17190068 catalogue of ehv cables
TRANSCRIPT
COMPANY
PROFILE
Universal Cables Limited (UCL) was established in the year 1962 as a modern mass production unit for the manufacture of paper insulated power cables in technical collaboration with the world's largest cable producer BICC, UK. Late Shri. M. P. Birla, who had adorned the chair of the company from the day of its inception for over 25 years enabled the company to flourish in a highly competitive world, while distinguishing itself by the latest technological tie ups with the foremost leaders in the world of this industry and the most up-to-date technology.
Universal Cables Limited entered into a collaboration agreement with M/s. ASEA BROWN BOVERI CABLE AB of Sweden in the year 1977 for the manufacture of Crosslinked Polythene Power Cable for the first time in the country. The Company is the foremost manufacturer of XLPE Cable with modern dry cured dry cooled process for voltage range extending from 1.1 kv to Extra High Voltage.
Under the collaboration agreement of M/s ASEA BROWN BOVERI CABLE AB, Sweden, UCL brought in complete know how of compounding of Polymer and produced complete range of dielectrics presently used in all special cables.
UCL emphasizes on in-house Research & Development. R & D programme is mainly directed to applied research for product development, process development and technological upgradation. R & D Laboratory of UCL is a recognized unit of Department of Scientific and Industrial Research of Govt. of India. This Laboratory has developed many new Cables for
special applications such as Flamuni range FRLS Cable, 1.1kv XLPE Cable, etc.
In 1983, UCL embarked on a joint venture with MPAVN for manufacture of Jelly Filled Telephone Cable in technical collaboration with one of the world's leading manufacturers of Telephone Cable, M/s Ericsson Cable AB of Sweden. This unit is named M/s. VINDHYA TELELINKS LIMITED and is situated at Rewa, only 50 KM away from the Power Cable Plant at Satna.
Since 1985, M/s. ASEA BROWN BOVERI CABLE AB, SWEDEN is further assisting this company in manufacture of Fluoro-plastic Cables, specifically for very high temperature operation and high frequency signalling circuitry.
In 1993, UCL & VTL jointly entered into the field of optical communication by way of manufacturing Optical Fibre Cables in technical and financial collaboration with M/s Ericsson Cables AB of Sweden under the name M/s BIRLA ERICSSON OPTICAL LIMITED (BEOL).
UCL also exports its products to various countries of the world, which has earned much recognition for its export efforts.
M/s. Universal Cables Limited is a vibrant progressive company, a leader in its field of activities, serving the aspiration of the nation in the field of Power Development.
1.0 INTRODUCTION:
After a decade of satisfactory experience in the manufacture of high voltage XLPE cables and intensive R&D, Unistar XLPE cables range now includes Extra High Voltage XLPE cables. They are suited to withstand a service voltage range from 66 KV upto and including 145 KV.
This marks a quantum jump both in respect of manufacturing technology and quality assurance techniques. This development has been possible because of very active all round support from our technical collaborator ASEA BROWN BOVERI CABLES AB, of Sweden-acknowledged world leaders in development and manufacture of Extra High Voltage XLPE cables. The manufacturing plant and testing laboratories of the company have been upgraded with large capital investment to adopt the technology.
'Unistar' EHV XLPE cables are designed for bulk trans-mission of electrical energy with minimum transmission losses for an effective service life of 50 years or more.
2.0 CABLE DESIGN:
2.1 Conductor: Conductor is made of stranded copper or aluminium having high compactness and smooth surface finish. 2.2 Conductor Shield: This is applied over the conductor with a semi-conducting compound which not only eliminates the risk of electrical discharge at the interface between conductor and insulation but also presents a very smooth protrusion free interface with the insulation to eliminate any localised stress concentration. 2.3 Insulation: Insulation is composed of a special super-clean grade of crosslinkable polythene and applied over the conductor screen to the desired thickness in a void free manner. 2.4 Core Screen: A semi-conducting layer similar to conductor screen is applied over the insulation for similar purpose and this is followed by a semi-conducting non-woven water barrier tape when required. Over this tape metallic part of the screen is applied in the form of spiral wrapping of copper wires. When the cable is installed in water-logged area or underwater, metallic part of the screen is often impervious metal sheath in place of copper wires. 2.5 Outer sheath for unarmoured cables: This is composed of ST-2 grade PVC to IS: 5831/84/ IEC-840 or black polythene with PE/AL moisture barrier tape depending upon the installation condition. 2.6 Armoured Cables: If required by installation conditions, further protection of on-ferrous metal wire armouring and extruded PVC sheath may be applied.
