Preparation method of extra-high voltage long-rod insulator of over 1100kv

Abstract

The invention relates to the technical field of insulator preparation, and discloses a preparation method of an extra-high voltage long-rod insulator above 1100kv. The preparation method comprises the following steps: S1, preparing materials; s2, preparing a mold; s3, dipping and rolling are carried out; s4, curing and demolding; and S5, post-processing and detecting. According to the preparation method of the extra-high voltage long-rod insulator above 1100kv, the epoxy resin impregnated paper system is adopted to prepare the extra-high voltage long-rod insulator above 1100kv, and the epoxy resin impregnated paper system has extremely high cohesion and a compact molecular structure, so that the mechanical strength of the long-rod insulator above 1100kv is obviously higher than that of a traditional ceramic insulator, and the curing shrinkage rate is low (1-2%); the prepared extra-high voltage long rod insulator with the voltage of more than 1100kv has the advantages of excellent size stability, difficulty in cracking due to environmental change, light weight, convenience in installation and maintenance, and difficulty in forming cracks on the surface, so that the prepared extra-high voltage long rod insulator with the voltage of more than 1100kv has good mechanical property and structural stability, and has the advantages of light weight and process flexibility.

Description

Technical Field

[0001] The invention relates to the technical field of insulator preparation, and in particular to a method for preparing an ultra-high voltage long rod insulator of more than 1100 kV. Background Art

[0002] Insulators are devices installed between conductors at different potentials or between conductors and ground potential components that can withstand voltage and mechanical stress.

[0003] UHV insulators above 1100kV refer to insulators used in UHV transmission systems with a rated voltage of 1100kV or above. UHV transmission systems generally refer to transmission technologies with voltage levels of 1000kV and above for AC and ±800kV and above for DC. This type of insulator plays a vital role in UHV transmission lines. Its main function is to support and fix the conductors in the transmission lines and prevent the current from directly passing through the insulators into the ground, ensuring the safe operation of the transmission system.

[0004] Among UHV insulators of 1100kV and above, ceramic insulators and composite insulators are the two most common types of UHV insulators. Ceramic insulators may cause flashover due to surface contamination in high humidity or polluted environments. Although composite insulators have good pollution flashover resistance, their silicone rubber materials may deteriorate under long-term high temperatures, and the preparation process is relatively complicated, resulting in poor mechanical properties and structural stability of the prepared insulators.

[0005] To this end, the present invention provides a method for preparing an ultra-high voltage long rod insulator of more than 1100kv. Summary of the invention

[0006] In order to make up for the deficiencies of the prior art, at least one technical problem raised in the background technology is solved.

[0007] The present invention provides a method for preparing a 1100kv or higher ultra-high voltage long rod insulator, comprising the following steps:

[0008] S1. Preparation of materials:

[0009] (1) Preparation of epoxy resin: high-performance phenolic epoxy resin is selected as the raw material to ensure that the prepared insulator has excellent insulation performance, mechanical strength and heat resistance;

[0010] (2) Preparation of impregnated paper: select high-quality insulating paper and pretreat it;

[0011] (3) Preparation of curing agent: T-31 epoxy resin curing agent is selected to promote the curing reaction of epoxy resin and form a stable insulation structure;

[0012] (4) Preparation of release agent, which is applied to the inner wall of the mold to prevent the insulator from sticking to the mold;

[0013] S2. Mould preparation:

[0014] (1) Design the mold according to the size and shape of the long rod insulator to ensure that the mold has sufficient strength and precision;

[0015] (2) Mold treatment: evenly apply mold release agent on the inner wall of the mold so that the long rod insulator can be easily removed after curing;

[0016] S3, dipping and rolling:

[0017] (1) Impregnation treatment: immerse the insulating paper in the pre-prepared epoxy resin to make the insulating paper fully wetted without bubbles and dry spots;

[0018] (2) Rolling: Roll the impregnated insulating paper into a rod shape according to the design requirements, paying attention to controlling the rolling tension and number of layers to ensure the structural stability and electrical performance of the insulator;

[0019] S4, curing and demoulding:

[0020] (1) Preheating treatment: Place the rolled insulator into a preheating furnace for preheating treatment to remove internal stress and volatiles;

