Waterproof voltage transformer and potting method

Abstract

The invention discloses a waterproof voltage transformer and a potting method, and belongs to the technical field. The dynamic balance valves are arranged on the shells of the voltage transformer, and the sealing positions between the shells are sealed in a combined mode through the nanometer hydrophobic coatings and the sealing rings. According to the voltage transformer, through sealing between the dynamic balance valve and the shell, equipment can be waterproof, and it is ensured that the equipment is used in a water invasion environment.

Description

Technical Field

[0001] The present invention relates to the technical field of electric power equipment, and more particularly to a waterproof voltage transformer and a potting method thereof. Background Art

[0002] Voltage transformers are essential, critical equipment in power systems, primarily used to convert high voltage to low voltage for measurement, monitoring, and protection. As power systems expand and become more intelligent, the demands on voltage transformers for reliability, accuracy, and environmental adaptability are increasing. However, in extreme environments like floods and waterlogging, the performance of traditional voltage transformers often fails to meet these requirements.

[0003] Existing transformers lack sufficient waterproofing: Traditional voltage transformers typically have an IP54 rating, which only protects against splashing water and cannot operate properly in submerged environments. During floods, equipment can be submerged in water for extended periods, degrading internal insulation and even causing short circuits. Existing waterproofing designs often rely on simple sealing rings or potting processes, which are inadequate for handling the extreme conditions of dynamic water pressure and prolonged submersion. Degraded insulation performance: When moisture enters the equipment, the insulation material's performance degrades significantly, increasing measurement errors and even causing equipment failure. Summary of the Invention

[0004] In response to the above problems, the present invention proposes a waterproof voltage transformer, wherein a dynamic balancing valve is provided on the housing of the voltage transformer, and the sealing between the housings adopts a combined seal of a nano-hydrophobic coating and a sealing ring.

[0005] Optionally, a dynamic balancing valve is used to adjust the pressure balance inside and outside the voltage transformer.

[0006] Optionally, the voltage transformer is cast and potted internally by using a mixed potting process of epoxy resin and silicon micropowder.

[0007] Optionally, the weight ratio of epoxy resin to silica powder is 3:1.

[0008] Optionally, before pouring, the epoxy resin and the silicon micropowder are pretreated respectively, and the pretreated epoxy resin and silicon micropowder are mixed and dispersed.

[0009] Optional pre-treatment of the epoxy resin includes:

[0010] After heating the epoxy resin to 40-50°C, add the curing agent in proportion;

[0011] Pretreatment of silicon powder includes:

[0012] The silicon micropowder was dried at 120°C for 2 hours and then sieved to remove agglomerated particles.

[0013] Optionally, the weight of the added curing agent is 10%-15% of the weight of the epoxy resin.

[0014] Optionally, sieve to 200 mesh to remove agglomerated particles.

[0015] Optionally, the pre-treated epoxy resin and silica powder are mixed and dispersed, including:

[0016] Preliminary mixing includes: adding the pretreated silicon micropowder to the pretreated epoxy resin, stirring while adding, and placing the mixture into a planetary mixer after all the silicon micropowder is added, and mixing the mixture for 10-15 minutes using the planetary mixer to obtain a mixture;

[0017] Vacuum degassing includes: placing the mixed material into a vacuum mixer and degassing at -0.095 MPa for 5-10 minutes.

[0018] Optional potting operations include:

[0019] Preheating the mold, including: heating the mold to 60-70℃;

[0020] Potting, including: pouring the vacuum degassed mixture into the preheated mold, filling it evenly, and using vacuum potting equipment to remove bubbles in the filling;

[0021] Curing, including:

[0022] The first stage: curing the filler at 80℃.

[0023] The second stage: curing the filler at 120℃.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The present invention proposes a waterproof voltage transformer. The housing of the voltage transformer is equipped with a dynamic balancing valve, and the seal between the housings utilizes a combination of a nano-hydrophobic coating and a sealing ring. The dynamic balancing valve and the seal between the housings make the voltage transformer waterproof, ensuring its use in water-intrusive environments.

