Oil guiding device and converter transformer

Abstract

The present application relates to the technical field of power devices, and particularly relates to an oil guiding device and a converter transformer. The oil guiding device comprises a flow control device and a flow guiding structure. The flow guiding structure is used for covering the oil inlet position of an outer oil flow area in the converter transformer, so as to increase the amount of cooling oil entering the winding coil. The flow control device is used for adjusting the covering area of the flow guiding structure at the oil inlet of the outer oil flow area. The flow control device can flexibly adjust the covering area of the flow guiding structure at the oil inlet of the converter transformer, so as to flexibly adjust the flow size of the oil flowing into the winding coil of the converter transformer, so that the converter transformer can easily reach the optimal internal heat exchange state, and the waste of the oil pump capacity is reduced.

Description

Technical Field

[0001] This invention relates to the field of power equipment technology, and more particularly to an oil guiding device and a converter transformer. Background Technology

[0002] After nearly 30 years of rapid development, my country's DC power transmission industry has reached a high level and is widely used. It has played a crucial role in optimizing the allocation of energy resources on a large scale, such as transmitting power from west to east, supplying power from north to south, and balancing hydropower and thermal power generation; in transforming the energy advantages of western and northern my country into economic advantages; and in alleviating power shortages and environmental capacity deficiencies in eastern and central China. With the increasing rated load of converter transformers, the heat dissipation problem of the internal coils of converter transformers has become increasingly important. Currently, the fixed oil flow rate in converter transformers makes it difficult for them to reach optimal operating conditions, resulting in poor heat dissipation and wasted oil pump capacity. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to address the shortcomings of the prior art by providing an oil guiding device and a converter transformer.

[0004] The technical solution of the oil guiding device of the present invention is as follows:

[0005] It includes a flow control device and a flow guiding structure. The flow guiding structure is used to cover the oil inlet position of the outer oil flow zone inside the converter transformer to increase the amount of cooling oil entering the winding coil. The flow control device is used to adjust the coverage area of ​​the flow guiding structure at the oil inlet of the outer oil flow zone.

[0006] The beneficial effects of the oil guiding device of the present invention are as follows:

[0007] The flow control device can flexibly adjust the coverage area of ​​the guide structure at the oil inlet of the converter transformer, thereby flexibly adjusting the flow rate of the oil flowing into the winding coil of the converter transformer, making it easier for the converter transformer to reach the optimal internal heat exchange state, and reducing the waste of oil pump capacity.

[0008] Based on the above solution, the oil guiding device of the present invention can be further improved as follows.

[0009] Furthermore, the flow guiding structure includes multiple telescopic sections arranged in a ring, each telescopic section extending and retracting radially along the cylindrical converter transformer to block the amount of oil entering the outer oil flow zone, and also includes a ring-shaped bracket supporting the multiple telescopic sections.

[0010] Furthermore, the telescopic part includes: a pneumatic / hydraulic / electric telescopic rod, a shielding plate connected to the telescopic rod and driven to extend and retract; the annular bracket is located below the shielding plate.

[0011] Furthermore, the shielding plate includes two planar plates. The first plate is a fixed plate with a fixed position and is fixedly connected to the annular bracket. The second plate is connected to the electric telescopic rod and slides and extends above the annular bracket. The second plate overlaps with the first plate or is unfolded separately.

[0012] Furthermore, the shielding plate includes a folded V-shaped annular fan blade with a V-shaped wedge groove. The telescopic rod drives the V-shaped annular fan blade to extend and retract, thereby adjusting the coverage area of ​​the multiple V-shaped fan rings at the oil inlet of the converter transformer.

[0013] Furthermore, the telescopic rod is strip-shaped; or, the telescopic rod is a multi-jointed hinged structure.

[0014] Furthermore, the outer surfaces of the telescopic part and the annular bracket are made of insulating material.

[0015] Furthermore, the flow control device includes a chip, which is used to obtain five extension distances of the telescopic section according to the following formula, where each extension distance is the flow channel width Δd, and controls the stroke of multiple telescopic sections with the minimum Δd. The formula is:

[0016]

[0017] The converter transformer is a forced oil circulation air-cooled converter transformer. The formula is the width Δd of the annular flow channel in the external oil flow region obtained by fitting the simulation calculation results of the rated operating oil inlet pressure of 14.83 kg / s and inlet temperature of 20℃, and the input temperature limit top oil temperature T. oil Average temperature T of valve side winding fa Valve-side winding hot spot temperature T ft Average temperature T of the grid-side winding wa Grid-side winding hot spot temperature T wt The relationship is given, where Δd is 0-100mm. The control formula under varying operating conditions can be obtained through a certain amount of numerical simulation, and combined with interpolation methods, the control formula for the entire converter transformer operating range can be obtained.

