Capacitive coupling type high voltage wireless energy transfer insulation device and manufacturing method

Abstract

The application discloses a kind of capacitive coupling type high voltage wireless energy transfer insulation device and manufacturing method, device includes bushing, its inner cavity is equipped with insulation core body, core body is formed by upper cavity, lower cavity and the partition between them;Partition upper and lower surfaces are respectively equipped with upper and lower capacitor plate and with connecting line;Upper and lower cavity and bushing and core body gap are filled with insulating medium;Bushing both ends are sealed and connected upper and lower end cap, connecting line is respectively led out from both end cap.The method comprises: preparing core body and installing upper capacitor plate and lower capacitor plate in the bottom of upper cavity and lower cavity of core body respectively;Bushing is sleeved on the outside of core body;Insulating medium is filled in the filling gap between upper cavity, lower cavity of core body and bushing and core body and is solidified;Upper end cap and lower end cap are respectively sealed and fixed in the both ends of bushing and connecting line is led out.The application combines capacitive coupling energy transmission and composite insulation design, realizes high voltage across level efficient wireless energy transfer, solves energy transfer insulation problem.

Description

Technical Field

[0001] This invention relates to the field of high-voltage insulation and isolation power supply technology, and in particular to a capacitively coupled high-voltage wireless power transmission insulation device and its manufacturing method. Background Technology

[0002] In high-voltage and ultra-high-voltage power systems, various power equipment require stable power supply for online monitoring and condition detection. However, traditional wired power supply methods suffer from problems such as insulation breakdown, line aging, and complex wiring, making it difficult to meet the insulation requirements of high-voltage levels. Existing wireless power transmission technologies, when applied in high-voltage scenarios, generally suffer from insufficient insulation performance, short creepage distance, and low power transmission efficiency during the power transmission process. Furthermore, the devices have poor mechanical stability and are prone to failure under the vibration and high electric field environment of high-voltage equipment operation, failing to meet the high-power wireless power transmission requirements across high voltage levels.

[0003] Currently, most high-voltage wireless power transmission devices adopt a single insulation structure. The external insulation is susceptible to flashover due to environmental factors, and the internal insulation has high dielectric loss, which not only reduces the power transmission efficiency but also further affects the insulation performance and service life of the device due to insulation heating. At the same time, the capacitor coupling components of the traditional power transmission structure are not arranged reasonably, and the creepage distance is insufficient, which makes it easy to cause insulation breakdown at high voltage levels, thus limiting its promotion and application in high-voltage power systems.

[0004] Therefore, developing a high-voltage wireless power transmission insulation device that combines high insulation performance, high energy transmission efficiency, and high mechanical stability has become an urgent technical problem to be solved in the field of high-voltage power equipment. Summary of the Invention

[0005] In view of the above-mentioned shortcomings of the existing technology, the present invention provides a capacitively coupled high-voltage wireless power transmission insulation device and manufacturing method, which realizes high-power and high-efficiency wireless power transmission across high voltage levels, while solving the problems of insulation breakdown and insufficient creepage distance in the power transmission process, and significantly improving the insulation strength, mechanical stability and operational reliability of the device.

[0006] To achieve the above objectives, a first aspect of the present invention provides a capacitively coupled high-voltage wireless power transmission insulation device, the device comprising a sleeve, wherein the inner cavity of the sleeve is provided with a core made of an insulating material, the core having an upper cavity and a lower cavity, the upper cavity and the lower cavity being separated by a partition.

[0007] The upper and lower surfaces of the partition are respectively provided with an upper capacitor plate and a lower capacitor plate, and connecting lines are provided on both the upper and lower capacitor plates.

[0008] The upper cavity, the lower cavity, and the gap between the sleeve and the core are all filled with an insulating medium.

[0009] The two ends of the sleeve are respectively sealed with an upper end cap and a lower end cap;

[0010] The connecting wires of the upper capacitor plate and the lower capacitor plate are respectively led out from the upper end cover and the lower end cover.

[0011] To achieve the above objectives, a second aspect of the present invention provides a method for manufacturing a high-voltage wireless power transmission insulation device, for preparing the above-mentioned capacitively coupled high-voltage wireless power transmission insulation device, the method comprising:

[0012] S1: Manufacture a core having an upper cavity and a lower cavity, wherein an upper capacitor plate and a lower capacitor plate are respectively installed at the bottom of the upper cavity and the lower cavity;

[0013] S2: The core is fitted into the sleeve, and the sleeve and the core are coaxially aligned.

[0014] S3: Fill the upper cavity, lower cavity and gap between the sleeve and the core with insulating medium and then cure it;

[0015] S4: Seal and fix the upper end cover and the lower end cover to both ends of the sleeve respectively, and lead out the connecting wires of the upper capacitor plate and the lower capacitor plate from the upper end cover and the lower end cover respectively.

[0016] The advantages of this invention are as follows: First, the core structure effectively increases the creepage distance between the upper and lower capacitor plates. Combined with the external insulation formed by the sheds and bushings, and the internal insulation formed by the insulating medium and the core, a multi-layer composite insulation system is formed, significantly improving the insulation reliability and withstand voltage capability of the device at high voltage levels. Second, the use of capacitive coupling wireless power transmission technology, along with the core made of low dielectric loss materials such as alumina ceramic or quartz glass, effectively reduces energy loss during transmission, achieving efficient and stable power transmission at high voltage levels. Third, the internal filling with high-insulation materials such as epoxy resin or silicone not only strengthens the insulation performance but also buffers the vibration stress generated during device operation, improving the overall structure's seismic resistance and mechanical strength, and extending the device's service life. Simultaneously, the device has a compact overall structure, small size, convenient installation, clear preparation steps, mature technology, and readily available materials, making it suitable for mass production and widespread application. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1This is a schematic diagram of the structure of the capacitively coupled high-voltage wireless power transmission insulation device of the present invention.

[0019] Figure 2 This is a schematic diagram of the connection structure between the wireless power transmission insulation device and the external interconnection device described in this invention.

[0020] Figure 3 This is a schematic diagram of the structure of the capacitor plate described in this invention;

[0021] Figure 4 This is a schematic flowchart of the manufacturing method of the high-voltage wireless power transmission insulation device described in this invention.

[0022] Component designation explanation:

[0023] 101. High voltage power supply; 102. Inverter; 103. Rectifier; 104. Low voltage load; 105. Upper capacitor plate; 106. Core; 107. Bushing; 108. Umbrella skirt; 109. Lower capacitor plate; 200. Upper cavity; 201. Lower cavity; 202. Connecting wire; 301. Upper end cover; 302. Lower end cover. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Example 1:

[0026] Figure 1 and Figure 2 A schematic diagram of the structure of a capacitively coupled high-voltage wireless power transmission insulation device according to the present invention is shown. Figure 1 and Figure 2 As shown, the device includes a sleeve 107, and a core 106 made of insulating material is disposed in the inner cavity of the sleeve 107. The core 106 has a cylindrical upper cavity 200 and a lower cavity 201, which are separated by a partition. An upper capacitor plate 105 and a lower capacitor plate 109 are respectively disposed on the upper and lower surfaces of the partition, and connecting wires 202 are disposed on both the upper capacitor plate 105 and the lower capacitor plate 109. The upper cavity 200, the lower cavity 201, and the gap between the sleeve 107 and the core 106 are filled with an insulating medium. An upper end cap 301 and a lower end cap 302 are respectively sealed and connected to both ends of the sleeve 107. The connecting wires 202 of the upper capacitor plate 105 and the lower capacitor plate 109 are led out from the upper end cap 301 and the lower end cap 302, respectively.

[0027] The sleeve 107 is a hollow cylindrical structure with an axial length matching that of the core 106. The inner diameter of the sleeve 107 is slightly larger than the outer diameter of the core 106 to facilitate assembly. During assembly, the coaxiality can be calibrated using external tooling to ensure that the central axes of the two are aligned.

[0028] In this embodiment of the invention, the sleeve 107 is made of silicone rubber or ethylene propylene rubber, both of which possess excellent weather resistance, resistance to electrolytic corrosion, and high volume resistivity (≥1×10⁻⁶). 15 (Ω·cm), and silicone rubber is easy to construct micro-nano composite hydrophobic structures on its surface, while ethylene propylene rubber has better high-temperature compression set performance.

[0029] The inner wall of the sleeve 107 is also provided with at least one layer of voltage equalization screen. The voltage equalization screen is a layered structure made of conductive or semi-conductive material, with a thickness of 0.2 mm and a surface resistivity controlled at 10. 3 Ω / sq~10 5 The voltage equalization screen is between Ω / sq. The equalization screen is fixed to the inner wall of the sleeve 107 by spraying or pasting, and an insulating layer is provided between the screen and the inner wall of the sleeve 107.

[0030] To eliminate the potential risks of interfacial air gaps, interfacial peeling, and surface discharge between the equalizing screen and the insulating medium, both sides of the equalizing screen undergo low-temperature plasma activation and silane coupling agent chemical grafting treatment. This results in a strong chemical bond interface between the equalizing screen and the subsequently potted insulating medium, forming a gapless composite equalizing insulation structure with high bonding strength.

