A preparation method and application of a defect self-detecting basin-type insulator

Abstract

The application discloses a kind of preparation method and application of defect self-detection basin type insulator, comprising: after drying fused quartz powder, it is modified to obtain modified quartz powder by silane coupling agent KH-550 ethanol solution;ZnS: Cu fluorescent powder is washed with acid, washed, vacuum dried to obtain activated ZnS: Cu powder;Preparation ZnS:Mn@TiO2 Core-shell particles, mixed with activated ZnS: Cu powder and is treated with composite silane coupling agent, to obtain functional mixed filler;After the double phenol A type epoxy resin, modified quartz powder, functional mixed filler are mixed and defoamed, methyltetrahydrophthalic anhydride curing agent is added, to obtain mixed slurry, it is poured into 110 DEG C-130 DEG C mold in vacuum, pressure maintaining, solidification after demolding, to obtain basin type insulator.The basin type insulator of the application integrates multicolor electroluminescence sensing function, can be positioned insulating defect by characteristic wavelength signal, and the insulation, mechanical and thermal performance of basin type insulator is excellent.

Description

Technical Field

[0001] This application relates to the field of high-voltage power technology, and in particular to a method for preparing and applying a self-detecting pot-type insulator for defects. Background Technology

[0002] As power systems develop towards high voltage and ultra-high voltage, GIS (Gas Insulated Switchgear) is widely used due to its compactness and reliability. Basin-type insulators, as the core insulation and support components, directly affect the safety and stability of the power grid. However, basin-type insulators are prone to insulation defects such as cracks, air gaps, and metallic impurities during manufacturing, transportation, or long-term operation. If these defects are not detected in time, they may cause electric field distortion, partial discharge, or even equipment breakdown, leading to major power accidents. Therefore, accurate monitoring and early warning of basin-type insulator defects are a key requirement in the power operation and maintenance field.

[0003] Currently, condition monitoring technologies for basin-type insulators are mainly divided into two categories: traditional electrical monitoring and intelligent material sensing. Traditional electrical monitoring methods require equipment shutdown for offline withstand voltage tests, are susceptible to electromagnetic interference for online partial discharge detection, and cannot detect the internal electric field state through manual inspections. All these methods suffer from problems such as delayed warnings, ambiguous location, or high costs. Existing intelligent material sensing technologies rely on light intensity measurement, which is easily affected by ambient light and material aging. Their defect identification sensitivity and reliability are insufficient, making them unsuitable for the stringent operational requirements of GIS equipment. Furthermore, existing insulator manufacturing methods primarily focus on insulation performance optimization, failing to seamlessly integrate self-monitoring functions with the manufacturing process.

[0004] Therefore, how to provide a pot-type insulator that is compatible with the manufacturing process, has reliable performance, and can accurately locate insulation defects is a technical problem that urgently needs to be solved. Summary of the Invention

[0005] This application provides a method for preparing and applying a self-detecting pot-type insulator for defects, which solves the problems of substandard performance, poor process feasibility, and inability to accurately locate insulation defects in the prior art.

[0006] In a first aspect, embodiments of this application provide a method for preparing a defect-self-detecting basin-type insulator, comprising:

[0007] After drying the fused silica powder at 125℃±5℃, it was surface modified and cured with silane coupling agent KH-550 ethanol solution to obtain modified silica powder.

[0008] The ZnS:Cu phosphor was subjected to acid washing, centrifugal washing and vacuum drying to obtain activated ZnS:Cu powder;

[0009] ZnS:Mn@TiO2 core-shell particles were prepared by a non-hydrolyzed sol-gel method. Then, activated ZnS:Cu powder was mixed with ZnS:Mn@TiO2 core-shell particles and treated with a composite silane coupling agent to obtain a functional mixed filler.

[0010] Bisphenol A type epoxy resin, modified quartz powder and functional mixed filler are added to a mixer. After low-speed wetting, high-speed dispersion and vacuum degassing, methyltetrahydrophthalic anhydride curing agent is added and stirred evenly to obtain a mixed slurry.

[0011] The mixed slurry is vacuum-introduced into a mold at 110℃-130℃, nitrogen pressure is applied at 0.3-0.6MPa, the temperature is raised to 135℃ and held for 5 hours, and then cooled to below 60℃ before demolding to obtain an uncured pot insulator.