[0018] The present invention provides a converter transformer, comprising a converter transformer body and an oil guiding device as described in any of the preceding claims.

[0019] Furthermore, the converter transformer body is a converter transformer body using a forced oil circulation and air cooling method. Attached Figure Description

[0020] Figure 1 This is one of the structural schematic diagrams of an oil guiding device according to an embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of the flow guiding structure;

[0022] Figure 3 This is one of the structural schematic diagrams of the telescopic part;

[0023] Figure 4 This is the second structural schematic diagram of the telescopic part;

[0024] Figure 5 One of the schematic diagrams of the internal oil flow of a converter transformer using the forced oil circulation air-cooled (OFAF) method with an oil guiding device according to this application installed;

[0025] Figure 6 This is a second schematic diagram of the structure of an oil guiding device according to an embodiment of the present invention;

[0026] Figure 7 This is a schematic diagram of the flow guiding structure;

[0027] Figure 8 A schematic diagram of a converter transformer equipped with an oil guiding device according to this application;

[0028] Figure 9 for Figure 4 Cross-sectional view;

[0029] Figure 10 for Figure 5 A magnified view of the dashed box in the image;

[0030] Figure 11 This is a schematic diagram of the robotic arm.

[0031] Figure 12 A schematic diagram of the internal oil flow of a converter transformer using the forced oil circulation air-cooled (OFAF) method without the oil guiding device of this application;

[0032] Figure 13 A second schematic diagram of the internal oil flow of a converter transformer using the forced oil circulation air-cooled (OFAF) method with an oil guiding device according to this application installed;

[0033] Figure 14 A fluid model diagram of a converter transformer using the forced oil circulation air-cooled (OFAF) method with an oil guiding device according to this application installed;

[0034] Figure 15 The internal temperature distribution cloud map of a converter transformer using the forced oil circulation air cooling (OFAF) method without the oil guiding device of this application is shown when the oil temperature at the inlet is 20℃ and the flow rate is 14.83kg / s.

[0035] Figure 16The internal temperature distribution cloud map of a converter transformer using the forced oil circulation air cooling (OFAF) method with an oil guiding device of this application is shown when the oil temperature at the inlet is 20℃ and the flow rate is 14.83kg / s. Detailed Implementation

[0036] To clearly illustrate the solutions in this invention, preferred embodiments are given below and described in detail with reference to the accompanying drawings.

[0037] like Figure 1 As shown, an oil guiding device according to an embodiment of the present invention includes a flow control device and a flow guiding structure. The flow guiding structure is used to cover the oil inlet 31 of the outer oil flow zone in the converter transformer to increase the oil flow rate entering the winding coil. The flow control device is used to adjust the coverage area of ​​the flow guiding structure at the oil inlet 31 of the outer oil flow zone.

[0038] The flow control device can flexibly adjust the coverage area of ​​the flow guiding structure at the oil inlet 31 of the converter transformer, thereby flexibly adjusting the flow rate of the oil flowing into the winding coil of the converter transformer, making it easier for the converter transformer to reach the optimal internal heat exchange state, and reducing the waste of oil pump capacity.

[0039] Optionally, in the technical solutions of various embodiments of the present invention, such as Figures 2 to 7 As shown, the flow guiding structure includes multiple telescopic sections 4 arranged in a ring. Each telescopic section 4 extends and retracts radially along the cylindrical converter transformer to block the amount of oil entering the outer oil flow zone. It also includes a ring-shaped support for supporting the multiple telescopic sections 4.

[0040] The annular support can be made of nylon (polyamide fiber) or epoxy resin, or other insulating materials used in the oil flow area inside the transformer, such as insulating paper or materials coated with insulating paper, to achieve the desired insulation effect. The annular support is installed inside the converter transformer via snap-fit ​​or adhesive bonding. The annular support includes an annular surface, and its overall shape can be consistent with... Figure 2 They have similar shapes. Multiple support feet are evenly spaced below the annular surface.

