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What is the charging kVAr taken by a 10 km length of the cable when connected to an 11 kV, 50 Hz supply? The capacitance measured between any two cores of a three phase belted cable is 0.5 µF/km.
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- 380 kVAr
- 150 kVAr
- 114 kVAr
- 400 kVAr
Correct Option: A
Let CL be the capacitance between any two cores.
CL = | ||
2 |
C0 = 2 CL = 2 × 0.5 × 10 = 10µF
IC = Vp.ω.C0 = | ω.2CL | |
√3 |
Total charging kVAr
= √3 (VL).(LC) × 10-3
= √3 × VL × | × 2CL × 10-3 | |
√3 |
= 2 (VL)². ω. CL × 10-3
= 2 × (11000)² × 2π × 50 × | × 10-3 × 10-6 | |
2 |
= 380 kVAr.