WO2018107537A1

WO2018107537A1 - Method for designing large-section submarine cable conductor based on special-shaped copper single line

Info

Publication number: WO2018107537A1
Application number: PCT/CN2016/113290
Authority: WO
Inventors: 梅文杰; 张翀; 潘文林; 陈新; 李文鹏; 李春梅; 高正平; 沈小伟
Original assignee: 全球能源互联网研究院; 江苏亨通高压海缆有限公司; 国网江苏省电力公司; 国网江苏省电力公司经济技术研究院
Priority date: 2016-12-12
Filing date: 2016-12-29
Publication date: 2018-06-21
Also published as: CN106874590B; CN106874590A; DE112016003098T5

Abstract

Disclosed is a method for designing a large-section submarine cable conductor based on a special-shaped copper single line. The method comprises the specific steps of: 1) calculating an outer diameter; 2) selecting a structure; 3) calculating an inclination angle of each special-shaped single line; 4) designing each special-shaped single line; 5) correcting a central angle corresponding to an extension line on two sides of the special-shaped single line; 6) calculating a filling coefficient of the special-shaped single line; 7) determining the sizes of the values of η and η'; and 8) obtaining a final design scheme. According to the design method, special-shaped copper single lines are used for designing a submarine cable conductor; the compressing coefficient design value of the conductor is 0.97; in combination with the influence of pitches on the arrangement of the special-shaped single lines; the water blocking effect of the conductor is improved; and the sectional area of each copper single line is kept consistent as much as possible, so that the skin effect and the proximity effect are reduced, and the conductor is suitable for transmitting an alternating current.

Description

Design method of special-shaped copper single-line large-section sea cable conductor

Technical field

The invention belongs to the field of power cables, and particularly relates to a design method of a large-profile copper single-wire large-section sea cable conductor.

Background technique

With the island development strategy and the rapid development of offshore renewable energy generation, offshore wind power is expanding rapidly, and the demand for submarine high-voltage power cables is growing.

The direct current transmission has the advantages of small line loss, easy interconnection with the grid, long-distance high-power transmission economy, and the solution of the voltage source converter and PWM technology for shutting down the device, especially the construction of the international energy Internet. The direct current transmission technology has received more and more attention. At present, the research and development of 500kV DC submarine cable requires a conductor section of 3000mm ² , but GB/T3956-2008 only specifies a nominal cross-sectional area of 0.5mm ² to 2500mm ² for 3000mm ² section. There is no clear requirement for the conductor. Part of the 3000mm ² section conductor design patent only considers the copper single-wire section as small as possible to facilitate the production and the stranding process. It does not consider the pitch problem of copper single-wire stranding, resulting in a 3000mm ² section conductor. The water blocking effect is not ideal, and the measurement of the resistance of the 3000mm ² section conductor is not yet mature.

Summary of the invention

The technical problem mainly solved by the present invention is to provide a design method for a large-profile copper single-wire large-section sea cable conductor.

In order to solve the above technical problem, a technical solution adopted by the present invention is: a design method for a special-shaped copper single-wire large-section sea cable conductor, comprising:

The specific steps include:

1) Calculation of the outer diameter: first calculate the cross-sectional area S of the conductor according to the formula (1);

Where k ₁ is the conductor coefficient, k ₂ is the stranding factor, ρ is the copper conductor resistivity, and R is the resistance;

Then, the calculated conductor cross-sectional area S is taken into the formula (2) to calculate the outer diameter D _A of the conductor;

Where η is the conductor fill factor and the value of η is set according to requirements;

2) Selection of structure: According to the outer diameter D _A of the conductor obtained in step 1) and the configuration of the production equipment, the ratio of W to H of the shaped single wire is controlled to be about 1.5, and the five-shaped circular compacted conductor structure of the shaped single-wire is proposed. a design scheme, wherein W is the width of the shaped single line, and H is the height of the shaped single line;

3) Calculation of the inclination angle of each shaped single line: Calculate the inclination angle δ of each shaped single line according to formula (3);

Where D is the outer diameter of the layer and L is the pitch of the layer;

