THIS SWITCH DIAGRAM IS USED TO UNDERSTAND ZERO SEQUENCE NETWORK
SINGLE LINE GROUND FAULT CURRENT DERIVATION
NOW WE ARE MOVING IN TO THE PROBLEM
POSITIVE SEQUENCE NETWORK
I AM INDICATING POSITIVE SEQUENCE REACTANCE ALSO X1
NOW NEGATIVE SEQUENCE NETWORK X2
now zero sequence reactance X0
b) now fault current in amps
Q3: (15 Points) Equi below are given as follows: pment ratings and per-unit reactances for the sy...
Problem 1. Equipment ratings and per-unit reactances for the system shown in figure 1. are given as follows Using a 100-MVA, 230-kV base for the transmission lines, draw the per-unit sequence networks Consider the impact of ?-Y phase shifts Synchronous generators: G 100 MVA 25kV X1-X2 0.2Xo 0.05 G2100 MVA 13.8 kV X,-X2 0.2 Xo 0.05 Transformers: TI 100 MVA 25/230 kV Xi-X-Xo-0.05 T2 100 MVA 13.8/230 kV X-X2 = Xo 0.05 Transmission lines: TL 12 100MVA 230 kV X,=X2=0.1...
can you calculating this question and explain why? thanks The ratings and sequence reactances of the components for the power system shown in Figure 2 are given in Table 1. The pre-fault voltage is 1/0° per unit (pu). Bus 8 L3 Bus 1 T1 Bus 4 T2 Bus 2 Bus 5 L1 L2 G1 Bus 3 T3 Bus 7 Bus 6 D.6975 Figure Draw the per unit impedance sequence networks and determine the per unit (a) Thevenin impedances of the...
The equipment ratings for a five bus system are given as Generator G1: 50 MVA, 12 kV, Xd ’’=X2=0.20, X0= 0.10 per unit Generator G2: 100 MVA, 15 kV, Xd ’’=0.2, X2=0.23, X0= 0.10 per unit Transformer T1: 50 MVA, 10 kV (Y)/138 kV (Y), X=0.10 per unit Transformer T1: 100 MVA, 15 kV (∆)/138 kV (Y), X=0.10 per unit Each 138 kV line: X1=40 Ohms, X0=100 ohms (1) Draw out the zero-, positive-, and negative- sequence reactance diagrams for the original system using a 100-MVA,...
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...
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...
QUESTION 4. A single-line diagram of a power system is shown in Figure Q3 below, where negative and zero-sequence reactances are also given. The neutrals of the generator and A-Y transformers are solidly grounded. The motor neutral is grounded through a reactance X.=0.05 per unit on the motor base. Prefault voltage is VF1.05<Oº per unit whereas prefault load current is zero. Take A-Y transformer phase shifts into consideration. M Line tool X, - X2 - 200 100 MVA X =...
A simple three-phase power system is shown in Figure 2. Assume that the ratings of the various devices in this system are as follows: • Generators G1, G2: 40 MVA, 13.2 kV, = 0.15 pu, = 0.15 pu, = 0.08 • Generator G3: 60 MVA, 13.8 kV, = 0.20 pu, 0.20 pu, - 0.08 • Transformers T1, T2, T3, T4: 40 MVA, 13.8/138 kV, X1 = X2 = 0.10 pu, XO 0.08 pu Transformers T5, T6: 30 MVA, 13.8/138 kV, X1 = X2...
Assuming there is a FAULT at BUS 3, Determine the thevenin equivalent of each series network as viewed from the fault bus. Given: -Prefault voltage is 1.0 per unit -Prefault load currents and delta-wye transformer phase shifts are neglected Synchronous generators G1 1000 MVA 15 kVX"-X2 0.18, Xo 0.07 per unit G2 1000 MVA 15 kV X: X, = 0.20, X,-0.10 per unit G3 500 MVA 13.8 kV X: X,-0.15, X,-0.05 per unit G4 750 MVA 13.8 kV X,-0.30, X,-0.40,...
The following are the answers: Autumn 2013 T1 G1 5 kV 50 MVA 5/20 kV 50 MVA 20 kV 50 MVA X 0.1 p.u Figure A13 In the system shown, per-unit series equivalent impedances are shown for each element. Before a balanced 3-phase fault occurs in the location shown, the pre-fault current is at its rated value at 90 % lagging power factor flowing from generator G1 The generator is operating at full voltage. How much current in kA is...