[0021] (2) Curing treatment: Place the preheated insulator into a curing furnace and cure it according to the predetermined curing process. The temperature and time should be strictly controlled during the curing process to ensure that the epoxy resin is fully cured and forms a stable insulation structure;

[0022] (3) Demolding: After curing is completed, wait for the insulator to cool to room temperature and then remove it from the mold; pay attention to maintaining the integrity of the insulator to avoid cracks or damage during the demolding process;

[0023] S5. Post-processing and testing:

[0024] (1) Stress relief treatment: keep the demoulded insulator at a specific temperature for a period of time to remove internal stress and improve the stability and service life of the insulator;

[0025] (2) Performance testing: Conduct electrical, mechanical, and heat resistance tests on the prepared insulators to ensure that they meet the requirements of the UHV transmission system;

[0026] (3) Surface treatment: The insulators shall be surface treated as needed, such as coating with an anti-fouling layer or performing other protective treatments to improve their performance and life.

[0027] Preferably, when the impregnated paper is pretreated in step S1, the impregnation process optimization, substrate treatment and hot pressing process adjustment are performed to improve the impregnation performance of the insulating paper and the bonding strength of the epoxy resin.

[0028] Preferably, when the impregnated paper is treated by impregnation process optimization, the following aspects are included:

[0029] (1) Control the impregnation parameters, accurately adjust the glue amount to 130% to 150%, control the volatile content to 6% to 7%, and ensure that the pre-curing degree is ≤ 65%. By adjusting the ratio of resin to curing agent and the mixing method, the resin fluidity is improved to promote uniform penetration;

[0030] (2) Optimize the resin formula, select the appropriate epoxy resin form (such as liquid or powder) and match it with a matching curing agent. If necessary, add a tackifier or cross-linking agent to enhance adhesion. At the same time, use an epoxy resin modified emulsion (such as styrene acrylic emulsion) to simultaneously improve the mechanical properties and water resistance of the impregnated paper.

[0031] Preferably, when the impregnated paper is treated by substrate treatment, the following aspects are included:

[0032] (1) Surface treatment of the substrate: ensure that the surface of the substrate is flat, without oil stains or depressions. Pre-treatment such as sanding and cleaning is required to avoid uneven impregnation; and the moisture content of the substrate should be controlled within the range of 6% to 10%. Too high a moisture content may cause sticking, and too low a moisture content may cause delamination.

[0033] (2) Selection of substrate type: Decorative base paper or filter paper with uniform fiber distribution and strong bonding force is preferred, and its pore structure is conducive to resin penetration.

[0034] Preferably, when the impregnated paper is processed by adjusting the hot pressing process, including matching the temperature and pressure, the hot pressing temperature is recommended to be set at 145-165°C, and the temperature difference between the upper and lower pressing plates is controlled at 3-5°C to avoid warping due to differences in curing speeds. The hot pressing pressure is appropriately increased and the hot pressing time is extended (such as increased to 10-15 seconds / mm thickness) to ensure sufficient flow and curing of the resin.

[0035] Preferably, during the curing treatment in step S4, a three-stage curing method is used to improve the mechanical and electrical properties of the insulator. The specific steps include: a first stage of low-temperature curing, a second stage of medium-temperature curing, and a third stage of high-temperature curing. The temperature and time of each stage should be adjusted according to the specific material and size of the insulator.

[0036] The beneficial effects of the present invention are:

[0037] The invention discloses a method for preparing a UHV long-rod insulator of more than 1100 kV. The UHV long-rod insulator of more than 1100 kV is prepared by adopting an epoxy resin impregnated paper system. Since the epoxy resin impregnated paper system has extremely high cohesive force and dense molecular structure, its mechanical strength is significantly higher than that of traditional ceramic insulators, and its curing shrinkage rate is low (1% to 2%), its dimensional stability is excellent, it is not easy to crack due to environmental changes, and it is light in weight, convenient to install and maintain, and it is not easy to form cracks on the surface. Therefore, the prepared UHV long-rod insulator of more than 1100 kV has good mechanical properties and structural stability.

