CN201690192U - 500kV and above 500kV power cable dry-type GIS terminal - Google Patents

Abstract

The utility model relates to a cable accessory in the field of power cable transmission systems, in particular to a dry type GIS terminal for a power cable of 500 kV or more. The dry type GIS terminal comprises an epoxy sleeve (1), a spring pressing mechanism (2) with a spring (2-1) and a stress cone (3), and also comprises a cable outlet fitting (4), a shielding case (5) and a tail pipe (6), wherein the stress cone (3) is arranged in the epoxy sleeve (1), the spring pressing mechanism (2) is arranged below the stress cone (3), and the stress cone (3) is made of liquid silicon rubber. The dry type GIS terminal has the following advantages: (1) the GIS terminal has stable and reliable performance, high yield and low comprehensive cost, and the liquid silicon rubber material of the stress cone is pure; (2) the manufacturing technique is simple, the GIS terminal is fabricated easily, the manufacturing cost is low, and before vulcanization, the liquid silicon rubber has lower viscosity and better liquidity, and more excellent technical formability, and can be formed with lower pressure; and (3) the quality of products is good.

Description

500kV and above 500kV power cable dry-type GIS terminal

technical field

The utility model relates to a cable accessory in the field of power cable transmission system, in particular to a dry-type GIS terminal for power cables of 500kV and above.

Background technique

At present, in the power cable transmission system with a voltage level of 500kV and above, the cables are mostly XLPE insulated power cables, and dry-type GIS terminals are used for electrical connection between XLPE insulated power cables and GIS combined electrical appliances. Realize the transmission of electric energy. With the construction of large-scale hydropower stations, pumped storage power stations, and UHV power grids, the use of dry-type GIS terminals is increasing. In power cable connection systems of 500kV and above, dry-type GIS terminals are important connectors. The reliability of the dry GIS terminal directly affects the reliability of the power transmission system.

In 500kV and above 500kV power cable dry-type GIS terminals, the stress cone of the dry-type GIS terminal is generally used as an integral prefabricated insulation structure type. The dry-type GIS terminal of this structure includes epoxy sleeves and springs. The spring compression mechanism and stress cone also include outgoing fittings, shielding cover and tail pipe. The stress cone is installed in the epoxy sleeve. There is a spring compression mechanism under the stress cone. The stress cone is made of EPDM rubber material. made. The spring pressing device tightens the overall prefabricated stress cone so that it is close to the tapered wall of the epoxy sleeve, and there is no need to add any insulating agent such as insulating oil or insulating gas to the dry GIS terminal. The main function of the stress cone is to uniform the electric field and enhance the insulation in the GIS terminal when the cable insulation shielding is cut off. At the same time, it also provides the necessary pressing force on the surface of the cable to improve the overall insulation level of the terminal. The stress cone is Key components of dry GIS terminals. Since the stress cone is made of EPDM material, the current dry-type GIS terminals for power cables of 500kV and above have the following defects:

(1) The quality of the material used to make the stress cone is difficult to control. The material of the stress cone is mainly a terpolymer of ethylene, propylene and non-conjugated dienes. Various additives are added during the kneading process, and the formula is complicated It is difficult to control the quality of the material; the viscosity of the material is high, the molding process is poor, and the yield of the stress cone is only about 60%.

(2) The manufacturing process is complicated, and the molding equipment required for processing the stress cone has a large pressure, a large volume, and high product manufacturing costs. When the EPDM material is processed into a stress cone, the structure of the equipment used for the rubber injection machine is shown in Figure 3. During production, the material EPDM rubber is placed in the barrel 21 and injected into the mold 23 through the injection mechanism 22. Inside, the mold 23 is composed of an upper mold 23-1 and a lower mold 23-2 that match each other. After heating, the material is vulcanized and formed into a stress cone in the cavity of the mold. Because the viscosity of EPDM rubber after plasticization is very high and its fluidity is poor, it needs tens of megabytes of pressure to inject it into the cavity. During the injection process, the cavity and equipment need to withstand very high pressure. Due to the molding mold The volume is very large, and a special large-scale rubber injection machine with a large tonnage and a large mold are required for rubber injection molding, and the materials used must be injected in one shot. Therefore, the production of stress cones for power cable dry-type GIS terminals of 500kV and above 500kV requires The rubber injection machine has a tonnage of more than 1,600 tons and a single injection of more than 80 liters of rubber can meet the requirements. Such equipment is large in size and high in equipment cost, and the increase in equipment cost causes the entire production cost to be extremely high.

(3) Due to the high hardness of EPDM rubber, Shore A60~70, the adhesion to the surface of the cable is poor, resulting in difficulty in product installation and an increase in product failure rate, and the air box of EPDM rubber is aging Post-mechanical properties (aging conditions: 135°C±3°C, 7d), compression set ≤ 15-25%, tensile strength change rate ≤ 20-30%, elongation change rate ≤ 20-30%, material The aging resistance and high temperature resistance of the product are poor, and the product must be operated under the environmental conditions of ≤100°C, the use is limited, and the scope of application is narrow.

Although the existing 500kV and above 500kV power cable dry-type GIS terminals have the above defects, people have been unable to solve this technical problem for a long time.

Contents of the invention

The purpose of this utility model is to overcome the deficiencies of the prior art and provide a dry-type GIS terminal for power cables of 500kV and above with stable and reliable performance, high yield, simple manufacturing process, easy manufacturing, low cost, and good quality.

