Question

ysy ews in fhe Figune 1,gven the per unit bus impedance matri 20 240 0140 0200 0200 a140 02275 0175 0175 Zp 200 G175 0310 0310 0200 0175 0310 0500 20 050 N2 Condinut the yusmai hee feut sccurs at bus 4 at no lead, find The fault current 2 The bus tages and 3The line carent 1during fault

symmetrical three phase fault at bus 4

the fault current

the bus voltages all

the line currents all

find y bus

Answer 1

(a) Y - bus matrix: Y_11 = (1/j 0.4 + 1/j 0.2 + 1/j 0.5) = -j 9.5 p middot u Y_12 = Y_21 = -1/z_12 = (-1/1 0.50) = j 2.0 p middot u Y_13 = Y_31 = -1/z_13 = (-1/j 0.20) = j 5. P middot u Y_14 = Y_41 = 0. Y_22 = (1/j 0.35 + 1/j 0.50 + 1/j 0.30) = -j 8.1905 p middot u Y_23 = -1/z_23 = -(1/j 0.3) = -j 3.333 p middot u Y_24 = 0. Y_33 = (1/j 0.20 + 1/j 0.30 + 1/j 0.19) = (-j 13.596) p middot u Y_43 = Y_34 = -1/z_39 = (-1/j 0.19) = + j 5.263 p middot u Y_44 = (1/j 0.19) = -j 5.263 p middot u Y_bus = j[-9.5 2.0 5.0 0.0 2.0 -8.1905 3.333 0 5.0 3.333 -13.596 5.263 0.0 0 5.263 -5.263] (Ans) \r\n (b) z_bus = j[0.240 0.140 0.200 0.140 0.2275 0.175 0.175 0.200 0.1750 0.310 0.310