[0026] The present invention also proposes a method for potting a waterproof voltage transformer, comprising: casting the interior of the voltage transformer using a mixed potting process of epoxy resin and silica powder, followed by potting. This potting process improves the waterproof performance of the voltage transformer, meeting power requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A structural diagram of a waterproof voltage transformer provided by the present invention;

[0028] Figure 2 A structural diagram of a dynamic balancing valve of a waterproof voltage transformer provided by the present invention;

[0029] Figure 3 A cross-sectional view of a combined sealing structure of a nano-hydrophobic coating and a sealing ring of a waterproof voltage transformer provided by the present invention;

[0030] Among them, 1 is the primary joint, 2 is the potting, 3 is the combined seal, 4 is the dynamic balancing valve, 5 is the secondary joint, 6 is the hydrophobic membrane, 7 is the automatic valve disc, 8 is the adaptive pressure control mechanism, 9 is the hydrophobic coating, 10 is the O-ring, and 11 is the sealing surface. DETAILED DESCRIPTION

[0031] Exemplary embodiments of the present invention will now be described with reference to the accompanying drawings. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to provide a thorough and complete disclosure of the present invention and to fully convey the scope of the present invention to those skilled in the art. The terminology used in the exemplary embodiments shown in the accompanying drawings is not intended to limit the present invention. In the accompanying drawings, identical elements are denoted by the same reference numerals.

[0032] Unless otherwise specified, the terms used herein (including technical terms) have the meanings commonly understood by those skilled in the art. In addition, it is understood that terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0033] Example 1:

[0034] The present invention proposes a waterproof voltage transformer, such as Figure 1 As shown, 1 is the primary joint, 2 is the potting, 3 is the combined seal, 4 is the dynamic balancing valve, and 5 is the secondary joint;

[0035] The housing of the voltage transformer is provided with a dynamic balancing valve, and the sealing between the housings adopts a combined sealing of a nano-hydrophobic coating and a sealing ring.

[0036] Among them, the dynamic balancing valve is used to adjust the pressure balance inside and outside the voltage transformer.

[0037] In the invention, the dynamic balancing valve, such as Figure 2 As shown, it includes: a hydrophobic membrane 6, an automatic valve flap 7 and an adaptive pressure control mechanism 8. A dynamic balancing valve is added to the outer shell of the transformer to adjust the pressure balance inside and outside the transformer.

[0038] The functions achieved include: (1) Pressure balance: When the pressure difference between the inside and outside of the device reaches a set threshold, it automatically opens to balance the pressure, preventing the device from deformation or damage due to excessive pressure difference. (2) Waterproof and dustproof: While balancing the pressure, it prevents external liquids (such as water) and solid particles from entering the device. (3) Breathable and waterproof: Allows gas to pass through, but blocks liquid penetration.

[0039] The working principle includes: (1) When the internal pressure of the device is higher than the external environment, the valve exhausts air outward. When the external pressure is higher than the internal pressure (such as when the device is immersed in water), the valve draws air inward. When the pressure difference reaches the set value (which should be preset according to the water depth), the valve flap automatically opens. (2) Using a hydrophobic membrane material (such as PTFE polytetrafluoroethylene), the pore diameter is smaller than the diameter of liquid water molecules (usually <0.2μm) but larger than the diameter of gas molecules, thereby achieving air permeability but not water permeability. The internal adaptive pressure control mechanism structure ensures that the valve remains closed when there is no pressure difference.

[0040] Technical features include: (1) Dynamic response: Response time is less than 1 second, adapting to rapid pressure changes (such as when the device is suddenly immersed in water). (2) Durability: Can withstand >100,000 opening and closing cycles. (3) Multi-layer filtration structure: First layer: coarse filter (intercepts particles >100μm), second layer: hydrophobic membrane (waterproof and breathable), third layer: activated carbon adsorption layer (optional, used to filter harmful gases) (4) Self-cleaning function: Utilizes airflow flushing when the valve is opened and closed to prevent sediment accumulation. Optional ultrasonic cleaning module (for highly polluted environments).

[0041] Nano hydrophobic coating and sealing ring combined seal, including:

[0042] The seal between the voltage transformer housings uses a combination of nano-hydrophobic coating and sealing ring, as shown in the screenshot Figure 3 As shown, 9 is a hydrophobic coating, 10 is an O-ring, and 11 is a sealing surface.

[0043] The functions to be achieved include: (1) Waterproof performance: Withstands hydrostatic pressure at depths greater than 10 meters. No leakage under dynamic water impact (such as heavy rain). (2) Durability: Coating wear resistance greater than 1000 friction cycles (load 1N). O-ring life greater than 10 years. (3) Environmental adaptability: Operating temperature range: -40°C to +150°C, salt spray corrosion resistance (>1000 hours).

[0044] The working principle includes: (1) Cleaning the sealing surface and performing plasma or chemical treatment to increase the surface activity. (2) Using a spraying or dipping process, the nano-hydrophobic material is evenly coated on the sealing surface. After the coating solidifies, a super-hydrophobic surface is formed. (3) A silicone O-ring (hardness 50-70 Shore A) is installed in the sealing groove, ensuring that the O-ring compression rate is between 15% and 25%. The O-ring is in close contact with the coated surface, forming a double seal.