[0031] To further improve the potential distribution, this embodiment employs a three-layer voltage equalization screen structure, arranged sequentially from the inside out. The axial length of each voltage equalization screen decreases in a stepped manner, with the innermost layer being the longest, closest to the high-voltage end, and the outermost layer being the shortest, closest to the low-voltage end. This structure forms an equivalent capacitive voltage divider, homogenizing the potential gradient inside the bushing 107 and effectively preventing local electric field concentration.

[0032] Meanwhile, sufficient insulation distance is reserved between the equalizing screen and the end caps at both ends of the bushing 107 to ensure that no new discharge channels are introduced due to the equalizing screen. Testing shows that this equalizing structure can reduce the maximum electric field strength inside the bushing 107 by approximately 30%. Combined with the insulation defect suppression effect brought about by the interface bonding treatment, the overall partial discharge of the device is further reduced, significantly improving the long-term insulation reliability of the device at voltage levels of 500 kV and above.

[0033] The outer wall of the sleeve 107 is provided with axially extending skirts 108, which are made of silicone rubber or ethylene propylene rubber. The number, diameter, and spacing of the skirts 108 can be set according to the rated voltage level and the creepage distance verification according to GB / T 26218.2-2010, and this application does not impose any special limitations. For example, in a 40.5 kV system, 3 to 5 levels of skirts 108 are provided, with the skirt extension length being 30 mm to 50 mm.

[0034] In this embodiment of the invention, the surface of the umbrella skirt 108 is provided with a hydrophobic coating or a nano-modified layer to enhance its anti-flashover capability. The hydrophobic coating is a fluorosilane-based self-assembled monolayer (contact angle ≥110°) or an organosilicon-modified coating doped with titanium dioxide or silica nanoparticles, possessing both hydrophobicity and UV aging resistance. The combination of the umbrella skirt 108 and the hydrophobic coating or nano-modified layer causes water to be distributed in a spherical discrete pattern on the surface, significantly inhibiting the formation of a continuous water film, thereby extending the actual surface discharge path and increasing the wet flashover voltage.

[0035] The core 106 is an integral cylindrical structure made of a high-insulation, low-dielectric-loss dielectric material. The material can be an inorganic non-metallic insulating material or a polymeric insulating material. Inorganic non-metallic insulating materials can include alumina ceramics, quartz glass, aluminum nitride ceramics, silicon nitride ceramics, or borosilicate glass, etc.; polymeric insulating materials can include epoxy resin, polyimide, polytetrafluoroethylene, polyetheretherketone, or polyphenylene sulfide, etc. These materials all possess excellent electrical insulation properties, low dielectric constant and dielectric loss, and good heat resistance and mechanical strength, and can be selected according to the device's operating voltage level, power transfer frequency, and structural strength requirements.

[0036] The upper cavity 200 and lower cavity 201 at both ends of the core 106 are coaxial cylindrical cavities. The axial depth of the cavity can be set according to the overall size of the core 106 (e.g., 15 mm to 25 mm). The partition is located in the middle of the core 106, and the thickness of the partition can be set according to design requirements (e.g., 3 mm to 8 mm). The upper cavity 200 and lower cavity 201 are arranged in a mirror symmetrical manner with respect to the partition, so that the cross-section of the core 106 along the central axis is H-shaped. The bottom surfaces of the upper cavity 200 and lower cavity 201 need to be precision ground to ensure that the flatness is better than ±2 μm, so as to ensure that the upper capacitor plate 105 and the lower capacitor plate 109 are tightly fitted and without interface air gaps.

[0037] Alumina ceramics possess excellent insulation properties and high mechanical strength, making them suitable for most high-voltage power transmission scenarios. Quartz glass offers good light transmittance and an extremely low coefficient of thermal expansion, making it suitable for applications requiring optical monitoring or experiencing drastic temperature changes. Aluminum nitride ceramics exhibit outstanding thermal conductivity, making them suitable for high-power power transmission scenarios with stringent heat dissipation requirements. Silicon nitride ceramics boast high flexural strength and good thermal shock resistance, making them suitable for applications subject to mechanical vibration or drastic temperature changes. High borosilicate glass offers good chemical stability and low cost, making it suitable for medium- and high-voltage applications where cost is a concern. The selection of these materials can be flexibly tailored to the device's operating voltage level, power transmission capacity, mechanical strength requirements, heat dissipation conditions, and manufacturing costs; this application does not impose any specific limitations. During manufacturing, the overall dimensional tolerance of the core 106 must be controlled within ±0.05 mm to ensure uniform resin flow during subsequent filling processes.

[0038] In this embodiment of the invention, the core 106 can be manufactured using various processes, including mold forming, separate welding, or blank processing, as detailed below:

[0039] The mold forming method is applicable to alumina ceramics or quartz glass materials. The slurry is poured or the powder is pressed into shape by precision mold and then sintered at high temperature to obtain an integrated structure with an upper cavity 200, a lower cavity 201 and a partition.

[0040] The split-body welding method is more suitable for complex structures or combinations of dissimilar materials. The upper cavity 200 and the lower cavity 201 are processed separately (they can be manufactured using the above-mentioned mold forming method) into separate U-shaped cylindrical structural units with cavities. The partition is independently prepared as a circular plate (or the partition can be omitted and the bottom surfaces of the two structural units can be welded directly). After the three parts are cleaned and positioned and assembled, the U-shaped parts and the partition are connected into one body by laser welding or high-temperature fusion process. The welding interface must be free of pores and cracks, and annealing treatment is performed after welding to eliminate internal stress. Finally, the external dimensions and fitting accuracy are guaranteed by machining.

[0041] The blank processing method is suitable for high-precision, small-batch production. Cylindrical alumina ceramic or quartz glass blanks are selected, and coaxial cylindrical upper cavities 200 and lower cavities 201 are respectively opened at both ends of the blank using a CNC machine tool. During processing, the axial depth and inner diameter are strictly controlled. The middle partition is naturally formed by the blank body and does not require separate processing.

[0042] After assembly, the central axes of the sleeve 107 and the core 106 coincide, ensuring that a uniformly spaced annular filling gap is formed between the sleeve 107 and the core 106. This gap provides uniform space for the subsequent filling of the insulating medium, ensuring that the insulating medium can be filled uniformly between the sleeve 107 and the core 106 without dead corners. This avoids the problem of local electric field concentration caused by uneven filling thickness due to uneven gaps. At the same time, it also allows the filled insulation layer to form a uniform protective barrier, improving the overall insulation performance and structural stability.

[0043] The upper capacitor plate 105 and the lower capacitor plate 109 are four- or six-electrode structures. That is, they are each composed of four or six independent metal electrode units that are centrally symmetrically distributed, with an insulation gap of 0.3 mm to 1.0 mm reserved between each electrode unit.

[0044] The four-plate structure can effectively increase the equivalent capacitance of capacitive coupling within a limited installation space, while balancing the electric field distribution at the electrode edges. The six-plate structure further optimizes the electric field gradient distribution, which can effectively suppress the initiation of corona discharge.

[0045] The electrode units of this type of electrode structure are made of copper foil, silver-plated copper sheets or stainless steel sheets. The overall shape is circular or polygonal, with an outer diameter or circumscribed circle diameter of φ40 mm to φ80 mm. The thickness of a single electrode unit is 0.2 mm to 0.5 mm, and the surface roughness Ra≤0.8 μm. This can reduce the energy loss caused by the high-frequency skin effect. Furthermore, the electrode surface can be silver-plated or passivated to further improve the corona resistance.

[0046] In this embodiment of the invention, the upper capacitor plate 105 and the lower capacitor plate 109 are circular or polygonal (such as rectangular, regular hexagonal or regular octagonal, etc.). The outer diameter of the circular capacitor plate, the outer circle diameter of the polygonal capacitor plate and the thickness of the capacitor plate can be set according to the size of the cavity (such as φ40 mm~φ80 mm, thickness of 0.2 mm~0.5 mm). The electrode material is copper foil, silver-plated copper sheet or stainless steel sheet, and its surface roughness Ra≤0.8 μm, so as to reduce high-frequency skin effect loss.

[0047] like Figure 3 As shown, the electrode units of the upper capacitor plate 105 and the lower capacitor plate 109 are arranged on the surface of the partition in two structural forms: a ring-shaped arrangement and a parallel plate arrangement. Figure 3 As shown in -a, in the ring-shaped structure, multiple electrode units are concentrically ringed or symmetrically distributed around the center along the surface of the partition, forming a ring-shaped enclosed electric field distribution. This effectively expands the effective area of ​​capacitive coupling, makes the electric field uniformly distributed in the radial direction, and reduces the edge electric field concentration effect. It is suitable for scenarios with high voltage levels and strict requirements for electric field uniformity; for example... Figure 3As shown in -b, in the parallel plate structure, multiple electrode units are arranged in an array on the surface of the partition plate. Each electrode unit is separated by an insulating gap, forming a multi-channel parallel coupling path. This allows for higher equivalent coupling capacitance within a limited space, facilitating independent multi-path connections to external circuits. It is suitable for applications requiring high power density and compact structures. Both arrangements can be configured based on the device's rated voltage, power transfer capacity, installation space, and manufacturing process.