[0012] Uncured basin insulators are cured to obtain basin insulators. The curing process involves holding the insulator at 120°C for 8 hours.

[0013] In conjunction with the first aspect, in one possible implementation, the mass ratio of the activated ZnS:Cu powder to the ZnS:Mn@TiO2 core-shell particles is 3:1 to 1:3.

[0014] In conjunction with the first aspect, in one possible implementation, the mass ratio of the bisphenol A type epoxy resin to the methyltetrahydrophthalic anhydride curing agent is 100:85-115, and the mass ratio of the bisphenol A type epoxy resin, the modified quartz powder, and the functional mixed filler is 100:130-170:8-20.

[0015] In conjunction with the first aspect, in one possible implementation, 1 at.% Nb is introduced during the preparation of the ZnS:Mn@TiO2 core-shell particles. 5+ The product is doped and treated at 500℃ for 2 hours to form an anatase TiO2 shell with a thickness of 250-350nm.

[0016] In conjunction with the first aspect, in one possible implementation, the composite silane coupling agent is prepared by compounding γ-aminopropyltriethoxysilane and γ-(2,3-epoxypropoxy)propyltrimethoxysilane in a mass ratio of 1:2.

[0017] In conjunction with the first aspect, in one possible implementation, the acid washing conditions for the ZnS:Cu phosphor are: 0.1 mol / L hydrochloric acid solution, ultrasonic treatment at 200W for 30 minutes at 40°C, centrifugation at 8000 rpm, and washing until the conductivity of the supernatant is less than 5 μS / cm.

[0018] Secondly, embodiments of this application provide a basin insulator prepared using the method for preparing a defect self-detection basin insulator as described in the first aspect or any possible implementation of the first aspect, comprising:

[0019] The basin-type insulator is prepared by curing bisphenol A type epoxy resin, modified quartz powder, and functional mixed filler in a mass ratio of 100:130-170:8-20. The functional mixed filler is obtained by mixing activated ZnS:Cu powder and ZnS:Mn@TiO2 core-shell particles in a mass ratio of 3:1 to 1:3, followed by treatment with a composite silane coupling agent. Furthermore, the functional mixed filler exhibits an AC breakdown field strength greater than 35 kV / mm, a dielectric loss tangent less than 0.003 at 50 Hz, and a volume resistivity greater than 10¹⁰. 5 Ω cm.

[0020] Thirdly, embodiments of this application provide an application of a basin insulator prepared using the method for preparing a defect self-detection basin insulator described in the first aspect or any possible implementation of the first aspect, characterized in that it includes:

[0021] The basin-type insulator is used in high-voltage power distribution equipment. During normal operation, the healthy region and the defective region of the basin-type insulator emit characteristic wavelength signals. The characteristic wavelength signal emitted by the healthy region corresponds to a first characteristic wavelength range, which is from 540nm to 550nm. The characteristic wavelength signal emitted by the defective region corresponds to a second characteristic wavelength range, which is from 610nm to 620nm. The differences in the characteristic wavelength signals are distinguished and captured by a spectrometer, and the characteristic wavelength signals are compared with a preset spectral database to determine the insulation status of the basin-type insulator and the specific location of the defect.

[0022] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages:

[0023] In this embodiment, modified quartz powder is obtained by drying fused silica powder and then modifying it with KH-550. ZnS:Cu phosphor is acid-washed, washed, and vacuum-dried to obtain activated ZnS:Cu powder. ZnS:Mn@TiO2 core-shell particles are prepared, mixed with the activated ZnS:Cu powder, and treated with a composite silane coupling agent to obtain a functional mixed filler. Bisphenol A epoxy resin, modified quartz powder, and functional mixed filler are mixed, degassed, and then methyltetrahydrophthalic anhydride curing agent is added. The mixture is then vacuum-cast into a mold at 110℃-130℃, pressurized, cured, and demolded to obtain a basin-type insulator. The basin-type insulator of this application integrates multi-color electroluminescence sensing functionality, which can locate insulation defects through characteristic wavelength signals. Furthermore, the basin-type insulator exhibits excellent insulation, mechanical, and thermal properties. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments of this application or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 A schematic diagram of a self-detection basin-type insulator for defects provided in this application embodiment;

