KR20120105841A - Electric power cable for wind turbine having high tear resistance - Google Patents

Abstract

PURPOSE: A power cable for a wind power generator is provided to prevent damage due to external impacts by replacing a braid layer with a dual insulation layer structure. CONSTITUTION: A central conductor(10) is made by twisting a plurality of metal strands. A separator tape(20) constantly distributes electric fields induced from the surface of the central conductor. An inner insulation layer(30) is extrusion-molded on the outer side of the central conductor. The inner insulation layer is made of silicon rubber with a high insulation property. An external insulation layer(40) is extrusion-molded on the outer side of the inner insulation layer.

Description

Electric power cable for wind turbine having high tear resistance}

The present invention relates to a power cable, and more particularly to a power cable for a wind generator for transmitting power generated from the wind generator.

Recently, as the depletion of fossil energy resources such as oil and coal accelerates, there is increasing interest in alternative energy to replace them. Among them, wind power generation converts the kinetic energy of the wind into electrical energy, and has no problems with resource depletion or environmental pollution. Accordingly, the power generation capacity of the wind generator is also increasing in size from 1,000KW to 2,000KW.

The wind power generator is provided with a windmill, a power generation unit equipped with a rotational force transmission mechanism, a generator, and the like on the top of the tower to be rotatable about the tower. The power generation unit is provided with a cable for power transmission.

This wind generator cable should be able to transfer the MV-class power generated in the power generation unit, and should have a strong characteristic to the mechanical oil or insulating oil used in the power generation unit. In addition, considering the sealed use environment and seasonal temperature difference, it should have excellent heat resistance and cold resistance, and should have characteristics that fire resistance and toxic substances do not occur in case of fire.

There is no current standard for the characteristics required for such a wind generator cable. However, manufacturers generally use heat resistance, cold resistance, and oil resistance (IRM-902 and insulating oil) based on IEC 60811, 60092-350, and 60092-351 standards. ), Mechanical strength, insulation resistance, withstand voltage characteristics, and the like.

The power cable for a conventional wind generator includes a center conductor 1, a separator tape 2, an insulating layer 3 and a braided layer 4, as shown in FIG. The insulating layer 3 may be made of silicon, satisfying insulation characteristics and withstand voltage characteristics, and implementing characteristics resistant to oil and heat. In particular, to compensate for the poor tear characteristics due to the characteristics of the silicon to form a braided layer (4) coated with a glass yarn or polyester braid varnish to complement the mechanical properties. By the way. In the case of the cable having the braided layer 4, the physical properties can be supplemented, but the manufacturing process is complicated due to the addition of the braiding process, which increases the manufacturing cost. In addition, the cable of the insulator structure composed only of silicon, excluding the braided layer 4, requires the development of materials suitable for the environment of the wind generator, which is required for the product development because it is required to satisfy both electrical and physical properties. There is a problem with difficulty.

The present invention has been made to solve the problems of the prior art as described above, by replacing the braided layer of the conventional power cable for a wind generator with a double insulation layer structure that satisfies both electrical and mechanical properties, electrical characteristics The purpose of the present invention is to provide a power cable for a wind power generator having excellent tear characteristics to prevent damage to the exterior from external shock.

Power cable for a wind generator according to the present invention for achieving the above technical problem, the center conductor is a plurality of metal wires gathered; A separator tape surrounding the center conductor; And an insulating layer provided to surround the separator tape and made of a polymer compound, wherein the insulating layer has a double insulating structure divided into an inner and an outer insulating layer.

Preferably, the inner insulation layer is made of silicone rubber.

Preferably, the outer insulation layer is made of flame retardant XLPO.

According to the present invention, while replacing the braided layer of the conventional power cable for a wind generator, the insulating layer is composed of an inner insulating layer specialized in electrical characteristics and an outer insulating layer specialized in tearing characteristics, electrical characteristics required in the environment of use of the wind generator And mechanical properties can be satisfied at the same time. In addition, it is possible to prevent the appearance damage from external impact due to excellent tear characteristics while eliminating the braided layer, and to secure the installation space and improve flexibility by reducing the size and weight of the cable. In addition, the braiding process is not included, thereby simplifying the manufacturing process, thereby reducing the manufacturing cost.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate preferred embodiments of the invention and, together with the description, And shall not be interpreted.
1 is a cross-sectional view showing the configuration of a power cable for a conventional wind generator.
2 is a cross-sectional view showing the configuration of a power cable for a wind generator according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms, and the inventor should appropriately interpret the concepts of the terms appropriately It should be interpreted in accordance with the meaning and concept consistent with the technical idea of the present invention based on the principle that it can be defined. Therefore, the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent all the technical ideas of the present invention. Therefore, It is to be understood that equivalents and modifications are possible.

2 is a cross-sectional view showing the configuration of a power cable for a wind generator according to the present invention.

2, in the wind power generator power cable according to the present invention, the center conductor 10, the separator tape 20, the inner insulation layer 30, and the outer insulation layer 40 are sequentially disposed.

The center conductor 10 is a composite twisted pair unit in which a plurality of metal wires are intentionally twisted. The metal wires are made of a single tin plated metal or an alloy of at least two metals. That is, the metal wire is made of a metal selected from copper (Cu), aluminum (Al), iron (Fe), nickel (Ni) or an alloy of these metals.

