Select a short-circuit withstanding (1-second short circuit length) cable for Feeder 1 in Figure 1. Values for cables are given in Table 1. The voltage of the supplying network is now 115 kV and the short-circuit power of the supplying network is 2000 MVA. Table 1. Technical information of 3-phase cables (10 kV and 20 kV) Product's name EA-number Structural information 20KV 20KV 20 KV 0624250 0624252 0624253 0624254 AHKAMK-W AHKAMKW AHKAMKWAHKAMKW AHKAMKW AHKAMKW AHKAMKW 3x50Al+35Cu 3x95 Al. 35Cu 3x120Al. 35Cu 3x150Al+35Cu 3x185Al+35Cu 3x240A1+70 Cu 3x300Al+70Cu 20kV 20kV 20 kV (8) 20KV 0624255 0624257 0624256 Diameter of conductor Diameter of out-most circle Cable's outer diameter Mass Delivery information Standard length Delivery reel mm 8.0 11.3 12.7 14.1 15.7 18.1 20.3 mm 28 32 34 35 37 40 43 mm 64 71 74 76 80 89 94 aluminium kg/km 510 910 1100 1350 1650 2200 2700 сорраг kg/km 305 305 305 305 305 600 600 cable kg/km 2350 3100 3450 3800 4300 5500 6250 E 500 500 500 500 500 500 500 K24 K26 K26 K26 K26 K28 K28 Cable + coil g 130 2450 2625 2800 3050 3930 4100 Mass Mechanical values (3) Minimum permissable bending phase 0.42 0.48 0.51 0.53 0.56 m 0.60 0.65 radius in installation force cable m 0.52 0.57 0.60 0.61 0.64 0.71 0.76 Minimum permissable bending phase 0.30 0.34 0.37 m 0.36 0.39 0.42 0.46 radius in the final installation cable m 0.36 0.40 0.42 0.43 0.45 0.50 0.53 Largest permissible installation traction with a cable grip KN 2.2 4.3 5.4 6.8 8.3 8.5 8.5 Largest permissible installation traction with a pulling grip Electric values KN 75 14.3 18.0 20.0 20.0 20.0 20.0 Phase conductors max. DC-resistance Phase conductors max. AC-resistance (1)(2) conductor 20°C 0/km 0.641 0.320 0.253 0.206 0.164 0.125 0.100 conductor 65°C 0/km 0.76 0.38 0.30 0.25 0.20 0.15 0.12 conductor 90°C 0/km 0.82 0.41 0.33 0.27 0.21 0.16 0.13 Power room wire's max. DC-resistance conductor 20°C n/km 0.524 0.524 0.524 0.524 0.524 0.268 0.268 Inductance per phase (1) mH/km 0.46 0.40 0.39 0.37 0.36 0.35 0.34 Useful capacitance(1) PF/km 0.17 0.21 0.23 0.24 0.26 0.30 0.32 Charging current (1) Earth fault current (1) Load capacity (3) On Earth (2) In Air (2) Thermal short circuit durability (3) A/km 0.6 0.8 0.8 0.9 10 1.1 12 A/km 1.8 2.3 2.5 2.6 2.9 3.2 3.5 conductor 65°C A 155 235 265 300 330 385 435 conductor 65°C A 160 230 265 300 345 400 460 conductor 90°C A 195 280 325 370 425 510 565 Largest permissible short circuit current of 1 second Phase conductor (5) Accidental contact protection(s) KA 4.7 11.3 14.1 17A 22.6 28.3 KA 2.2 2.5 2.6 2.3 29 4.3 4.5 Power room wire (7) KA 5.0 5.0 5.0 5.0 5.0 9.7 9.J SAMENTE (1) Approximate value (2) (3) See the initial assumptions for the product from the datasheet Bending must be done carefully, with even single bends (4) Contact protection circuit is closed (5) Conductor's temperature is 90°C before short circuit and 250°C after it (6) Contact protection's temperature is 90°C before short circuit and 250°C after it (7) (8) Power room wire's temperature is 55°C before the short circuit and 250°C after it Cables available also with a 35 mm² power room wire