[0041] Optionally, in one embodiment of the present invention, the telescopic part 4 includes: a pneumatic / hydraulic / electric telescopic rod 40, a shield connected to the telescopic rod 40 and driven to extend and retract, and an annular bracket located below the shield.

[0042] Optionally, in the above technical solution, the shielding sheet comprises two planar sheets, such as... Figure 3 As shown, the first fixed piece 41 is fixedly connected to the ring bracket, and the second piece 42 is connected to the electric telescopic rod 40, which slides and extends above the ring bracket. The second piece 42 and the first fixed piece 41 are either in an overlapping state or in a separate unfolded state.

[0043] The shielding sheet can be made of insulating cardboard.

[0044] Alternatively, in another embodiment, the technical solution includes a telescopic portion with a shape such as... Figure 6 , Figure 7 ,as well as Figure 11 As shown, Figure 6 The above includes multiple telescopic sections, only one of which is shown. The shielding plate includes a folded V-shaped annular fan blade with a V-shaped wedge groove. The telescopic rod 40 drives the V-shaped annular fan blade to extend and retract, thereby adjusting the coverage area of ​​the multiple V-shaped annular fan blades at the oil inlet 31 of the converter transformer.

[0045] Optionally, in the above technical solution, the shape of the telescopic rod 40 is as follows: Figure 3 , Figure 4 The strip shape shown; or, as... Figure 11 The telescopic rod 40 shown is a hinged structure consisting of multiple straight rods.

[0046] Optionally, in the above technical solution, the outer surfaces of the telescopic part 4 and the annular bracket are made of insulating material. The insulating material can be epoxy resin or insulating paint, and an epoxy resin layer and insulating paint can be coated on the outer surfaces of the telescopic part 4 and the annular bracket. Other insulating materials of this embodiment can also be used, such as insulating paper or materials whose entire surface is coated with insulating paper.

[0047] Optionally, in the technical solutions of the two embodiments above, the flow control device includes a chip. The chip is used to obtain five telescopic distances of the telescopic section 4 according to the following formula: the stroke of each telescopic section's adjusted telescopic distance is the difference between the maximum stroke of the telescopic section and the flow channel width Δd, where the flow channel width Δd is the width through which the oil flows. The stroke of the multiple telescopic sections 4 is controlled with the minimum Δd, and the formula is:

[0048]

[0049] The converter transformer is a forced oil circulation air-cooled converter transformer. The formula is the width Δd of the annular flow channel in the external oil flow region obtained by fitting the simulation calculation results of the rated operating oil inlet pressure of 14.83 kg / s and inlet temperature of 20℃, and the input temperature limit top oil temperature T. oil Average temperature T of valve side winding fa Valve-side winding hot spot temperature T ft Average temperature T of the grid-side winding wa Grid-side winding hot spot temperature T wtThe relationship is given, where Δd is 0-100mm. The control formula under varying operating conditions can be obtained through a certain amount of numerical simulation, and combined with interpolation methods, the control formula for the entire converter transformer operating range can be obtained.

[0050] In an embodiment of the invention, the telescopic part 4 of the flow guiding structure is a hydraulic telescopic rod 40, with a total of 12 telescopic parts 4. Correspondingly, there are also 12 shielding plates, each with an arc of π / 6. A total of 12 shielding plates are needed to cover the entire circumference. The hydraulic telescopic rod 40 controls the internal pressure oil to evenly supply the second plate 42 of the 12 internal shielding plates to perform uniform radial extension and contraction. By controlling the coverage area of ​​the telescopic part 4 through the above formula, the flow rate of the external oil flow area is adjusted, thereby adjusting the amount of oil entering the transformer core and realizing the temperature regulation of the transformer.

[0051] In several embodiments of the present invention, such as Figure 1 As shown, an oil guiding device according to an embodiment of the present invention includes a flow control device 1 and a flow guiding structure 2. The flow guiding structure 2 is used to cover the oil inlet 31 of the converter transformer, and the flow control device 1 is used to adjust the coverage area of ​​the flow guiding structure 2 on the oil inlet 31 of the converter transformer.