The technical solution to achieve the above purpose is: a dry-type GIS terminal for power cables of 500kV and above, including epoxy sleeves, spring compression mechanisms with springs and stress cones, and outlet fittings, shielding covers and tail pipes , the stress cone is installed in the epoxy casing, and a spring pressing mechanism is arranged under the stress cone, and the stress cone is made of liquid silicone rubber.

Further, the stress cone is composed of conductors and insulators.

After adopting the above-mentioned technical scheme, the dry-type GIS terminal of the power cable of 500kV and above 500kV of the utility model has many advantages because the production material of the stress cone of the key component is improved from EPDM rubber to liquid silicone rubber:

(1) Stable and reliable performance, high yield and low overall cost. The material quality of the stress cone is easy to control, the material of the stress cone is simple liquid silicone rubber, no need to mix separately, the formula is simple, and the quality of the material is easy to control; the material has low viscosity, good molding process, and the yield of the stress cone can reach 90%. Left and right, the performance of the product of the invention is more stable and reliable, the yield rate is high, time and energy are saved, and the overall cost is reduced by more than 40%.

(2) The manufacturing process is simple, the manufacturing is easy, and the manufacturing cost is low. Liquid silicone rubber is a type of silicone rubber compared to mixing type semi-solid silicone rubber and common room temperature vulcanized single-component silicone rubber. Liquid silicone rubber has lower viscosity and better fluidity before vulcanization, and the viscosity is only ternary. 1/10 of ethylene propylene rubber, with more excellent process formability, so the production process is simple, easy to manufacture, the required molding pressure is small, and there is no need for special large-scale rubber injection machines and large molds with high pressure for injection molding. Only ordinary injection equipment and molds can be used to complete the injection molding. For example, if a liquid silicone rubber two-component injection machine is used, the required pressure of the injection machine is only a few megabytes, which is the same as that of an EPDM rubber injection machine. 1/10, the glue injection machine can inject continuously, up to 400 liters at a time, the glue injection volume can meet the needs of stress cone production for power cable dry-type GIS terminals of 500kV and above 500kV, the equipment is small in size, and the equipment cost is greatly reduced. It is easy to obtain and easy to manufacture, so the manufacturing cost of the present invention is low.

(3) The product quality is good. Due to the low hardness of liquid silicone rubber, Shore A35~45, it has good adhesion to the surface of the cable, easy product installation, low product failure rate, mechanical properties of liquid silicone rubber air box after aging (aging condition: 135°C) ±3°C, 7d), compression set ≤ 15%, tensile strength change rate ≤ 10%, elongation change rate ≤ 10%, the material has good aging resistance and high temperature resistance, and the product is 100~ It can run for a long time under the environmental condition of 150 ℃, the product quality is good, and the application range is wide.

The utility model solves the complex technical problem of using EPDM rubber in the prior art with a simple and ingenious technical solution, and solves this technical problem that people have been difficult to solve for a long time.

Description of drawings

Fig. 1 is the structural representation of the utility model with 20 cables;

Fig. 2 is a structural schematic diagram of the glue injection machine when the stress cone of the utility model part 3 is made of liquid silicone rubber;

Fig. 3 is a structural schematic diagram of the rubber injection machine when the stress cone of the existing part 3 is made of EPDM rubber.

Detailed ways

Below in conjunction with accompanying drawing and embodiment the utility model is described in further detail.

Example

As shown in Figure 1, a 500kV and above 500kV power cable dry-type GIS terminal includes an epoxy sleeve 1, a spring compression mechanism 2 with a spring 2-1, a stress cone 3, and an outlet fitting 4 , the shielding cover 5 and the tailpipe 6, the stress cone 3 is installed in the epoxy sleeve 1, the spring compression mechanism 2 is arranged under the stress cone 3, and the stress cone 3 is made of liquid silicone rubber.

As shown in Figure 2, when the stress cone 3 of the utility model is made, a liquid silicone rubber two-component glue injection machine is used. The tonnage of the glue injection machine is 100 tons. During the process, the two-component liquid silicone rubber material of component A and component B is placed in the two rubber barrels 24 of the injection machine, and the material is injected into the material tube 27 through the injection pump 26 on the injection frame 25. After the materials are mixed by the mixer 28, they are injected into the mold cavity in the mold 29, and the mold 29 is locked by a clamping mechanism 30, and finally the mold 29 is heated and vulcanized to form the integral prefabricated insulating part 1.

The utility model is not limited to the above-mentioned embodiments, and all technical solutions formed by equivalent replacement or equivalent replacement all belong to the protection scope of the utility model.

Claims (2)

1. A dry-type GIS terminal for power cables of 500kV and above, including an epoxy sleeve (1), a spring compression mechanism (2) with a spring (2-1), and a stress cone (3), and also includes There are outlet fittings (4), shielding cover (5) and tail pipe (6), the stress cone (3) is installed in the epoxy sleeve (1), and a spring compression mechanism (2) is arranged under the stress cone (3) , characterized in that: the stress cone (3) is made of liquid silicone rubber. 2. The 500kV and above 500kV power cable dry-type GIS terminal according to claim 1, characterized in that: the stress cone (3) is composed of a conductor (3-1) and an insulator (3-2). the

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