Capacitive bushing for high-insulativity photovoltaic power grid and manufacturing method of capacitive bushing

Abstract

The invention provides a high-insulativity capacitive bushing for a photovoltaic power grid and a manufacturing method thereof.The bushing comprises a core body, the surface of the core body is provided with two sets of silicone rubber umbrella skirts and mounting flanges, one end of one set of silicone rubber umbrella skirts is provided with a voltage-sharing ball, one end of the other set of silicone rubber umbrella skirts is provided with a sealing plug module, and the sealing plug module is connected with the core body. A wiring terminal is arranged at one end of the core body; the two groups of silicone rubber umbrella skirts and the mounting flange are combined to form a complete mounting cavity, the core body is arranged in the mounting cavity, the sealing plug module is in threaded connection with the silicone rubber umbrella skirts, and the core body penetrates through the middle part of the sealing plug module; the sealing plug module facilitates the maintenance of the capacitive bushing, improves the sealing performance of the capacitive bushing, effectively prevents internal insulating oil or gas from leaking, and prevents impurities such as water vapor, dust and the like from entering the capacitive bushing to finally cause insulation failure, equipment failure and even safety accidents.

Description

Technical Field

[0001] This invention relates to the field of capacitor bushings, and more specifically to a high-insulation capacitor bushing for photovoltaic power grids. Background Technology

[0002] Capacitive bushings used in photovoltaic grids are key components in high-voltage electrical equipment (such as transformers and switchgear) that provide insulation and electrical connection when the high-voltage core passes through a grounded metal casing or tank. They utilize an internal capacitive voltage divider structure to distribute the electric field evenly, preventing partial discharge and breakdown, and ensuring safe equipment operation.

[0003] In existing technologies, to facilitate the installation and maintenance of capacitive bushings, the ends of the bushings are usually designed as removable plug structures. However, due to the insufficient sealing of a single plug, the insulating oil or other substances filling the inside of the capacitive bushing may leak out. Gases (such as those in resin-impregnated paper bushings) are prone to leakage. Therefore, we propose a highly insulating capacitor bushing for photovoltaic power grids to address this issue. Summary of the Invention

[0004] To address the above problems, the present invention provides a high-insulation capacitor bushing for photovoltaic grids, comprising a core, the surface of which is provided with two sets of silicone rubber skirts and mounting flanges, one end of one set of silicone rubber skirts being provided with an equalizing ball, the other end of the other set of silicone rubber skirts being provided with a sealing plug module, and one end of the core being provided with a wiring terminal.

[0005] The two sets of silicone rubber umbrella skirts and mounting flanges combine to form a complete mounting cavity. The core is disposed inside the mounting cavity. The sealing plug module is connected to the silicone rubber umbrella skirts by threads, and the core passes through the middle of the sealing plug module.

[0006] Preferably, the interior of the mounting cavity formed by the two sets of silicone rubber umbrella skirts and mounting flanges is further provided with several sets of insulating layers, which are arranged according to the transmission voltage level, and a capacitor screen is provided between two adjacent sets of insulating layers.

[0007] Preferably, the sealing plug module includes a plug body, a mounting groove, a limiting ring, a connecting ring, and a sealing ring. The plug body is disposed at the end of the silicone rubber skirt, the mounting groove is opened inside the plug body, the limiting ring is disposed inside the mounting groove, the connecting ring is disposed on the surface of the limiting ring, and the sealing ring is disposed on the surface of the connecting ring.

[0008] Preferably, the limiting ring is formed into a circular ring shape, and the inner wall of the mounting groove is in contact with the surface of the limiting ring.

[0009] Preferably, the sealing ring is made of an elastic material, and both sides of the bottom end of the sealing ring are designed to be inclined.

[0010] Preferably, the sealing plug module further includes several sets of rubber strips, which are arranged in a ring at equal intervals on the surface of the plug body.