[0052] In this transformer, the oil inlet 31 of the converter transformer 3 is into which cooling oil, also known as transformer oil, flows. The flow guiding structure 2 is adapted to the oil inlet 31 of the converter transformer 3, similar to a valve. When the flow control device 1 adjusts the coverage area of ​​the flow guiding structure 2 on the oil inlet 31 of the converter transformer 3, the flow rate of the oil flowing into the converter transformer 3 can be flexibly adjusted, making it easier for the converter transformer 3 to reach the optimal operating condition and reducing the waste of oil pump capacity.

[0053] Specifically, when the coverage area of ​​the regulating guide structure 2 at the oil inlet 31 of the converter transformer 3 increases, the flow rate of the oil flowing into the converter transformer 3 decreases; when the coverage area of ​​the regulating guide structure 2 at the oil inlet 31 of the converter transformer 3 decreases, the flow rate of the oil flowing into the converter transformer 3 increases.

[0054] Optionally, such as Figure 6 and Figure 7 As shown, in the above technical solution, the flow guiding structure 2 is a V-shaped annular fan blade with multiple V-shaped wedge grooves 20. The flow control device 1 controls the extension and retraction of the multiple V-shaped wedge grooves 20 of the V-shaped annular fan blade to adjust the coverage area of ​​the V-shaped annular fan blade at the oil inlet 31 of the converter transformer 3.

[0055] Since the oil inlet 31 of the converter transformer 3 is annular, the current guiding structure 2 needs to be adapted to the oil inlet 31 of the converter transformer 3. Therefore, the current guiding structure 2 is a V-shaped annular fan blade. The V-shaped annular fan blade is made of elastic steel sheet or foldable insulating cardboard, etc., so that the V-shaped annular fan blade has elasticity, so as to facilitate expansion and contraction, that is, to change the difference between the radius of the inner ring and the radius of the outer ring of the V-shaped annular fan blade, so as to adjust the coverage area of ​​the V-shaped annular fan blade on the oil inlet 31 of the converter transformer 3, thereby adjusting the flow rate of the oil flowing into the converter transformer 3.

[0056] The V-shaped annular fan-shaped flow guiding structure 2 is installed over the oil inlet 31 of the converter transformer 3, such as... Figures 8 to 10 As shown, the flow regulation process is as follows:

[0057] 1) When the multiple V-shaped wedge grooves 20 of the V-shaped annular fan blade are compressed, the difference between the radius of the inner ring and the radius of the outer ring of the V-shaped annular fan blade becomes smaller, and the coverage area of ​​the V-shaped annular fan blade at the oil inlet 31 of the converter transformer 3 decreases. At this time, the flow rate of the oil flowing into the converter transformer 3 increases, and the flow rate of the oil flowing out from the oil outlet 32 ​​of the converter transformer 3 also increases.

[0058] 2) When the multiple V-shaped wedge grooves 20 of the V-shaped annular fan blade are extended, the difference between the radius of the inner ring and the radius of the outer ring of the V-shaped annular fan blade increases, and the coverage area of ​​the V-shaped annular fan blade at the oil inlet 31 of the converter transformer 3 increases. At this time, the flow rate of the oil flowing into the converter transformer 3 decreases, and the flow rate of the oil flowing out from the oil outlet 32 ​​of the converter transformer 3 also decreases.

[0059] Optionally, in the above technical solutions, such as Figure 6 and Figure 11 As shown, another embodiment of the telescopic part 4 includes a crank-slider mechanism or a swing guide mechanism consisting of a crank 10 composed of multiple straight rods, a connecting rod 11, a slider 13, and a slider guide rail 12. The slider guide rail 12 of the crank-slider mechanism overlaps the inner and outer rings of the V-shaped annular fan blades. Under the action of the crank 10 and the connecting rod 11, the slider 13 moves along the slider guide rail 12 to adjust the coverage area of ​​the V-shaped annular fan blades at the oil inlet 31 of the converter transformer 3. In the crank-slider mechanism and the swing guide mechanism, the crank 10 and the connecting rod 11 are hinged, and the mode of movement is known to those skilled in the art and will not be described in detail here.

[0060] The difference between the crank-slider mechanism and the swing guide rod mechanism lies in whether the crank 10 can rotate normally. In this application, the purpose of "adjusting the coverage area of ​​the V-shaped annular fan blades at the oil inlet 31 of the converter transformer 3" can also be achieved by driving the crank 10 to swing. Therefore, either the crank 10-slider 13 mechanism or the swing guide rod mechanism is acceptable.

