High Voltage and Extra High Voltage Cables

High Voltage and Extra High Voltage Cables

GUIDE TO THE SELECTION OF EHV AND HV CABLES EHV and HV cables are specially designed on the basis of the project data. To determine appropriate design of a high voltage cable for a particular project, the following minimum information regarding the operating and installation conditions is required: Installation Data Length and profile of route (incl. height variations) Details of laying arrangements (e.g. trefoil or flat arrangement) Special conditions (e.g. water, heat, cold) Underground cables; Method of laying: Direct burial, in ducts or pipes, etc. Spacing between cables and cable groups Thermal resistivities and kinds of soil along the route Depth of laying Minimum, maximum and average ground temperatures Cables in air; Minimum, maximum and average ambient air temperatures Type of installation (e.g. on racks) and details of arrangement Details of ventilation (for cables in tunnels) Whether exposed to direct sunlight Special conditions, for example fire risk Other parallel installed power cables, if any: Type and cross-sections of conductors, carried load & load factor, voltage and layout details. Data on termination layout details; Switchgear Power transformers Overhead lines (type of conductor, cross-section and length) Operating Conditions Nominal voltage of system Highest voltage of system Impulse withstand voltage System frequency Maximum rated current; for continuous operation for cyclic operation (a load curve is essential) for overload operation, if any (duration is also essential) Symmetrical and asymmetrical short-circuit currents, both between phases and to earth. Circuit breaker tripping time. Required screen earthing: At both ends or single point bonding or cross bonding Required cable type Accessories Terminations (required type) Joints Others Environmental conditions: The altitude above sea level, if above 1000 m. Whether excessive atmospheric pollution is expected

High Voltage Cables 66 kv TO 400 kv COPPER WIRE SCREENED, COPOLYMER COATED COPPER TAPE SHIELDED CABLES Typical construction XLPE insulated, copper wire screened, copolymer coated copper tape shielded,* HDPE outer sheathed cables with copper or aluminium conductor Main Properties Radially and longitudinally watertight Designed for usage in high fault current Easy to handle Lighter and more flexible than lead sheathed cables Resistant to heavy vibrations Available in long delivery lenghts to reduce number of joints Corrosion-free screen area * Copolymer coated aluminium tape can be applied instead of copolymer coated copper tape on request.

High Voltage Cables 66 kv TO 400 kv COPPER WIRE SCREENED, LEAD SHEATHED CABLES Typical construction XLPE insulated, copper wire screened, lead sheathed, HDPE or PVC outer sheathed cables with copper or aluminium conductor Main Properties Radially and longitudinally watertight Suitable to carry high fault currents Suitable for use in hostile environments or underground (at or near water table) Corrosion and moisture resistant Resistant to aggressive chemical substances Offers good protection against rodents

High Voltage Cables 66 kv TO 400 kv LEAD SHEATHED CABLES Typical construction XLPE insulated, lead sheathed, HDPE or PVC outer sheathed cables with copper or aluminium conductor Main Properties Radially and longitudinally watertight Corrosion and moisture resistant Suitable for use in hostile environments or underground (at or near water table) Especially suitable for submarine installation Resistant to aggressive chemical substances Offers good protection against rodents Lead sheath acts as a screen

XLPE INSULATED CABLES - TYPICAL CONSTRUCTIONS Following data are typical values and are given only for information purposes. High voltage cables are individually designed according to a given application. Hence, specific values of high voltage cable designs are computed as part of the technical proposal. TYPE OF CABLE 132 KV (C u/ XL P E/ Cu-W/ Cu-T/HDPE) 220 KV (Cu / XL P E/ Pb-S/H DPE) 400 KV (Cu/XLPE/Cu-W/ Pb-S/HDPE) Cross section mm 2 1x630 1x1400 1x2500 Diameter of conductor, approx. mm 30.6 47.2 63.5 Thickness of insulation mm 17 23 28 No.&diameter of copper wires in screen mm 60x1.42 86x1.45 Thickness of lead sheath Mm 2.9 3.2 Thickness of copper tape (Copolymer coated) mm 0.20 Overall diameter, approx. mm 88 117 153 Weigh of cable, approx. kg/km 11,000 31,070 52,400 DC resistance of conductor at 20 C Ω/km <0.0283 <0.0129 <0.0072 AC resistance of conductor at 90 C: - In flat formation, separation distance: 2D Ω/km 0.0383 0.0172 0.0108 - In trefoil formation Ω/km 0.0392 0.0178 0.0113 Max. permissible conductor temperature C 90 90 90 Max. permissible conductor temperature during short-circuit C 250 250 250 Highest system voltage kv 145 245 420 Short duration power frequency withstand voltage (at 20 C for 1 minute) kv 275 460 610 Impulse withstand voltage kv 650 1050 1425 Permissible short circuit current for conductor for 1 second ka 90.0 200.3 357.7 Permissible fault current for metallic sheath/ screen for 1 second ka 14.0 18.7 40.0 Operating capacitance at 20 C µ F/km 0.18 0.20 0.213 Capacitance current per phase (at 50 Hz) A/km 4.3 8.0 14.7 Partial discharge at 1.5 x Uo pc <5 <5 <5 Dielectric loss factor, tan δ <10x10-4 <10x10-4 <10x10-4 Min. bending radius m 1.8 2.34 3.06 Max. pulling strength (when pulling from conductor) kn 31.5 70 125 Max. side wall pressure kn/m 5 5 5 91