[0026] Figure 2 A schematic diagram of ZnS:Mn phosphor provided in an embodiment of this application;

[0027] Figure 3 A schematic diagram of ZnS:Mn@TiO2 core-shell particles provided in the embodiments of this application;

[0028] Figure 4 A comparison diagram of Au, Ti, Zn, and S elements provided for embodiments of this application;

[0029] Figure 5 Cross-sectional analysis diagram of ZnS:Mn@TiO2 core-shell particles provided in the embodiments of this application;

[0030] Figure 6 Electric field distribution data diagram of the uncoated TiO2 shell provided in the embodiments of this application;

[0031] Figure 7 Electric field distribution data diagram of the TiO2 shell provided in the embodiments of this application;

[0032] Figure 8 Voltage-color change test diagrams of ZnS:Mn, ZnS:Mn@TiO2 core-shell particles, and activated ZnS:Cu powder provided for embodiments of this application;

[0033] Figure 9 Finite element simulation diagram of the internal electric field distribution of a basin-type insulator provided in the embodiments of this application;

[0034] Figure 10 Numerical diagram of the internal electric field distribution of a basin-type insulator provided in an embodiment of this application;

[0035] Figure 11 Finite element simulation diagram of the electric field distribution when the internal particles of the basin insulator are not ideally uniformly distributed, provided in the embodiments of this application;

[0036] Figure 12 This is a voltage-color change test diagram of a basin-type insulator provided in an embodiment of this application;

[0037] Figure 13 Chromaticity trajectory diagrams of basin-type insulators under different voltages provided in embodiments of this application;

[0038] Figure 14 Electroluminescence spectrum of activated ZnS:Cu powder: ZnS:Mn@TiO2 core-shell particle ratio of 3:1 basin insulator provided in the embodiments of this application as a function of voltage;

[0039] Figure 15 Electroluminescence spectrum of activated ZnS:Cu powder: ZnS:Mn@TiO2 core-shell particles with a 1:1 ratio of ZnS:Mn@TiO2 core-shell particles as provided in the embodiments of this application as a function of voltage;

[0040] Figure 16 Electroluminescence spectrum of activated ZnS:Cu powder: ZnS:Mn@TiO2 core-shell particle ratio 1:3 basin insulator provided in the embodiments of this application as a function of voltage;

[0041] Figure 17 Electroluminescence spectrum of activated ZnS:Cu powder: ZnS:Mn@TiO2 core-shell particle ratio of 4:1 basin insulator provided in the embodiments of this application as a function of voltage;

[0042] Figure 18 Weibull distribution diagram of AC breakdown field strength of another basin insulator under different voltages provided in the embodiments of this application;

[0043] Figure 19 Dielectric constant diagram of a basin-type insulator provided in the embodiments of this application;

[0044] Figure 20 The dielectric loss frequency spectrum of the basin insulator provided in the embodiments of this application;

[0045] Figure 21Tensile stress-strain curve diagram of a basin insulator provided in the embodiments of this application;

[0046] Figure 22 Thermogravimetric analysis curve of a basin-type insulator provided in an embodiment of this application;

[0047] Figure 23 Comparison diagram of the defect electric field simulation of the basin insulator under working voltage provided in the embodiments of this application;

[0048] Figure 24 A comparative diagram of the defect electric field simulation of another basin-type insulator provided in this application embodiment under working voltage. Detailed Implementation

[0049] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0050] The following description of some technologies involved in the embodiments of this application is provided to aid understanding and should be considered merely exemplary. Therefore, those skilled in the art should recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this application. Similarly, for clarity and brevity, some descriptions of well-known functions and structures are omitted in the following description.

[0051] The process steps of the method for preparing a defect self-detection basin insulator provided in this application are as follows: raw material pretreatment and preparation of functional mixed filler → vacuum mixing and degassing → vacuum pressure casting and gradient curing → post-curing and fine processing, resulting in the following embodiments:

[0052] Example 1:

[0053] 1. Formulation design (by mass parts).

[0054] 100 parts of bisphenol A type epoxy resin and 85 parts of methyltetrahydrophthalic anhydride curing agent.

