Gen Xd-j0.25 pu Bus 2 Bus 1 X12-j .0504 pu- X13-j0.0373 pu X24-j0.0372 pu X43 =j 0.0636 pu Bus 3 Bus 4 Gen Xd j0.25 pt 0.1357 j0.1234 j0.1278 j0.1143 7 -ї0. 1234 j0. 1466 іо.1246 j01266 Busj0.1278 j0.1246 j0.1492 j0.1222 j0.1143 jo.1266 j0.1222 j0.1357 pu 3 5 , 3-9-$"it Determine in pu: a) the three-phase fault subtransient current on Bus 3 b) the contributions to the fault current from line 1-3 and line 4-3. c) the contributions to the...
1. A three-phase synchronous generator connected to a 345-KV transmission line through a transformer as shown in Figure P1. Parameters of both generator and transformer are given in the figure. Transformer losses and exciting current are neglected. A three-phase short-circuit occurs on the line side of the circuit breaker when the generator is operated at rated terminal voltage and at no-load. The breaker interrupts the fault three cycles after fault inception. Neglect the effect of the transformer on the time...
The single-line diagram of a three-phase power system is shown. Equipment ratings are given as follows: The inductor connected to generator 3 neutral has a reactance of \(0.05\) pu using generator 3 ratings as a base.1. Draw the zero-, positive-, and negative -sequence reactance diagrams using a \(1000 \mathrm{MVA}, 765 \mathrm{kV}\) base in the zone of line \(1-2\).2. Faults at bus 2 are of interest. Determine the Thevenin equivalent of each sequence network as viewed from the fault bus. Prefault voltage...
Four-bus power system shown in Fig. 1 are as follows: Generator G1: 200 MVA, 7.2 kv, X -0.15 p.u Generator G2: 250 MVA, 9.6 kV, X-0.12 p.u Generator G3: 500 MVA, 10 kV, X-0.25 p.u Transformer T1:200 MVA, 7.2 Δ /132 Y kV, X= 0.05 p.u Transformer T2: 250 MVA, 9.6 Δ /132 Y kV, X =0.15 p.u Transformer T3: 500 MVA, 10 Δ /132 Y kV, x-0.1 p.u Each 132-kV line:X,-10 Ω 1- A three-phase short circuit occurs at...
A single line diagram of a power system is shown in Fig. 2. The system data with equipment ratings and assumed sequence reactances are given the following table. The neutrals of the generator and A-Y transformers are solidly grounded. The motor neutral is grounded through a reactance Xn 0.05 per unit on the motor base. Assume that Pre-fault voltage is takin as VF-1.0 ,0° per unit and Pre- fault load current and Δ-Y transformer phase shift are neglected In the...
The ratings of the components shown in the one-line diagram are G1: 25 MVA, 13.8 kV, x-0.15 pu G2:15MVA, 13 kV, x = 0.1 5 pu. TI : 25 MVA, 13.2/69 kV, x-0. I 1 pu T2: 25 MVA, 69/13.2 kV,x-0.220 pu Transmission line: j65 ohms/pha bus 2 BE 165Ω ISMVA e ratings of generator 1 as base valu 25MVA 13.8 kV 1 5% 69113.2 kV13kV 1 1% 13.2169k 1 1% 1- Draw the reactance diagram. 2- Find the Y-bus...
3.13 A single-line diagram of a three-phase power system is shown in Fig. 3.51. The ratings of the equipment are shown below Generator G: 100 MVA, 11 kV, Xi -X2-0.20 pu, Xo -0.05 pu Generator G2 : 100 MVA, 20 kV, Xi=X2=0.25 pu, Xo=0.03 pu, X,,-0.05 pu Transformer T: 100 MVA, 11/66 kV, Xi -X2-Xo 0.06 pu Transformer T2: 100 MVA, 11/66 kV, Xi-X2 = Xo 0.06 pu Line: 100 MVA, X,-X2 = 0.15 pu, Xo = 0.65 pu A...
A 50 Hz, 250 MVA synchronous generator having inertia constant H=5 MJ/MVA is connected to an infinite bus through transformer and transmission line as shown below. The transformer reactance is based on 500 MVA, while the other impedances are based on the generator MVA Infinite bus 1 2 3 XL 0.1 pu - oto G1 V= 1.0 pu X 0.1 pu Xd = 0.3 pu at 500 MVA The generator is delivering 0.8 of full load current at a power...
Transformer TI : 50 MVA, 10 kV Y/138 kV Y, X=0.10 per unit; Transformer T2: 100 MVA, 15 kV D/138 kV Y, X-0.10 per unit; Each 138-kV line: X1-400 A three-phase short circuit occurs at bus 5, where the prefault voltage is 15 kV. Prefault load current is neglected. (a)Draw the positive-sequence reactance diagram in per-unit on a 100-MVA, 15-kV base in the zone of generator G2. Determine: (b) the The'venin equivalent at the fault, (c) the subtransient fault current...
The Fig. P1.1 is a one-line diagram of a simple power system. There prefault system is on no-load with 1.0 pu voltage and prefault currents are zero. A BOLTED THREE-PHASE FAULT occurs at point P. (a) Draw the pre-fault single-phase equivalent circuit showing numerical values. (b) (i) Calculate the subtransient current in the fault (ii) Calculate the voltages at the busses during the fault. (iii)Calculate the e subtransient current in the lines. (c)) Determine the Zbus relating the bus currents...