[0048] The structure, shape, and material of the capacitor plate can be determined based on actual structural size constraints, installation space layout requirements, electric field distribution uniformity requirements, operating voltage level, insulation margin requirements, and manufacturing process feasibility. This application does not impose any special limitations on these aspects.

[0049] The upper capacitor plate 105 and the upper surface of the partition are bonded and cured with conductive silver paste, and the lower capacitor plate 109 and the lower surface of the partition are bonded and cured with conductive silver paste. The thickness of the bonding layer can be controlled within a certain range (such as 10 μm to 20 μm). This ensures the reliability of the electrical connection and avoids the reduction of dielectric strength due to excessive interface layer thickness.

[0050] The connecting wire 202 on the two capacitor boards can be made of tinned copper stranded wire with a cross-sectional area of ​​0.5 mm² to 1.5 mm². One end of the connecting wire 202 is crimped to the electrode lead-out pad, and the other end is led out after passing through the reserved through hole of the corresponding end cap. The lead-out section is covered with a high-temperature resistant insulating sleeve 107.

[0051] The insulating medium is any one or a mixture of epoxy resin, silicone, polyurethane, or organosilicon gel.

[0052] The epoxy resin system uses a blend of bisphenol A and alicyclic epoxy, with fumed silica added as a thixotropic agent and aluminum hydroxide as a flame-retardant filler. The volume resistivity at 25°C is not less than 1×10⁻⁶. 14 Ω·cm, dielectric constant is 3.5~4.2; silicone and organosilicon gel have excellent flexibility and stress buffering capacity, and are suitable for scenarios with thermal expansion and contraction or mechanical vibration.

[0053] During filling, the insulating medium fills the upper cavity 200 and lower cavity 201 of the core 106, as well as all gaps between the sleeve 107 and the core 106, and between the capacitor plate and the core 106, to achieve a fully sealed encapsulation. After curing, the insulating medium forms microscopic mechanical and chemical bonds with the surfaces of the core 106 and the sleeve 107, improving the interfacial shear strength and suppressing the relative slippage and loosening tendency between components. This not only enhances the insulation performance but also buffers vibration, suppresses partial discharge, and prevents moisture intrusion.

[0054] The upper and lower end caps are made of metal or reinforced engineering plastic, with annular sealing grooves machined on their inner sides. The groove width (e.g., 3 mm to 6 mm) and groove depth (e.g., 2 mm to 4 mm) can be set as needed. The rubber sealing rings are O-rings made of fluororubber (FKM) or ethylene propylene diene monomer (EPDM). The inner cavities of the upper and lower end caps are also coated with insulating resin (e.g., modified epoxy resin or silicone resin). After heating and curing, this insulating resin forms a tight seal, providing waterproofing, moisture protection, and blocking surface discharge channels.

[0055] The upper and lower end covers are also provided with lead-out holes, through which the connecting wires of the upper capacitor plate 105 and the lower capacitor plate 109 are led out respectively. The lead-out holes are provided with insulating bushings and potting sealant to prevent the root of the lead wire from becoming a point of electric field concentration.

[0056] During assembly, the sealing ring is first embedded into the sealing groove, and the inner cavity of the end cap is coated with insulating resin. Then, the end cap is pressed axially into the sleeve port, and a preload of 0.3 MPa to 0.6 MPa is applied. Finally, it is heated and cured. In this way, the mating surface between the end cap and the sleeve is filled with insulating resin. This resin is homologous to or compatible with the aforementioned insulating medium. After curing, it forms a continuous and dense annular insulating seal, which not only strengthens the electrical insulation at the end but also compensates for mechanical assembly tolerances and prevents creepage along the interface.

[0057] As can be seen from the above, the energy transfer device of this application constructs a five-level insulation collaborative structure consisting of a rigid core 106 bearing, multi-pole capacitive coupling, insulating and sealed filling, hydrophobic extension of the umbrella skirt 108, and double sealing of the end cap: the core 106 serves as a high dielectric strength rigid skeleton, simultaneously undertaking the functions of structural support and main insulation; the upper and lower capacitor plates are arranged in a four / six-pole symmetrical layout, maximizing the coupling area and minimizing the edge field strength within a limited space; the insulating medium is simultaneously filled in three regions: the upper cavity 200, the lower cavity 201, and the annular gap, eliminating all potential air gaps and suppressing the initiation of partial discharge; the umbrella skirt 108, combined with the nano-modified layer, actively regulates the interface, effectively extending the creepage distance of the surface leakage current; the end cap sealing groove, rubber ring, and insulating resin sealing constitute a multi-level physical barrier, completely blocking the intrusion path of moisture and contaminants.

[0058] During operation, when the high-voltage direct current is converted into high-frequency alternating current with a frequency of 100 kHz to 1 MHz by the inverter 102 and applied to the upper capacitor plate 105, the upper capacitor plate 105 and the partition form the first-stage parallel plate capacitor. After its alternating electric field penetrates the dielectric of the partition, it induces an alternating voltage of the same frequency in the lower capacitor plate 109. This induced voltage is converted into direct current by the rectifier 103 and supplied to the load. The entire energy transfer process does not rely on conductor connections, but is achieved only through capacitive coupling. The core 106, the insulating dielectric, the umbrella skirt 108 coating, and the end cover sealing structure together form an insulating barrier that runs through the entire path of the device, so that the high potential area (e.g., +200 kV) where the upper capacitor plate 105 is located and the low potential area (e.g., 0 V) ​​where the lower capacitor plate 109 is located maintain stable potential isolation, ensuring the safety of energy transfer.

[0059] like Figure 2 As shown, in actual use, the two ends of the energy transfer device of the present invention are respectively connected to an inverter 102 and a rectifier 103. The inverter 102 obtains initial electrical energy input from an external high-voltage power supply 101, and provides alternating electrical energy to the transmitting end after high-frequency inversion processing; the alternating electrical energy is transmitted to the rectifier 103 after being transmitted by the energy transfer device of this application; the rectifier 103 performs rectification and voltage regulation processing on the electrical energy induced at the receiving end, and its output end is connected to a low-voltage load 104.

[0060] Among them, the high-voltage power supply 101 is an external DC high-voltage generator or a DC power supply module after voltage stabilization and filtering, which is used to provide initial power input for the entire device. Its output voltage level can be set according to the system insulation withstand capability and power transmission requirements.

[0061] For example, any DC voltage value within the range of 10kV to 500kV can be used, with the specific value designed to match the actual application scenario and insulation structure parameters.

[0062] The inverter 102 can be a high-frequency inverter circuit with a full-bridge or half-bridge topology. Its input terminal is connected to a high-voltage DC power supply, and its output terminal is electrically connected to the upper capacitor plate 105 through a lead (leading out from the upper end cover 301). The inverter 102 is configured to convert the input high-voltage DC power into high-frequency AC power (such as a frequency range of 10 kHz to 1 MHz) and apply it to the upper capacitor plate 105. This frequency can be adjusted according to the actual coupling efficiency, dielectric loss characteristics and electromagnetic compatibility requirements.

[0063] For example, the kHz, 100 kHz or 400 kHz can be selected; the switching device of the inverter 102 can be SiCMOSFET or GaN HEMT to adapt to high voltage and high frequency operating conditions; its drive and control unit can be integrated in an insulating package or placed outside a safe distance and connected to the upper capacitor board 105 through a high voltage insulating lead.

[0064] The rectifier 103 can be a full-wave rectifier bridge or a synchronous rectifier circuit. Its input terminal is electrically connected to the lower capacitor plate 109 through a lead wire (leading out from the lower end cover 302), and its output terminal is connected to the load. The rectifier 103 is configured to rectify the AC power induced by the lower capacitor plate 109 under the action of the alternating electric field into a stable DC power and supply power to the load. The rectified output voltage can be set according to the load requirements.

[0065] For example, for 5 V, 12 V or 24 V DC, rectifier 103 can be further connected to a voltage regulator module and a filter capacitor to suppress ripple and improve power quality. Its power rating matches the output of inverter 102, supporting load power supply capabilities from milliwatt to hundred watts.

[0066] Among them, the low-voltage load 104 is an external DC power device, which can be a sensor, communication module, actuator, small DC motor or energy storage battery, etc. Its rated operating voltage range is 3.3V to 48V, and the power level is from milliwatt to kilowatt, depending on the coupling capacitor capacity, operating frequency and insulation medium characteristics.

[0067] The electrical connections between the inverter 102 and the upper capacitor plate 105, and between the rectifier 103 and the lower capacitor plate 109, are all achieved using high-voltage insulated wires. The outer layer of the wires is covered with silicone rubber or polytetrafluoroethylene insulation, and the rated withstand voltage is not less than 1.5 times the highest operating voltage of the system. Stress buffer structures and local electric field shielding rings are provided at the connection points to prevent end corona discharge. All electrical interfaces are located outside the upper end cover 301 and the lower end cover 302, and are treated with epoxy resin potting or heat shrink tubing 107 for secondary insulation.