2.7 Conductive outer layer: A conductive outer layer facilitates testing of the non-metallic outer sheath. This test is important to ensure the physical integrity of the cable from time to time, be it at the factory, after transportation, directly after laying upon completion of the installation, or periodically thereafter. The construction details of three designs of EHV XLPE cables are shown in figure 1 to 3:
Fig. 1 Copper Wire screen, standard design:
Fig. 2 Copper Wire screen, water tight design:
(i) Radial water sealing is achieved by a corrosion resistant metal polyethylene laminate.
(ii) Longitudinal water sealing is achieved by a water swellable tape applied over the copper wire.
Fig. 3 Lead sheath screen: (i) Radial water sealing is achieved by a corrosion resistant-lead sheath.
(ii) Longitudinal water sealing is achieved by a water swellable tape applied under sheath.
3.0 CONSTRUCTION:
Construction details of Unistar EHVXLPE cables are given in tables 1 to 3.
4.0 TECHNICAL PARAMETERS:
Technical parameters of Unistar EHV XLPE cables are given in tables 4 to 8.
5.0 PROCESSING:
Unistar EHV XLPE cables are processed in a modern triple extrusion manufacturing line with 'ASEA' dry cure and dry cooling arrangement. The material handling system is completely mechanised and the plant is air-pressurised with clean air to avoid any contamination. The processing parameters are determined by computer programming and the entire line of processing is controlled, from a central control console with the help of closed circuit TV.
Fig. 4 Catenary continuous vulcanizing extrusion line. 6.0 TESTING & QUALITY ASSURANCE:
Unistar EHV XLPE cables are tested to IEC 840, SS 4241417 and IS - 7098 (III) for routine and type tests. Besides this EHV XLPE cable samples are subjected to long term evaluation testing programme and accelerating ageing for verifying the compliance to the expected designed life.
The Quality Control of EHV XLPE cables during manufacture is very critical and expert supervision is required for raw material testing, in process checks and also for final
Fig. 5. The products are supported by qualified research and development.
testing. A specially trained quality assurance team works round the clock for maintenance of the quality at an optimum level.
The Quality of Unistar EHV XLPE cable also has been verified by independent testing at Central Power Research Institute, Bangalore.
7.0 INSTALLATION & ACCESSORIES:
Service Engineers of the company have been specially trained for installation of EHV XLPE cables together with suitable accessories and they provide all assistance to the customers for this purpose. Accessories for indoor and outdoor termination and also for straight through joint, are being supplied by KABELDON AB of Sweden - a subsidiary company of our collaborator ABB Cables AB. Details of accessories and their installation instructions are available on request.
The Company also accepts complete turn-key jobs for the supply installation, testing and commissioning of EHV XLPE Cables.
Fig. 6. Outdoor termination.
Fig. 7. We can help you to install a maintenance-free cable network. 8.0 TECHNICAL SERVICE:
A team of trained service Engineers will be happy to assist the customers for selection of EHVXLPE cables of the right design and accessories needed for the intended application. They will also provide all necessary after-sales service.
TABLE-1 SINGLE CORE CABLES – 66 KV
Approx Wt/KM Area
(sq. mm.)
Approx. Conductor Diameter
(mm)
Insulation Thickness
(mm)
Screen Area
(sq. mm)
Outer Sheath
Thickness (mm)
Approx. Overall
Diameter (mm)
With Al. Conductor
(Kg)
With Cu. Conductor
(Kg)
185 240 300 400 500 630 800 1000
16.2 18.6 20.6 23.6 26.7 30.2 35.0 38.5
12.0 12.0 12.0 12.0 12.0 12.0 12.0 12.0
35 35 35 35 35 35 35 35
2.5 2.6 2.7 2.8 2.9 3.0 3.1 3.2
53.0 56.0 58.0 61.0 65.0 69.0 76.0 79.0
2450 2750 3000 3450 3900 4450 5400 6100
3500 4100 4700 5650 6600 8000
-- --
TABLE-2
SINGLE CORE CABLES – 110 KV
Approx Wt/KM Area
(sq. mm.)
