CN111863485A - A circuit breaker pole component and its manufacturing method - Google Patents

Abstract

The invention discloses a method for manufacturing a pole post part of a circuit breaker, which comprises the following steps: roughening the surface of a vacuum interrupter, and the roughening treatment includes sandblasting and acid etching; Silica sol coating is carried out; the arc extinguishing chamber is heat treated; according to the difference of the outer covering insulating layer, the solid-sealed pole product is prepared and formed by the automatic pressure gel (APG) process or the injection molding process. The invention also discloses a circuit breaker pole component, which is prepared by the above-mentioned preparation method. The invention provides a circuit breaker pole component and a manufacturing method thereof, which can improve the mechanical impact resistance characteristics of the solid-sealed pole and improve the partial discharge characteristics, while avoiding the appearance of multiple interface layers in the product and improving the process stability.

Description

A circuit breaker pole component and its manufacturing method

technical field

The invention relates to a circuit breaker pole component and a manufacturing method thereof, belonging to the technical field of power transmission and distribution switchgear.

Background technique

Circuit breakers used in the medium voltage field can break normal rated current, short circuit current and withstand the voltage across the circuit breaker when it is in the open position. The interruption of the current will create an arc between the contacts, and the arc will be extinguished at the zero-crossing point under AC and in a suitable medium. In the medium pressure system, only vacuum and SF ₆ technologies have been widely used, and the market share of vacuum technology in the medium pressure field has an absolute advantage.

The core component of vacuum technology is the vacuum interrupter. At present, the vacuum interrupter has been widely used to the voltage level of 40.5kV and below, and 145kV voltage level products are also being launched for use. In addition to meeting the voltage and current requirements that may arise during operation, maintaining the vacuum in the interrupter for more than 30 years is an important quality indicator. In order to achieve this requirement, it is particularly necessary to apply modern production technology and optimize the design.

Due to the difference in physical properties between the ceramic surface of the vacuum interrupter and the insulating materials (thermosetting materials such as epoxy or thermoplastic materials such as nylon) covered by the ceramic shell, the interface between the two is peeled off or broken, which will lead to product performance defects or safety hazards. At present, in order to overcome this defect, a buffer layer (silicon rubber) is mostly used on the surface of the porcelain shell to alleviate this problem.

Existing production processes for encapsulating silicone rubber (buffer layers) have inherent drawbacks. If this kind of technical solution is adopted, there is at least an outer insulating layer (epoxy or thermoplastic insulating material layer)/adhesive layer/buffer layer/adhesive layer/ceramic layer/vacuum layer from the outside to the inside of the solid-sealed pole. , a total of 6 media, 5 contact surfaces. If there is an air gap or uneven stress on any contact surface, it is very easy to cause interface deterioration, resulting in partial discharge, which eventually leads to irrecoverable breakdown and damage to the product.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to overcome the defects of the prior art, and to provide a method that can improve the mechanical shock resistance and partial discharge characteristics of the solid-sealed pole, avoid the appearance of multiple interface layers in the product, and improve the process stability. Circuit breaker pole components and methods of making the same.

In order to solve the above-mentioned technical problems, the technical scheme adopted in the present invention is:

A method for manufacturing a circuit breaker pole component, comprising the following steps:

Roughening the surface of the vacuum interrupter;

Silica sol coating on the surface of vacuum interrupter;

Heat treatment of the vacuum interrupter;

According to the difference of the outer cladding insulating layer, the solid-sealed pole product is prepared and formed by an automatic pressure gel (APG) pouring process or an injection molding process.

Roughening treatment includes sandblasting treatment and acid etching treatment.

The sandblasting process is as follows: the surface of the vacuum interrupter is sandblasted with Al ₂ O ₃ or SiO ₂ particles, the particle size is 20-200 μm, the blasting pressure is set to 1-5MPa, and the time is 15-100s. After sandblasting, clean the vacuum interrupter with deionized water and then dry it with oil-free air. Through the impact of Al ₂ O ₃ or SiO ₂ particles on the ceramic surface, the loss of the matrix on the surface of the arc-extinguishing chamber forms pits to achieve the purpose of increasing the surface roughness and surface area. This process also removes the contamination on the surface of the arc-extinguishing chamber. It increases the surface energy and wettability, and finally increases the bond strength with the resin.