[0038] The invention discloses a method for preparing a UHV long-rod insulator of more than 1100 kV. The method adopts an epoxy resin impregnated paper system to prepare the UHV long-rod insulator of more than 1100 kV. Since the epoxy resin impregnated paper system has excellent dielectric properties, small partial discharge, low temperature rise, and no insulating oil inside, the leakage risk of the oil-impregnated paper bushing is avoided. Therefore, the prepared UHV long-rod insulator of more than 1100 kV has good electrical properties and safety.

[0039] The method for preparing a UHV long-rod insulator of more than 1100kv described in the present invention adopts an epoxy resin impregnated paper system to prepare the UHV long-rod insulator of more than 1100kv. Since the epoxy resin impregnated paper product is lighter than the ceramic insulator, and the process design is flexible and the complex structure can be customized, although the composite insulator has obvious advantages in lightweight, the composite structure of its core rod material (such as epoxy resin) and silicone rubber may have the risk of interface separation at extremely low temperatures. Therefore, the prepared UHV long-rod insulator of more than 1100kv has the advantages of lightweight and process flexibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a preparation flow chart of the ultra-high voltage long rod insulator of 1100kv or above according to the present invention. DETAILED DESCRIPTION

[0041] The subject matter described herein will now be discussed with reference to example embodiments. It should be understood that the discussion of these embodiments is only to enable those skilled in the art to better understand and implement the subject matter described herein, and the functions and arrangements of the elements discussed may be changed without departing from the scope of protection of the contents of this specification. Each example may omit, replace or add various processes or components as needed. In addition, the features described relative to some examples may also be combined in other examples.

[0042] Example

[0043] The following is a further detailed description of the technical solution of the present invention in conjunction with the accompanying drawings and specific embodiments. Figure 1The present application provides a method for preparing a 1100kv or higher ultra-high voltage long rod insulator, comprising the following steps:

[0044] S1. Material preparation:

[0045] (1) Preparation of epoxy resin: high-performance phenolic epoxy resin is selected as the raw material to ensure that the prepared insulator has excellent insulation performance, mechanical strength and heat resistance;

[0046] (2) Preparation of impregnated paper: select high-quality insulating paper and pretreat it;

[0047] (3) Preparation of curing agent: T-31 epoxy resin curing agent is selected to promote the curing reaction of epoxy resin and form a stable insulation structure;

[0048] (4) Preparation of release agent, which is applied to the inner wall of the mold to prevent the insulator from sticking to the mold;

[0049] S2. Mould preparation:

[0050] (1) Design the mold according to the size and shape of the long rod insulator to ensure that the mold has sufficient strength and precision;

[0051] (2) Mold treatment: evenly apply mold release agent on the inner wall of the mold so that the long rod insulator can be easily removed after curing;

[0052] S3, dipping and rolling:

[0053] (1) Impregnation treatment: immerse the insulating paper in the pre-prepared epoxy resin to make the insulating paper fully wetted without bubbles and dry spots;

[0054] (2) Rolling: Roll the impregnated insulating paper into a rod shape according to the design requirements, paying attention to controlling the rolling tension and number of layers to ensure the structural stability and electrical performance of the insulator;

[0055] S4, curing and demoulding:

[0056] (1) Preheating treatment: Place the rolled insulator into a preheating furnace for preheating treatment to remove internal stress and volatiles;

[0057] (2) Curing treatment: Place the preheated insulator into a curing furnace and cure it according to the predetermined curing process. The temperature and time should be strictly controlled during the curing process to ensure that the epoxy resin is fully cured and forms a stable insulation structure;

[0058] (3) Demolding: After curing is completed, wait for the insulator to cool to room temperature and then remove it from the mold; pay attention to maintaining the integrity of the insulator to avoid cracks or damage during the demolding process;

[0059] S5. Post-processing and testing:

[0060] (1) Stress relief treatment: keep the demoulded insulator at a specific temperature for a period of time to remove internal stress and improve the stability and service life of the insulator;

[0061] (2) Performance testing: Conduct electrical, mechanical, and heat resistance tests on the prepared insulators to ensure that they meet the requirements of the UHV transmission system;

[0062] (3) Surface treatment: The insulators shall be surface treated as needed, such as coating with an anti-fouling layer or performing other protective treatments to improve their performance and life.