Approx. Conductor Diameter
(mm)
Insulation Thickness
(mm)
Screen Area
(sq. mm)
Outer Sheath
Thickness (mm)
Approx. Overall
Diameter (mm)
With Al. Conductor
(Kg)
With Cu. Conductor
(Kg)
400 500 630 800 1000
23.6 26.7 30.2 35.0 38.5
17.5 17.0 16.5 16.0 16.0
95 95 95 95 95
3.2 3.3 3.4 3.4 3.6
75.0 78.0 80.0 86.0 90.0
5050 5400 5950 6900 7650
7200 8150 9500
-- --
TABLE-3
SINGLE CORE CABLES – 132 KV
Approx Wt/KM Area
(sq. mm.)
Approx. Conductor Diameter
(mm)
Insulation Thickness
(mm)
Screen Area
(sq. mm)
Outer Sheath
Thickness (mm)
Approx. Overall
Diameter (mm)
With Al. Conductor
(Kg)
With Cu. Conductor
(Kg)
400 500 630 800 1000
23.6 26.7 30.2 35.0 38.5
21.0 20.0 20.0 19.0 19.0
95 95 95 95 95
3.5 3.5 3.6 3.6 3.8
80.0 84.0 87.0 95.0 98.0
5800 6100 6750 7600 8400
7950 8800 10300
-- --
TABLE-4
CONDUCTOR RESISTANCE
Maximum D. C. Resistance at 20ºC (Ohm/KM) Cross Section (Sq. mm) Aluminium Copper
165 240 300 400 500 630 800 1000
0.164 0.125 0.100
0.0778 0.0605 0.0469 0.0367 0.0291
0.0991 0.0754 0.0601 0.0470 0.0366 0.0283 0.0221 0.0176
TABLE-5 APPROXIMATE CAPACITANCE (uF/KM)
Rated Voltage of the Cable Area (Sq. mm) 66 KV 110 KV 132 KV
185 240 300 400 500 630 800 1000
0.16 0.18 0.19 0.21 0.23 0.25 0.28 0.30
- - -
0.16 0.18 0.20 0.23 0.24
- - -
0.15 0.16 0.18 0.20 0.21
TABLE-6 APPROXIMATE INDUCTANCE FOR SINGLE CORE CABLES
LAID IN TREFOIL FORMATION (mH/KM)
Rated Voltage of the Cable Area (Sq. mm) 66 KV 110 KV 132 KV
185 240 300 400 500 630 800 1000
0.42 0.40 0.39 0.38 0.36 0.35 0.34 0.33
- - -
0.41 0.40 0.38 0.37 0.36
- - -
0.43 0.41 0.40 0.38 0.37
TABLE-7
APPROXIMATE DIELECTRIC LOSSES, WATT/KM/PHASE, AT RATED VOLTAGE
Rated Voltage of the Cable Area (Sq. mm) 66 KV 110 KV 132 KV
185 240 300 400 500 630 800 1000
73 82 86 95
104 113 127 136
- - -
203 228 253 291 304
- - -
272 290 326 363 381
TABLE-8 APPROXIMATE CHARGING CURRENT, AMPS/KM, AT RATED VOLTAGE
Rated Voltage of the Cable Area (Sq. mm) 66 KV 110 KV 132 KV
185 240 300 400 500 630 800 1000
1.9 2.1 2.3 2.5 2.7 3.0 3.3 3.6
- - -
3.2 3.6 4.0 4.6 4.8
- - -
3.6 3.8 4.3 4.8 5.0
SCREEN BONDING METHODS
BOTH-ENDS BONDING Both-ends bonding of screens, means that the screens are connected and earthed at both ends of the cable route. In this case a current will appear in the screen. This will cause losses in the screen, which reduces the cable current-carrying capacity. These losses are smaller for cables in trefoil formation than in flat formation.
SINGLE-POINT BONDING Single-point bonding of screens, means that the screens are connected and earthed only at one end of the cable route. In this case, a voltage will be induced between screen and earth, but no current will appear. This induced voltage is proportional to the cable length and current. Single-point bonding can only be used for limited route lengths.