Select a short-circuit withstanding (1-second short circuit length) cable for Feeder 1 in Figure 1. Values for cables are given in Table 1. The voltage of the supplying network is now 115 kV and the short-circuit power of the supplying network is 2000 MVA. Table 1. Technical information of 3-phase cables (10 kV and 20 kV) Product's name EA-number Structural information 20KV 20KV 20 KV 0624250 0624252 0624253 0624254 AHKAMK-W AHKAMKW AHKAMKWAHKAMKW AHKAMKW AHKAMKW AHKAMKW 3x50Al+35Cu 3x95 Al. 35Cu 3x120Al. 35Cu 3x150Al+35Cu 3x185Al+35Cu 3x240A1+70 Cu 3x300Al+70Cu 20kV 20kV 20 kV (8) 20KV 0624255 0624257 0624256 Diameter of conductor Diameter of out-most circle Cable's outer diameter Mass Delivery information Standard length Delivery reel mm 8.0 11.3 12.7 14.1 15.7 18.1 20.3 mm 28 32 34 35 37 40 43 mm 64 71 74 76 80 89 94 aluminium kg/km 510 910 1100 1350 1650 2200 2700 сорраг kg/km 305 305 305 305 305 600 600 cable kg/km 2350 3100 3450 3800 4300 5500 6250 E 500 500 500 500 500 500 500 K24 K26 K26 K26 K26 K28 K28 Cable + coil g 130 2450 2625 2800 3050 3930 4100 Mass Mechanical values (3) Minimum permissable bending phase 0.42 0.48 0.51 0.53 0.56 m 0.60 0.65 radius in installation force cable m 0.52 0.57 0.60 0.61 0.64 0.71 0.76 Minimum permissable bending phase 0.30 0.34 0.37 m 0.36 0.39 0.42 0.46 radius in the final installation cable m 0.36 0.40 0.42 0.43 0.45 0.50 0.53 Largest permissible installation traction with a cable grip KN 2.2 4.3 5.4 6.8 8.3 8.5 8.5 Largest permissible installation traction with a pulling grip Electric values KN 75 14.3 18.0 20.0 20.0 20.0 20.0 Phase conductors max. DC-resistance Phase conductors max. AC-resistance (1)(2) conductor 20°C 0/km 0.641 0.320 0.253 0.206 0.164 0.125 0.100 conductor 65°C 0/km 0.76 0.38 0.30 0.25 0.20 0.15 0.12 conductor 90°C 0/km 0.82 0.41 0.33 0.27 0.21 0.16 0.13 Power room wire's max. DC-resistance conductor 20°C n/km 0.524 0.524 0.524 0.524 0.524 0.268 0.268 Inductance per phase (1) mH/km 0.46 0.40 0.39 0.37 0.36 0.35 0.34 Useful capacitance(1) PF/km 0.17 0.21 0.23 0.24 0.26 0.30 0.32 Charging current (1) Earth fault current (1) Load capacity (3) On Earth (2) In Air (2) Thermal short circuit durability (3) A/km 0.6 0.8 0.8 0.9 10 1.1 12 A/km 1.8 2.3 2.5 2.6 2.9 3.2 3.5 conductor 65°C A 155 235 265 300 330 385 435 conductor 65°C A 160 230 265 300 345 400 460 conductor 90°C A 195 280 325 370 425 510 565 Largest permissible short circuit current of 1 second Phase conductor (5) Accidental contact protection(s) KA 4.7 11.3 14.1 17A 22.6 28.3 KA 2.2 2.5 2.6 2.3 29 4.3 4.5 Power room wire (7) KA 5.0 5.0 5.0 5.0 5.0 9.7 9.J SAMENTE (1) Approximate value (2) (3) See the initial assumptions for the product from the datasheet Bending must be done carefully, with even single bends (4) Contact protection circuit is closed (5) Conductor's temperature is 90°C before short circuit and 250°C after it (6) Contact protection's temperature is 90°C before short circuit and 250°C after it (7) (8) Power room wire's temperature is 55°C before the short circuit and 250°C after it Cables available also with a 35 mm² power room wire

Power System Analysis and Design (MindTap Course List)

6th Edition

ISBN:9781305632134

Author:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Publisher:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Chapter3: Power Transformers

Section: Chapter Questions

Problem 3.47P: Consider the oneline diagram shown in Figure 3.40. The three-phase transformer bank is made up of...

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