4) Design of single-shaped single-line: According to step 2), five design schemes of profiled single-line circularly-pressed conductor structure are proposed, and one of the design schemes is selected to obtain the size R _{1 of} each single-shaped single-line. , R ₂ , θ and the number of roots per layer n;

Wherein R ₁ and R ₂ are the outer and inner arc radii of the odd-shaped single line, respectively, and θ is the central angle corresponding to the extended line of the odd-shaped single-line, θ=360/n, where n is the actual number of shaped single lines of each layer;

5) Correction of the central angle corresponding to the extension line of the shaped single line: the central angle θ corresponding to the extension line of the shaped single line obtained in step 4) and the calculation of the inclination angle δ of each shaped single line in step 3) are substituted into the correction formula (4), thereby Correct the θ angle to θ ₀ ;

θ ₀ = θ * cos δ (4)

Where δ is the angle of inclination of each shaped single line calculated in step 3), and finally R ₁ , R ₂ and θ _{0 of} each shaped single line are obtained;

6) Calculation of the special-shaped single-line filling coefficient: Generally, the special-shaped single-line circular pressing structure has a larger filling coefficient than the circular single-line circular pressing structure, and the filling coefficient η' of each layer can be obtained by the formula (5);

Where R ₁ and R ₂ are the outer and inner arc radii of the odd-shaped single line, respectively, θ ₁ and θ ₂ respectively correspond to the arc, n is the number of odd-shaped single-line, r is the chamfer radius of the odd-shaped single line, and the value of r is considered comprehensively. The value that the cable manufacturer can actually produce and the value of the conductor design are determined;

7) judging the magnitude of the value of η and η': if η' is greater than η, then performing step 8), if η' is less than η, adjusting the value of η or r, performing steps 1) to 6);

8) The final design is obtained: the dimensions of each shaped single line R ₁ , R ₂ , θ ₀ , n and r.

In a preferred embodiment of the present invention, the five designs of the profiled single-line circularly-pressed conductor structure in the step 2) include: a. the center line adopts a 5-layer twist with a cross-sectional area of 50 mm ² circularly pressed conductor. The same type of single-line circular compacted conductor, b. The center line adopts a 5-layer stranded shaped single-line circular compacted conductor with a cross-sectional area of 70 mm ² circularly pressed conductor, c. The center line adopts a cross-sectional area of 95 mm ² 6-layer stranded profiled single-line circular compacted conductor of pressed conductor, d. centerline adopts 6-layer stranded shaped single-line circular compacted conductor with cross-sectional area of 185mm ² circular compacted conductor, e. centerline adopts diameter 6-layer stranded profiled single-wire round compacted conductor of 6mm solid copper rod.

In a preferred embodiment of the present invention, in the step 4), the center line is selected to be a 6-layer stranded shaped single-line circularly pressed conductor having a 6 mm diameter solid copper rod.

In a preferred embodiment of the invention, the centerline uses a 6-layer stranded profiled single-wire circular compacted conductor having a 6 mm diameter solid copper rod for informal stranding.

The invention has the beneficial effects of the invention: a design method of a special-shaped copper single-wire large-section sea cable conductor according to the invention, the design method adopts a special-shaped copper single-wire design sea-shell conductor, and the design value of the conductor compaction coefficient is 0.97, which is greatly affected by the pitch. The water-blocking effect of the conductor is improved, the cross-sectional area of each copper single wire is kept consistent, the skin effect and the proximity effect are reduced, and it is suitable for transmitting alternating current.

DRAWINGS

FIG. 1 is a structural schematic view of a conductor designed by a copper-shaped single-wire large-section cable conductor design method.

2 is a schematic cross-sectional view of a profiled single wire of a profiled copper single-wire large-section cable conductor design method.

FIG. 3 is a schematic diagram of a profiled single-wire structure of a special-shaped copper single-wire large-section sea line conductor design method.

detailed description

The preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings, in which the advantages and features of the invention can be more readily understood by those skilled in the art.

Referring to FIG. 1 to FIG. 3, an embodiment of the present invention includes: a method for designing a large-profile copper single-wire large-section submarine cable conductor, comprising:

The specific steps include:

1) Calculation of the outer diameter: First, the conductor cross-sectional area S is calculated according to the formula (1).