[0061] In this arrangement, the slider guide 12 of the crank-slider mechanism overlaps the inner and outer rings of the V-shaped annular fan blade. Specifically, one end of the slider guide 12 is fixedly connected to the inner ring of the V-shaped annular fan blade, and the other end is fixedly connected to the outer ring of the V-shaped annular fan blade. The preferred solution is that the distance between these two connection points is equal to the difference between the radius of the inner ring and the radius of the outer ring.

[0062] Optionally, in the above technical solutions, such as Figure 11 As shown, the telescopic part also includes a motor 14, which drives the crank 10 to swing, thereby adjusting the coverage area of ​​the V-shaped annular fan blades on the oil inlet 31 of the converter transformer. The motor 14 can be a stepper motor 14 or a servo motor 14.

[0063] The combination of the crank-slider mechanism and motor 14 described above can be referred to as a robotic arm, or the combination of the swing guide rod mechanism and motor 14 can be referred to as a robotic arm. The crank-slider mechanism or the swing guide rod mechanism can be installed at the oil inlet of the converter transformer 3, depending on the actual situation; no specific installation method is limited here.

[0064] Optionally, in the above technical solution, the flow control device 1 further includes a chip. The chip is used to control the extension range of each telescopic part 4, determined according to the formula in the above embodiment. That is, the chip is used to obtain the five extension distances of the telescopic part 4 according to the formula, and control the stroke of each telescopic part's adjustment distance each time with the minimum flow channel width Δd. The stroke is the difference between the maximum stroke of the telescopic part and the flow channel width Δd, where the flow channel width Δd is the width through which the oil flows.

[0065] This stroke is achieved by the motor 14 driving the crank 10 to swing, thus adjusting the extension and retraction stroke of the telescopic part. This further enhances the intelligence level of the oil guiding device of this application.

[0066] Currently, there are two main internal cooling methods for high-voltage converter transformers: forced oil circulation air cooling (OFAF) and forced oil circulation guided air cooling (ODAF).

[0067] By installing an oil guiding device of the present invention on a converter transformer of the forced oil circulation air cooling (OFAF) method, the heat dissipation effect of the forced oil circulation air cooling (OFAF) converter transformer can be improved, and the shortcomings of the traditional forced oil circulation directional air cooling (ODAF) converter transformer in terms of oil flow electrification, oil impurities and transient operation can be solved.

[0068] Optionally, in the above technical solution, the chip is specifically used to: control the motor 14 to adjust the extension length to the optimal value based on the optimal correspondence between the temperature and extension length at multiple preset positions of the forced oil circulation air-cooled converter transformer.

[0069] The temperatures at multiple preset locations include: the top oil temperature, bottom oil temperature, average grid-side winding temperature, grid-side winding hot spot temperature, valve-side winding average temperature, and valve-side winding hot spot temperature of the forced oil circulation air-cooled converter transformer.

[0070] The process of obtaining the optimal correspondence is as follows:

[0071] S1. The temperature at multiple preset locations at multiple times and the corresponding optimal telescopic distance can be obtained in advance. Specifically:

[0072] For example, by acquiring the temperature at multiple preset locations at a first moment, and analyzing the cooling performance and head of the forced oil circulation air-cooled converter transformer, the corresponding optimal oil flow rate is obtained; by acquiring the temperature at multiple preset locations at a second moment, and analyzing the cooling performance and head of the forced oil circulation air-cooled converter transformer, the corresponding optimal oil flow rate is obtained; thus, the first correspondence between multiple sets of "temperature at multiple preset locations" and "optimal oil flow rate" is obtained.

[0073] S2. Through the specific dimensional parameters of the flow guide structure 2, the second correspondence between the "oil flow rate" flowing through the flow guide structure 2 and the "extension distance of the expansion joint" can be obtained mathematically.

[0074] S3. Based on the first and second correspondences, the correspondence between "temperature at multiple preset positions" and "optimal extension distance" is obtained, that is, the optimal correspondence between the temperature at multiple preset positions and the extension distance of the forced oil circulation air-cooled converter transformer is obtained. Specifically, the optimal extension distance can be obtained by using the data curves obtained through numerical simulation or data curves obtained through artificial intelligence big data analysis, and by using the temperature at multiple preset positions of the forced oil circulation air-cooled converter transformer obtained in real time, as well as the optimal correspondence.