[0011] Preferably, each of the two sets of silicone rubber umbrella skirts is provided with a connecting wire module at one end near the mounting flange. The connecting wire module includes a connecting ring and a wiring hole. The connecting ring is located at one end of the silicone rubber umbrella skirt, and the wiring hole is opened on the surface of the connecting ring.

[0012] Preferably, the outer surface of both sets of silicone rubber umbrella skirts is provided with a hydrophobic coating, and the hydrophobic coating does not come into contact with the insulating layer and the capacitive screen.

[0013] This invention also provides a method for manufacturing a high-insulation capacitor bushing for photovoltaic power grids, the method being applied to the aforementioned high-insulation capacitor bushing for photovoltaic power grids, comprising:

[0014] Obtain at least one set of characteristic electrical stress parameters for the target photovoltaic grid, wherein the characteristic electrical stress parameters include at least one of steady-state DC bias voltage parameters, transient overvoltage waveform parameters, and high-frequency harmonic spectrum parameters;

[0015] The component distribution of the characteristic electrical stress parameters is calculated by using a preset insulation gradient distribution optimization model to obtain spatial material component distribution data. The spatial material component distribution data is used to indicate the target material component ratio at different spatial locations inside the silicone rubber umbrella skirt of the high-insulation photovoltaic grid capacitor bushing.

[0016] The silicone rubber umbrella skirt is constructed by dynamically proportioning and layer-by-layer molding based on the spatial material composition distribution data.

[0017] Preferably, the step of constructing the silicone rubber umbrella skirt by dynamically proportioning and layer-by-layer molding based on the spatial material composition distribution data includes:

[0018] A pre-designed multi-channel material delivery system provides various insulating material components to the online dynamic mixing unit;

[0019] The online dynamic mixing unit generates a mixture with the target material composition ratio corresponding to the current construction location in real time based on the spatial material composition distribution data;

[0020] The mixture is applied to the periphery of the core or the pre-formed insulating layer through a dispensing nozzle, and the newly applied mixture is rapidly cured to obtain the silicone rubber umbrella skirt.

[0021] The beneficial effects of this invention are:

[0022] In this invention, the core body has two sets of silicone rubber skirts and mounting flanges on its surface. One set of silicone rubber skirts has an equalizing ball at one end, and the other set has a sealing plug module at one end. One end of the core body has a terminal block. The two sets of silicone rubber skirts and mounting flanges combine to form a complete mounting cavity. The core body is disposed inside the mounting cavity. The sealing plug module is threaded to the silicone rubber skirts, and the core body passes through the middle of the sealing plug module. The sealing plug module facilitates maintenance of the capacitor bushing and also increases the sealing performance of the capacitor bushing, effectively preventing internal insulating oil from... Gas leakage also prevents impurities such as water vapor and dust from entering the capacitor bushing, ultimately leading to insulation failure, equipment malfunction, or even safety accidents.

[0023] This invention also includes a connecting ring, a wiring hole, and a water-repellent coating; the wiring hole facilitates the installation of the grounding wire, and sealing the wiring hole after installation reduces gaps in the capacitor bushing, further preventing internal insulating oil from... Gas leakage is prevented, while external liquids are prevented from entering through the gaps in the wiring holes, making the capacitor bushing more stable during use. The hydrophobic coating can be made of RTV room temperature vulcanized silicone rubber, which reduces moisture retention and protects the surface of the capacitor bushing. It also allows the contamination layer to maintain high surface resistance in humid environments, increasing the flashover voltage by more than %. The hydrophobic coating does not come into contact with the insulating layer and the capacitor screen, ensuring the dielectric performance of the capacitor screen. Attached Figure Description

[0024] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0025] Figure 2 This is a partial cross-sectional view of the present invention;

[0026] Figure 3 This is a partial structural diagram of the present invention;

[0027] Figure 4 This is a partial structural diagram of the present invention;

[0028] Figure 5 This is a partial cross-sectional view of the present invention.