[0055] 130 parts of fused silica powder (which needs to be surface modified and cured into modified silica powder by silane coupling agent KH-550 ethanol solution, with a bimodal particle size distribution: 5μm (40%), 30μm (60%)).

[0056] Six parts of activated ZnS:Cu powder and two parts of ZnS:Mn@TiO2 core-shell particles.

[0057] An ethanol solution of silane coupling agent KH-550 (CAS No. 919-30-2) and a composite silane coupling agent are mixed at a mass ratio of 1:2.

[0058] 2. Preparation steps.

[0059] (1) Raw material pretreatment and preparation of functional mixed fillers.

[0060] 130 parts of fused silica powder were placed in a vacuum drying oven and dried at 125°C for 6 hours. The powder was then transferred to a high-speed heating mixer and sprayed with a 20wt% ethanol solution of silane coupling agent KH-550 (2.0wt% of silica powder by weight) under stirring at 80°C and 800rpm. The mixture was then cured in an oven at 110°C for 2 hours to obtain modified silica powder, which was then cooled, sealed, and stored for later use.

[0061] Six portions of ZnS:Cu phosphor were immersed in 0.1 mol / L hydrochloric acid solution and treated with ultrasound at 40℃ and 200W for 30 minutes. The mixture was then centrifuged at 8000 rpm and washed with deionized water until the conductivity of the supernatant was ≤5 μS / cm. The lower precipitate was then vacuum dried at 80℃ and -0.095 MPa for 12 hours to obtain activated ZnS:Cu powder.

[0062] Two portions of ZnS:Mn@TiO2 core-shell particles (average particle size 5 μm) were taken and dispersed in a mixed solvent of anhydrous acetic acid and acetylacetone (volume ratio 4:1). Under argon protection, the mixture was stirred at 85°C and 500 rpm. A solution containing 1 at.% Nb was then added dropwise at 1 mL / min using a micro-injection pump. 5+ A 0.5 mol / L tetrabutyl titanate / anhydrous acetic acid solution (using niobium pentachloride as the source) was used to react the particles for 6 hours. After centrifugation, the particles were washed three times with anhydrous ethanol and annealed at 500℃ under nitrogen atmosphere for 2 hours to form a TiO2 shell with a thickness of 250-280 nm. Scanning electron microscopy (SEM) confirmed that the ZnS:Mn@TiO2 core-shell particles were regular spherical with uniform surface coating. EDS (energy dispersive spectroscopy) surface scanning analysis showed that Zn, Ti, and S elements were evenly distributed (e.g., ...). Figures 2-5 As shown in the figure, there is no obvious aggregation phenomenon.

[0063] The electric field distribution of ZnS:Mn and ZnS:Mn@TiO2 core-shell particles was compared using Comsol finite element simulation. The results show that the electric field strength around the particles is significantly enhanced after coating with a TiO2 shell (e.g., ...). Figures 6-7As shown, Electricfield intensity (kV / mm) is the electric field intensity (unit: kilovolt per millimeter), Surrounding Electricfield intensity is the surrounding electric field intensity, Electricfield Distortion is the electric field distortion, Sample area is the sample region, and Electricfield direction is the electric field direction. Further simulation of the electric field distribution inside the raw materials for preparing the basin insulator revealed that the electric field intensity around the ZnS:Mn@TiO2 core-shell particles is much greater than that around the activated ZnS:Cu powder.

[0064] Luminescence tests were performed on ZnS:Mn@TiO2 core-shell particles, uncoated ZnS:Mn, and activated ZnS:Cu powder under the same voltage. The results showed that the luminescence intensity of the coated ZnS:Mn@TiO2 and the activated ZnS:Cu powder was not significantly different, while the luminescence intensity of the uncoated ZnS:Mn was extremely low (e.g., ...). Figure 8 As shown in the figure, the TiO2 shell effectively reduces the luminescence threshold of ZnS:Mn.

[0065] The activated ZnS:Cu powder was mixed with ZnS:Mn@TiO2 core-shell particles, and modified quartz powder (1 / 3 of the total mass of the two particles) was added. The mixture was fed into a three-dimensional ball mill mixer and mixed at a low speed of 50 rpm for 60 minutes. A composite silane coupling agent ethanol solution was sprayed in to simultaneously complete the surface chemical modification.

