CN204270715U - A halogen-free flame-retardant low-temperature resistant medium-voltage wind power cable - Google Patents

Abstract

The utility model discloses a halogen-free, flame-retardant, low-temperature and medium-voltage wind energy cable, which includes a cable core, and the cable core is formed by twisting three power cores and three ground cores located in the gap between the three power cores; There is a filling layer in the gap of the core, and the halogen-free flame-retardant tape, the first outer sheath and the second outer sheath are sequentially extruded outside the cable core; between the first outer sheath and the second outer sheath, there is also a Reinforcing layer; the utility model also discloses a production method of the cable. The cable has low temperature resistance, frequent torsion resistance, salt spray resistance, and drag resistance in the harsh wind farm environment, and keeps the cable smoothly transmitting power to meet the normal operation of wind power equipment.

Description

A halogen-free flame-retardant low-temperature resistant medium-voltage wind power cable

technical field

The utility model belongs to the field of power cables, in particular to a halogen-free, flame-retardant, low-temperature and medium-voltage wind energy cable.

Background technique

Among the many renewable energy sources, wind power generation is currently the fastest growing and most economically applicable. Wind power generation is safe, clean, and rich in resources. Wind energy is inexhaustible and inexhaustible. It is an everlasting renewable resource.

With the gradual increase of the unit capacity of wind turbines, the structure of wind turbine units is diversified; the mainstream models on land are developing from 2MW to 3MW, and the mainstream models on sea are developing from 3MW to more than 5MW. Therefore, large-scale wind turbines have become a development trend. The wind energy cables with a voltage level of 1.8/3kV and below commonly used in China can no longer meet the operating requirements of large-capacity wind turbines, and the low-temperature-resistant medium-voltage wind energy cables with a rated voltage of 26/35kV and below are used in conjunction with them.

Wind energy cables generally have the characteristics of excellent torsion resistance. At the same time, wind energy cables generally require cables to have good low temperature resistance, salt spray resistance, and drag resistance, so as to ensure that the cables are in the harsh environment of severe cold inland and offshore salt spray corrosion. use. However, for rated voltage 26/35kV and below low temperature medium voltage wind energy cables, it is far from enough to only consider the performance requirements of the cable such as torsion resistance, low temperature resistance, and salt spray resistance. Reasonable metal shielding structure and ground wire structure design, It is also a guarantee to ensure the safe operation of the cable.

From the perspective of ensuring that the operation safety requirements of large-capacity wind turbines are met, it is particularly necessary to develop a halogen-free flame-retardant low-temperature resistant medium-voltage wind energy cable to gradually meet the requirements of the development trend of large-scale wind turbines. 26/35kV and below low temperature resistant medium voltage wind energy cable conductors and insulation shielding layer materials, research on insulating layer materials, as well as the design of cable metal shielding structure and ground wire structure are the key to halogen-free flame retardant low temperature medium voltage wind energy cables.

Utility model content

The technical problem to be solved by the purpose of this utility model is to provide a halogen-free flame-retardant low-temperature resistant medium-voltage wind energy cable. And keep the cable to transmit power smoothly to meet the normal operation of wind power equipment.

A halogen-free, flame-retardant, low-temperature and medium-voltage wind energy cable described in the utility model includes a cable core, and the cable core is formed by twisting three power cores and three ground cores located in the gaps between the three power cores; There is a filling layer in the gap of the cable core, and the halogen-free flame-retardant tape, the first outer sheath and the second outer sheath are sequentially extruded outside the cable core; There is a reinforcing layer; the power line core is composed of a power line conductor and a conductor shielding semiconducting layer, an insulating layer, an insulating shielding layer, a semiconducting wrapping layer and a metal shielding layer extruded sequentially outside the conductor; the described The ground wire core is composed of a ground wire conductor and a semiconductive layer extruded outside the ground wire conductor.

As a further improvement, the conductor shielding semiconducting layer is a cross-linked halogen-free semiconducting shielding layer based on EPDM.

As a further improvement, the insulating layer is a cross-linked medium-voltage ethylene-propylene insulating rubber based on EPDM.

As a further improvement, the insulating shielding layer is a strippable cross-linked halogen-free semi-conductive shielding layer based on vinyl acetate copolymer and nitrile rubber.

As a further improvement, the metal shielding layer is braided shielding of tinned copper wires.

As a further improvement, the outer sheath is made of halogen-free, low-smoke, UV-resistant thermosetting elastomer material.