[0029] In the diagram: 1. Core; 2. Silicone rubber umbrella skirt; 3. Mounting flange; 4. Equalizing ball; 5. Terminal block; 6. Insulation layer; 7. Capacitor screen; 8. Sealing plug module; 81. Pipe plug body; 82. Mounting groove; 83. Limiting ring; 84. Connecting ring; 85. Sealing ring; 86. Rubber strip; 9. Connecting wire module; 91. Connecting ring; 92. Wiring hole; 10. Water-repellent coating. Detailed Implementation

[0030] The technical solution of the present invention will now be clearly and completely described with reference to the embodiments and accompanying drawings. Obviously, the described embodiments are merely one embodiment of the present invention, and not all embodiments. Based on this embodiment, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Specific embodiments are as follows:

[0031] A high-insulation capacitor bushing for photovoltaic power grids, such as Figures 1-5 The device includes a core 1, with two sets of silicone rubber skirts 2 and mounting flanges 3 on its surface. One set of silicone rubber skirts 2 has an equalizing ball 4 at one end, and the other set of silicone rubber skirts 2 has a sealing plug module 8 at one end. A terminal block 5 is located at one end of the core 1. The two sets of silicone rubber skirts 2 and mounting flanges 3 combine to form a complete mounting cavity. The core 1 is placed inside the mounting cavity. The sealing plug module 8 is threadedly connected to the silicone rubber skirts 2, and the core 1 passes through the middle of the sealing plug module 8. The sealing plug module 8 facilitates maintenance of the capacitor bushing and also increases its sealing performance, effectively preventing internal insulating oil from leaking out. Gas leakage also prevents water vapor, dust and other impurities from entering the capacitor bushing, ultimately leading to insulation failure, equipment malfunction or even safety accidents. It should be noted that the number of silicone rubber umbrella skirts 2 can be different for different application scenarios. For example, for wall penetration scenarios, there are two sets of silicone rubber umbrella skirts 2, while for non-wall penetration scenarios, there is one set. There is no limitation here.

[0032] The mounting cavity formed by the two sets of silicone rubber umbrella skirts 2 and the mounting flange 3 is further provided with several sets of insulating layers 6. These insulating layers 6 are arranged according to the transmission voltage levels. The insulating layers 6 provide high electrical insulation strength between phases and between phase and ground, ensuring no breakdown occurs under rated and impulse overvoltages. Specifically, the insulating layers 6 have continuously gradient-changing inner, transition, and outer regions along the radial direction. The inner region tightly covers the core 1; the epoxy resin matrix of the inner region is filled with high dielectric constant nanofiller (in this application, nano-sized titanium dioxide is used). )),Depend on It can be seen that, at charge density Under certain circumstances, by improving This can directly reduce the electric field strength in the region. ,in, The dispersion is as follows; at the same time, since the surface of the core 1 is the region with the highest natural electric field intensity in the entire bushing, the high dielectric constant nanofiller prevents the electric field on the surface of the core 1 from concentrating, which greatly improves the starting discharge voltage of the bushing.

[0033] The concentration of the filler in the transition zone B varies in a gradient. Specifically, the concentration of the high dielectric constant filler continues to decrease radially, while the concentration of the nonlinear conductivity filler reaches a peak or maintains a specific functional distribution according to actual needs.

[0034] In the outer region C near the inner wall of the mounting flange 3, the concentration of high dielectric constant filler (TiO2) has been reduced to a negligible level. In order to efficiently conduct the heat generated inside the silicone rubber umbrella skirt 2 due to dielectric loss and Joule heating to the mounting flange 3, which serves as a large heat sink, fillers with high thermal conductivity and high insulation performance, such as nano aluminum nitride (AlN) or hexagonal boron nitride (h-BN), can be gradually added in this region.