[0045] Example 2:

[0046] The present invention also proposes a potting method for a voltage transformer, which adopts a mixed potting process of epoxy resin and silicon micropowder to cast the interior and then pot it.

[0047] Among them, the potting process includes:

[0048] For the internal casting of the voltage transformer, a mixed potting process of epoxy resin and silicon powder is adopted.

[0049] Material selection: epoxy resin, silica powder.

[0050] Ratio design: Epoxy resin: silica powder = 3:1 (weight ratio): This ratio balances the material's fluidity, mechanical properties, and processability. Too much silica powder will increase viscosity and affect the potting effect; too little will not fully exert its reinforcing effect.

[0051] Material pretreatment:

[0052] Epoxy resin pretreatment:

[0053] Heat the epoxy resin to 40-50°C to reduce the viscosity.

[0054] Add curing agent in proportion (usually 10-15% of the resin weight).

[0055] Silica powder pretreatment:

[0056] Dry at 120℃ for 2 hours to remove moisture.

[0057] Sieve (200 mesh) to remove agglomerated particles.

[0058] Mixing and dispersing:

[0059] Initial mixing:

[0060] Slowly add silica powder into epoxy resin while stirring.

[0061] Use a planetary mixer (speed 200-300 rpm) to mix for 10-15 minutes.

[0062] Vacuum degassing:

[0063] Place the mixture into a vacuum mixer and degas at -0.095 MPa for 5-10 minutes.

[0064] Make sure the mixture is free of bubbles and flows smoothly.

[0065] Potting operation:

[0066] Preheat the mold:

[0067] Heat the mold to 60-70℃ to reduce the temperature difference between the potting material and the mold.

[0068] Pour the mixture into the mold, making sure it is filled evenly.

[0069] Use vacuum potting equipment to further eliminate bubbles.

[0070] Curing:

[0071] The first stage: curing at 80℃ for 2 hours.

[0072] Second stage: curing at 120℃ for 4 hours.

[0073] The structural design of the present invention is as follows:

[0074] Shell design:

[0075] Material: Aluminum alloy (surface anti-corrosion treatment).

[0076] Thickness: 3mm, ensuring mechanical strength.

[0077] Sealed design:

[0078] Sealing structure: O-ring + hydrophobic coating.

[0079] Hydrophobic coating: nano hydrophobic material spraying.

[0080] Dynamic pressure balanced breathing valve design:

[0081] Hydrophobic membrane: PTFE material, micropore diameter <0.2μm.

[0082] Spring pressure threshold: ±50Pa.

[0083] Material selection is as follows:

[0084] (1) Shell material:

[0085] Aluminum alloy: Model 6061, surface anodized.

[0086] Anti-corrosion coating: epoxy resin primer + polyurethane topcoat.

[0087] (2) Potting material:

[0088] Epoxy resin: Model E-51.

[0089] Silica powder: particle size 5-20μm, purity >99%.

[0090] Curing agent: amine curing agent (addition amount 10%).

[0091] (3) Sealing material:

[0092] O-ring: Silicone rubber, hardness 60 Shore A.

[0093] The process is implemented as follows:

[0094] (1) Shell processing:

[0095] Machining:

[0096] Use machine tools to process housing parts.

[0097] Ensure dimensional accuracy (tolerance ±0.1mm).

[0098] Surface treatment:

[0099] Anodizing: film thickness 10-15μm.

[0100] Spray anti-corrosion coating: thickness 50-70μm.

[0101] (2) Potting process:

[0102] Material Mixing:

[0103] Epoxy resin and silica powder are mixed in a ratio of 3:1.

[0104] Use a planetary mixer to mix for 10 minutes and vacuum degas for 5 minutes. Potting operation:

[0105] Preheat the mold to 60°C.

[0106] Fill with vacuum potting equipment to ensure there are no bubbles.

[0107] Curing:

[0108] The first stage: curing at 80℃ for 2 hours.

[0109] Second stage: curing at 120℃ for 4 hours.

[0110] (3) Dynamic pressure balance breathing valve installation:

[0111] Valve body installation:

[0112] Drill a hole on the top of the shell and install the breathing valve.

[0113] Hydrophobic membrane fixation:

[0114] Use a pressure ring to secure the hydrophobic membrane, ensuring it is flat and wrinkle-free.