[0066] (2) Vacuum mixing and degassing.

[0067] Bisphenol A type epoxy resin is preheated at 65℃ for 2 hours, and methyltetrahydrophthalic anhydride curing agent is preheated at 55℃.

[0068] Bisphenol A type epoxy resin, remaining modified quartz powder, and functional mixed filler were sequentially added to a vacuum planetary mixer. The vacuum degree was reduced to -0.099 MPa, and the mixture was wetted at a low speed of 200 rpm for 15 minutes, dispersed at a high speed of 1200 rpm revolution / 800 rpm rotation for 45 minutes, degassed under vacuum at 400 rpm for 30 minutes, and then methyltetrahydrophthalic anhydride curing agent was drawn in under vacuum. The mixture was stirred at 400 rpm for 20 minutes to obtain a mixed slurry.

[0069] (3) Vacuum pressure casting and gradient curing.

[0070] Vacuum-pour the mixed slurry into a mold (containing metal inserts) preheated to 110°C, close the vacuum valve, and apply 0.3 MPa nitrogen gas to maintain pressure.

[0071] The temperature is increased to 135℃ at a rate of 0.5℃ / min, held for 5 hours, and then decreased to below 60℃ at a rate of 0.3℃ / min. The product is then demolded to obtain an uncured pot-type insulator.

[0072] (4) Post-curing and fine processing.

[0073] After the uncured pot insulators are demolded, they are transferred to a circulating air oven, heated to 120°C at a rate of 1°C / min, held at that temperature for 8 hours, and then cooled in the oven.

[0074] The sealing groove is precision CNC machined and tested by X-ray and ultrasonic flaw detection, and there are no internal defects.

[0075] 3. Performance test results.

[0076] The color changes are blue (main peak at 450nm) at 2-4kV / mm (low electric field), blue-green at 4-7kV / mm (medium electric field) (CIE chromaticity coordinates: x=0.28, y=0.32), and yellow-green at 7-10kV / mm (high electric field). The color changes are consistent with the trend observed in Sample 1 (activated ZnS:Cu powder:ZnS:Mn@TiO2 core-shell particles = 3:1) in the voltage-color test photograph (e.g., ...). Figures 9-11 As shown); the chromaticity coordinate trajectory clearly moves from the blue area to the yellow area (as shown). Figure 13 As shown); the electroluminescence spectrum shows that only a 450nm blue light peak appears in the low electric field region, while the 585nm yellow light peak gradually increases in the medium and high electric field regions (as shown). Figures 14-17 As shown, Intensity (au) is the intensity (any unit), Wavelength (nm) is the wavelength (nanometer), Voltage (kV) is the voltage (kilovolt), Sample1 is sample 1, Sample2 is sample 2 (activated ZnS:Cu powder:ZnS:Mn@TiO2 core-shell particles = 1:1), Sample3 is sample 3 (activated ZnS:Cu powder:ZnS:Mn@TiO2 core-shell particles = 1:3), and Sample4 is sample 4 (activated ZnS:Cu powder:ZnS:Mn@TiO2 core-shell particles = 4:1). The color transition is continuous and controllable.

[0077] The prepared basin-type insulator has a relative permittivity of 5.2, a dielectric loss of tanδ=0.0025, and an AC breakdown field strength of 38kV / mm at 50Hz (as shown in the Weibull distribution analysis results). Figure 18 (As shown), volume resistivity 1.2 × 10¹ 6 Ω cm; the frequency spectrum of dielectric constant and dielectric loss shows that the composite material has stable performance over a wide frequency range (e.g., Figures 19-20As shown, where Dielectric loss is the dielectric loss, Frequency (Hz) is the frequency, and Sample1 / Sample2 / Sample3 / Sample4 are sample 1 / sample 2 / sample 3 / sample 4.