[0035] Taking a bushing with a rated voltage of 110kV as an example, its core radius... for The inner layer region of the silicone rubber umbrella skirt 2 is from a radius of... arrive The annular region, at this time, is adjusted by nano (Its own relative permittivity is approximately 100) volume fraction in an epoxy resin matrix (relative permittivity is approximately 3.8) This causes it to smoothly decrease from the highest value on the surface of core 1, at which point its distribution function can be:

[0036]

[0037] In the formula, It is the maximum volume fraction. It is the attenuation coefficient.

[0038] For example, when , So on the surface of core 1 place, At this time, through The macroscopic relative permittivity at this point was estimated. Reachable And on the outer edge of this area place, The corresponding relative permittivity The value was reduced to approximately 5.5, which significantly improved the insulation margin.

[0039] The transition zone is arrive Within this range, in this region, nano The volume fraction of the filler continues to follow an exponential function. Descending, from The percentage decreased from 5.5% to place The corresponding relative permittivity at this time It is close to 3.9 for pure epoxy resin matrix.

[0040] In addition, a capacitor screen 7 is provided between two adjacent sets of insulating layers 6. At this time, the insulating layer 6 can serve as a mechanical support to fix the core 1 and the capacitor screen 7 and resist the deformation caused by thermal cycling and mechanical vibration. The capacitor screen 7 can generate a controllable capacitive voltage division effect in the insulating layer 6, so that the voltage is distributed in a linear gradient, ensuring long-term operational reliability.

[0041] The sealing plug module 8 includes a plug body 81, a mounting groove 82, a limiting ring 83, a connecting ring 84, and a sealing ring 85. The plug body 81 is located at the end of the silicone rubber shed 2. The mounting groove 82 is located inside the plug body 81. The limiting ring 83 is located inside the mounting groove 82. The connecting ring 84 is located on the surface of the limiting ring 83. The sealing ring 85 is located on the surface of the connecting ring 84. The core 1 is placed in the mounting cavity formed by the two sets of silicone rubber sheds 2 and the mounting flange 3. The sealing plug module 8 is aligned with the opening at the top of the mounting cavity. The plug body 81 is rotated into the mounting cavity, and the plug body 81 enters the mounting cavity. The combination of the limiting ring 83 and the connecting ring 84 moves synchronously with the plug body 81. The sealing ring 85 is pushed into the mounting cavity by the combination of the limiting ring 83 and the connecting ring 84. This facilitates the maintenance of the capacitor bushing. At the same time, the sealing ring 85 also increases the sealing performance of the capacitor bushing, effectively preventing internal insulating oil from entering. Gas leakage also prevents impurities such as water vapor and dust from entering the capacitor bushing, ultimately leading to insulation failure, equipment malfunction, or even safety accidents.

[0042] The limiting ring 83 is formed into a circular shape, and the inner wall of the mounting groove 82 is in contact with the surface of the limiting ring 83. During the process of rotating the plug body 81 to enter the interior of the mounting cavity, the combination of the limiting ring 83 and the connecting ring 84 rotates inside the mounting groove 82. The combination of the limiting ring 83 and the connecting ring 84 pushes the sealing ring 85 to move synchronously with the plug body 81, preventing the sealing ring 85 from rotating during the movement, thereby avoiding the problem of excessive friction between the sealing ring 85 and the mounting cavity, which makes installation inconvenient.

[0043] The sealing ring 85 is made of elastic material, and both sides of the bottom end of the sealing ring 85 are designed with an inclination. The sealing ring 85 is made of elastic material, which can generate a continuous rebound force after compression, automatically filling the micro gaps caused by mechanical vibration, thereby improving the sealing performance of the capacitor sleeve. The inclination design at the bottom end of the sealing ring 85 forms a guide area when inserted axially, which makes it easier to calibrate the position of the sealing ring 85 with the mounting cavity.