Where k ₁ is the conductor coefficient, k ₂ is the stranding coefficient, ρ is the copper conductor resistivity, and R is the resistance. In this embodiment, k _{1 is} 1.02, k _{2 is} 1.03, and ρ is 1.724 1×10 ^-8. Ω·m, R is 0.0060 Ω/km, and S is 3018.9 mm ² .

The calculated conductor cross-sectional area S is then taken into equation (2) to calculate the conductor outer diameter D _A .

Where η is the conductor filling factor, and the value of η is set according to requirements. In this embodiment, η is 0.97, and D _A ≈ 62.95 mm is obtained, which is further corrected to 63.0 mm.

2) Selection of structure: According to the outer diameter D _A of the conductor obtained in step 1) and the configuration of the production equipment, the ratio of W to H of the shaped single line is controlled to be about 1.5, where W is the width of the shaped single line, and H is the shaped The height of the single wire is such that five designs of the profiled single-line circularly-pressed conductor structure are proposed, as shown in Table 1, including: a. The center line adopts a 5-layer stranded shaped single wire with a cross-sectional area of 50 mm ² circularly pressed conductor. Round compacted conductor, b. The center line adopts a 5-layer stranded shaped single-line circular compacted conductor with a cross-sectional area of 70 mm ² circularly pressed conductor, c. The center line adopts a circular compacted conductor with a cross-sectional area of 95 mm ² 6-layer stranded shaped single-line circular compacted conductor, d. center line adopts 6-layer stranded shaped single-line circular compacted conductor with cross-sectional area of 185mm ² circularly pressed conductor, e. center line adopts 6mm diameter solid copper A 6-layer stranded profiled single-line circular compacted conductor.

Table 1 Design table of special-shaped single-line circular compacted conductor structure

3) Calculation of the inclination angle of each profiled single line: Calculate the inclination angle δ of each profiled single line according to formula (3).

Where D is the outer diameter of the layer, L is the pitch of the layer, and the pitch is the distance of the copper single wire around the conductor. If a profile is given to the conductor, it can be found that the copper single wire is oblique, that is to say When entering at a certain angle, the area of copper single wire entering is larger than the normal cross-sectional area of copper single wire. When the normal arrangement is made, part of the copper single wire arrangement does not enter. The gap of copper single wire is large, and the water blocking effect is not ideal. From the angle, the copper single wire will be all arranged in, the copper single wire is compactly distributed, and the water blocking effect is good.

4) Design of single-shaped single-line: According to step 2), five design schemes of special-shaped single-line circular compacted conductor structure are proposed, and one of the design schemes is selected after comparison. Scheme a and scheme b adopt the 91 frame of cable manufacturer's conventional configuration. The winch (the maximum number of stranded layers is 5 layers) can be produced, but the width of the innermost profiled single line is too large (close to 2), and it is easy to turn over when twisted, which is not conducive to production, and the maximum cross-sectional area of the shaped single line 36.48mm ² or 35.28mm ² , the requirements for copper rods and wire drawing machines are too high, and the production difficulty is too great. Although the aspect ratio and cross-sectional area of the shaped single line are small, the cross-sectional area of the shaped single line in the scheme b is slightly smaller, and the production and processing are difficult. Small, but according to the company's many test results, the water-blocking effect of the scheme a water-blocking conductor is better. Therefore, when using the 91-frame stranding machine, the scheme a is a better choice than the scheme b.

Scheme c, scheme d and scheme e need to adopt 127 frame stranding machine (the maximum number of stranded layers is 6 layers) to produce, the cross-sectional area of the shaped single line is obviously reduced, the aspect ratio is more reasonable, the production difficulty, the twisting difficulty and The efficiency is greatly improved. The ratio of the profiled single line width is similar in scheme c and scheme d. The maximum cross-sectional area of the different shaped single wires is 31.14mm ² and 29.64mm ² . According to the results of many trials of the company, the resistance of the two The water-blocking effect of the water conductor is similar. Therefore, compared with the scheme c, the scheme d is superior because the cross-sectional area of the shaped single line is slightly smaller and the production processing is less difficult.

