QUESTION 1 [50 MARKS] A single line diagram of power transmission line network is illustrated in...

Transcribed Image Text:

QUESTION 1 [50 MARKS] A single line diagram of power transmission line network is illustrated in Figure 1. Develop solution to determine the short-circuit breaking current to justify the correct rating for a circuit breaker at point P. Note : All answers should be in 4 decimal placement. j2n 30 MVA Y 13.8 kV = X = 0.15 pu X, = 0.15 pu X2 = 0.15 pu 35 MVA 13.2 kV/115 kV 0.1 pu X=1 2002 Xserles =j 80n P* 35 MVA 115 kV/13.2 KV 0.1 pu edee 20 MVA 12.5 KV 20 X = 0.2 pu X2= 0.2 pu X= 0.5 pu 10 MVA 12.5 kV X1 = 0.2 pu X2= 0.2 pu X = 0.5 pu Figure 1. QUESTION 1 [50 MARKS] A single line diagram of power transmission line network is illustrated in Figure 1. Develop solution to determine the short-circuit breaking current to justify the correct rating for a circuit breaker at point P. Note : All answers should be in 4 decimal placement. j2n 30 MVA Y 13.8 kV = X = 0.15 pu X, = 0.15 pu X2 = 0.15 pu 35 MVA 13.2 kV/115 kV 0.1 pu X=1 2002 Xserles =j 80n P* 35 MVA 115 kV/13.2 KV 0.1 pu edee 20 MVA 12.5 KV 20 X = 0.2 pu X2= 0.2 pu X= 0.5 pu 10 MVA 12.5 kV X1 = 0.2 pu X2= 0.2 pu X = 0.5 pu Figure 1.