The acid etching treatment process is specifically as follows: the surface of the porcelain parts of the vacuum interrupter is acid-etched with an etching solution, and the acid-etching time is 10-60 minutes. After acid etching, rinse with deionized water and then dry with oil-free air. The etching solution is a mixture of HNO ₃ with a mass fraction of 68% and HF with a mass fraction of 40% in a volume ratio of 1:1. The size of the particles on the surface of the arc-extinguishing chamber after acid etching becomes smaller, and the pores between the particles become larger, which also achieves the purpose of increasing the surface roughness and surface area. At the same time, the pollutants in the arc extinguishing chamber are also removed, the surface energy and wettability are increased, and the bonding strength with the resin is finally increased.

The silica sol coating process is as follows: 20%-50% SiO ₂ hydrosol is uniformly coated on the surface of the vacuum interrupter, and the coating thickness is 0.1-100 μm.

Coating methods include, but are not limited to, dip pulling, spin coating, or spray coating.

The specific heat treatment of the arc-extinguishing chamber is as follows: the arc-extinguishing chamber is placed in a drying oven with a relative humidity of 30% to 75% for natural drying at room temperature, taken out after 3 to 24 hours, and then heat treated in an oven at 150°C for 1 to 6 hours, and then slowly cooled to room temperature.

A circuit breaker pole component is prepared by the above method for manufacturing a circuit breaker pole component.

Beneficial effects of the present invention: The present invention discloses a circuit breaker pole component and a manufacturing method thereof. By treating the surface of the vacuum interrupter, the adhesion between the vacuum interrupter and the outer covering insulating material is increased, so that the Improve the mechanical shock resistance of the solid-sealed pole and improve the partial discharge characteristics, while avoiding the appearance of multiple interface layers in the product, and improving the process stability; A small number of micro-cracks appear on the surface of the ceramic, so excessive surface treatment will reduce the strength and fracture toughness of the ceramic itself, thereby affecting its service life. Use silica sol to treat the ceramic surface, and the silica sol will occupy the surface micro-cracks formed by the surface treatment. After heat treatment, a stable Si-O-Si layer is formed, the bonding strength is significantly improved compared with the traditional coupling agent, and the crack repair effect is achieved.

Description of drawings

FIG. 1 is a process flow diagram of a method for manufacturing a pole component of a circuit breaker according to the present invention.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention, and cannot be used to limit the protection scope of the present invention.

Specific Example 1

As shown in FIG. 1 , the present invention provides a method for manufacturing a circuit breaker pole component. The 40.5kV vacuum interrupter is made of etching solution (68% mass fraction of HNO ₃ and mass fraction of 40% HF, 1:1 volume ratio) blend) for acid etching, and the acid etching time is 30 min. After acid etching, rinse with deionized water and then dry with oil-free air. The 30% SiO ₂ hydrosol was evenly coated on the surface of the vacuum interrupter by the pulling and dipping method, and the coating thickness was 20 μm. The interrupter was placed in a 60% RH drying box to dry naturally at room temperature. Heat treatment in an oven at 150 °C for 3 h, and then slowly cool to room temperature. The solid-sealed pole is formed by the APG process or the injection molding process. All the trial-produced products can pass the partial discharge test (GB/T 7354-2018 high voltage test technology partial discharge measurement).

Comparative Example 1

The 40.5kV vacuum interrupter was acid-etched with etching solution (68% mass fraction of HNO ₃ and mass fraction of 40% HF, blended in a volume ratio of 1:1), and the acid etching time was 30 min. After acid etching, rinse with deionized water and then dry with oil-free air. The silane coupling agent was evenly coated on the surface of the vacuum interrupter with a coating thickness of 20 μm. The interrupter was placed in a 60% RH drying oven to dry naturally at room temperature, taken out after 12 hours, and then heat-treated in an oven at 150 °C for 3 hours. Then cool slowly to room temperature. The solid-sealed pole is cast and formed by the APG process. None of the trial-produced products passed the partial discharge test (GB/T 7354-2018 Partial discharge measurement of high-voltage test technology).

Specific embodiment 2

As shown in Figure 1, the surface of the 40.5kV vacuum interrupter was blasted with Al ₂ O ₃ particles, the particle size was 100 μm, the blasting pressure was set to 2.5 MPa, and the time was 30 s. After sandblasting, clean the vacuum interrupter with deionized water and then dry it with oil-free air. The 30% SiO ₂ hydrosol was evenly coated on the surface of the vacuum interrupter by the pulling and dipping method, and the coating thickness was 20 μm. The interrupter was placed in a 60% RH drying box to dry naturally at room temperature. Heat treatment in an oven at 150 °C for 3 h, and then slowly cool to room temperature. The solid-sealed pole is formed by the APG process or the injection molding process. All the trial-produced products can pass the partial discharge test (GB/T7354-2018 high-voltage test technology partial discharge measurement).