[0063] Preferably, when the impregnated paper is pretreated in step S1, the impregnation process optimization, substrate treatment and hot pressing process adjustment are performed to improve the impregnation performance of the insulating paper and the bonding strength of the epoxy resin.

[0064] Preferably, when the impregnated paper is treated by impregnation process optimization, the following aspects are included:

[0065] (1) Control the impregnation parameters, accurately adjust the glue amount to 130% to 150%, control the volatile content to 6% to 7%, and ensure that the pre-curing degree is ≤ 65%. By adjusting the ratio of resin to curing agent and the mixing method, the resin fluidity is improved to promote uniform penetration;

[0066] (2) Optimize the resin formula, select the appropriate epoxy resin form (such as liquid or powder) and match it with a matching curing agent. If necessary, add a tackifier or cross-linking agent to enhance adhesion. At the same time, use an epoxy resin modified emulsion (such as styrene acrylic emulsion) to simultaneously improve the mechanical properties and water resistance of the impregnated paper.

[0067] Preferably, when the impregnated paper is treated by substrate treatment, the following aspects are included:

[0068] (1) Surface treatment of the substrate: ensure that the surface of the substrate is flat, without oil stains or depressions. Pre-treatment such as sanding and cleaning is required to avoid uneven impregnation; and the moisture content of the substrate should be controlled within the range of 6% to 10%. Too high a moisture content may cause sticking, and too low a moisture content may cause delamination.

[0069] (2) Selection of substrate type: Decorative base paper or filter paper with uniform fiber distribution and strong bonding force is preferred, and its pore structure is conducive to resin penetration.

[0070] Preferably, when the impregnated paper is processed by adjusting the hot pressing process, including matching the temperature and pressure, the hot pressing temperature is recommended to be set at 145-165°C, and the temperature difference between the upper and lower pressing plates is controlled at 3-5°C to avoid warping due to differences in curing speeds. The hot pressing pressure is appropriately increased and the hot pressing time is extended (such as increased to 10-15 seconds / mm thickness) to ensure sufficient flow and curing of the resin.

[0071] Preferably, during the curing treatment in step S4, a three-stage curing method is used to improve the mechanical and electrical properties of the insulator. The specific steps include: a first stage of low-temperature curing, a second stage of medium-temperature curing, and a third stage of high-temperature curing. The temperature and time of each stage should be adjusted according to the specific material and size of the insulator.

[0072] In summary, the present invention adopts the epoxy resin impregnated paper system to prepare the ultra-high voltage long rod insulator above 1100kv. Since the epoxy resin impregnated paper system has extremely high cohesive force and dense molecular structure, its mechanical strength is significantly higher than that of traditional ceramic insulators, and the curing shrinkage rate is low (1% to 2%), the dimensional stability is excellent, it is not easy to crack due to environmental changes, and it is light in weight, convenient to install and maintain, and it is not easy to form cracks on the surface. Therefore, the prepared ultra-high voltage long rod insulator above 1100kv has good mechanical properties and structural stability, and since the epoxy resin impregnated paper system has excellent dielectric properties, The local discharge is small, the temperature rise is low, and there is no insulating oil inside, which avoids the risk of leakage of oil-impregnated paper bushings. Therefore, the prepared ultra-high voltage long rod insulators above 1100kv have good electrical performance and safety. At the same time, since epoxy resin impregnated paper products are lighter than ceramic insulators, and the process design is flexible, complex structures can be customized. Although the composite insulator has obvious advantages in lightweight, the composite structure of its core rod material (such as epoxy resin) and silicone rubber may have the risk of interface separation under extremely low temperatures. Therefore, the prepared ultra-high voltage long rod insulators above 1100kv have the advantages of lightweight and process flexibility.

[0073] An example of the present specific implementation mode is described above, but the present embodiment is not limited to the above-mentioned specific implementation mode, which is merely illustrative and not restrictive. A person skilled in the art may make many forms inspired by the present embodiment, all of which are protected by the present embodiment.