CROSS-BONDING Cross-bonding of screens, means that the screens belonging to adjoining cables are connected as in the figure.
In this case, a voltage will be induced between screen and earth, but no current will appear. The maximum induced voltage will appear at the link boxes for cross-bonding, see figure. This method permits a cable current-carrying capacity as high as with single-point bonding but longer route lengths than the latter. It requires screen separation and additional link boxes, though. CURRENT RATING
The cables should at least have a cross section adequate to meet the system requirements for power transmission capacity. The evaluation of the overall cost of a cable system should include the capitalized cost of losses, both on load and no load losses. Since the cost of losses is normally evaluated based on the marginal cost of energy and installed power, overall optimization may often lead to using larger cable cross sections than the minimum ones meeting current carrying requirements.
On load losses are basically the ohmic losses in the conductor and the metallic screen. The XLPE cables can be loaded continuously to a conductor temp, of 90°C. However, to keep a safety margin, or to keep the losses lower, or to avoid possible thermal instability due to drying out the surrounding soil, it may be advantageous to limit the operating temp, to, say, 65°C. No load losses are basically the dielectric losses. Here it is the choice of dielectric material that counts, especially for application at 100 KV or more. Thanks to its small loss angle, XLPE presents much lower dielectric losses than paper or rubber as cable insulation material. The continuous current ratings given in tables 9 to 12 are calculated according to IEC Publ. 287 on the following conditions. Ground temp. : 30°C
Ambient air temp. : 40°C
Depth of laying (L) :1.0Mtr.
Distance between cable axes
laid in flat formation (S) : 70 mm + De
Thermal resistivity of soil : 150 °C cm/Watt.
TABLE-9 CURRENT RATING FOR 66 KV CABLES WITH ALUMINIUM CONDUCTOR
Cross
Section Cables in Ground Cables in Air
Flat Formation Trefoil Formation Flat Formation Trefoil Formation Cond-uctor
Screen SPB / CB Both Ends SPB / CB Both Ends SPB / CB Both Ends SPB / CB Both Ends
Sq. mm
Sq. mm. 65ºC 90ºC 65ºC 90ºC 65ºC 90ºC 65ºC 90ºC 65ºC 90ºC 65ºC 90ºC 65ºC 90ºC 65ºC 90ºC
185 240 300 400 500 630 800
1000
35 35 35 35 35 35 35 35
235 275 310 355 405 460 525 590
300 350 395 450 515 590 665 745
220 250 280 310 345 380 415 445
280 320 360 400 445 490 545 585
225 260 295 335 385 440 495 545
285 330 375 430 490 560 630 700
225 260 290 330 380 430 485 530
285 330 370 420 485 545 615 685
305 360 415 480 555 650 745 850
410 485 555 645 755 880 10101160
295 335 385 440 505 575 650 720
395 460 525 610 695 795 905 1010
290 340 390 455 525 610 700 785
395 460 525 620 715 830 950 1075
290 340 390 450 520 600 685 770
395 460 525 610 710 820 935 1055
TABLE-10 CURRENT RATING FOR 66 KV CABLES WITH COPPER CONDUCTOR
Cross Section Cables in Ground Cables in Air
Flat Formation Trefoil Formation Flat Formation Trefoil Formation Cond-uctor Screen SPB / CB Both Ends SPB / CB Both Ends SPB / CB Both Ends SPB / CB Both Ends Sq. mm
Sq. mm. 65ºC 90ºC 65ºC 90ºC 65ºC 90ºC 65ºC 90ºC 65ºC 90ºC 65ºC 90ºC 65ºC 90ºC 65ºC 90ºC
165 240 300 400 500 630
35 35 35 35 35 35
305 350 395 450 515 580
385 445 505 575 650 740
275 305 335 370 405 435
350 395 435 480 525 570
290 335 375 425 485 545
370 425 480 540 615 595
290 335 370 420 475 530
365 420 475 535 605 675