[0044] The sealing plug module 8 also includes several sets of rubber strips 86, which are arranged in a ring at equal intervals on the surface of the plug body 81. The rubber strips 86 can increase the friction between the operator's hand and the plug body 81, thereby allowing the operator to rotate the plug body 81 more effectively.

[0045] Both sets of silicone rubber umbrella skirts 2 are equipped with a connecting wire module 9 near the mounting flange 3. The connecting wire module 9 includes a connecting ring 91 and a wiring hole 92. The connecting ring 91 is located at one end of the silicone rubber umbrella skirt 2, and the wiring hole 92 is formed on the surface of the connecting ring 91. The wiring hole 92 facilitates the installation of the grounding wire. After installation, the wiring hole 92 is sealed, reducing the gaps in the capacitor bushing and further preventing internal insulating oil from... Gas leakage is prevented, while external liquids are prevented from entering through the gap in the wiring hole 92, making the capacitor bushing more stable during use.

[0046] Both sets of silicone rubber umbrella skirts 2 have a hydrophobic coating 10 on their outer surfaces. The hydrophobic coating 10 does not contact the insulating layer 6 or the capacitor screen 7. The hydrophobic coating 10 can be an RTV room temperature vulcanized silicone rubber coating. Its hydrophobicity can reduce moisture retention, achieve protection of the surface of the capacitor bushing, and also allow the contamination layer to maintain a high surface resistance in a humid environment, which can increase the flashover voltage by more than 50%. The fact that the hydrophobic coating 10 does not contact the insulating layer 6 or the capacitor screen 7 can ensure the dielectric performance of the capacitor screen 7.

[0047] This application also provides a method for manufacturing the aforementioned high-insulation photovoltaic grid capacitor bushing, specifically including the following steps:

[0048] S100: Obtain at least one set of characteristic electrical stress parameters of the target photovoltaic grid, wherein the characteristic electrical stress parameters include at least one of steady-state DC bias voltage parameters, transient overvoltage waveform parameters, and high-frequency harmonic spectrum parameters;

[0049] Assuming the aforementioned 110kV bushing, the characteristic electrical stress parameters of the photovoltaic power station are quantified as: steady-state DC bias voltage. (This parameter mainly affects the space charge distribution within the insulator); the transient overvoltage waveform is a standard lightning impulse wave, with an amplitude of... (This parameter determines the impact insulation level of the bushing); significant harmonic components are superimposed on the fundamental frequency, mainly concentrated at f1=3.5kHz and f2=7kHz, with amplitudes of 5% and 3% of the fundamental frequency, respectively. These harmonics are the main source of dielectric loss and heat generation; at the same time, the preset material library contains complete parameters for basic epoxy resin (E51), acid anhydride curing agent (MTHPA), nano TiO2 suspension (40% solid content), nano SiC suspension (35% solid content) and nano AlN suspension (40% solid content).

[0050] S200: The component distribution of the characteristic electrical stress parameters is calculated using a preset insulation gradient distribution optimization model to obtain spatial material component distribution data;

[0051] After calculation using the preset optimization model, the corresponding material composition ratio vector is obtained as follows: {epoxy resin: 87.2% vol, curing agent: 8.0% vol, TiO2: 3.5% vol, SiC: 1.3% vol, AlN: 0% vol}. Then, the data file corresponding to this distribution data is loaded to instruct the processing system to process according to the data file.

[0052] Subsequently, the discrete spatial material composition distribution data is fitted into a continuous material distribution function using an interpolation algorithm. Then, according to a preset forming strategy (e.g., from the inside out, spiraling upwards layer by layer), the spatial material composition distribution data is translated into an executable instruction sequence (similar to G-code). This sequence precisely defines the three axes (R, ..., ...) of the workpiece forming and motion subsystem at every moment during the manufacturing process. The coordinates (Z) and the instantaneous flow rate of each metering pump in the material storage and conveying subsystem, which are synchronized with it.

