Long Transmission Lines

2,789 views

Published on

Questions on long transmission lines

Published in: Business, Technology
0 Comments
1 Like
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
2,789
On SlideShare
0
From Embeds
0
Number of Embeds
1
Actions
Shares
0
Downloads
62
Comments
0
Likes
1
Embeds 0
No embeds

No notes for slide

Long Transmission Lines

  1. 1. Long Transmission Lines 1. A 132 kv transmission line, having constants A,B,C, D is preceded and terminated by 132/33kV transformers. The short circuit impedances of the transformers measured on their 33kV sides are Z1 for the input transformers and Z2 for the output transformer. Neglecting the magnetizing currents of the transformers, calculate the constants A, B, C, and D representing the complete system. [(A+16Z1), (AZ2+B/16+16CZ1Z2+DZ1), 16C, (16CZ2+D)] 2. In a 3 phase transmission line with 132kV at the receiving end the following are the transmission constants: A = D = 0.98 |_3°, B = 110|_75°, C = 0.0005|_88°Siemens(S). if the load at the receiving end is 50MVA at 0.8 lagging pf determine the voltage, current and pf at the sending end. [95.37|_11.346°KV, 196.88|_-24.41°, 0.8115(lagging)] 3. A 3 phase transmission line has the following circuit constants: A1= 0.97|_0.6°, B1 = 60|_70°. If a second line ahving the constants A2 = 0.97|_0.4°; B2 = 50|_76° is connected in parallel with the first line, determine the sending-end voltage when delivering 50MW at 132KV and 0.8 lagging pf at the receiving end. [80.081|_3.626°V] 4. A transmission circuit is represented by a symmetrical π network in which the series impedance is 120|_60°Ω, and each shunt admittance is 2.5x10-3|_90°S. calculate (a) the value of the general circuit constants ABCD, and (b) the characteristic impedance of the circuit. [0.7552|_11.456°, 120|_120°, 4.3665x10-3|_94.927° ; 165.78|_-17.46°] 5. A 2 port resistive network has input terminals A and B, and output terminals C and D. the resistances measured across AB when terminals CD are first short-circuited and then open- circuited are, respectively, 720Ω and 1240Ω. The resistance measured across CD with AB open- circuited is 910Ω. Determine the equivalent T- network. [552.1 Ω, 222.1 Ω, 687.9 Ω]

×