore, during the long-term operation of transformer 100, sealing failure may occur due to aging of the sealing material, allowing external moisture to penetrate the transformer 100, or condenser liquid leakage may cause the second cooling medium to enter the transformer 100, resulting in a decrease in the insulation strength of the first cooling medium and further accelerating its aging. According to the embodiments of this application, by detecting changes in conductivity, signals of transformer 100 sealing failure, condenser leakage, or internal moisture can be detected in a timely manner, providing timely early warning information.

[0054] Therefore, according to the embodiments of this application, a conductivity sensor 201 is used to detect the conductivity of the first cooling medium, which reflects the operating state of the first cooling medium. The controller can output corresponding prompt information based on the detection value of the conductivity sensor 201.

[0055] During operation, the load on transformer 100 is dynamically changing. A sudden surge in load can cause a dramatic increase in heat, leading to rapid evaporation of the phase-change cooling medium, exceeding the condenser 202's condensation capacity. This insufficient condensation results in a continuous increase in internal pressure within the casing 101, posing a safety risk. Conversely, a sudden drop in load or shutdown can cause vapor condensation, leading to a partial vacuum within the casing 101. Furthermore, during transformer system operation, leakage of the cooling medium is unavoidable, resulting in insufficient internal pressure within the casing 101. To balance the internal and external pressures of transformer 100 and control pressure fluctuations within the system, it is preferable to maintain the internal pressure of casing 101 at approximately one atmosphere, thereby ensuring stable and reliable operation of the cooling system.

[0056] Therefore, in order to avoid sudden rises and falls in system pressure, according to the embodiments of this application, the transformer system further includes a pressure regulating unit 211, which is connected to the interior of the housing 101 and is used to regulate the pressure inside the housing 101 to maintain it within a predetermined range, thereby ensuring effective cooling circulation and improving the safety and reliability of the cooling system during operation.

[0057] like Figure 1 As shown, the pressure regulating unit 211 may include a breather valve 206, which is located at the top of the housing 101 and communicates with the interior of the housing 101. When the load on the transformer 100 increases or the ambient temperature rises, the internal liquid level rises, the amount of steam increases, and the gas at the top is compressed, causing the overall system pressure to rise and exceed the positive pressure opening pressure value set by the breather valve 206. The positive pressure valve inside the breather valve 206 is opened under the action of the pressure difference, and the excess gas inside is discharged to the outside atmosphere of the transformer 100 through the opened valve passage. As the gas is discharged, the internal pressure of the transformer 100 gradually decreases. When the internal pressure drops to the positive pressure closing pressure value of the breather valve 206, the valve closes and stops venting. When the load on the transformer 100 decreases or the ambient temperature decreases, the internal pressure of the transformer 100 decreases and falls below the negative pressure opening pressure value set by the breather valve 206. The negative pressure valve of the breather valve 206 then opens, drawing in gas. When the internal pressure rises back to the negative pressure closing pressure value of the breather valve 206, the valve closes.

[0058] Furthermore, in order to prevent the introduction of impurities (such as dust, gases that affect conductivity, or moisture) when the gas is drawn in from the outside, the transformer system also provides a first filter 207 at the air inlet of the breather valve 206 to ensure that the gas entering the housing 101 is dry, pure, and does not affect the conductivity of the cooling medium.

[0059] Although the solution using the breather valve 206 is simple in structure and low in cost, during the exhaust process, the transformer 100 directly discharges the gaseous cooling medium into the external environment, which will cause the loss of the first cooling medium and lead to environmental pollution. In addition, after the filter device has been working for a long time, its filtration function is prone to deterioration or failure, which can cause external impurities or water vapor to enter the transformer 100.

[0060] To prevent the gas inside the casing 101 from exchanging with external substances, such as Figure 5As shown in the embodiment of this application, the pressure regulating unit 211 includes a storage tank 204, a third connecting pipe 401, and a first valve 404 disposed on the third connecting pipe 401. The storage tank 204 may be pre-filled with a portion of a gaseous first cooling medium or other gas (e.g., nitrogen). The third connecting pipe 401 connects the interior of the housing 101 to the interior of the storage tank 204. The first valve 404 is used to control the gas connection or disconnection between the storage tank 204 and the interior of the housing 101.