Comparative Example 2

The surface of the 40.5kV vacuum interrupter was blasted with Al ₂ O ₃ particles, the particle size was 100 μm, the blasting pressure was set to 2.5 MPa, and the time was 30 s. After sandblasting, clean the vacuum interrupter with deionized water and then dry it with oil-free air. Coating the coupling agent evenly on the surface of the vacuum interrupter with a coating thickness of 20 μm, placing the interrupter in a 60% RH drying oven to dry naturally at room temperature, taking it out after 12 hours, and then heat treatment in a 150 ℃ oven for 3 hours, and then Cool slowly to room temperature. The solid-sealed pole is formed by the APG process or the injection molding process. None of the trial-produced products passed the partial discharge test (GB/T 7354-2018 Partial discharge measurement of high-voltage test technology).

Comparative Example 3

After cleaning the 40.5kV vacuum interrupter with deionized water, a 30% _SiO2 hydrosol was evenly coated on the surface of the vacuum interrupter by pulling and dipping with a coating thickness of 20 μm. Dry naturally at room temperature in a RH drying box, take it out after 12 hours, heat treatment in an oven at 150 °C for 3 hours, and then slowly cool to room temperature. The solid-sealed pole is formed by the APG process or the injection molding process. None of the trial-produced products passed the partial discharge test (GB/T 7354-2018 Partial discharge measurement of high-voltage test technology).

Comparative Example 4

After the surface of the 40.5kV vacuum interrupter was cleaned with deionized water, the coupling agent was evenly coated on the surface of the vacuum interrupter with a coating thickness of 20 μm, and the interrupter was placed in a 60% RH drying box at room temperature. It was dried, taken out after 12 hours, heat-treated in an oven at 150 °C for 3 hours, and then slowly cooled to room temperature. The solid-sealed pole is formed by the APG process or the injection molding process. None of the trial-produced products passed the partial discharge test (GB/T 7354-2018 Partial discharge measurement of high-voltage test technology).

Table 1

The above-mentioned six sets of test results are shown in Table 1, from which it can be seen that the circuit breaker pole components prepared according to the method of the present invention can pass the partial discharge test regardless of the APG process or the injection molding process. However, the pole components of the circuit breaker prepared without the surface treatment method of the present invention cannot pass the partial discharge test. It can be seen that, the method for manufacturing a circuit breaker pole component provided by the present invention can overcome the defects of the production process in the prior art and meet the actual production requirements by treating the surface of the vacuum interrupter.

Specific embodiment 3

As shown in FIG. 1 , the present invention provides a method for manufacturing a circuit breaker pole component. The surface of a 40.5kV vacuum interrupter is sandblasted with _SiO2 particles, the particle size is 50 μm, and the sandblasting pressure is set to 2MPa; for 50s. After sandblasting, clean the vacuum interrupter with deionized water and then dry it with oil-free air. The 20% SiO ₂ hydrosol was evenly coated on the surface of the vacuum interrupter by the pulling and dipping method, and the coating thickness was 30 °C. Heat treatment in an oven at 150 °C for 4 h, and then slowly cool to room temperature. The solid-sealed pole is formed by the APG process or the injection molding process. All the trial-produced products can pass the partial discharge test (GB/T 7354-2018 high voltage test technology partial discharge measurement).

Specific Example 4

As shown in Figure 1, the surface of the 12kV vacuum interrupter was blasted with Al ₂ O ₃ particles, the particle size was 100 μm, the blasting pressure was set to 2.5 MPa, and the time was 30 s. After sandblasting, clean the vacuum interrupter with deionized water and then dry it with oil-free air. The 30% SiO ₂ hydrosol was evenly coated on the surface of the vacuum interrupter by the pulling and dipping method, and the coating thickness was 20 μm. The interrupter was placed in a 60% RH drying box to dry naturally at room temperature. Heat treatment in an oven at 150 °C for 3 h, and then slowly cool to room temperature. The solid-sealed pole is formed by the APG process or the injection molding process. The trial-produced products can pass the partial discharge test (GB/T7354-2018 high voltage test technology partial discharge measurement). The trial-manufactured product was installed in a circuit breaker assembly of a metal-armored switchgear. According to the standard GB/T 1984-2014 high-voltage AC circuit breaker, a mechanical break-in test device was used to perform 20,000 repetitions on the circuit breaker assembly with samples. For the manipulation test, the manipulation frequency was set to 3 times/min. After this test, the sample can still pass the partial discharge test (GB/T 7354-2018 High Voltage Test Technology Partial Discharge Measurement).