[0075] In other words, the chip can adjust the extension distance to the optimal value based on the temperature at multiple preset locations of the forced oil circulation air-cooled converter transformer, i.e., according to the formula... Adjust the telescopic distance of the telescopic part to the optimal value.

[0076] It can ensure heat dissipation inside the forced oil circulation air-cooled converter transformer and maximize the efficiency of the oil pump. That is, the chip can flexibly adjust the flow rate of the oil entering the oil inlet 31 of the forced oil circulation air-cooled converter transformer according to the internal heat load of the transformer, so that the internal heat dissipation reaches the optimal energy efficiency point.

[0077] The oil guiding device of this invention can also adaptively optimize internal heat dissipation by importing data curves obtained through numerical simulation after data verification or through artificial intelligence big data analysis. Furthermore, this device can maximize the efficiency of the oil pump. For converter transformers using the forced oil circulation air-cooled (OFAF) method, the oil flow mainly flows directly from the outside of the coil to the outlet. However, the rated flow rate of the oil pump is often higher than the minimum oil flow rate required by the converter transformer. If this oil pump is directly used in a forced oil circulation guided air-cooled (ODAF) converter transformer, there will be insufficient head. Through intelligent control, the optimal operating point of oil pump flow rate and head can be achieved. Finally, this intelligent heat dissipation device has the advantage of low manufacturing and maintenance costs.

[0078] This embodiment presents an oil guiding device, which is an intelligent adaptive oil guiding device for optimizing the internal heat dissipation of a converter transformer. The guiding structure 2 is made of foldable insulating cardboard. The flow control device 1 includes a robotic arm, i.e., a crank-slider mechanism or a swing guide rod mechanism, and a temperature measuring device for collecting temperatures at multiple preset locations. The oil guiding device is placed above the oil inlet of the converter transformer using forced oil circulation air cooling (OFAF) for guiding the flow. Numerical simulations were used to compare the impact of adding an oil guiding device of this embodiment on the internal temperature distribution. Figures 12 to 16 As shown.

[0079] Figure 15 The image shows the internal temperature distribution of a converter transformer using the forced oil circulation air-cooled (OFAF) method without the oil guiding device described in this application, when the inlet oil temperature is 20℃ and the flow rate is 14.83 kg / s. Figure 16 The internal temperature distribution cloud map of a converter transformer using the forced oil circulation air cooling (OFAF) method with an oil guiding device according to this application is shown when the oil temperature at the inlet is 20℃ and the flow rate is 14.83kg / s. A comparison of the results from Ansys Fluent numerical simulations shows that after the flow guiding baffle is applied, the highest and average temperatures of the grid-side and valve-side windings both decrease by about 2℃, and the top oil temperature decreases by about 4℃. This is because the flow guiding structure forces more cooling oil into the winding coils.

[0080] In another embodiment, the oil guiding device of this application is installed in a converter transformer of forced oil circulation air cooling (OFAF) mode. The device can also adaptively import numerical simulation data curves after data verification or data curves after artificial intelligence big data analysis to achieve the best internal heat dissipation. The device can maximize the efficiency of the oil pump and achieve the optimal operating point of oil pump flow and head through intelligent control.

[0081] Among them, the flow guiding structure 2 is an overall ring shape to fit the outside of the converter transformer. The mechanical arm, namely the crank 10 slider 13 mechanism or the swing guide rod mechanism, is controlled by a mechanical power device to achieve the function of the whole extending and contracting inside.

[0082] In the flow guiding structure 2, the main material of the shielding part is insulating paper, which is folded into a V-shape to achieve the function of expansion and contraction.

[0083] The mechanical control structure of the oil guiding device is connected to the internal temperature measuring point, and the extension distance of the telescopic part is intelligently and adaptively adjusted by the input parameters of the internal temperature measuring point.

[0084] The relationship between temperature and relative length within the mechanical control structure of the oil guiding device is derived from data curves obtained through data verification and numerical simulation, or data curves analyzed using artificial intelligence and big data, ensuring optimal internal heat dissipation. Intelligent control can be achieved by adjusting the extension distance to reach the optimal operating point for oil pump flow and head.

[0085] Compared with the prior art, the present invention has the following beneficial effects:

[0086] 1) It combines the design concepts of converter transformers with forced oil circulation air cooling (OFAF) and forced oil circulation guided air cooling (ODAF), which can give full play to the advantages of both and effectively improve their shortcomings in application.