The center line adopts the scheme of circularly pressing the conductor structure, which needs to be twisted twice. At the same time as meeting the needs of convenient production and stranding process, the production efficiency is too low, and the water blocking effect of the center line itself is required to be good, and the scheme e The center line adopts a 6mm diameter solid copper rod made by 8mm solid copper rod through wire drawing annealing. It has better water blocking effect, high production efficiency and low production cost, so the advantages are obvious. Scheme d and scheme e The profiled single-line aspect ratio and the maximum cross-sectional area are similar, and even the latter's profiled single-line maximum cross-sectional area is smaller.

Therefore, in the five special-shaped conductor structure design schemes, the scheme e is most suitable both in processing difficulty and in production efficiency. The center line adopts a 6-layer stranded shaped single-line circle with a 6 mm diameter solid copper rod. The shaped compacted conductors are irregularly stranded to obtain the dimensions R ₁ , R ₂ , θ of each single shaped single wire and the number n of each layer;

Wherein R ₁ and R ₂ are the outer and inner arc radii of the odd-shaped single-line, respectively, and θ is the central angle corresponding to the extended line of the odd-shaped single-line, θ=360/n, where n is the actual number of the shaped single-line of each layer.

5) Correction of the central angle corresponding to the extension line of the shaped single line: the central angle θ corresponding to the extension line of the shaped single line obtained in step 4) and the calculation of the inclination angle δ of each shaped single line in step 3) are substituted into the correction formula (4), thereby Correct the θ angle to θ ₀ .

θ ₀ = θ * cos δ (4)

Where δ is the angle of inclination of each profiled single line calculated in step 3), and finally R ₁ , R ₂ and θ _{0 of} each profiled single line are obtained.

6) Calculation of the special-shaped single-line filling coefficient: Generally, the special-shaped single-line circular pressing structure has a larger filling coefficient than the circular single-line circular pressing structure, and the filling coefficient η' of each layer can be obtained by the formula (5).

Where R ₁ and R ₂ are the outer and inner arc radii of the odd-shaped single line, respectively, θ ₁ and θ ₂ respectively correspond to the arc, n is the number of odd-shaped single-line, r is the chamfer radius of the odd-shaped single line, and the value of r is considered comprehensively. The value that the cable manufacturer can actually produce and the design value of the conductor design are determined. When the solution e is used in this embodiment, the value of the chamfering radius is r=0.3 mm. At present, the minimum single-line chamfer radius of the cable manufacturer can be 0.16 mm. Therefore, the above-mentioned r=0.3mm chamfer radius can be fully realized, and the formula (6) is calculated by approximation theory. The larger the outer circle radius and the inner circle radius are, the closer the calculated value is to the theoretical value, due to the mold chamfer radius. The calculation result is only an approximation, so the mold chamfer radius and conductor structure should be further corrected according to the actual production trial conditions.

7) Judging the magnitude of the values of η and η': if η' is larger than η, step 8) is performed, and if η' is smaller than η, adjusting the value of η or r, performing steps 1) to 6), this embodiment The radius of the chamfer around the middle mold is r=0.3mm, and η′=0.997 can be calculated by the above formula. It can be seen that the filling factor of the shaped single-line circular compacting structure is much larger than the circular copper single-line circular compacting structure coefficient of 0.9, which satisfies The theoretical calculation of the outer diameter of the cable assumes η = 0.97.

8) The final design is obtained: as shown in Table 2, the dimensions of each shaped single line are R ₁ , R ₂ , θ ₀ , n and r.

Table 2 center line is

Winch cage process parameter table

Compared with the prior art, the present invention relates to a method for designing a special-shaped copper single-wire large-section sea cable conductor. The design method adopts a special-shaped copper single-wire design sea cable conductor, and the design value of the conductor compaction coefficient is 0.97, combined with the pitch. The influence greatly improves the water blocking effect of the conductor. The cross-sectional area of each copper single wire is consistent, which reduces the skin effect and the proximity effect, and is suitable for transmitting alternating current.

The above is only the embodiment of the present invention, and is not intended to limit the scope of the invention, and the equivalent structure or equivalent process transformation of the present invention and the contents of the drawings may be directly or indirectly applied to other related technologies. The fields are all included in the scope of patent protection of the present invention.