Claims

1. A method for preparing a 1100kv or higher ultra-high voltage long rod insulator, characterized in that: The following steps are involved: S1. Preparation of materials: (1) Preparation of epoxy resin, selecting high-performance phenolic epoxy resin as raw material; (2) Preparation of impregnated paper: select high-quality insulating paper and pretreat it; (3) Preparation of curing agent, select T-31 epoxy resin curing agent; (4) Preparation of release agent, which is applied to the inner wall of the mold to prevent the insulator from sticking to the mold; S2. Mould preparation: (1) Design the mold according to the size and shape of the long rod insulator; (2) Mold treatment: evenly apply mold release agent on the inner wall of the mold; S3, dipping and rolling: (1) Impregnation treatment: immerse the insulating paper in the pre-prepared epoxy resin to make the insulating paper fully wetted without bubbles and dry spots; (2) Rolling and forming: rolling the impregnated insulating paper into a rod shape according to the design requirements; S4, curing and demoulding: (1) Preheating treatment: Place the rolled insulator into a preheating furnace for preheating treatment to remove internal stress and volatiles; (2) Curing treatment: placing the preheated insulator into a curing furnace and curing it according to a predetermined curing process; (3) Demolding: After curing is completed, the insulator is removed from the mold after cooling to room temperature; S5. Post-processing and testing: (1) Stress relief treatment: keep the demoulded insulator at a specific temperature for a period of time to remove internal stress and improve the stability and service life of the insulator; (2) Performance testing: Conduct electrical, mechanical, and heat resistance tests on the prepared insulators to ensure that they meet the requirements of the UHV transmission system; (3) Surface treatment: The insulators shall be surface treated as needed, such as coating with an anti-fouling layer or performing other protective treatments to improve their performance and life.

2. The method for preparing a 1100kv or higher ultra-high voltage long rod insulator according to claim 1, characterized in that: When the impregnated paper is pretreated in step S1, the impregnation process optimization, substrate treatment and hot pressing process adjustment are performed to improve the impregnation performance of the insulating paper and the bonding strength of the epoxy resin.

3. The method for preparing a 1100kv or higher ultra-high voltage long rod insulator according to claim 2, characterized in that: When dealing with impregnated paper through impregnation process optimization, the following aspects are included: (1) Control the impregnation parameters, accurately adjust the glue amount to 130% to 150%, control the volatile content to 6% to 7%, and ensure that the pre-curing degree is ≤ 65%. By adjusting the ratio of resin to curing agent and the mixing method, the resin fluidity is improved to promote uniform penetration; (2) Optimize the resin formula, select the appropriate epoxy resin form (such as liquid or powder) and match it with a matching curing agent. If necessary, add a tackifier or cross-linking agent to enhance adhesion. At the same time, use an epoxy resin modified emulsion (such as styrene acrylic emulsion) to simultaneously improve the mechanical properties and water resistance of the impregnated paper.

4. The method for preparing a 1100kv or higher ultra-high voltage long rod insulator according to claim 2, characterized in that: When treating impregnated paper through substrate treatment, the following aspects are included: (1) Surface treatment of the substrate: ensure that the surface of the substrate is flat, without oil stains or depressions. Pre-treatment such as sanding and cleaning is required to avoid uneven impregnation; and the moisture content of the substrate should be controlled within the range of 6% to 10%. Too high a moisture content may cause sticking, and too low a moisture content may cause delamination. (2) Selection of substrate type: Decorative base paper or filter paper with uniform fiber distribution and strong bonding force is preferred, and its pore structure is conducive to resin penetration.

5. The method for preparing a 1100kv or higher ultra-high voltage long rod insulator according to claim 2, characterized in that: When the impregnated paper is processed through hot pressing process adjustments, including matching temperature and pressure, the hot pressing temperature is recommended to be set at 145-165°C, and the temperature difference between the upper and lower pressing plates is controlled at 3-5°C to avoid warping due to differences in curing speed. The hot pressing pressure should be appropriately increased and the hot pressing time should be extended (such as increasing to 10-15 seconds / mm thickness) to ensure sufficient flow and curing of the resin.

6. The method for preparing a 1100kv or higher ultra-high voltage long rod insulator according to claim 1, characterized in that: During the curing process in step S4, a three-stage curing method is used to improve the mechanical and electrical properties of the insulator. The specific steps include: a first stage of low-temperature curing, a second stage of medium-temperature curing, and a third stage of high-temperature curing. The temperature and time of each stage should be adjusted according to the specific material and size of the insulator.

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