Comparative Example 5

As shown in Figure 1, the surface of the 12kV vacuum interrupter was blasted with Al ₂ O ₃ particles, the particle size was 100 μm, the blasting pressure was set to 2.5 MPa, and the time was 30 s. After sandblasting, clean the vacuum interrupter with deionized water and then dry it with oil-free air. Coating the coupling agent evenly on the surface of the vacuum interrupter with a coating thickness of 20 μm, placing the interrupter in a 60% RH drying oven to dry naturally at room temperature, taking it out after 12 hours, and then heat treatment in a 150 ℃ oven for 3 hours, and then Cool slowly to room temperature. The solid-sealed pole is formed by the APG process or the injection molding process. The trial-produced products can pass the partial discharge test (GB/T 7354-2018 high voltage test technology partial discharge measurement). The manufactured sample is installed in a circuit breaker assembly of a metal-armored switchgear. According to the standard GB/T 1984-2014 high-voltage AC circuit breaker, the circuit breaker assembly with the sample is repeated 20,000 times using a mechanical running-in test device. Sexual manipulation test, the manipulation frequency was set to 3 times/min. After this test, the sample could not pass the partial discharge test (GB/T7354-2018 High Voltage Test Technology Partial Discharge Measurement).

The above is only the preferred embodiment of the present invention, it should be pointed out that: for those skilled in the art, without departing from the principle of the present invention, several improvements and modifications can also be made, and these improvements and modifications are also It should be regarded as the protection scope of the present invention.

Claims (10)

1. A method for manufacturing a pole part of a circuit breaker is characterized in that: the method comprises the following steps:

roughening the surface of the vacuum arc-extinguishing chamber;

coating silica sol on the surface of the vacuum arc-extinguishing chamber;

carrying out heat treatment on the arc extinguish chamber;

and (3) preparing and molding the solid-sealed polar pole product by utilizing an automatic pressure gel process or an injection molding process according to different outer coating insulating layers.

2. The method of claim 1, wherein the method further comprises: the roughening treatment includes two modes of sand blasting treatment and acid etching treatment.

3. According to claim2 the method for manufacturing the pole part of the circuit breaker is characterized in that: the sand blasting process comprises the following specific steps: using Al on the surface of the vacuum arc-extinguishing chamber₂O₃Or SiO₂Carrying out sand blasting treatment on particles, wherein the particle size of the particles is 20-200 mu m, the sand blasting pressure is set to be 1-5 MPa, the time is 15-100 s, and after sand blasting, cleaning the vacuum arc-extinguishing chamber with deionized water and then drying the vacuum arc-extinguishing chamber with oilless air.

4. The method of claim 2, wherein the method further comprises: the acid etching treatment process specifically comprises the following steps: and (3) carrying out acid etching on the surface of the vacuum arc-extinguishing chamber porcelain piece by using etching liquid, wherein the acid etching time is 10-60 min, and after the acid etching is finished, cleaning by using deionized water and then drying by using oilless air.

5. The method of claim 4, wherein the method further comprises: the etching solution is HNO with the mass fraction of 68 percent₃And 40% by mass of HF in a volume ratio of 1: 1 proportion is mixed.

6. The method of claim 1, wherein the method further comprises: the silica sol coating process specifically comprises the following steps: 20 to 50 percent of SiO₂The hydrosol is uniformly coated on the surface of the vacuum arc-extinguishing chamber, and the thickness of the coating is 0.1-100 mu m.

7. The method of claim 6, wherein the method further comprises: coating methods include dip-coating, spin coating, or spray coating.

8. The method of claim 1, wherein the method further comprises: the arc extinguish chamber heat treatment specifically comprises the following steps: and (3) naturally drying the arc extinguishing chamber in a drying oven with relative humidity of 30-75% at room temperature, taking out after 3-24 h, carrying out heat treatment in an oven with the temperature of 150 ℃ for 1-6 h, and cooling to room temperature.

9. The method of claim 1, wherein the method further comprises: if the outer coating layer is made of a thermosetting insulating material, an automatic pressure gel process is selected, and if the outer coating layer is made of a thermoplastic insulating material, an injection molding process is selected.

10. A circuit breaker pole component is characterized in that: the circuit breaker pole part manufactured by the method for manufacturing the circuit breaker pole part according to any one of claims 1 to 9.

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