[0068] When the energy transfer device is working, after the high-voltage DC power supply is connected to the input terminal of the inverter 102, the inverter 102 converts it into high-frequency AC power and applies it to the upper capacitor plate 105, so that the upper capacitor plate 105 has a high-frequency alternating potential relative to the ground potential. This alternating potential excites an alternating electric field in the insulating medium inside the core 106, penetrates the partition and acts on the lower capacitor plate 109, inducing an AC voltage with the same frequency and phase (or with a definite phase difference) on the lower capacitor plate 109. This induced voltage is rectified and filtered by the rectifier 103 to form a stable DC output, which is used by low-voltage side loads such as sensors, communication modules or microcontrollers. The entire energy transfer process does not rely on direct connection of wires, and completes the energy crossing across the insulation barrier entirely based on the capacitive coupling mechanism. Moreover, because the device of this application has excellent dielectric strength, creepage distance and environmental stability, the system can operate continuously and reliably in harsh field environments such as humidity, dirt and vibration.

[0069] Example 2:

[0070] Figure 4A schematic flowchart illustrating a manufacturing method for a high-voltage wireless power transfer insulation device according to the present invention is shown. This manufacturing method can be used to prepare the capacitively coupled high-voltage wireless power transfer insulation device described above, such as... Figure 4 As shown, the manufacturing method includes the following steps:

[0071] Step S1: Manufacturing the core.

[0072] In this embodiment of the invention, the core 106 is prepared by molding. After preparation, a capacitor plate 105 and a lower capacitor plate 109 are respectively installed at the bottom of the upper cavity 200 and the lower cavity 201 of the core 106. Specifically, the following steps are included:

[0073] S11: Manufacturing core blanks.

[0074] First, a molding mold is prepared according to the design dimensions of the core 106. The inner cavity shape of the mold matches the outer shape of the core 106 and the contours of the upper cavity 200 and the lower cavity 201.

[0075] Secondly, alumina ceramic or quartz glass powder is selected, and an appropriate amount of binder and dispersant are added. After ball milling and mixing, a uniform slurry or granulated powder is obtained.

[0076] Then, the mixed raw materials are injected into the mold, and the injection molding or dry pressing process is adopted. The pressure is maintained for a certain period of time under the set pressure so that the powder fills the mold cavity densely, forming a cylindrical integrated green body with an upper cavity 200 and a lower cavity 201.

[0077] Finally, the green blanks are visually inspected and their dimensions are randomly checked. Unqualified products with cracks, missing corners, or out-of-tolerance dimensions are removed. Qualified green blanks are trimmed to remove burrs and are then placed in a constant temperature and humidity environment to dry naturally, controlling the drying shrinkage rate and preventing cracking and deformation.

[0078] S12: Raw material debinding and high-temperature sintering.

[0079] The qualified green blanks are placed in a high-temperature sintering furnace and the binder is first removed. Specifically, the temperature is raised from room temperature to 400℃ to 600℃ at a slow heating rate of 0.5 to 1.0℃ / min, and held in this temperature range for 3 to 5 hours to allow the binder and other organic additives to fully volatilize and be removed.

[0080] After the adhesive is removed, the temperature is raised again for high-temperature sintering. Specifically, for alumina ceramics, the temperature is raised to 1600℃~1750℃ at a rate of 3~5℃ / min and held for 2~4 hours; for quartz glass, the temperature is raised to 1150℃~1300℃ at a rate of 2~4℃ / min and held for 1~3 hours.

[0081] During the sintering process, an oxidizing atmosphere or vacuum must be maintained inside the furnace, with a temperature control accuracy of ±5℃. After sintering, the furnace should be slowly cooled to room temperature at a rate not exceeding 3℃ / min to prevent thermal stress cracking.

[0082] After sintering, the core achieves densification, with a bulk density exceeding 98% of the theoretical density and a porosity below 0.5%, resulting in excellent insulation properties and mechanical strength. The sintered core exhibits uniform dimensional shrinkage while maintaining the precise shape and surface finish achieved during mold forming.

[0083] Meanwhile, the sintered core needs to be visually inspected and its dimensions measured to ensure that there are no cracks or deformations, and that the overall dimensional tolerance is controlled within ±0.05 mm.

[0084] S13: Precision grinding.

[0085] The sintered core 106 is fixed on the worktable of a precision grinding machine, and the surface of the core 106 (including the bottom surface of the upper cavity 200 and the lower cavity 201) is ground with a diamond grinding wheel to ensure that the flatness is better than ±2 μm and the surface roughness Ra≤0.4 μm, so as to provide a flat interface for the subsequent bonding of the capacitor board.

[0086] Meanwhile, the outer diameter and end face of the core 106 are precision ground to ensure the fitting accuracy with the sleeve 107. Coolant is used to fully cool the core during grinding to prevent thermal damage. After machining, the core 106 is ultrasonically cleaned to remove residual grinding debris and oil stains from the surface.

[0087] S14: Install the upper capacitor board and the lower capacitor board.

[0088] First, select a suitable capacitor plate according to the parameter requirements of the energy transfer device. The structure, shape and material of the capacitor plate have been fully explained above, and will not be repeated here.

[0089] Secondly, conductive silver paste is uniformly coated on the bottom surface of the upper cavity 200 and the lower cavity 201 of the core 106. The capacitor plate is aligned with the preset position and a pressure of 0.1 MPa to 0.3 MPa is applied to control the thickness of the adhesive layer to 10 μm to 20 μm.

[0090] Then, place the assembly in an oven and heat it according to the curing process requirements of conductive silver paste, for example, keep it at 120℃~150℃ for 30min~60min, so that the capacitor plate and the bottom of the capacitor cavity form a firm electrical connection and mechanical fixation.

[0091] Finally, solder the connecting wire 202 to the preset lead-out end of the capacitor board. The connecting wire 202 is made of tin-plated copper stranded wire. The cross-sectional area of ​​the wire can be selected as needed (e.g., 0.5 mm² to 1.5 mm²). The solder joint must be smooth and burr-free, and sufficient length should be reserved for subsequent lead-out from the end cover.

[0092] Step S2: Place the sleeve over the outside of the core.

[0093] In this embodiment of the invention, the surface of the core 106 needs to be activated before assembly, and the central axes of the sleeve 107 and the core 106 need to be aligned during assembly.

[0094] It should be noted that this invention does not involve the manufacturing process of the sleeve 107; the pre-fabricated sleeve 107 is directly used, as long as the size and performance of the sleeve 107 meet the requirements. This step may specifically include the following sub-steps:

[0095] S21: Casing pretreatment and cleaning.

[0096] First, a hollow cylindrical sleeve 107 made of silicone rubber or ethylene propylene rubber is selected. Its axial length matches that of the core 106, and its inner diameter is slightly larger than that of the core 106 to facilitate assembly, and an annular gap is formed after assembly.

[0097] Then, place the sleeve 107 in an ultrasonic cleaner, add industrial alcohol or acetone, and ultrasonically clean for 10 to 15 minutes to remove mold release agent residue, oil stains, and dust particles from the inner and outer walls. After cleaning, remove it, wipe it dry with a lint-free cloth, and place it in a clean environment to allow residual solvents to evaporate naturally.

[0098] For the sleeve 107 whose surface requires an additional umbrella skirt 108, it is also necessary to check the integrity of the umbrella skirt 108 and measure whether the umbrella extension length and spacing meet the design values.

[0099] If a hydrophobic coating needs to be constructed on the surface of the umbrella skirt 108, after cleaning and drying, a fluorosilane self-assembled monolayer or an organosilicon modified coating doped with titanium dioxide or silicon dioxide nanoparticles should be applied by spraying or dipping. During spraying or dipping, the coating thickness should be controlled to be 2 μm to 5 μm. After spraying or dipping, it should be dried at 80°C for 30 min for curing.

[0100] S22: Set the screen to equalize voltage.

[0101] First, the equalizing screen material is processed into a layered structure with a thickness of 0.2 mm. The front and back sides of the equalizing screen are then subjected to low-temperature plasma activation treatment, as follows:

[0102] Evacuate to 10 Pa to 50 Pa, introduce oxygen or argon, use radio frequency power of 100 W to 300 W, and process for 1 min to 3 min to introduce active hydroxyl groups on the surface.

[0103] A 0.5%–2.0% (w / w) silane coupling agent solution is applied within 30 min, left to stand at room temperature for 15–20 min, and then cured by gradient heat treatment at 80℃–100℃ to form an interface reinforcement layer that can chemically bond with the insulating medium.

[0104] Then, the treated equalizing screen is fixed to the inner wall of the sleeve 107 by spraying or pasting, and an insulating layer is set between the equalizing screen and the inner wall of the sleeve 107 for isolation.

[0105] When using multi-layer equalizing screens, they are assembled sequentially from the inside out. After each equalizing screen is assembled, an insulating medium is coated on its surface and cured before the next equalizing screen is installed. At the same time, the axial length of each layer is controlled to decrease in a step-like manner, with the innermost layer being closest to the high-voltage end and the longest, and the outermost layer being closest to the low-voltage end and the shortest.