[0053] Next, pre-processing preparation is carried out. Specifically, a copper core 1 that meets the size requirements is vertically installed on the rotating chuck of the workpiece forming and motion subsystem, ensuring that its central axis coincides with the rotation center of the platform. Then, the surface of the core 1 is sandblasted to increase roughness, followed by ultrasonic cleaning with solvents such as acetone to remove oil stains, and finally dried in an oven. In particular, before the deposition begins, a thin layer of silane coupling agent (such as KH-560) needs to be uniformly coated on the surface of the core 1 and cured by heating to enhance the chemical bonding between the subsequently deposited epoxy resin composite material and the metal core 1, ensuring that a seamless, gapless, and strong interface is formed between the two.

[0054] S300: Precisely positions the dispensing nozzle of the online dynamic mixing and dispensing subsystem to the starting position of the main insulator deposition; typically, this position is selected at a point on the surface of core 1 near the mounting flange to ensure the integrity of the joint structure with the flange.

[0055] Specifically, the controller operates at a constant angular velocity (e.g., according to the command sequence) The system rotates while the sprinkler head slowly moves outward along the R-axis, starting from the inner diameter, forming a spiral laying trajectory. Throughout the sprinkler head's movement, the controller adjusts the position of the sprinkler head according to its current position. The system uses coordinates to query the target material group distribution ratio in real time and sends precise flow rate commands to the material storage and delivery subsystem. Subsequently, various basic material components are injected into the online dynamic mixing unit according to dynamically changing proportions. The resulting instantaneous mixture is continuously and smoothly applied to the surface of core 1 or the previously cured layer through the distribution nozzle. Then, the preset focused UV-LED array immediately irradiates the newly applied material with energy, allowing it to quickly reach a preliminary curing state. After a complete annular layer (0.1 mm thick) is applied and cured, the distribution nozzle moves upward 0.1 mm along the Z-axis to start the deposition cycle of the next layer. Repeating the above process, as the Z-axis coordinate continuously increases, one 0.1 mm thick annular layer after another is stacked to form an umbrella skirt.

[0056] Example 2

[0057] The difference from Example 1 is that a base concentration of nonlinear conductive filler (e.g., nanoscale silicon carbide (SiC)) can be additionally filled into the inner layer region to counteract rapidly rising transient overvoltages; wherein, in order to optimize the DC electric field distribution and take into account the transient response, the volume fraction of SiC nanofiller is... This region exhibits a Gaussian distribution:

[0058]

[0059] Taking the aforementioned copper capacitor bushing as an example, peak concentration It is 8%, the peak position. Set as Distribution width for Therefore, under steady-state DC conditions, due to the nonlinear conductivity characteristics of SiC, the conductivity... The highest area (i.e.) The surrounding area will experience a lower electric field strength, thus distributing the DC voltage stress more evenly throughout the insulating medium; and under AC transients, the dielectric constant of this region is also increased by SiC, and is comparable to that of nanomaterials. The gradient attenuation works together to adapt to mixed AC / DC operating conditions.

[0060] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A capacitor bushing for a high-insulation photovoltaic power grid, characterized in that: The device includes a core (1), on the surface of which are provided two sets of silicone rubber skirts (2) and mounting flanges (3). One end of one set of silicone rubber skirts (2) is provided with a pressure equalizing ball (4), and the other end of the silicone rubber skirts (2) is provided with a sealing plug module (8). One end of the core (1) is provided with a wiring terminal (5). The silicone rubber skirts (2) are a composite gradient insulation structure. The composite gradient insulation structure is an integral molded structure composed of multiple insulating material components, and the volume ratio of the multiple insulating material components inside the silicone rubber skirts (2) is distributed in a preset spatial gradient. The two sets of silicone rubber umbrella skirts (2) and mounting flanges (3) are combined to form a complete mounting cavity. The core (1) is set inside the mounting cavity. The sealing plug module (8) is connected to the silicone rubber umbrella skirt (2) by threads. The core (1) passes through the middle of the sealing plug module (8).