[0087] 2) By using a temperature measuring device connected to the control system, the influence range of the flow guiding mechanism can be flexibly adjusted according to the internal heat load, so that the internal heat dissipation of the converter transformer with the forced oil circulation air cooling (OFAF) method equipped with an oil guiding device of the present invention reaches the optimal energy efficiency point.

[0088] 3) The curve showing the relationship between input temperature and extension length in the control system, that is, the curve corresponding to the optimal correspondence between temperature and extension distance at multiple preset positions of the forced oil circulation air-cooled converter transformer. This curve can be a numerical simulation data curve after data verification or a data curve after artificial intelligence big data analysis, and has the ability of intelligent adaptive control.

[0089] 4) It reduces the waste of oil pump capacity, so that the oil pump is at the optimal operating point of the head-flow curve that is suitable for the internal heat dissipation of the converter transformer.

[0090] An embodiment of the present invention provides a converter transformer, including a converter transformer body and an oil guiding device as described above, wherein the guiding structure 2 is disposed on the oil inlet 31 of the converter transformer body.

[0091] The converter transformer body refers to the various models of converter transformers currently available on the market.

[0092] Optionally, in the above technical solution, the converter transformer body is a converter transformer body with forced oil circulation and air cooling.

[0093] Among them, the converter transformer body with forced oil circulation and air cooling refers to the various models of converter transformers with forced oil circulation and air cooling currently available on the market.

[0094] An embodiment of the present invention provides a power system including a converter transformer as described above.

[0095] In this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0096] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0097] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. An oil guiding device, characterized in that, It includes a flow control device and a flow guiding structure. The flow guiding structure is used to cover the oil inlet position of the outer oil flow zone inside the converter transformer to increase the amount of cooling oil entering the winding coil. The flow control device is used to adjust the coverage area of ​​the flow guiding structure at the oil inlet of the outer oil flow zone. The flow guiding structure includes multiple telescopic sections arranged in a ring. Each telescopic section expands and contracts radially along the cylindrical converter transformer to block the amount of oil entering the outer oil flow zone. The flow guiding structure also includes a ring-shaped support that supports the multiple telescopic sections. The flow control device includes a chip, which is used to obtain five extension distances of the telescopic section according to the following formula, where each extension distance is the channel width Δ. d 1. △ d 2. △ d 3. △ d 4. △ d 5. The stroke of the multiple telescopic sections is controlled with the minimum flow channel width, and the formula is: ， ， ， ， ； The converter transformer is a forced oil circulation air-cooled converter transformer. The oil inlet pressure is 14.83 kg / s, and the inlet temperature is 20℃. The formula is the width of the annular flow channel in the external oil flow region obtained based on the operating conditions and interpolation method, and the input temperature limit top oil temperature. T oil Average temperature of valve side winding T fa Valve-side winding hot spot temperature T ft Average temperature of grid-side winding T wa Grid-side winding hot spot temperature T wt The relationship is given, and the width of the flow channel is 0-100mm.

2. The oil guiding device according to claim 1, characterized in that, The telescopic part includes: a pneumatic / hydraulic / electric telescopic rod, a shielding plate connected to the telescopic rod and driven to extend and retract; the annular bracket is located below the shielding plate.

3. The oil guiding device according to claim 2, characterized in that, The shielding plate includes two planar plates. The first plate is a fixed plate with a fixed position and is fixedly connected to the annular bracket. The second plate is connected to the electric telescopic rod and slides and extends above the annular bracket. The second plate overlaps with the first plate or is unfolded separately.

4. The oil guiding device according to claim 2, characterized in that, The shielding plate includes a folded V-shaped annular fan blade with a V-shaped wedge groove. The telescopic rod drives the annular fan blade to extend and retract, thereby adjusting the coverage area of ​​the multiple annular fan blades at the oil inlet of the converter transformer.

5. An oil guiding device according to claim 3 or 4, characterized in that, The telescopic rod is strip-shaped; or, the telescopic rod is a hinged structure consisting of multiple rods.

6. The oil guiding device according to claim 2, characterized in that, The outer surfaces of the telescopic part and the annular bracket are made of insulating material.

7. A converter transformer, characterized in that, It includes the converter transformer body and an oil guiding device as described in any one of claims 1 to 6.

8. A converter transformer according to claim 7, characterized in that, The converter transformer body is a converter transformer body using a forced oil circulation and air cooling method.

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