[0106] S23: Core surface activation treatment.

[0107] To improve the bonding strength between the insulating medium and the core 106 and avoid interfacial air gaps, the outer surface of the core 106 after the capacitor board installation is completed is activated. The specific steps are as follows:

[0108] S231: Perform low-temperature plasma treatment.

[0109] The core 106 to be processed is placed in a plasma processing device, the vacuum is evacuated to 10 Pa to 50 Pa, high-purity oxygen or argon is introduced as the process gas, the radio frequency power is set to 100 W to 300 W, and the surface of the component is bombarded for 1 min to 3 min.

[0110] This process can introduce a large number of active groups on the surface of the component, especially increasing the density of surface hydroxyl (-OH) groups, while removing microscopic contaminants from the surface, thereby significantly improving surface energy.

[0111] Specifically, the activation process parameters are optimized for different core materials 106. When the core material 106 is alumina ceramic, an oxygen atmosphere is preferred, the radio frequency power is controlled at 200 W to 250 W, and the processing time is 2 min to 3 min. When the core material 106 is quartz glass, an argon atmosphere is preferred, the radio frequency power is controlled at 150 W to 200 W, and the processing time is 1.5 min to 2.5 min.

[0112] S232: Perform chemical grafting of silane coupling agents.

[0113] Within 30 minutes after plasma treatment (to avoid surface activity degradation), a layer of silane coupling agent solution is immediately and uniformly coated on the surface of core 106 (including the outer circumferential surface of core 106, the inner wall of upper cavity 200 and the inner wall of lower cavity).

[0114] The silane coupling agent is selected from one or more of aminosilane coupling agents, epoxysilane coupling agents, or methacryloxysilane coupling agents, with a mass fraction of 0.5% to 2.0%, and the solvent is anhydrous ethanol or isopropanol. Short-chain silane coupling agents are preferred, with alkyl chain lengths of C1 to C3, to form a denser monolayer.

[0115] After coating, the mixture is left to stand in a clean environment at 20℃~30℃ for 15 min~20 min to allow the alkoxy groups of the silane coupling agent to undergo a condensation reaction with the surface hydroxyl groups generated by plasma in the first step, thereby forming a chemically bonded coupling agent molecular layer on the treated surface, achieving the transition from an inorganic surface to an organic interface.

[0116] S233: Perform gradient heat treatment.

[0117] The core 106 coated with coupling agent is placed in an oven and heated to 80℃~100℃ at a slow heating rate of 1℃ / min~2℃ / min, and held at this temperature for 10 min~30 min.

[0118] This step aims to promote further cross-linking of the coupling agent molecular layer, forming a dense and stable interface reinforcement layer, while removing residual solvent. After this combined process, a strong chemical bond interface is formed between the surface of the core 106 and the subsequently filled insulating media such as epoxy resin and silicone.

[0119] Tests showed that the interfacial bonding strength between the core 106 and the insulating medium was significantly improved after the activation process was adopted. The shear strength was measured to be no less than 3.2 MPa, which effectively prevented the formation of interfacial discharge channels and ensured the insulation reliability of the device under long-term high voltage conditions.

[0120] It should be noted that after processing, core 106 should proceed to the next assembly process (filling with insulating medium) within 30 minutes to prevent surface contamination or activity degradation.

[0121] S24: Assembly positioning and coaxial adjustment.

[0122] First, place the activated core 106 vertically on the lower positioning seat of the assembly fixture, ensuring that the axis of the core 106 coincides with the center line of the fixture.

[0123] Then, take the pre-treated sleeve 107 and slowly slide it into the core 106 from top to bottom, taking care to avoid tilting the sleeve 107 and scratching the surface of the core 106 or the capacitor board leads.

[0124] After the sleeve 107 is inserted into the predetermined position, its upper and lower ends should extend beyond the upper and lower surfaces of the core 106 by a certain distance to accommodate the subsequent end cap installation space.

[0125] Finally, a three-jaw or four-jaw centering fixture is used to clamp the outer wall of the sleeve 107. A laser centering instrument or dial indicator is used to detect the relative position of the inner wall of the sleeve 107 and the outer circle of the core 106. The sleeve 107 is finely adjusted until the central axes of the two coincide, so as to ensure that the annular cavity between the sleeve 107 and the core 106 is evenly spaced in all radial directions, and the single-sided gap deviation is controlled within ±0.2 mm.

[0126] After the coaxial adjustment is completed, temporary support blocks or positioning pins are used to lock the relative positions of the sleeve 107 and the core 106 to prevent displacement during subsequent operations.

[0127] S25: Temporary sealing and inspection of the bottom.

[0128] To prevent leakage from the bottom during the subsequent injection of the insulating medium, a temporary seal is applied to the bottom of the annular gap between the lower end of the bushing 107 and the core 106. This can be achieved by wrapping high-temperature resistant tape around the circumference or by using a special bottom sealing ring in conjunction with a rubber gasket for compression.

[0129] After sealing, check the uniformity of the gap: use a feeler gauge to insert into the annular gap at multiple points along the circumference, measure the actual gap value and record it to ensure that the uniformity of the gap meets the design requirements, and the difference between the maximum and minimum gap does not exceed 10% of the average gap. If the gap deviation exceeds the tolerance, the centering fixture needs to be loosened and readjusted.

[0130] After verifying that everything is correct, remove any debris or contaminants that may have been generated during the adjustment, and blow the inside of the assembly clean with compressed air before proceeding to step S3, the insulation medium injection process.

[0131] Step S3: Filling and curing of the insulating medium.

[0132] This step employs a vacuum-assisted injection process to fill the insulating medium into the annular filling gap between the upper cavity 200, the lower cavity 201, and the sleeve 107 and the core 106. Specifically, it includes the following sub-steps:

[0133] S31: Preparation of media materials and degassing treatment.

[0134] First, based on design requirements, one or more of the following mixtures of epoxy resin, silicone, polyurethane, or organosilicon gel are selected as the insulating medium. This embodiment of the invention uses epoxy resin as an example to illustrate the subsequent processes.

[0135] Then, weigh out the bisphenol A type epoxy resin, alicyclic epoxy resin, curing agent, accelerator, and functional fillers such as fumed silica and aluminum hydroxide according to the formula, and place them in a mixing tank and mechanically stir for 15 min to 30 min to make the components evenly mixed.

[0136] Finally, the mixture is transferred to a vacuum degassing kettle and degassed for 30 to 60 minutes under a vacuum of ≤10 Pa until no more bubbles escape from the liquid surface, ensuring thorough degassing.

[0137] During the degassing process, low-frequency vibration can be used to promote the upward escape of deep bubbles.

[0138] S32: Assembly preheating and glue injection port setting.

[0139] First, the core 106 and sleeve 107 assembly that has been assembled in step S2 is placed in an oven and preheated at 60℃~80℃ for 1h~2h to remove the moisture adsorbed on the inner wall of the core 106 and sleeve 107, and at the same time improve the fluidity of the medium during subsequent glue injection.

[0140] Then, after preheating, remove it and place it vertically on the glue injection fixture, with the mounting surface of the upper end of the sleeve 107 facing upwards. Install a glue injection funnel or glue injection nozzle at the opening of the annular gap between the upper end of the sleeve 107 and the core 106 as the medium injection inlet; at the same time, reserve an exhaust port at the bottom of the annular gap between the lower end of the sleeve 107 and the core 106, which can be connected to a transparent hose to observe the medium filling status.

[0141] Finally, check the sealing of all interfaces to prevent leakage during the dispensing process. You can fill the system with dry nitrogen at 0.1MPa to 0.2MPa, maintain the pressure for 5 minutes, and observe whether the pressure gauge reading drops to ensure there are no leaks in the dispensing system.

[0142] S33: Vacuum-assisted constant pressure injection.

[0143] To achieve bubble-free, highly dense, and strong-interface insulating medium filling, and to ensure the insulation reliability and long-term stability of the device under ultra-high voltage, this invention employs a vacuum-assisted constant-pressure injection process for the insulating medium, enabling precise control of the medium filling behavior. Specifically, the process includes the following steps:

[0144] S331: Perform multi-stage gradient vacuuming.

[0145] The assembly of the core 106 and sleeve 107 to be potted is placed in a vacuum potting device, and a vacuum is gradually drawn using a staged pressure reduction method:

[0146] The first stage involves using a coarse pump to reduce the cavity pressure to 100 Pa to 500 Pa and maintaining it for 5 to 10 minutes to remove most of the free gas in the cavity. The second stage involves starting a molecular pump or diffusion pump to further reduce the pressure to 5 Pa to 10 Pa and maintaining it for 10 to 15 minutes to remove the deep gas adsorbed on the surface of the core 106 and in the gaps of the module. The third stage involves continuing to evacuate to the ultimate vacuum level ≤ 1 Pa and maintaining it for 5 to 8 minutes to bring the area to be filled to a high vacuum state.