[0061] When the internal pressure of the transformer housing 101 is within a safe range, the first valve 404 is closed. When the internal pressure of the transformer housing 101 exceeds the safe range, the first valve 404 opens, allowing the storage tank 204 to communicate with the inside of the housing 101. This allows the inside of the housing 101 to release air into the storage tank 204, or allows the storage tank 204 to pressurize the inside of the housing 101, thereby regulating the internal pressure of the transformer housing 101.

[0062] By connecting the interior of the housing 101 to the storage tank 204, a closed-loop circulation system is constructed, allowing the charging and discharging operations of the transformer 100 to be carried out in a relatively sealed environment. This not only prevents moisture or impurities from entering the transformer 100, but also prevents the direct emission of internal gases into the external environment. The insulating cooling medium is recycled, which is environmentally friendly and reduces operating costs. Furthermore, by setting up the storage tank 204, high-purity gaseous primary cooling medium can be replenished to the transformer 100, effectively maintaining a dry and oxygen-free environment inside the transformer 100, significantly improving the long-term reliability of the equipment.

[0063] However, when the transformer 100 is charged and vented by simply opening the first valve 404 and relying solely on the pressure difference between the storage tank 204 and the housing 101, the venting process requires the pressure inside the transformer 100 to be higher than the pressure inside the storage tank 204 for gas to flow naturally into the storage tank 204. If the storage tank 204 is already filled with gas and has a high pressure, the venting efficiency will be very low or even impossible. Furthermore, during the charging process, the pressure inside the storage tank 204 needs to be higher than the pressure inside the transformer 100 for gas to flow naturally into the transformer 100. If the pressure in the storage tank 204 is insufficient, the pressure inside the transformer 100 cannot be effectively replenished. Therefore, according to some embodiments of this application, the pressure regulating unit 211 also includes a pumping device disposed on the third connecting pipe 401. The pumping device may be an exhaust pump 402 and an intake pump 403, which are connected in parallel on the third connecting pipe 401. The exhaust pump 402 is used to transport the gas in the housing 101 to the storage tank 204, and the intake pump 403 is used to transport the gas in the storage tank 204 to the housing 101.

[0064] When the internal pressure of the transformer housing 101 is high, the first valve 404 and the exhaust pump 402 are opened, and the intake pump 403 is closed, so that the gas inside the housing 101 is transported to the storage tank 204; when the transformer 100 needs to be pressurized, the first valve 404 and the intake pump 403 are opened, and the exhaust pump 402 is closed, so that the gas in the storage tank 204 is transported to the inside of the housing 101.

[0065] By setting up an intake pump 403 and an exhaust pump 402, it can cope with more severe and frequent pressure fluctuations, and can also perform inflation and deflation operations normally under low pressure difference or negative pressure difference conditions. Therefore, it can achieve active, precise and rapid pressure control.

[0066] Since the liquid level of the first cooling medium also changes with the load of the transformer 100 and the external ambient temperature, if the liquid level is too low, it will be difficult to submerge the heating components; if the liquid level is too high, it may submerge the condenser 202 and affect the liquefaction of steam. Therefore, a liquid level adjustment function is added to the transformer system to control the liquid level inside the casing 101.

[0067] Figure 6 A schematic diagram of the structure of the pressure control unit of a transformer system according to an embodiment of this application is shown. Figure 5 The pressure control unit of the transformer system shown is further enhanced with a liquid level regulation function, which enables the pressure regulation and liquid level regulation functions to work together and be organically combined to realize a closed-loop active control system.

[0068] like Figure 6As shown, according to an embodiment of this application, the pressure regulating unit 211 further includes a fourth connecting pipe 501 and a second valve 504. The storage tank 204 can store not only gas but also a certain amount of liquid. Since the density of liquid is greater than that of gas, the liquid first cooling medium accumulates at the bottom of the storage tank. The fourth connecting pipe 501 connects the lower part of the storage tank 204 to the lower part of the housing 101. The second valve 504, disposed on the fourth connecting pipe 501, is used to control the connection or disconnection between the storage tank 204 and the housing 101 to adjust the liquid level of the cooling medium in the housing 101.