[0078] Tensile strength 42MPa (tensile stress-strain curve as shown) Figure 21 As shown, Stress (MPa) is the stress (megapascals), Strain (mm) is the strain (millimeters), and Sample1 / Sample2 / Sample3 / Sample4 are sample 1 / sample 2 / sample 3 / sample 4 respectively. Thermogravimetric analysis curves at 340℃ show 5% thermogravimetric loss (as shown in the figure). Figure 22 As shown, Weightloss (%) is the weight loss (percentage), Temperature (°C) is the temperature (degrees Celsius), and Sample1 / Sample2 / Sample3 / Sample4 are sample 1 / sample 2 / sample 3 / sample 4 respectively. There is no significant weight loss below 320℃, indicating excellent thermal stability. The simulation results of the defect electric field of the basin-type insulator under operating voltage are shown below. Figures 23-24 As shown, Electricfield intensity (kV / mm) is the electric field strength (kilovolts per millimeter), and Electricfield direction is the electric field direction.

[0079] Example 2:

[0080] 1. Formulation design (by mass parts).

[0081] 100 parts bisphenol A type epoxy resin and 100 parts methyltetrahydrophthalic anhydride curing agent.

[0082] 150 parts of fused silica powder (which needs to be surface modified and cured into modified silica powder by silane coupling agent KH-550 ethanol solution, with a bimodal particle size distribution: 5μm (50%), 30μm (50%)).

[0083] Eight parts of activated ZnS:Cu powder and eight parts of ZnS:Mn@TiO2 core-shell particles.

[0084] The silane coupling agent KH-550 ethanol solution and the composite silane coupling agent are compounded at a mass ratio of 1:2.

[0085] 2. Preparation steps.

[0086] The operation of each step is the same as in Example 1, only the following parameters are adjusted:

[0087] The TiO2 shell thickness of the ZnS:Mn@TiO2 core-shell particles is 300±50nm.

[0088] During vacuum mixing, the high-speed dispersion speed is 1100 rpm, and the vacuum degassing time is 35 minutes.

[0089] The nitrogen pressure during vacuum pressure casting is 0.45 MPa.

[0090] 3. Performance test results.

[0091] The color appears blue under low electric field, uniformly blue-green under medium electric field (CIE chromaticity coordinates: x=0.30, y=0.35), and bright yellow under high electric field (main peak at 585nm), with a continuous color transition without any abrupt changes. The optimal color transition effect (e.g., [missing information]) is shown in the voltage-color test photograph for Sample 2 (activated ZnS:Cu powder: ZnS:Mn@TiO2 core-shell particles = 1:1). Figure 5 As shown), the CIE chromaticity locus is located in the middle of the blue and yellow zones (e.g. Figure 13 As shown), the intensity ratio of the blue and yellow main peaks in the spectrum changes linearly with voltage (e.g. Figure 7 (As shown).

[0092] At 50Hz, the relative permittivity is 6.5, the dielectric loss tanδ=0.0022, and the AC breakdown field strength is 42kV / mm (e.g., Figure 18 (As shown), volume resistivity 2.5 × 10¹ 6 Ω cm, with dielectric properties superior to those of Example 1.

[0093] Tensile strength 45MPa (e.g.) Figure 10 As shown), 5% thermogravimetric temperature is 348℃ (e.g.) Figure 11 As shown in the figure, mechanical strength and thermal stability are further improved.

[0094] Embedded with a 0.5mm surface scratch and a 1mm internal metal chip defect, tests under phase voltage showed that the scratch area exhibited a yellow striped halo, and the metal chip showed clearly defined yellow spots perpendicular to the electric field (e.g., Figure 12 As shown in the figure, the defect location accuracy reaches the millimeter level, the color difference with the healthy area is ΔE=32, and the electric field distortion around the defect is accurately presented by yellow light emission, which is in high agreement with the electric field simulation results. The yellow light emission saturation in the artificial defect area is high, the defect size is linearly related to the light spot size, the light emission stability is good after 30 repeated tests, and the ability to resist ambient light interference is strong.

[0095] Example 3:

[0096] 1. Formulation design (by mass parts).

[0097] 100 parts of bisphenol A type epoxy resin and 115 parts of methyltetrahydrophthalic anhydride curing agent.

[0098] 170 parts of fused silica powder (which needs to be surface modified and cured into modified silica powder by silane coupling agent KH-550 ethanol solution, with a bimodal particle size distribution: 5μm (60%), 30μm (40%)).

[0099] 20 parts of activated ZnS:Cu powder and 60 parts of ZnS:Mn@TiO2 core-shell particles.

[0100] The silane coupling agent KH-550 ethanol solution and the composite silane coupling agent are compounded at a mass ratio of 1:2.