390 455 525 610 710 815
525 620 715 820 960
1110
365 420 475 535 610 685
500 580 655 740 845 950
375 435 500 575 660 755
505 595 680 780 905
1035
370 430 495 565 650 735
505 590 670 770 890
1015
TABLE-11 CURRENT RATING FOR 110 KV & 132 KV CABLES WITH ALUMINIUN CONDUCTOR
Cross Section Cables in Ground Cables in Air
Flat Formation Trefoil Formation Flat Formation Trefoil Formation Cond-uctor Screen SPB / CB Both Ends SPB / CB Both Ends SPB / CB Both Ends SPB / CB Both Ends Sq. mm
Sq. mm. 65ºC 90ºC 65ºC 90ºC 65ºC 90ºC 65ºC 90ºC 65ºC 90ºC 65ºC 90ºC 65ºC 90ºC 65ºC 90ºC
400 500 630 800
1000
95 95 95 95 95
350 400 455 520 570
445 510 580 665 735
275 300 320 345 360
360 390 420 450 480
335 380 430 490 540
420 485 550 620 690
325 365 415 460 505
415 470 525 590 650
480 555 645 765 845
645 750 875 995
1145
425 475 530 585 645
580 650 735 810 900
450 525 605 690 775
610 705 815 935
1060
440 510 580 660 735
600 690 795 905
1015
TABLE-12 CURRENT RATING FOR 110 KV & 132 KV CABLES WITH COPPER CONDUCTOR
Cross
Section Cables in Ground Cables in Air
Flat Formation Trefoil Formation Flat Formation Trefoil Formation Cond-uctor Screen SPB / CB Both Ends SPB / CB Both Ends SPB / CB Both Ends SPB / CB Both Ends Sq. mm
Sq. mm. 65ºC 90ºC 65ºC 90ºC 65ºC 90ºC 65ºC 90ºC 65ºC 90ºC 65ºC 90ºC 65ºC 90ºC 65ºC 90ºC
400 500 630
95 95 95
445 505 570
560 645 730
320 335 360
415 440 470
420 475 535
535 610 685
405 445 500
515 580 645
610 705 810
815 950
1095
505 555 610
695 775 860
570 655 745
770 890
1020
550 625 710
750 915 975
RATING FACTORS
1. RATING FACTOR FOR CROSS SECTION OF METAL SCREEN: Single core cables in Trefoil Formation, Screen Bonded at Both Ends. For Singe Point Bonding or Crossbonding no rating factor applies. 1.1 Rating Factor for 66 KV Cables:
Conductor Sq. mm. Copper Screen Sq. mm. Al. Cu. 16 35 50 95 150 300
300 500 800
1000
185 300 500 630
1.01 1.01 1.02 1.02
1 1 1 1
0.99 0.99 0.99 0.98
0.98 0.97 0.92 0.94
0.97 0.95 0.92 0.90
0.95 0.92 0.88 0.84
1.2 Rating Factor for 66 KV Cables:
Conductor Sq. mm. Copper Screen Sq. mm. Al. Cu. 16 35 50 95 150 300
300 500 800
1000
- 300 500 630
1.03 1.04 1.06 1.08
1.02 1.03 1.04 1.06
1.01 1.02 1.03 1.04
1 1 1 1
0.99 0.98 0.97 0.96
0.97 0.95 0.92 0.90
2. RATING FACTORS FOR CABLES IN GROUND: 2.1 Rating Factor for Depth of Laying:
Depth (Metre) 0.5 0.7 0.9 1.0 1.2 1.5 Rating Factor 1.10 1.05 1.01 1.0 0.98 0.95
2.2 Rating Factor for Thermal Resistivity of Soil:
Thermal Resistivity (ºC cm/Watt) 70 100 120 150 200 250 300
Rating Factor 1.35 1.19 1.10 1.0 0.88 0.80 0.72 2.3 Rating Factor for Ground Temp.:
Ground Temperature ºC Conductor Temp ºC 10 15 20 25 30 35 40 45
90 65
1.15 1.26
1.12 1.20
1.08 1.13
1.04 1.07
1.0 1.0
0.96 0.93
0.91 0.85
0.86 0.76
2.4 Rating Factor for Groups of Cable in Ground:
Number of Groups Distance cc Between
groups (mm) 1 2 3 4 5 6 7 8 9
100
200
400
600
800
2000
1
1
1
1
1
1
0.76
0.81
0.85
0.88
0.90
0.96
0.67
0.71
0.77
0.81
0.84
0.93
0.59
0.65
0.72
0.77
0.81
0.92
0.55
0.61
0.69
0.74
0.79
0.91
0.49
0.56
0.64
0.71
0.76
0.91
0.49
0.56
0.66
0.72
0.77
0.91
0.47
0.53
0.63
0.70
0.75
0.90
0.46
0.52
0.62
0.69
0.75
0.90
2.5 Rating Factors for Phase Spacing (one group in Flat Formation with Cross Bonded or Single Bonded Screen):
Spacing ‘S’ mm De De + 70 200 250 300 350 400
Rating Factor 0.93 1 1.03 1.05 1.07 1.06 1.10
3. RATING FACTOR FOR CABLES INSTALLED IN PIPES IN THE GROUND Single Core Cables partially installed
in separate Pipes* Single Core Cables in separate
Pipes. Single Core Cables in a common
Pipe.
