CN201690195U - 500kV and above 500kV power cable outdoor terminal - Google Patents

Abstract

The utility model relates to cable accessories of power cable power transmission system field, especially relates to a 500 kV and more than 500 kV power cable outdoor terminal, which comprises a casing tube (1), an insulating agent (2), a stress cone (3), an epoxy sleeve (4), and a spring pressing mechanism (5), also comprises outgoing line hardware fittings, an upper cover board (7), a lower base board (8) and a tail tube (9), the stress cone (3) is sleeved in the casing tube (1), the epoxy sleeve (4) is sleeved outside the stress cone (3), the spring pressing mechanism (5) is arranged under the stress cone (3), and the stress cone (3) is made from liquid silicon rubber. The utility model has advantages that (1) the performance is stabilized and reliable, the yield is high, and the integrated cost is low; (2) the manufacturing process is simple, the manufacturing is easy, the manufacturing cost is low, the liquid silicon rubber has low viscosity, good flow property, excellent process forming performance, and small required forming pressure before sulfuration; (3) the product quality is good.

Description

500kV and above 500kV power cable outdoor terminal

technical field

The utility model relates to a cable accessory in the field of power cable transmission system, in particular to an outdoor terminal of a power cable of 500kV or above.

Background technique

At present, in power cable transmission systems with voltage levels above 500kV and 500kV, cables are mostly XLPE insulated power cables, and outdoor terminals are used to connect XLPE insulated power cables and overhead lines to realize power transmission. transmission. With the construction of large-scale hydropower stations, pumped storage power stations, and UHV power grids, the use of outdoor terminals is increasing. In the power cable connection system of 500kV and above, outdoor terminals are important connectors. The reliability of outdoor terminals It directly affects the reliability of the transmission system.

In the outdoor terminals of power cables of 500kV and above, the stress cone of the commonly used outdoor terminal is a structural type of integral prefabricated insulation. The outdoor terminal of this structure includes bushing, insulating agent, stress cone, epoxy sleeve and The spring compression mechanism also includes outlet fittings, upper cover plate, lower bottom plate and tail pipe. The stress cone is installed in the casing, and the stress cone is covered with an epoxy sleeve. A spring compression mechanism is arranged under the stress cone. The stress cone consists of three Made of ethylene propylene rubber material. The main function of the stress cone is to uniform the electric field and enhance the insulation in the outdoor 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 outdoor terminals. Since the stress cone is made of EPDM material, the current outdoor terminals of 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 it requires a special large-scale rubber injection machine with a large tonnage and a large mold to perform rubber injection molding, and the materials used must be injected at one time. Therefore, the production of stress cones for outdoor terminals of power cables with 500kV and above requires rubber injection. The tonnage of the machine must reach more than 1,600 tons, and the single injection of glue must reach more than 80 liters to meet the requirements. Such equipment has a large volume and high 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 outdoor terminals of power cables of 500kV and above have the above-mentioned defects, people have been unable to solve this technical problem for a long time.

Utility model content

The purpose of the utility model is to overcome the deficiencies of the prior art and provide an outdoor 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: an outdoor terminal for power cables of 500kV and above, including a sleeve, an insulating agent, a stress cone, an epoxy sleeve and a spring compression mechanism, and also includes an outlet fitting, an upper cover plate, and a lower base plate and the tail pipe, the stress cone is installed in the casing, the stress cone is covered with an epoxy sleeve, and a spring compression 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.

Further, the insulating agent is insulating oil or insulating gas.

After adopting the above technical scheme, the utility model has many advantages because the material of the key component stress cone 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 utility model is more stable and reliable, the yield rate is high, time and energy are saved, and the comprehensive 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 outdoor terminals of power cables of 500kV and above, the equipment is small in size, the cost of equipment is greatly reduced, and the production equipment is easy to obtain , easy to make, so the utility model has low manufacturing cost.

(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.

Embodiment one

As shown in Figure 1, an outdoor terminal for power cables of 500kV and above includes a bushing 1, an insulating agent 2, a stress cone 3, an epoxy sleeve 4, and a spring compression mechanism 5, as well as outlet fittings 6, upper The cover plate 7, the lower base plate 8, the tail pipe 9, and the stress cone 3 are composed of a conductor 3-1 and an insulator 3-2, and the insulating agent 2 is insulating oil. The stress cone 3 is installed in the casing 1, and the epoxy sleeve 4 is placed on the outside of the stress cone 3. The casing 1 is filled with insulating oil, and the spring compression mechanism 5 connected with the tail pipe 9 is arranged under the stress cone 3. The tightening mechanism 5 includes a spring 5-1 and a spring seat 5-2. The spring 5-1 is arranged between the stress cone 8 and the spring seat 5-2. The stress cone 3 is made of liquid silicone rubber.

Embodiment two

As shown in FIG. 1 , it is basically the same as the first embodiment, except that the insulating agent 2 is insulating gas, and the bushing 1 is filled with insulating gas.

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 required 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 stress cone 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 (3)

1. 500kV and the above power cable outdoor terminal of 500kV, include sleeve pipe (1), insulating compound (2), stress cone (3), epoxy cover (4) and spring compression mechanism (5), also include outlet gold utensil (6), upper cover plate (7), lower shoe (8) and tail pipe (9), stress cone (3) is contained in the sleeve pipe (1), stress cone (3) outer suit epoxy cover (4), be provided with spring compression mechanism (5) below the stress cone (3), it is characterized in that: described stress cone (3) is made by liquid silastic.

2. 500kV according to claim 1 and the above power cable outdoor terminal of 500kV is characterized in that: described stress cone (3) is made up of electric conductor (3-1) and insulator (3-2).

3. 500kV according to claim 1 and the above power cable outdoor terminal of 500kV is characterized in that: described insulating compound (2) is insulating oil or insulating gas.

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