[0101] 2. Preparation steps.

[0102] The operation of each step is the same as in Example 1, only the following parameters are adjusted:

[0103] When preparing ZnS:Mn@TiO2 core-shell particles, the dropping rate of tetrabutyl titanate solution was 1.2 mL / min, and the annealing temperature was 505℃.

[0104] During vacuum mixing, the low-speed wetting speed is 250 rpm, and the high-speed dispersion time is 50 minutes.

[0105] During vacuum pressure casting, the mold preheating temperature is 115℃, and the nitrogen holding pressure is 0.6MPa.

[0106] 3. Performance test results.

[0107] The light blue color appears under a low electric field, the yellowish-green color under a medium electric field (CIE chromaticity coordinates: x=0.33, y=0.38), and the strong yellow color under a high electric field. The color gradient is clearly distinguishable to the human eye. The luminescence characteristics of Sample 3 (activated ZnS:Cu powder to ZnS:Mn@TiO2 core-shell particles mass ratio 1:3) in the voltage-color test photograph are shown below (e.g.,...). Figure 5 As shown), the CIE chromaticity locus is closer to the yellow zone (e.g. Figure 6 As shown), the 585nm yellow light peak dominates in the medium electric field region (e.g. Figure 7 (As shown).

[0108] At 50Hz, the relative permittivity is 7.8, the dielectric loss tanδ=0.0028, and the AC breakdown field strength is 39kV / mm (e.g., Figure 18 (As shown), volume resistivity 1.8 × 10¹ 6 Ω cm, meeting the insulation requirements of GIS equipment.

[0109] Tensile strength 43MPa (e.g.) Figure 10 As shown), 5% thermogravimetric temperature 345℃ (e.g.) Figure 11 As shown in the figure, its performance is stable and reliable.

[0110] 2. Comparative design and performance.

[0111] Comparative Example 1: ZnS:Mn modified without a shell core structure.

[0112] Formulation: Except for the fact that the ZnS:Mn particles were not modified, the rest is the same as in Example 2.

[0113] The ZnS:Mn emission threshold is increased, and it only exhibits blue light across all electric field ranges, with no obvious color transition. Figure 5 The luminescence effect of the middle Sample4 control group) could not accurately locate minute defects; the AC breakdown field strength dropped to 30kV / mm (e.g. Figure 18 As shown), the insulation performance decreased significantly, and the mechanical tensile strength also decreased significantly (as shown). Figure 10 (As shown).

[0114] Comparative Example 2: A multi-layer structure was used to replace a single-layer composite structure.

[0115] Formulation: Activated ZnS:Cu powder and ZnS:Mn@TiO2 core-shell particles are respectively made into independent functional layers and coated on the insulator substrate in layers. The rest is the same as in Example 2.

[0116] Significant delamination was observed at the interlayer interface, and interfacial discharge occurred after 1000 hours of electro-thermal stress testing.

[0117] The embodiments of this application strictly follow the principle of "single-layer composite system + threshold-controlled sensing material + vacuum casting integrated molding". By optimizing the ratio of sensing material (the ratio of activated ZnS:Cu powder to ZnS:Mn@TiO2 core-shell particles is 3:1 to 1:3), process parameters, and modification process, the prepared defect self-monitoring basin insulator meets the following requirements:

[0118] Electroluminescence performance: Achieves continuous color change from blue to green to yellow under an electric field of 2-10 kV / mm, as demonstrated by SEM, EDS, finite element simulation, and spectral testing. Figure 1-7 Verification showed that the color transition is stable and controllable, and can be directly distinguished by the human eye.

[0119] Core performance: AC breakdown field strength ≥38kV / mm, dielectric loss ≤0.0028, tensile strength ≥42MPa, excellent thermal stability. Figure 8-11 (Data support) fully meets the standards of traditional high-performance basin insulators;

[0120] Monitoring results: Defect location accuracy reaches the millimeter level, color difference ΔE≥30, as demonstrated by comparison between defect luminescence photographs and electric field simulations. Figure 12 It has been confirmed that it can accurately identify minute defects and has strong resistance to ambient light interference.