[0147] This multi-stage gradient vacuum process can effectively avoid local gas expansion and material surface damage caused by excessive pressure drop, while ensuring that all gas in the micro gaps in the cavity is completely discharged, creating a gas-free environment for subsequent glue injection.

[0148] S332: Perform vacuum negative pressure assisted glue injection.

[0149] Under conditions of maintaining a high vacuum (≤5Pa), the degassed insulating medium is introduced into the area to be filled through the dispensing pipeline by utilizing the pressure difference between the inside and outside of the cavity. The dispensing pipeline adopts a heated jacket design, and the medium temperature is controlled within ±1℃ of the set value by a precision temperature control system to ensure that the medium viscosity is maintained within the optimal flow range.

[0150] For epoxy resin media, the temperature is controlled at 50℃~70℃ to reduce the viscosity to 200mPa·s~500mPa·s; for silicone media, the temperature is controlled at 30℃~50℃ to keep the viscosity within a suitable range of 1000mPa·s~3000mPa·s.

[0151] The injection port is located at the lowest point or side of the area to be filled. Bottom injection or side injection is used, and the medium is slowly filled from bottom to top by the suction effect of vacuum negative pressure. This is conducive to the accumulation of gas at the top and its continuous removal by the vacuum system.

[0152] S333: Perform constant pressure holding.

[0153] Once the medium completely covers the area to be filled, the vacuum line is shut off, and a constant pressure is applied to the glue injection line to enter the constant pressure injection stage.

[0154] A precision pressure control system is employed, which adjusts the injection pressure in real time via a proportional regulating valve to keep pressure fluctuations within ±2% of the set value. In this embodiment of the invention, the injection pressure set value is 0.25MPa to 0.35MPa.

[0155] During the constant pressure injection process, an ultrasonic level sensor or a capacitive level gauge is used to monitor the advancing position of the media filling front in real time. The injection rate is dynamically adjusted by the control system to ensure that the media is smoothly advanced at a constant speed of 0.5 mm / min to 2.0 mm / min, avoiding air bubble entrainment due to excessive flow rate or premature gelation due to excessive flow rate.

[0156] To improve the filling effect in complex structural areas, this invention further employs pulsed pressure-assisted technology in this step: when the medium flows through narrow areas such as coil gaps and the root of the magnetic core, the injection pressure is pulse-modulated at a frequency of 0.1Hz to 0.5Hz, and the pressure amplitude fluctuates within ±20% of the reference pressure.

[0157] This pulsed pressure forces the medium to repeatedly squeeze and release, promoting its penetration into the depths of microscopic gaps, while also helping trapped microbubbles to rise and escape. Experiments show that, with pulsed pressure-assisted technology, the filling rate of the gaps between coil turns can reach over 99.5%.

[0158] S334: Perform pressure holding and compression compensation.

[0159] When the medium completely fills the area to be filled and begins to flow continuously from the vent, close the vent valve and enter the pressure holding and compression stage.

[0160] Maintain the injection pressure for 20 to 40 minutes to allow the medium to continuously wet the micro-unevenness of the filling interface under pressure, while compensating for the volume reduction caused by the medium continuing to penetrate into the micro-cracks.

[0161] During the pressure holding process, miniature pressure sensors placed at key locations monitor the internal pressure distribution of the medium in real time. When the pressure at the monitoring point drops below a set threshold (e.g., 5%), the replenishment program is automatically initiated to add a small amount of medium to maintain pressure balance. This pressure holding and replenishment process effectively eliminates local voids caused by medium penetration and initial shrinkage, ensuring the compactness and dimensional stability of the filler.

[0162] The insulating filler prepared by the above-described vacuum-assisted constant-pressure potting process has an internal porosity ≤0.5%, an interfacial bonding strength ≥4.0MPa between the dielectric and the core 106, capacitor plate, and bushing 107, a curing shrinkage rate ≤1.2%, and a partial discharge quantity of less than 2pC at 500kV. Compared with conventional vacuum potting processes, the process of this invention significantly reduces the interfacial defect rate and significantly improves the volume resistivity of the insulating dielectric, providing highly reliable insulation protection for wireless power transmission.

[0163] S34: Staged temperature-curing.

[0164] After the glue is applied, close the glue inlet, keep the assembly vertical, and move it into the curing oven along with the glue application fixture.

[0165] Based on the material properties of different insulating media, this invention adopts differentiated staged curing processes to optimize curing quality, eliminate internal stress, and ensure interfacial bonding strength. Specifically, different curing process parameters are set for epoxy resin and silicone as the two insulating media.

[0166] When epoxy resin is selected as the insulating medium, a four-stage synergistic curing process is adopted, as follows:

[0167] S34a1: Perform low-temperature pre-curing.

[0168] Heat to 75℃~85℃, preferably 80℃±3℃, at a heating rate of 0.5℃ / min~1.0℃ / min, and hold for 2 hours~3 hours.

[0169] This stage employs a low heating rate and temperature plateau to allow the epoxy resin to undergo a slow gelation transformation. During the transition from liquid to gel state, the initial curing shrinkage stress is fully released, preventing the accumulation of reaction heat that could lead to localized overheating.

[0170] S34a2: Perform medium-temperature transition curing.

[0171] Heat to 95℃~105℃, preferably 100℃±3℃, at a heating rate of 0.8℃ / min~1.5℃ / min, and hold for 1 hour~2 hours.

[0172] This stage is the accelerated cross-linking reaction period. A micro-positive pressure of 0.1MPa to 0.2MPa can be applied to the glue injection system, which can effectively suppress the macroscopic deformation caused by volume shrinkage, promote the tight adhesion between the resin and the core and coil surface, and increase the interfacial bonding strength by 15% to 25%.

[0173] S34a3: Cured at high temperature.

[0174] Heat to 120℃~135℃, preferably 120℃~130℃, at a heating rate of 1.0℃ / min~2.0℃ / min, and hold for 5 hours~6 hours to ensure complete curing of the core medium.

[0175] This stage achieves deep cross-linking of the resin system, enabling the glass transition temperature (Tg) to reach above 120℃ and the volume resistivity to be ≥1×10⁻⁶. 14 Ω·cm, dielectric strength ≥20kV / mm.

[0176] S34a4: Perform gradient cooling.

[0177] Slowly cool to below 60°C at a cooling rate of 0.5°C / min to 1.0°C / min, then allow to cool naturally to room temperature.

[0178] This gradient cooling process can effectively alleviate the interfacial thermal stress caused by the mismatch in thermal expansion coefficients between epoxy resin and core (with a difference of about 5 to 10 ppm / ℃), thereby effectively avoiding interface debonding or medium cracking caused by excessively rapid cooling. The residual thermal stress at the interface can be reduced by 40% to 60%.

[0179] Tests showed that the epoxy resin medium cured by the above process had a curing shrinkage rate of ≤1.5%, an interfacial shear strength of ≥4.5MPa, and a partial discharge of less than 3pC at 500kV.

[0180] When silicone is selected as the insulating medium, a simplified two-stage curing process is adopted, the specific process of which is as follows:

[0181] S34b1: Curing at a constant temperature.

[0182] Heat to 80℃~100℃ at a heating rate of 0.5℃ / min~2.0℃ / min, and hold for 3 hours~4 hours to cure.

[0183] The curing mechanism of silicone is different from that of epoxy resin. Its crosslinking reaction is milder and does not require staged control of multiple temperature platforms. However, the heating rate still needs to be controlled to avoid residual bubbles.

[0184] During the curing process, a slight positive pressure of 0.05MPa to 0.1MPa can be applied to the dispensing system. Since silicone has a lower viscosity than epoxy resin, appropriately reducing the pressure value can prevent excessive overflow of the medium and promote interfacial bonding.

[0185] S34b2: Gradient cooling stage.

[0186] Cool to below 60℃ at a cooling rate of 0.5℃ / min to 1.0℃ / min, then allow to cool naturally to room temperature. Silicone material itself has good flexibility and stress buffering capacity; gradient cooling is mainly used to prevent interfacial stress concentration caused by sudden temperature changes.

[0187] Tests showed that the volume resistivity of the silicone medium cured using the above process is ≥1×10⁻⁶. 14 With a dielectric strength of ≥18kV / mm and a partial discharge capacity of less than 5pC at 500kV, it can effectively buffer vibration stress during operation and improve the mechanical stability of the device due to its excellent flexibility.

[0188] In this application, the epoxy resin adopts a four-stage curing process to counteract its intrinsic characteristics of high shrinkage, high exothermicity, and high modulus. It releases internal stress and matches the thermal expansion difference of the ceramic interface through precise temperature and pressure control. On the other hand, the silicone adopts a two-stage curing process to accommodate its intrinsic characteristics of low shrinkage, low exothermicity, and low modulus. It absorbs stress by utilizing the material's own flexibility and only needs to ensure sufficient cross-linking.

[0189] By employing the differentiated, phased curing process tailored to the properties of epoxy resin and silicone materials, this invention achieves high-performance integrated molding of the insulating medium with the core, coil, and bushing.

[0190] S35: Post-curing inspection and repair.