0.94 0.90 0.90 The rating factor given for single core cables partially installed in separate pipes, applies only when a cable section between screen earthing points are partially laid in pipes under the following conditions - The cables are laid in trefoil formation over the major portion of the section - The pipes are laid in fiat formation - The pipe length is not more than 10% of the section between earthing points - One cable per Pipe - The Pipe diameter is two times the cable diameter. 4. RATING FACTOR FOR CABLES IN THE AIR: 4.1 Rating Factor for ambient air temp:
Air Temp ºC 15 20 25 30 35 40 45 50 55
Rating Factor 1.25 1.21 1.16 1.11 1.05 1.0 0.94 0.87 0.81 OVER LOAD 105°C As infrequently as possible, the cables may be overloaded and the conductor temp. may reach upto 105ºC. Both occurrence and duration of these overloads should be kept to a minimum, though, in the interests of sparing the cable life Cyclic and emergency rating can be calculated through IEC: 833-2 EMERGENCY LOAD 130°C Upon emergency, the conductor temperature is allowed to rise upto 130°C However the duration of the emergency load should be restricted to not more that 50 Hours at a time and 500 Hours per year in order not to shorten the cable life substantially SHORT-CIRCUIT CURRENTS The permissible short-circuit current of a cable is determined by the maximum permissible conductor temperature (250°C), and by the duration of the short-circuit current At high peak currents the dynamic forces between the conductors must be taken into account Thermally maximum short-circuit currents Formula to calculate the thermally equivalent short-circuit current at different durations Where Ik = I1/tk Where Ik = short-circuit current during time tk
I1 = short-circuit current for 1 s from Tables 13 and 14 tk = short-circuit durations.
This formula is valid only in the time interval 0.2 - 5s.
TABLE-13
Max. Short-Circuit on the conductor during 1s. kA Conductor Temperature before Short Circuit
Aluminium Conductor Copper Conductor Cross Section
Mm2 65ºC 90ºC 65ºC 90ºC
185 240 300 400 500 630 800
1000
19.2 24.8 31.1 41.4 51.8 65.2 82.8 104
17.5 22.7 28.3 37.8 47.2 59.5 75.6 94.5
29.0 37.6 47.0 62.7 78.4 98.7 125 157
26.5 34.5 42.9 57.2 71.5 90.1 114 143
TABLE-14
Max. Short-Circuit on the Screen during 1s. kA
Metallic Screen Cross Section mm2 Metallic Screen Temperature before the Short Circuit
Copper Screen Lead Sheath 50ºC 70ºC
16 25 35 50 95
150 300
110 170 240 340 650 1030 2070
3.4 5.4 7.5 11 21 32 64
3.3 5.1 7.1 10 19 30 60
Tablet 13 and 14 are based on the following formula
Mechanical forces from short-circuit currents Formula to calculate the dynamic forces between two conductors F = 0.2 x is2 S Where is = peak current, kA
S = centre – to - centre spacing between conductors, m F = force N/m
Note : All figures given are non-binding and indicative only
Where I = maximum short-circuit current, A i = current density. A/mm2, 1s S = conductor or screen cross section, mm2
t = duration of short-circuit current, s E = 1 0 for conductor = 1 2 typical for metal screens K = 148 for Al, 226 for Cu and 41 for Pb B = 228 for Al. 234 for Cu and 230 for Pb ot = final temperature, ºC oi = initial temperature ºC