2. The capacitor bushing for a high-insulation photovoltaic grid according to claim 1, characterized in that: The two sets of silicone rubber umbrella skirts (2) and mounting flanges (3) are arranged inside the mounting cavity, and several sets of insulating layers (6) are arranged according to the transmission voltage. A capacitor screen (7) is arranged between two adjacent sets of insulating layers (6).

3. The capacitor bushing for a high-insulation photovoltaic grid according to claim 1, characterized in that: The sealing plug module (8) includes a plug body (81), a mounting groove (82), a limiting ring (83), a connecting ring (84), and a sealing ring (85). The plug body (81) is located at the end of the silicone rubber umbrella skirt (2). The mounting groove (82) is opened inside the plug body (81). The limiting ring (83) is located inside the mounting groove (82). The connecting ring (84) is located on the surface of the limiting ring (83). The sealing ring (85) is located on the surface of the connecting ring (84).

4. A capacitor bushing for a high-insulation photovoltaic grid according to claim 3, characterized in that: The limiting ring (83) is formed into a circular shape, and the inner wall of the mounting groove (82) is in contact with the surface of the limiting ring (83).

5. A capacitor bushing for a high-insulation photovoltaic grid according to claim 3, characterized in that: The sealing ring (85) is made of elastic material, and both sides of the bottom end of the sealing ring (85) are designed to be inclined.

6. A capacitor bushing for a high-insulation photovoltaic grid according to claim 3, characterized in that: The sealing plug module (8) also includes several sets of rubber strips (86), which are arranged in a ring at equal intervals on the surface of the plug body (81).

7. A capacitor bushing for a high-insulation photovoltaic grid according to claim 1, characterized in that: Both sets of silicone rubber umbrella skirts (2) are provided with a connecting wire module (9) at one end near the mounting flange (3). The connecting wire module (9) includes a connecting ring (91) and a wiring hole (92). The connecting ring (91) is located at one end of the silicone rubber umbrella skirt (2), and the wiring hole (92) is opened on the surface of the connecting ring (91).

8. A capacitor bushing for a high-insulation photovoltaic grid according to claim 1, characterized in that: Both sets of silicone rubber umbrella skirts (2) have a hydrophobic coating (10) on their outer surfaces. The hydrophobic coating (10) does not contact the insulating layer (6) or the capacitor screen (7).

9. A method for manufacturing a high-insulation capacitor bushing for photovoltaic power grids, applicable to the high-insulation capacitor bushing for photovoltaic power grids described in any one of claims 1-8, characterized in that, include: Obtain at least one set of characteristic electrical stress parameters for the target photovoltaic grid, wherein the characteristic electrical stress parameters include at least one of steady-state DC bias voltage parameters, transient overvoltage waveform parameters, and high-frequency harmonic spectrum parameters; The component distribution of the characteristic electrical stress parameters is calculated by using a preset insulation gradient distribution optimization model to obtain spatial material component distribution data. The spatial material component distribution data is used to indicate the target material component ratio at different spatial locations inside the silicone rubber umbrella skirt (2) of the high-insulation photovoltaic grid capacitor bushing. Based on the spatial material composition distribution data, the silicone rubber umbrella skirt (2) is constructed by dynamically proportioning and layer-by-layer molding.

10. The method according to claim 9, characterized in that, The process of constructing the silicone rubber umbrella skirt (2) by dynamically proportioning and layer-by-layer molding based on the spatial material composition distribution data includes: A pre-designed multi-channel material delivery system provides various insulating material components to the online dynamic mixing unit; The online dynamic mixing unit generates a mixture with the target material composition ratio corresponding to the current construction location in real time based on the spatial material composition distribution data; The mixture is applied to the periphery of the core (1) or the pre-formed insulating layer by a dispensing nozzle, and the newly applied mixture is rapidly cured to obtain the silicone rubber umbrella skirt (2).

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