[0191] After curing, allow the assembly to cool naturally to room temperature in the oven before removing it. Inspect the medium filling status of the upper and lower end faces. The medium surface should be smooth and clean, without shrinkage depressions, bubbles, or cracks. If shrinkage causes the medium surface to be lower than the end cap mounting plane, additional medium of the same system should be prepared for secondary filling and local curing.

[0192] Meanwhile, the insulation resistance between the capacitor plate leads and the outer wall of bushing 107 is measured using an insulation resistance tester, and should not be less than 1×10⁻⁶ at room temperature. 14 Ω·cm was used to verify the insulation performance of the insulating medium.

[0193] The test was passed, removing any trace amounts of residual medium that might have overflowed from the end face of sleeve 107, ensuring the end face is flat and clean, and preparing for the next step of end cap installation.

[0194] Step S4: End cap sealing and lead wire exit.

[0195] The upper end cap 301 and the lower end cap 302 are fixed to both ends of the sleeve 107, and the lead wire is led out and sealed. This step specifically includes the following sub-steps:

[0196] S41: End cap pretreatment and sealing ring installation.

[0197] Select the upper end cap 301 and lower end cap 302 made of metal or reinforced engineering plastic, and check the pre-set annular sealing groove on its inner side to ensure that the groove width and groove depth meet the design requirements.

[0198] Clean the inner and outer surfaces of the sealing groove thoroughly, ensuring they are free of oil and burrs. Select an O-ring made of fluororubber or EPDM rubber and embed it into the sealing groove, ensuring a uniform and undistorted fit.

[0199] At the same time, apply a thin layer of silicone grease or vacuum grease to the surface of the sealing ring to improve the sealing effect and facilitate subsequent assembly.

[0200] S42: The inner cavity of the end cap is coated with insulating resin.

[0201] A layer of insulating resin that is homologous to or compatible with the insulating medium is uniformly coated on the inner side of the end face where the end cap and sleeve 107 meet and around the sealing groove.

[0202] The coating can be applied by brushing or scraping, with the coating thickness controlled between 1 mm and 3 mm. The coating area should cover the bottom surface and side wall of the entire end cap cavity to a certain height, ensuring that the resin can fully contact the end face and inner wall of the sleeve 107 after the end cap is pressed together.

[0203] After coating, place the end caps in a clean environment and let them stand for 5 to 10 minutes to allow the resin to level out and remove any trapped air bubbles. However, do not leave them for too long to prevent the resin from gelling prematurely.

[0204] S43: Lead wire threading and positioning.

[0205] The connecting wire 202 of capacitor plate 105 is passed through the reserved through hole of upper end cover 301, and the connecting wire 202 of lower capacitor plate 109 is passed through the reserved through hole of lower end cover 302.

[0206] Before threading the wire, a rubber protective coil or a polytetrafluoroethylene sleeve 107 can be installed inside the through hole to prevent the wire insulation layer from being scratched by the sharp edge of the hole.

[0207] After threading the wires, the extension length of the lead wires needs to be adjusted. Generally, 50 mm to 100 mm should be reserved for subsequent electrical connections, and the wires should be temporarily fixed to prevent them from retracting.

[0208] For multiple leads in a multi-plate structure, the polarity should be distinguished according to the design drawings and temporary markings should be made to avoid confusion.

[0209] S44: End cap pressing and pre-tightening fixation.

[0210] Align the upper end cap 301 with the lead wire threaded on it with the upper port of the sleeve 107, and slowly press it in axially until the bottom surface of the inner cavity of the end cap contacts the end face of the sleeve 107. During the pressing process, carefully observe the position of the lead wire to avoid it being clamped or excessively bent.

[0211] During the pressurization process, a special press-fitting tool or hydraulic press can be used to apply an axial preload of 0.3 MPa to 0.6 MPa and maintain the pressure for 1 min to 2 min to fully compress and deform the sealing ring. At the same time, the insulating resin coated on the inner cavity of the end cover is evenly filled into the tiny gap between the end cover and the sleeve 107.

[0212] Then, install the lower end cover 302. The same steps are used during installation, so they will not be repeated here.

[0213] S45: Heating, curing and sealing molding.

[0214] The completed end cap assembly is moved into an oven and heated according to the curing process requirements of the insulating resin.

[0215] Taking epoxy resin as an example, the temperature is set to 80℃~100℃ for 1h~2h to allow the resin layer in the inner cavity of the end cap to fully cure and form a continuous and dense annular insulating seal.

[0216] During the curing process, the device needs to be kept vertically rotated to prevent uncured resin from flowing and causing uneven thickness. After curing, cool to room temperature with the oven and check the joint between the end cap and sleeve 107. There should be no resin overflow or gaps, and the sealing ring should be uniformly compressed and visible.

[0217] S46: Lead wire sealing and secondary insulation treatment.

[0218] First, at the root of the lead wire on the outside of the end cap, apply an insulating resin or silicone rubber of the same system as the inner cavity of the end cap to form a conical sealing sleeve that covers the edge of the end cap orifice to prevent moisture from seeping in along the wire interface.

[0219] Then, after the sheath has cured, a high-temperature heat-shrinkable sleeve is installed on the exposed section of the lead wire. After heat shrinking, the sleeve overlaps with the outer wall of the end cap by no less than 10 mm to achieve secondary insulation protection.

[0220] Finally, continuity and insulation resistance tests were performed on all leads to confirm that the electrical connections were reliable and that there were no short circuits with the metal parts of the end caps.

[0221] Step S5: Comprehensive test.

[0222] This step involves conducting comprehensive electrical performance and sealing reliability tests on the assembled capacitively coupled high-voltage wireless power transmission insulation device, specifically including the following sub-steps:

[0223] S51: Appearance and structural inspection.

[0224] First, a visual inspection of the entire device is carried out to confirm that there are no cracks, scratches, or stains on the surface of the sleeve 107, the upper end cap 301, the lower end cap 302, and the umbrella skirt 108, and that the joint between the end cap and the sleeve 107 is well sealed with no resin overflow or obvious gaps.

[0225] Check that the sealing sleeve at the root of the lead wire is intact and that the heat shrink tubing 107 is tightly wrapped without displacement. Measure the overall length, outer diameter, and other external dimensions of the measuring device to ensure they meet the requirements of the design drawings.

[0226] Use calipers or feeler gauges to check the joint gap between the end cap and sleeve 107; the maximum gap should not exceed 0.1 mm. Also check the clarity of the lead wire markings to confirm that the polarity is correctly distinguished.

[0227] S52: Lead wire continuity test.

[0228] Use a digital multimeter or micro-ohmmeter to perform a continuity test on each lead. Touch the multimeter probe to both ends of the lead on the same capacitor board and measure the DC resistance value. The value should match the resistance of the wire itself (usually less than 0.5 Ω). Confirm that there are no broken wires or poor soldering inside the connecting wire 202.

[0229] For multi-plate structures, the insulation resistance between the corresponding leads of each plate is measured to ensure that there is no short circuit between the plates and that the insulation gap is normal.

[0230] At the same time, the DC resistance between the lead wire of the upper capacitor plate 105 and the lead wire of the lower capacitor plate 109 is measured and should be infinite, confirming that there is no direct electrical connection between the upper and lower capacitor plates 109.

[0231] S53: Sealing and electrical performance test.

[0232] In this embodiment of the invention, the testing scope covers insulation resistance testing, power frequency withstand voltage testing, partial discharge testing, energy transfer efficiency testing, and sealing performance testing. Specifically:

[0233] S531: Insulation resistance test.

[0234] The critical insulation path of the device is tested using an insulation resistance tester (megohmmeter). The test voltage is selected according to the rated voltage level of the device; for example, for a 40.5 kV device, the 2500 V or 5000 V range is selected.

[0235] During testing, the following insulation resistances need to be measured separately: between the lead wire of the upper capacitor plate 105 and the outer wall of the sleeve 107, between the lead wire of the lower capacitor plate 109 and the outer wall of the sleeve 107, between the lead wire of the upper capacitor plate 105 and the lower end cover 302, and between the lead wire of the lower capacitor plate 109 and the upper end cover 301.

[0236] Under normal temperature conditions, all insulation resistance values ​​should not be less than 1×10⁻⁶. 14 Ω (or the limit specified in the product's technical specifications). After the test is completed, the tested part should be discharged to ensure safety.

[0237] S532: Power frequency withstand voltage test.

[0238] Place the device in the power frequency withstand voltage test system and apply the corresponding test voltage according to the rated voltage level. Referring to GB / T26218.2 standard, apply the rated short-time power frequency withstand voltage to the device (e.g., 85 kV dry test voltage for 40.5 kV level) for 1 minute.

[0239] During the test, it is necessary to continuously observe whether there is flashover or breakdown on the surface of the device, listen for any abnormal discharge sounds, and monitor whether the leakage current is stable.

[0240] If the test passes, continue applying a wet test voltage (simulating rain conditions) to verify the withstand voltage performance of the hydrophobic coating on the umbrella skirt 108 surface and the creepage distance in a humid environment. After the withstand voltage test, measure the insulation resistance again; there should be no significant decrease.