[0069] As an example, when the load on transformer 100 increases, the temperature rises, the coolant boils violently leading to a rise in the liquid level, and a large amount of steam causes an increase in internal pressure, the excess coolant can be transferred to storage tank 204 by opening the second valve 504. This reduces the total volume of liquid inside transformer 100, providing physical space for gas expansion, and the pressure regulation response is fast. If the pressure value is still higher than the safety threshold after draining the coolant, the first valve 404 can be opened to transfer the top gas to storage tank 204, further reducing the gas inside transformer 100 and achieving rapid pressure relief. According to some embodiments of this application, the above-mentioned draining and venting operations can be performed sequentially or simultaneously; no specific limitations are imposed here.

[0070] As another example, in the event of a decrease in pressure and liquid level due to a reduction in the load on transformer 100, liquid in storage tank 204 can be transferred to transformer 100 housing 101. By raising the liquid level, localized overheating caused by exposure of coil 102 due to the reduced liquid level can be prevented. Simultaneously, the replenishment of liquid indirectly prevents further pressure drop. If the pressure remains too low, gas (e.g., a gaseous first cooling medium) in storage tank 204 can be transferred to transformer 100 housing 101 to increase the internal pressure of transformer 100, eliminate negative pressure, and prevent deformation of transformer 100 housing 101.

[0071] According to an embodiment of this application, in order to achieve rapid response and precise control of liquid level regulation, the pressure regulating unit 211 further includes an inlet pump 503 and a drain pump 502, which are connected in parallel on the fourth connecting pipe 501. During the draining process, the second valve 504 and the drain pump 502 are opened and the inlet pump 503 is closed, and the first cooling medium in the receiving cavity of the housing 101 is discharged into the storage tank 204; during the inlet process, the second valve 504 and the inlet pump 503 are opened and the drain pump 502 is closed, and the first cooling medium in the storage tank 204 is delivered to the receiving cavity of the housing 101. By setting the inlet pump 503 and the drain pump 502, a stable and effective driving force can be provided for the flow of liquid, realizing rapid, stable, and efficient liquid level control.

[0072] In addition, to prevent excessive internal pressure in the housing 101 from causing a safety hazard in the event of a malfunction of the breathing valve 206, the intake pump 403, or the exhaust pump 402, a safety valve 208 is provided on the top of the housing 101 for use in case the pressure regulating unit 211 fails.

[0073] When transformer 100 is shut down or operating at low power (e.g., below 20% of rated power), especially in cold environments, the temperature of the first cooling medium decreases as transformer 100 no longer generates heat or generates very little heat. This causes the liquid level to drop, which is insufficient to maintain a liquid level above the predetermined level. If transformer 100 suddenly starts up at this time, the phase change cooling cycle cannot take effect in time, resulting in a prolonged heating process for the transformer system.

[0074] To avoid this situation, such as Figure 3 As shown in the embodiment of this application, the transformer system further includes a level sensor 209, a heater 210, and a controller (not shown) disposed in the housing 101. The level sensor 209 is used to detect the level of the first cooling medium, the heater 210 is used to heat the first cooling medium, and the controller is configured to control the heater 210 to heat the first cooling medium based on the detection result of the level sensor 209, thereby maintaining the level of the first cooling medium within the housing 101 within a predetermined range and further improving the overall operating performance.

[0075] As an example, when the transformer 100 is in a shutdown or low-power operation state, when the level gauge 209 detects that the level of the first cooling medium in the housing 101 is lower than a predetermined threshold, the controller receives the result and starts the heater 210 to heat the first cooling medium. After the first cooling medium is heated, its volume increases until the level gauge 209 detects that the level has reached the preset threshold, at which point the controller shuts off the heater 210.

[0076] Although Figures 1 to 6 In the example shown, the condenser 202 is housed within the casing 101 of the transformer 100; however, the condenser 202 can also be installed separately from the transformer 100. When the condenser 202 is located outside the transformer 100, it can be cooled by air cooling or by other methods. Figure 1 The external cooling circulation system is used for cooling. Below, in conjunction with... Figures 7 to 9 A detailed description of an example of a transformer system in which the condenser 202 and the transformer 100 are separately configured.