A method for producing a halogen-free, flame-retardant, low-temperature and medium-voltage wind energy cable, comprising the following steps:

1) Firstly, the strippable cross-linked halogen-free layer with EPDM as the base material conductor shielding semi-conductive layer, EPDM as the base material insulation layer, vinyl acetate copolymer and nitrile rubber as the base material The semi-conductive insulating shielding layer is separately processed into extruded compounded rubber;

2) Preparation of the power core: the stranded power core conductor is extruded in layers through the catenary three-layer co-extruded continuous sulfur production method, and the conductor shielding semi-conductive layer and ethylene-propylene insulation are also extruded at one time. Layer and insulation shielding layer, the extrusion temperature is controlled at 70°C-90°C, the production line speed is controlled at 5-10 m/min, after extrusion, it is heated and vulcanized continuously in a closed steam pipeline, and the pressure of the steam pipeline is controlled at 0.9MPa～1.2MPa ; After vulcanization, it is cooled by water-cooled pipes to form a power core, and the water temperature in the cooling section is controlled at 30°C to 50°C;

3) Overlap and wrap a layer of nylon semi-conductive tape outside the power core to form a semi-conductive wrapping layer;

4) Braid tinned copper wire shielding layer outside the nylon semi-conductive tape;

5) Preparation of ground wire core: Extrude the stranded ground wire core conductor into a layer of halogen-free semi-conductive rubber with EPDM as the base material through the single-layer continuous sulfur production method, and control the extrusion temperature at 70°C- 80°C, the production line speed is controlled at 10-15 m/min. After extrusion, it is heated and vulcanized continuously in a closed steam pipeline. The pressure of the steam pipeline is controlled at 0.9MPa~1.2MPa; The temperature of the section water is controlled at 30°C to 50°C;

6) Then twist the three power cores braided with tinned copper wire shielding layer and the three ground cores with extruded semi-conductive layer into cable cores in the back-twisting cable forming machine, and the ground cores are located in the power cores In the gap, the control range of the cable pitch is 20 to 25 times the outer diameter of the cable, and the halogen-free semi-conductive rubber filling strip is densely filled in the cable gap, and the entire cable core is tied tightly with a flame-retardant halogen-free tape ;

7) Extrude the inner sheath of halogen-free flame-retardant polyurethane material through an extruder outside the cable core tied tightly with flame-retardant halogen-free tape, and the extrusion temperature is 155°C-180°C;

8) Weave a reinforced layer of dipped polyester cord outside the polyurethane inner sheath;

9) Finally, extrude the halogen-free flame-retardant polyurethane sheath material on the outermost layer of the cable through an extruder outside the reinforcing layer of the dipped polyester cord. The extrusion temperature is 155°C-180°C, and the production line speed is 8-10m /min.

The beneficial effects of the utility model are:

1. This utility model has developed a halogen-free flame-retardant and low-temperature-resistant medium-voltage wind energy cable. The cable insulation core adopts halogen-free conductor shielding rubber, ethylene-propylene insulating rubber for 35kV and below, and halogen-free semi-conductive cross-linkable and strippable Three-layer co-extrusion of insulating shielding rubber; the developed halogen-free conductor shielding rubber, halogen-free semi-conductive cross-linkable and peelable insulating shielding rubber have volume resistivity ≤ 100Ω·cm, halogen-free performance: PH value ≥ 4.3, conductivity weighted value ≤ 10μs/mm; the dielectric loss tanδ (95-100°C) of the ethylene-propylene insulating rubber of the rated voltage lower than 35kV halogen-free flame-retardant low-temperature medium-voltage wind power cable is 400×10 ⁴ , and the minimum volume resistivity is 400×10 4 10 ¹⁶ Ω·cm; the dielectric loss tanδ (95-100°C) of the ethylene-propylene insulating rubber of the rated voltage 35kV halogen-free flame-retardant low-temperature medium-voltage wind power cable is 50×10 ⁴ , and the minimum volume resistivity is 10 ¹⁶ Ω·cm. Therefore, it can ensure that the partial discharge level of the cable is excellent, the discharge capacity is ≤5Pc, and the insulation resistance performance is excellent;

2. Each power core of the utility model adopts a tinned copper wire weaving structure, which can effectively suppress and suppress electromagnetic waves from being emitted to the outside, and reduce interference to equipment.

3. The utility model places three ground wires in the gap between the cable cores, which not only conduct the fault current, but also balance the electric field, so as to ensure the safe operation of the cable.