The separator tape 20 binds twisted metal wires by surrounding and surrounding the outer circumference of the center conductor 10, and also serves to uniformly disperse the electric field induced on the surface of the center conductor 10. The separator tape 20 may be a cotton woven tape, a polyester tape (for example, Teflon tape) or a polystyrene tape.

The inner insulation layer 30 is extruded to the outer circumference of the center conductor 10 surrounded by the separator tape 20 to provide an insulation function that can satisfy the electrical characteristics of the cable. The inner insulating layer 30 is made of silicone rubber having high insulating properties.

The outer insulation layer 40 is extruded to the outer periphery of the inner insulation layer 30 to serve to give a function as a sheath (cable) of the cable. The outer insulating layer 40 is made of flame-retardant XLPO excellent in heat resistance, cold resistance and oil resistance, and particularly excellent in tear property. In addition, the outer insulation layer 40 is made of non-halogen (halogen free) to reduce the amount of toxic gases generated and the amount of smoke generated during combustion.

In the present invention, unlike the prior art, the structure of the insulating layer is composed of a double insulating structure divided into the internal insulating layer 30 and the external insulating layer 40, the internal insulating layer 30 is characterized by the insulating properties, the external insulation Layer 40 is configured such that tear characteristics are specialized. Through this, it is possible to prevent the appearance damage due to external impact by reinforcing the tear characteristics that were weak in the conventional single insulating layer structure. In addition, it is not necessary to include a braiding process that has been conventionally performed to reinforce tear characteristics.

Hereinafter, a wind generator power cable according to a specific embodiment of the present invention will be described in comparison with a comparative example.

Example 1

The separator tape is wound around the tin-plated center conductor and an internal insulation layer made of insulated silicone rubber of 2 mm thickness is extruded. A power cable specimen was fabricated by extruding the outer insulation layer of non-halogen flame-retardant XLPO material having a thickness of 2 mm again on the outer circumference of the inner insulation layer.

Example 2

The separator tape is wound around the tin-plated center conductor and the inner insulation layer of 3.5 mm thick insulating silicone rubber is extruded. A power cable specimen was manufactured by extruding an outer insulating layer made of non-halogen flame-retardant XLPO material having a thickness of 0.5 mm to the outer circumference of the inner insulating layer.

Comparative Example 1

The separator tape is wound around the tin-plated center conductor, and an insulating layer made of an insulating silicone rubber material having a thickness of 4 mm is extruded. The PET braid was wound around the outer periphery of the insulating layer, and a varnish coating layer was formed to fabricate a power cable specimen.

Comparative Example 2

The separator tape was wound around the tin-plated center conductor, and a power cable specimen was fabricated by extruding an insulating layer made of non-halogen flame-retardant XLPO material having a thickness of 4 mm.

Measurement and evaluation of physical properties

The results of measuring tear strength, insulation properties, and flexibility of the power cable specimens according to Examples 1 to 2 and Comparative Examples 1 to 2 are summarized in Table 1 below. Deviations from the criterion values of tear strength, insulation properties and flexibility are shown in italics in Table 1. Brief experimental conditions are as follows.

㉠ tear strength (kgf / cm)

Tear strength was measured by the test method ASTM D624 using die “B”. Tear strength is estimated to have excellent tearing properties when higher than 15 kgf / cm. At this time, in Comparative Example 1, the test was performed except for the varnish braided layer.

㉡ Insulation characteristics (Ωcm)

Insulation properties were evaluated by measuring the volume resistance by the test method ASTM D257. Volume resistivity is estimated to have good insulation properties at values higher than 1.0E15.

㉢ flexibility (kgf)

The Instron 5662 was used to fasten the cable to the "c" tool and to apply a compression force until the change in the compression length of the measuring instrument was 50 mm. The higher the compression force, the lower the flexibility. Flexibility is estimated to have good flexibility at values lower than 4.5 kgf.

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Tear strength (kgf / cm) 18 21 13 24 Insulation Characteristics (Ωcm) 1.8E15 2.3E15 7.3E15 6.7 E14 Flexibility (kgf) 4.2 3.8 4.3 5.8

As summarized in Table 2, Examples 1 and 2 all met the reference values in tear strength, insulation properties and flexibility.

On the other hand, Comparative Example 1 satisfied the reference value in insulation properties and flexibility, but did not meet the reference value in tear strength 13kgf / cm, Comparative Example 2 satisfied the reference value in tear properties, but the insulation properties are 6.7E14, flexibility This 5.8kgf did not meet the standard.

As such, the wind power generator power cable according to the present invention satisfies both the electrical characteristics and the tear characteristics, it can be seen that the excellent wind generator power cable can be manufactured even if the braiding process was performed to compensate for the conventional tear characteristics. .

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It will be understood that various modifications and changes may be made without departing from the scope of the appended claims.

10 center conductor 20 separator tape
30: inner insulation layer 40: outer insulation layer

Claims (3)

A central conductor in which several metal wires are gathered;
A separator tape surrounding the center conductor; And
And an insulating layer provided to surround the separator tape and made of a high molecular compound.
The insulation layer is a wind generator power cable, characterized in that consisting of a double insulation structure divided into an inner and outer insulation layer. The method of claim 1,
The inner insulation layer is a power cable for a wind generator, characterized in that made of silicon rubber. The method of claim 1,
The outer insulation layer is a power cable for a wind generator, characterized in that made of flame retardant XLPO.

Images