[0077] Figure 7 A schematic diagram of the structure of a transformer system according to a second embodiment of this application is shown. Figure 8 and Figure 9A schematic diagram of another example of transformer 100 is shown. The following will be combined with... Figures 7 to 9 A second embodiment of this application is described. The transformer system of the second embodiment can be used on the transformer 100 of the first embodiment, and the transformer system of the first embodiment can be used on the transformer 100 of the second embodiment.

[0078] Figure 7 An example is shown where the transformer 100 and condenser 202 are separately installed and applied in the engine room 600. (See example...) Figure 7 As shown, the transformer 100 system includes a transformer 100 and a condenser 202. The transformer 100 is located inside the nacelle 600, and the condenser 202 is located outside the nacelle 600 and above the transformer 100. The condenser 202 and the transformer 100 are connected by a circulation pipeline, which includes an exhaust pipe and a return pipe. The exhaust pipe is connected between the upper part of the housing 101 and the condenser 202, and is used to transport the first cooling medium, which has evaporated into a gaseous state in the housing 101, to the condenser 202. The return pipe is connected between the lower part of the condenser 202 and the housing 101, and is used to transport the liquid first cooling medium, which has been condensed by the condenser 202, back to the housing 101 of the transformer 100.

[0079] By placing the condenser 202 outside the engine compartment 600, not only is internal space saved, but a sufficient height difference is also created between the condenser 202 and the transformer 100. This allows the gas generated by the heat absorption and evaporation of the phase change cooling medium inside the transformer 100's casing 101 to naturally rise into the condenser 202. After condensing into liquid in the condenser 202, the gas flows downwards under gravity and returns to the transformer 100's casing 101, enabling the phase change cooling medium to spontaneously circulate. To prevent resistance or poor circulation of the phase change cooling medium, a circulation pump can be installed on the circulation pipeline to drive continuous circulation. Since the force generated by the height difference is sufficient to circulate the phase change cooling medium, the circulation pump only needs to provide a small driving force to assist circulation. Figure 7 In the example shown, condenser 202 is cooled by air; therefore, compared with... Figure 1 Compared to the example shown, the radiator 203 and the piping connected to it are omitted.

[0080] In the above embodiments, the condenser can be a plate-fin or tube-fin heat exchanger, and can be a single-pass heat exchanger. When air cooling is used, the condenser can also be actively cooled by installing a fan. In addition, when the condenser is located outside the nacelle 600, it can share a support structure with other components on the top of the wind turbine nacelle 600.

[0081] According to an embodiment of this application, the transformer system further includes a pressure regulating unit 211 and a controller. According to one embodiment of this application, such as... Figure 7 As shown, the pressure regulating unit 211 can be installed on the condenser 202. For example, the pressure regulating unit 211 includes a breather valve 206. The transformer system can also have a first filter 207 installed at the inlet of the breather valve 206 to ensure that the gas entering the housing 101 is dry and pure, preventing contamination of the cooling medium inside the housing 101. The operation of the breather valve 206 is basically the same as described above and below, and will not be repeated here.

[0082] Figure 8 A pressure regulating unit 211 according to another embodiment of the application is shown. For example... Figure 8 As shown, the pressure regulating unit 211 includes a storage tank 204, a breather valve 206 disposed above the storage tank 204, and a pressure sensor 205. The storage tank 204 is pre-filled with a portion of dry gas (e.g., dry air, nitrogen, or other inert gas), and is disposed above the condenser 202 or above the housing 101 of the transformer 100. It is connected to the interior of the housing 101 of the transformer 100 via a connecting pipe 312, and is used to control the pressure inside the housing 101.