4. In order to strengthen the anti-torsion ability of the cable, the utility model designs a reinforced layer of dipped polyester wire rope outside the inner sheath of the cable. Between the sheath and the polyurethane outer sheath, when the polyurethane outer sheath is extruded, it can be tightly combined with the polyurethane inner sheath and the outer sheath at a temperature of 180°C to form an integral body, which greatly improves the torsion resistance of the cable.

Description of drawings

Fig. 1 is a structural representation of the utility model.

Detailed ways

As shown in Figure 1, a halogen-free, flame-retardant, low-temperature and medium-voltage wind energy cable described in the present invention includes a cable core, and the cable core is composed of three power cores and three ground wires located in the gap between the three power cores The core is stranded; the gap of the cable core is provided with a filling layer 7, and the outside of the cable core is sequentially extruded with a halogen-free flame-retardant tape 8, a first outer sheath 9 and a second outer sheath 11; in the first outer sheath 9 and the second outer sheath 11 are also provided with a strengthening layer 10; the power line core is composed of the power line conductor 1 and the conductor shielding semiconducting layer 2, insulating layer 3, insulating layer extruded sequentially outside the conductor 1 The shielding layer 4, the semiconductive wrapping layer 5 and the metal shielding layer 6 are composed; the ground core is composed of a ground conductor 12 and a semiconductive layer 13 extruded outside the ground conductor.

The conductor shielding semiconducting layer is a cross-linked halogen-free semiconducting shielding layer based on EPDM, the volume resistivity of the conductor shielding layer and the insulating shielding layer is ≤100Ω·cm, and the halogen-free performance: PH value≥ 4.3, the weighted value of conductivity ≤ 10μs/mm; the insulating layer is a cross-linked medium-voltage ethylene-propylene insulating rubber based on EPDM, and the rated voltage is lower than 35kV. The dielectric loss tanδ (95-100°C) of the ethylene-propylene insulating rubber of the cable has a maximum value of 400×104; the dielectric loss tanδ (95-100°C) of the ethylene-propylene insulating rubber of the rated voltage 35kV ) with a maximum value of 50×104 and a minimum volume resistivity of 1016 Ω·cm; the insulating shielding layer is a strippable cross-linked halogen-free semi-conductive shielding layer based on vinyl acetate copolymer and nitrile rubber; The metal shielding layer is braided shielding of tinned copper wires; the reinforcing layer is braided by dipped polyester cords, and the breaking strength of the dipped polyester cords is greater than 1070N.

The above is only the preferred implementation method of the utility model, and it should be pointed out that for those of ordinary skill in the art, without departing from the principle of the utility model, some improvements can also be made, and these improvements should also be regarded as Protection scope of the present utility model.

Claims (6)

1. press a wind energy cable in Halogen-free flame-retardant low-temperature resistant, it is characterized in that: comprise cable core, its cable core is by three power wire core and is arranged in that three wire core in three power wire core gaps are stranded to be formed; The gap of cable core is provided with packed layer (7), and cable core extrudes halogen-free flameproof band (8), the first oversheath (9) and the second oversheath (11) outward successively; Reinforced layer (10) is also provided with between the first oversheath (9) and the second oversheath (11); Described power wire core is by power line conductor (1) and is extruded in conductor (1) conductor screen semi-conductive layer (2) outward, insulating barrier (3), insulation screen (4), semiconductive lapping layer (5) and metal screen layer (6) successively and forms; Described wire core is by gnd conductor (12) and be extruded in gnd conductor (12) semi-conductive layer outward (13) and form.

2. press wind energy cable in Halogen-free flame-retardant low-temperature resistant according to claim 1, it is characterized in that, described conductor screen semi-conductive layer (2) for Ethylene Propylene Terpolymer be the cross-linking type Halogen semiconductive shielding layer of base-material.

3. press wind energy cable in Halogen-free flame-retardant low-temperature resistant according to claim 1, it is characterized in that, described insulating barrier (3) be with Ethylene Propylene Terpolymer be base-material cross-linking type in press second third insulation rubber.

4. press wind energy cable in Halogen-free flame-retardant low-temperature resistant according to claim 1, it is characterized in that, described insulation screen (4) for acetate ethylene copolymer and acrylonitrile-butadiene rubber be the peelable cross-linking type Halogen semiconductive shielding layer of base-material.

5. press wind energy cable in Halogen-free flame-retardant low-temperature resistant according to claim 1, it is characterized in that, described metal screen layer (6) is tinned copper wire braid shielded.

6. press wind energy cable in Halogen-free flame-retardant low-temperature resistant according to claim 1, it is characterized in that, described reinforced layer (10) is woven by impregnation polyester cord and forms.