Claims

A method for designing a special-shaped copper single-wire large-section cable conductor, which comprises:

The specific steps include:

1) Calculation of the outer diameter: first calculate the cross-sectional area S of the conductor according to the formula (1);

Where k 1 is the conductor coefficient, k 2 is the stranding factor, ρ is the copper conductor resistivity, and R is the resistance;

Then, the calculated conductor cross-sectional area S is taken into the formula (2) to calculate the outer diameter D A of the conductor;

Where η is the conductor fill factor and the value of η is set according to requirements;

2) Selection of structure: According to the outer diameter D A of the conductor obtained in step 1) and the configuration of the production equipment, the ratio of W to H of the shaped single wire is controlled to be about 1.5, and the five-shaped circular compacted conductor structure of the shaped single-wire is proposed. a design scheme, wherein W is the width of the shaped single line, and H is the height of the shaped single line;

3) Calculation of the inclination angle of each shaped single line: Calculate the inclination angle δ of each shaped single line according to formula (3);

Where D is the outer diameter of the layer and L is the pitch of the layer;

4) Design of single-shaped single-line: According to step 2), five design schemes of profiled single-line circularly-pressed conductor structure are proposed, and one of the design schemes is selected to obtain the size R 1 of each single-shaped single-line. , R 2 , θ and the number of roots per layer n;

Wherein R 1 and R 2 are the outer and inner arc radii of the odd-shaped single line, respectively, and θ is the central angle corresponding to the extended line of the odd-shaped single-line, θ=360/n, where n is the actual number of shaped single lines of each layer;

5) Correction of the central angle corresponding to the extension line of the shaped single line: the central angle θ corresponding to the extension line of the shaped single line obtained in step 4) and the calculation of the inclination angle δ of each shaped single line in step 3) are substituted into the correction formula (4), thereby Correct the θ angle to θ 0 ;

θ 0 = θ * cos δ (4)

Where δ is the angle of inclination of each shaped single line calculated in step 3), and finally R 1 , R 2 and θ 0 of each shaped single line are obtained;

6) Calculation of the special-shaped single-line filling coefficient: Generally, the special-shaped single-line circular pressing structure has a larger filling coefficient than the circular single-line circular pressing structure, and the filling coefficient η' of each layer can be obtained by the formula (5);

Where R 1 and R 2 are the outer and inner arc radii of the odd-shaped single line, respectively, θ 1 and θ 2 respectively correspond to the arc, n is the number of odd-shaped single-line, r is the chamfer radius of the odd-shaped single line, and the value of r is considered comprehensively. The value that the cable manufacturer can actually produce and the value of the conductor design are determined;

7) judging the magnitude of the value of η and η': if η' is greater than η, then performing step 8), if η' is less than η, adjusting the value of η or r, performing steps 1) to 6);

8) The final design is obtained: the dimensions of each shaped single line R 1 , R 2 , θ 0 , n and r.
The method for designing a profiled copper single-wire large-section submarine cable conductor according to claim 1, wherein the five designs of the profiled single-line circularly-pressed conductor structure in the step 2) include: a. 5-layer stranded profiled single-line circular compacted conductor with a cross-sectional area of 50 mm 2 circularly pressed conductor, b. 5-layer stranded profiled single-wire circular compacted conductor with a cross-sectional area of 70 mm 2 circularly pressed conductor , c. The center line adopts a 6-layer stranded shaped single-line circular compacted conductor with a cross-sectional area of 95 mm 2 circularly pressed conductor, and d. The center line adopts a 6-layer stranded profile with a cross-sectional area of 185 mm 2 circularly pressed conductor. Single-line circularly pressed conductor, e. The center line uses a 6-layer stranded profiled single-wire circular compacted conductor with a 6mm diameter solid copper rod.
The method for designing a special-shaped copper single-wire large-section submarine cable conductor according to claim 2, wherein: in the step 4), the center line is selected to be a 6-layer stranded shaped single-line circular tight with a diameter of 6 mm solid copper rod. Pressure conductor.
The method for designing a special-shaped copper single-wire large-section cable conductor according to claim 3, wherein the center line adopts a 6-layer stranded shaped single-line circular compact conductor with a diameter of 6 mm solid copper rod, and is irregular. Stranded.