[0083] exist Figure 8 In the example shown, storage tank 204 is located above condenser 202 and connected to condenser 202 via connecting pipe 312 for communication with the interior of transformer 100 housing 101. Breather valve 206 and pressure sensor 205 are located on storage tank 204. When the pressure inside transformer 100 housing 101 rises and exceeds the positive pressure opening pressure value set by breather valve 206, the positive pressure valve inside breather valve 206 is opened under the action of the pressure difference. Excess gas inside is discharged to the outside atmosphere of transformer 100 through the opened valve passage. As the gas is discharged, the internal pressure of transformer 100 gradually decreases. When the internal pressure of housing 101 drops to the positive pressure closing pressure value of breather valve 206, the valve closes, stopping the exhaust. When the internal pressure of transformer 100 decreases and falls below the negative pressure opening pressure value set by breather valve 206, the negative pressure valve of breather valve 206 opens, drawing in gas. When the internal pressure rises back to the negative pressure closing pressure value of breather valve 206, the valve closes.

[0084] When the negative pressure valve of the breather valve 206 opens, drawing in air, it may introduce moisture from the external environment. When the positive pressure valve of the breather valve 206 opens, the internal gaseous phase change cooling medium will be discharged, resulting in a reduction in the amount of phase change cooling medium. Furthermore, to prevent the exchange of phase change cooling medium between the system's internal components and the external environment's gas, such as... Figure 9As shown, a diaphragm 212 is installed inside the storage tank 204 to isolate the gas inside the system from the external environment, preventing gas exchange between the system and the external environment. The diaphragm 212 divides the space inside the storage tank 204 into a first chamber and a second chamber. A breather valve 206 is installed in the first chamber, allowing gas exchange between the first chamber and the external environment. The second chamber is connected to the interior of the shell 101 via a connecting pipe 312. Because the diaphragm 212 has a certain degree of elasticity, it can change shape according to the pressure within the system, thus controlling the internal pressure of the shell 101. Furthermore, the diaphragm 212 can cooperate with the breather valve 206 to jointly regulate the internal pressure of the shell 101 and effectively prevent gas exchange between the shell 101 and the external environment.

[0085] In the preceding description, although in the description Figure 5 and Figure 6 The pressure regulating unit 211 shown is exemplified by the condenser 202 being installed inside the housing 101 of the transformer 100. However, Figure 5 and Figure 6 The pressure regulating unit 211 shown can also be used Figures 8 to 9 The transformer 100 is shown as a separate unit from the condenser 202. Similarly, refer to... Figure 8 and Figure 9 The pressure regulating unit 211 described can also be applied to a structure where the condenser 202 is located inside the transformer 100 housing 101. Further details will not be provided here.

[0086] According to an embodiment of this application, a wind turbine generator set is also provided, which includes the aforementioned transformer system. Due to the high overall safety of the transformer system, users can install it within the tower or nacelle 600 of the wind turbine generator set as needed.

[0087] While the embodiments of the present invention have been described in detail above, those skilled in the art can make various modifications and variations to the embodiments of the present invention without departing from the spirit and scope thereof. It should be understood that, to those skilled in the art, these modifications and variations will still fall within the spirit and scope of the embodiments of the present invention as defined in the claims.

Claims

1. A transformer system, characterized in that, The transformer system includes a transformer (100) and a cooling system. The transformer (100) includes a housing (101), an iron core (103) disposed in the housing (101), and a coil (102) wound on the iron core (103). The housing (101) can be filled with a first cooling medium, which is a phase change cooling medium. The cooling system is used to condense the phase change cooling medium evaporated in the housing (101) into a liquid and then return it to the housing (101).

2. The transformer system according to claim 1, characterized in that, The transformer system also includes a conductivity sensor (201), which is disposed in the housing (101) and is used to detect the conductivity of the first cooling medium.

3. The transformer system according to claim 2, characterized in that, The transformer system also includes a controller configured to receive a detection signal from the conductivity sensor (201) and output a prompt message about the operating status of the first cooling medium based on the detection signal.

4. The transformer system according to claim 1, characterized in that, The cooling system includes a condenser (202), a radiator (203), and a first pipe (301) and a second pipe (306) connecting the condenser (202) and the radiator (203). A second cooling medium can circulate in the cooling system. The first pipe (301) is used to transport the second cooling medium cooled by the radiator (203) to the condenser (202), and the second pipe (306) is used to transport the second cooling medium heated in the condenser (202) to the radiator (203).