[0115] Spring adjustment:

[0116] Adjust the screw to set the spring preload (±50Pa).

[0117] Test verification is as follows:

[0118] (1) Waterproof performance test:

[0119] Water immersion test:

[0120] Water depth 10 meters, soak for 72 hours.

[0121] Result: There is no water seepage inside the equipment, and the insulation resistance is >100MΩ.

[0122] High-pressure water jet test:

[0123] Water pressure 1MPa, lasting 30 minutes.

[0124] Result: No leakage, the equipment operates normally.

[0125] (2) Electrical performance test:

[0126] Insulation resistance test:

[0127] At 1000V DC, the insulation resistance is greater than 10GΩ.

[0128] Hi-pot test:

[0129] Under 3kV AC, there is no breakdown or flashover within 1 minute.

[0130] The waterproof voltage transformer of the present invention achieves the following remarkable effects through the comprehensive design of a multi-layer sealing structure, a dynamic pressure balance breathing valve, a nano-hydrophobic coating, and a high-performance potting material:

[0131] Excellent waterproof performance: With a protection level of IP68, the device can withstand long-term immersion in water and withstand high-pressure water shock, ensuring that the device can continue to operate stably after floods.

[0132] Excellent insulation performance: Epoxy resin + silica powder potting material significantly improves insulation strength and moisture and heat resistance, ensuring long-term reliability of the equipment in humid environments.

[0133] Strong environmental adaptability: The dynamic pressure balance breathing valve and weather-resistant materials enable the equipment to operate stably in a temperature range of -40℃ to +85℃ and in harsh environments such as salt spray and heavy rain.

[0134] The present invention significantly improves the reliability, safety and maintenance efficiency of voltage transformers in extreme environments such as flood disasters, and has broad application prospects.

[0135] At the same time, the present invention also solves the problems of traditional potting materials (such as ordinary epoxy resin) having unstable insulation performance in hot and humid environments, prone to aging, lack of dynamic pressure balance mechanism, and the possibility of sealing failure due to the pressure difference between the inside and outside of the equipment after being immersed in water.

[0136] The present invention also realizes high protection level design, intelligent monitoring and early warning, new material application, adaptive communication technology, etc.

[0137] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0138] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A waterproof voltage transformer, characterized in that: The housing of the voltage transformer is provided with a dynamic balancing valve, and the sealing between the housings adopts a combined seal of a nano-hydrophobic coating and a sealing ring; The dynamic balancing valve is used to adjust the pressure balance inside and outside the voltage transformer.

2. A potting method for a waterproof voltage transformer, characterized in that: include: The voltage transformer is potted and sealed by pouring the interior thereof using a mixed potting process of epoxy resin and silicon micropowder.

3. The potting method according to claim 2, characterized in that: The weight ratio of the epoxy resin to the silicon powder is 3:

1.

4. The potting method according to claim 2, characterized in that: Before pouring, the epoxy resin and the silicon micropowder are pretreated respectively, and the pretreated epoxy resin and silicon micropowder are mixed and dispersed.

5. The potting method according to claim 4, characterized in that: Pretreatment of epoxy resin, including: After heating the epoxy resin to 40-50°C, add the curing agent in proportion; Pretreatment of silicon powder includes: The silica powder was dried at 120°C for 2 hours.

6. The potting method according to claim 5, characterized in that: The silicon micropowder was dried at 120°C for 2 hours and then sieved to remove agglomerated particles.

7. The potting method according to claim 5, characterized in that: The weight of the added curing agent is 10%-15% of the weight of the epoxy resin.

8. The potting method according to claim 5, characterized in that: Sieve to 200 mesh to remove agglomerated particles.

9. The potting method according to claim 4, characterized in that: Mixing and dispersing the pretreated epoxy resin and silica powder, including: Preliminary mixing includes: adding the pretreated silicon micropowder to the pretreated epoxy resin, stirring while adding, and placing the mixture into a planetary mixer after all the silicon micropowder is added, and mixing the mixture for 10-15 minutes using the planetary mixer to obtain a mixture; Vacuum degassing includes: placing the mixed material into a vacuum mixer and degassing at -0.095 MPa for 5-10 minutes.

10. The potting method according to any one of claims 2 to 9, characterized in that: Potting operations, including: Preheating the mold, including: heating the mold to 60-70℃; Potting, including: pouring the vacuum degassed mixture into the preheated mold, filling it evenly, and using vacuum potting equipment to remove bubbles in the filling; Curing, including: The first stage: curing the filler at 80℃; The second stage: curing the filler at 120℃.

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