TESTS OF CABLES & ACCESSORIES ACC. TO IEC 62067, IEC 60840 Routine tests of cables Measurement of electrical resistance of conductor Partial discharge test (max. 10 pc at 1.5Uo) High voltage test (at 2.5Uo for 30 minutes) Electrical test on outer sheaths (this is carried out when required for a particular project, depending on the function of the sheath) Type tests on system; cable & accessories Sample tests of cables Conductor examination and measurement of electrical resistance Measurement of thickness of insulation, metallic and non-metallic sheaths Measurement of diameters, if required Hot set test for XLPE insulation Measurement of capacitance Lightning impulse (IEC 62067) Water penetration test (IEC 62067; depending on cable design) a. Partial Discharge Test at ambient temperature (max. 5 pc at 1.5Uo) b. Tanδ Measurement (Required in IEC 62067) c. Heating Cycle Voltage Test d. Partial Discharge Tests -at ambient temperature (max. 5 pc at 1.5Uo) -at high temperature (max. 5 pc at 1.5Uo) e. Impulse Voltage Test followed by a power frequency voltage test f. Tests of outer protection for buried joints. g. Examination of the accesories after completion of the tests. Electrical tests after installation Type test of cables a. Electrical tests on completed cable: Bending test followed by partial discharge test (max. 5pC at 1.5Uo) Tanδ measurement Heating cycle voltage test followed by partial discharge measurements Impulse withstand test followed by a power frequency voltage test b. Type tests on cable components: Check of cable construction Measurement of volume resistivity of extruded semi-conducting layers Tests for determining the mechanical properties of insulation and non-metallic sheaths Ageing test on pieces of completed cable to check compatibility of materials Loss of mass test on PVC sheaths Pressure test at high temperature on sheaths Test on PVC sheaths at low temperature Heat shock test for XLPE insulation Carbon black content of PE sheaths Shrinkage test for XLPE insulation Test under fire conditions (depending on cable design) Water penetration test (depending on cable design) Phase checking Measurement of DC resistance of conductor Capacitance measurement Measurement of insulation resistance AC High Voltage test Measurement of sequence impedances DC Voltage test on outer sheats In our laboratories, we can perform all necessary tests of cables upto 400 kv rated voltage according to IEC, BS, HD, VDE, NEMA, AEIC, ICEA, SS, NFC, TS, GOST and other world standards and customers specifications.

CABLE ACCESSORIES & CONTRACTING SERVICES Cable Accessories The quality of accessories is as important as the cable itself. Power failures occur due to mishandling or improper conditions during installation works as well as incorrect selection of accessories. Accessories should withstand the operation related dimensional changes and the working conditions as long as the service life of the cable. This can only be achieved by proper accessories selection and meticulous attention to the installation process. Followings are the most important points to be followed: Care must be exercised in stripping the semiconductive layer above the insulation without damaging the insulation. High degree of cleanliness must be maintained in preparing the insulation layer for jointing and terminating processes according to instructions. Insulation and inner semi-conductive materials of the joint must be identical to the material used in the cable. To avoid thermal stress during the operation of the cable system, it is highly recommended to use fixing clamps to attach single core cables to walls, poles or consoles. 94

CABLE ACCESSORIES & CONTRACTING SERVICES Contracting Services Demirer Kablo provides all the necessary services for the execution of high voltage cable turnkey projects and partial cable system installations. Our main services are; Consulting Site survey and system design Most suitable cable design and accessories selection Project design and engineering Installation technique determination Accessories selection & supply Supply of the necessary equipment, tools and test devices for execution Civil works Steel construction works Cable laying, mounting of accessories Fault location, site testing Supervision and commissioning Training Maintenance and repair The most reliable and economical solutions are offered by evaluating the customer's requirements and the local conditions. Demirer Kablo's Contracting group with its expertise in high voltage cable systems and with its skilled installation team utilising modern installation, erection and test exuipment is willing to provide the best service to its customers.

400KV PREQUALIFICATION AND TYPE TEST REPORTS

DEM RER KABLO TESISLERI SANAYI ve TICARET A.š. stanbul Bozüyük Ankara zmir Head Office Tel : Barbaros Bulvar 49 Preveze Han 34353 Be ikta - stanbul / TURKEY : +90 (212) 261 51 63 Pbx +90 (212) 227 48 00 Pbx Telefax : +90 (212) 258 16 56 +90 (212) 261 84 86 Factory Tel : Yaft Mevkii Bozüyük / TURKEY : +90 (228) 314 28 00 Pbx Telefax : +90 (228) 314 28 08 Contact e.mail addresses : Export Sales Dept. Local Sales Dept. Technical Dept. Purchasing Dept. : export@masscable.com.tr : satis@masscable.com.tr : technical@masscable.com.tr : purchase@masscable.com.tr Web site : www.masscable.com.tr