5. The transformer system according to claim 4, characterized in that, The condenser (202) is disposed in the housing (101) and located above the iron core (103), so that the phase change cooling medium can be condensed into liquid by the condenser (202) after evaporation and drip down.

6. The transformer system according to claim 5, characterized in that, The projected area of ​​the condenser (202) on the iron core (103) covers at least 80% of the cross-sectional area of ​​the iron core (103).

7. The transformer system according to claim 1, characterized in that, The housing (101) includes a bottom wall (1011) and a top wall (1012) disposed opposite to each other, and a side wall (1013) connecting the bottom wall (1011) and the top wall (1012). At least a portion of the inner surface of the side wall (1013) is adapted to the outer contour of the coil (102) and has a predetermined interval with the outer contour of the coil (102). The iron core (103) includes three iron core units. The coil (102) includes three coil units respectively wound on the three iron core units. The side wall (1013) of the housing (101) includes a plurality of outwardly protruding arc-shaped portions corresponding to the outer peripheral surface of the coil (102) unit.

8. The transformer system according to claim 3, characterized in that, The transformer system also includes a level gauge (209) and a heater (210) disposed in the housing (101). The level gauge (209) is used to detect the level height of the first cooling medium, and the heater (210) is used to heat the first cooling medium. The controller is also configured to control the operation of the heater (210) based on the detection result of the level gauge (209).

9. The transformer system according to claim 1, characterized in that, The cooling system includes a condenser (202), which is located on the outside of the housing (101) and connected to the inside of the housing (101) through a pipe, so that the phase change cooling medium can be condensed into liquid by the condenser (202) after evaporation and transported back to the housing (101).

10. The transformer system according to claim 9, characterized in that, The transformer system also includes a pressure regulating unit (211), which includes a breather valve (206) located on the upper part of the condenser (202).

11. The transformer system according to any one of claims 1-9, characterized in that, The transformer system also includes a pressure regulating unit (211), which includes a storage tank (204), a breather valve (206) installed on the storage tank (204), and a pressure sensor (205). The storage tank (204) is filled with gas and communicates with the interior of the housing (101) through a connecting pipe (312).

12. The transformer system according to claim 11, characterized in that, The storage tank (204) is provided with a diaphragm (212), which divides the interior of the storage tank (204) into a first chamber and a second chamber. The breathing valve (206) is installed in the first chamber, and the connecting pipe (312) connects the second chamber and the interior of the shell (101).

13. The transformer system according to any one of claims 1-8, characterized in that, The transformer system also includes a pressure regulating unit (211), which is connected to the interior of the housing (101) and is used to regulate the pressure inside the housing (101). The pressure regulating unit (211) includes a breather valve (206), which is located on the upper part of the housing (101).

14. The transformer system according to any one of claims 1-9, characterized in that, The transformer system further includes a pressure regulating unit (211), which is connected to the interior of the housing (101) and is used to regulate the pressure inside the housing (101). The pressure regulating unit (211) includes a storage tank (204), a third connecting pipe (401), an exhaust pump (402), and an intake pump (403). The third connecting pipe (401) connects the interior of the housing (101) with the interior of the storage tank (204). The exhaust pump (402) and the intake pump (403) are connected in parallel on the third connecting pipe (401). The exhaust pump (402) is used to transport the gas inside the housing (101) to the storage tank (204), and the intake pump (403) is used to transport the gas in the storage tank (204) to the housing (101).

15. The transformer system according to claim 14, characterized in that, The pressure regulating unit (211) further includes a fourth connecting pipe (501), an inlet pump (503), and a drain pump (502). The fourth connecting pipe (501) connects the lower part of the storage tank (204) to the bottom of the housing (101). The inlet pump (503) and the drain pump (502) are connected in parallel on the fourth connecting pipe (501). The storage tank (204) can also store the first cooling medium. The inlet pump (503) is used to transport the liquid in the storage tank (204) to the housing (101), and the drain pump (502) is used to transport the liquid in the housing (101) to the storage tank (204).

16. A wind turbine generator set, characterized in that, The wind turbine generator set includes a transformer system as described in any one of claims 1-15.

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