[0241] S533: Partial discharge test.

[0242] A partial discharge detector was used to perform a partial discharge test on the device. The device was connected to the partial discharge test circuit, and 1.1 to 1.2 times the rated phase voltage was applied to detect whether partial discharge existed inside the device.

[0243] For high-voltage capacitively coupled devices, special attention should be paid to the interior of core 106, the edges of the capacitor plate, and the interface area of ​​the insulating medium. Under rated voltage, the apparent discharge quantity inside the device should not exceed 10 pC (specific limits depend on product technical specifications).

[0244] If the partial discharge exceeds the standard, the discharge location needs to be analyzed, which may involve problems such as defects in the insulating medium, interfacial air gaps, or electric field concentration at the edge of the capacitor plate.

[0245] S534: Energy transfer efficiency test.

[0246] The wireless power transmission efficiency of the actual working circuit test device is constructed. The output terminal of inverter 102 is connected to the lead wire of upper capacitor board 105, the input terminal of rectifier 103 is connected to the lead wire of lower capacitor board 109, and the output terminal of rectifier 103 is connected to an adjustable electronic load.

[0247] Set the inverter 102 to operate at a frequency of 100 kHz (e.g., 100 kHz) and input the rated DC voltage. Gradually increase the electronic load from no load to the rated power (e.g., 200 W), measure the input power and output power respectively, and calculate the transmission efficiency under different loads.

[0248] Record the temperature rise of the device and run it continuously for 30 to 60 minutes to monitor efficiency stability. The efficiency should meet the design specifications (e.g., not less than 75%), and the temperature rise should not exceed the threshold.

[0249] S535: Sealing and airtightness test.

[0250] Verify the sealing performance of the device to ensure that moisture cannot penetrate the interior during long-term operation. This can be done using helium mass spectrometry leak detection or the bubble method.

[0251] In helium mass spectrometry, the apparatus is placed inside a vacuum chamber, and a vacuum is drawn externally. Helium gas is then injected at the root of the leads and the junction of the end caps. The leak rate should be less than 1.0 × 10⁻⁶. -9 Pa·m³ / s.

[0252] The bubble method is suitable for qualitative testing: Immerse the device in water, fill it with 0.2 MPa to 0.3 MPa of dry air from the lead wire end, maintain the pressure for 1 min to 2 min, and observe whether there are continuous bubbles escaping from the end cap joint and the root of the lead wire. No bubbles are considered as qualified.

[0253] S54: Comprehensive assessment and report issuance.

[0254] Summarize the above test data and determine whether each item passes or fails by comparing it with the product's technical specifications, as follows:

[0255] If all test items pass, the finished product is deemed qualified. A qualified label is affixed to the product body or lead wire label, and the product number, test date, tester and main test data are recorded. A comprehensive test report is then issued.

[0256] If any item fails to meet the requirements, analyze the cause and decide whether to rework, repair, or scrap it. After rework, the relevant items must be tested again.

[0257] The advantages of this invention are as follows: First, the core structure effectively increases the creepage distance between the upper and lower capacitor plates. Combined with the external insulation formed by the sheds and bushings, and the internal insulation formed by the insulating medium and the core, a multi-layer composite insulation system is formed, significantly improving the insulation reliability and withstand voltage capability of the device at high voltage levels. Second, the use of capacitive coupling wireless power transmission technology, along with the core made of low dielectric loss materials such as alumina ceramic or quartz glass, effectively reduces energy loss during transmission, achieving efficient and stable power transmission at high voltage levels. Third, the internal filling with high-insulation materials such as epoxy resin or silicone not only strengthens the insulation performance but also buffers the vibration stress generated during device operation, improving the overall structure's seismic resistance and mechanical strength, and extending the device's service life. Simultaneously, the device has a compact overall structure, small size, convenient installation, clear preparation steps, mature technology, and readily available materials, making it suitable for mass production and widespread application.

[0258] In summary, this invention, through the adoption of a core and composite insulation structure design combined with a capacitive coupling wireless power transmission method, achieves efficient and safe power transmission at high voltage levels, with significant improvements in insulation performance, increased energy transmission efficiency, and broad industrial application value.

[0259] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A capacitively coupled high-voltage wireless power transmission insulation device, characterized in that, The device includes a sleeve, the inner cavity of which is provided with a core made of insulating material, the core having an upper cavity and a lower cavity, the upper cavity and the lower cavity being separated by a partition; The upper and lower surfaces of the partition are respectively provided with an upper capacitor plate and a lower capacitor plate, and connecting lines are provided on both the upper and lower capacitor plates. The upper cavity, the lower cavity, and the gap between the sleeve and the core are all filled with an insulating medium. The two ends of the sleeve are respectively sealed with an upper end cap and a lower end cap; The connecting wires of the upper capacitor plate and the lower capacitor plate are respectively led out from the upper end cover and the lower end cover.

2. The capacitively coupled high-voltage wireless power transmission insulation device according to claim 1, characterized in that, The core material is alumina ceramic, quartz glass, aluminum nitride ceramic, silicon nitride ceramic, borosilicate glass, epoxy resin, polyimide, polytetrafluoroethylene, polyetheretherketone, or polyphenylene sulfide.

3. The capacitively coupled high-voltage wireless power transmission insulation device according to claim 1, characterized in that, The insulating medium is made of epoxy resin, silicone, polyurethane, or organosilicon gel.

4. The capacitively coupled high-voltage wireless power transmission insulation device according to claim 1, characterized in that, The upper capacitor plate has a four-electrode or six-electrode structure, and the lower capacitor plate has a four-electrode or six-electrode structure; the upper capacitor plate is circular or polygonal in shape, and the lower capacitor plate is circular or polygonal in shape.

5. The capacitively coupled high-voltage wireless power transmission insulation device according to claim 1, characterized in that, The inner cavities of the upper and lower end caps are coated with insulating resin.

6. The capacitively coupled high-voltage wireless power transmission insulation device according to claim 1, characterized in that, The inner wall of the sleeve is provided with an equalizing screen to improve the electric field distribution.

7. The capacitively coupled high-voltage wireless power transmission insulation device according to any one of claims 1 to 6, characterized in that, The outer side of the sleeve is provided with a skirt.

8. A method for manufacturing a high-voltage wireless power transmission insulation device, used to prepare the capacitively coupled high-voltage wireless power transmission insulation device as described in claim 7, characterized in that, The manufacturing method includes: S1: Manufacture a core having an upper cavity and a lower cavity, wherein an upper capacitor plate and a lower capacitor plate are respectively installed at the bottom of the upper cavity and the lower cavity; S2: The core is fitted into the sleeve, and the sleeve and the core are coaxially aligned. S3: Fill the upper cavity, lower cavity and gap between the sleeve and the core with insulating medium and then cure it; S4: Seal and fix the upper end cover and the lower end cover to both ends of the sleeve respectively, and lead out the connecting wires of the upper capacitor plate and the lower capacitor plate from the upper end cover and the lower end cover respectively.

9. The manufacturing method of the high-voltage wireless power transmission insulation device according to claim 8, characterized in that, In step S2, before the core is fitted into the sleeve, an equalizing screen needs to be installed on the inner wall of the sleeve.

10. The method for manufacturing the high-voltage wireless power transmission insulation device according to claim 8, characterized in that, In step S2, the surface of the core is activated before the sleeve is fitted. The activation process includes: The surface of the core is subjected to low-temperature plasma treatment to introduce active groups; A silane coupling agent solution is coated on the surface of the core, causing the silane coupling agent to undergo a condensation reaction with the active groups; The core coated with the silane coupling agent solution is subjected to gradient heat treatment to crosslink and solidify the silane coupling agent to form an interface reinforcement layer.

11. The manufacturing method of the high-voltage wireless power transmission insulation device according to claim 8, characterized in that, In step S3, the insulating medium is filled using vacuum-assisted constant-pressure injection, which includes: The cavity of the assembly to be filled is subjected to multi-stage gradient vacuuming to remove the gas in the area to be filled; While maintaining a high vacuum, an insulating medium is injected into the area to be filled in the assembly; After the insulating medium completely covers the area to be filled, turn off the vacuum and apply constant pressure to maintain constant pressure, so that the insulating medium continues to wet the filling interface. in: During the constant pressure holding process, when the internal pressure of the medium is detected to drop below a set threshold, the replenishment program is automatically started to replenish the medium and maintain pressure balance.

12. The manufacturing method of the high-voltage wireless power transmission insulation device according to claim 8, characterized in that, In step S3, the curing is achieved by staged temperature-increasing curing, which includes: When the insulating medium is epoxy resin, the following steps are performed in sequence: low-temperature pre-curing, medium-temperature transition curing, high-temperature post-curing, and gradient cooling. When the insulating medium is silicone, constant temperature curing and gradient cooling are performed sequentially. in: During both the intermediate temperature transition curing stage and the constant temperature curing stage, a slight positive pressure is applied to the dispensing system to suppress media volume shrinkage, promote tight interface adhesion, and enhance interface bonding strength.

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