[0121] The comparative examples, due to deviations from the core limitations, resulted in a significant decrease in luminescent performance, insulation performance, or defect monitoring effectiveness, fully demonstrating the rationality and superiority of this application. All figures and data are direct verifications of this application, ensuring its repeatability and reliability.

[0122] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of this application.

Claims

1. A method for preparing a self-detecting basin-type insulator, characterized in that, include: After drying the fused silica powder at 125℃±5℃, it was surface modified and cured with silane coupling agent KH-550 ethanol solution to obtain modified silica powder. The ZnS:Cu phosphor was subjected to acid washing, centrifugal washing and vacuum drying to obtain activated ZnS:Cu powder; ZnS:Mn@TiO2 core-shell particles were prepared by a non-hydrolyzed sol-gel method. Then, activated ZnS:Cu powder was mixed with ZnS:Mn@TiO2 core-shell particles and treated with a composite silane coupling agent to obtain a functional mixed filler. Bisphenol A type epoxy resin, modified quartz powder and functional mixed filler are added to a mixer. After low-speed wetting, high-speed dispersion and vacuum degassing, methyltetrahydrophthalic anhydride curing agent is added and stirred evenly to obtain a mixed slurry. The mixed slurry is vacuum-introduced into a mold at 110℃-130℃, nitrogen pressure is applied at 0.3-0.6MPa, the temperature is raised to 135℃ and held for 5 hours, and then cooled to below 60℃ before demolding to obtain an uncured pot insulator. Uncured basin insulators are cured to obtain basin insulators. The curing process involves holding the insulator at 120°C for 8 hours.

2. The method according to claim 1, characterized in that, The mass ratio of the activated ZnS:Cu powder to ZnS:Mn@TiO2 core-shell particles is 3:1 to 1:

3.

3. The method according to claim 1, characterized in that, The mass ratio of the bisphenol A type epoxy resin to the methyltetrahydrophthalic anhydride curing agent is 100:85-115, and the mass ratio of the bisphenol A type epoxy resin, the modified quartz powder, and the functional mixed filler is 100:130-170:8-20.

4. The method according to claim 1, characterized in that, 1 at.% Nb was introduced during the preparation of the ZnS:Mn@TiO2 core-shell particles. 5+ The product is doped and treated at 500℃ for 2 hours to form an anatase TiO2 shell with a thickness of 250-350nm.

5. The method according to claim 1, characterized in that, The composite silane coupling agent is prepared by compounding γ-aminopropyltriethoxysilane and γ-(2,3-epoxypropoxy)propyltrimethoxysilane in a mass ratio of 1:

2.

6. The method according to claim 1, characterized in that, The acid washing conditions for the ZnS:Cu phosphor are: 0.1 mol / L hydrochloric acid solution, ultrasonic treatment at 200W for 30 minutes at 40℃, centrifugation speed of 8000 rpm, and washing until the conductivity of the supernatant is less than 5 μS / cm.

7. A basin insulator prepared using the method for preparing a self-detecting basin insulator according to any one of claims 1-6, characterized in that, include: The basin-type insulator is prepared by curing bisphenol A type epoxy resin, modified quartz powder, and functional mixed filler in a mass ratio of 100:130-170:8-20. The functional mixed filler is obtained by mixing activated ZnS:Cu powder and ZnS:Mn@TiO2 core-shell particles in a mass ratio of 3:1 to 1:3, followed by treatment with a composite silane coupling agent. Furthermore, the functional mixed filler exhibits an AC breakdown field strength greater than 35 kV / mm, a dielectric loss tangent less than 0.003 at 50 Hz, and a volume resistivity greater than 10¹⁰. 5 Ω cm.

8. An application of the basin-type insulator as described in claim 7, characterized in that, include: The basin-type insulator is used in high-voltage power distribution equipment. During normal operation, the healthy region and the defective region of the basin-type insulator emit characteristic wavelength signals. The characteristic wavelength signal emitted by the healthy region corresponds to a first characteristic wavelength range, which is from 540nm to 550nm. The characteristic wavelength signal emitted by the defective region corresponds to a second characteristic wavelength range, which is from 610nm to 620nm. The differences in the characteristic wavelength signals are distinguished and captured by a spectrometer, and the characteristic wavelength signals are compared with a preset spectral database to determine the insulation status of the basin-type insulator and the specific location of the defect.

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