Open Circuit Breaker B52. Using per unit and symmetrical component analysis, calculate the power system fault currents at Bus 2 (Line 2 out of service) for the Ø-G faults 400 MVA 15 kV B1 T1 T2 Ak 400 MVA 15/345 kV LV Δ Δ 851 0- HV Y Y 04 852 345 KV 100 mi 821 2 Line 2 Gen Xd" (per unit) X2 (per unit) 1 0.225 0.225 2 0.20 0.20 Transformer Data: Line 3 345 kV 50 mi 280 Mvar o Xpu (+/-/0) 0.06 0.05 Line 1 841 0 842 345 KV 200 mi 822 800 MW T2 800 MVA 345/15 kV XO (per unit) 0.0625 0.045 83 40 Mvar 80 MW 800 MVA 15 kV Sbase=100MVA Vbase Bus1 = 15kV Vbase Bus 3 = 15kV Vbase Lines = 345kV Neutral Reactance (pu) Xd' (per unit) Solidly grounded 0.45 0.20 0.40

Open Circuit Breaker B52. Using per unit and symmetrical component analysis, calculate the power system fault currents at Bus 2 (Line 2 out of service) for the Ø-G faults 400 MVA 15 kV B1 T1 T2 Ak 400 MVA 15/345 kV LV Δ Δ 851 0- HV Y Y 04 852 345 KV 100 mi 821 2 Line 2 Gen Xd" (per unit) X2 (per unit) 1 0.225 0.225 2 0.20 0.20 Transformer Data: Line 3 345 kV 50 mi 280 Mvar o Xpu (+/-/0) 0.06 0.05 Line 1 841 0 842 345 KV 200 mi 822 800 MW T2 800 MVA 345/15 kV XO (per unit) 0.0625 0.045 83 40 Mvar 80 MW 800 MVA 15 kV Sbase=100MVA Vbase Bus1 = 15kV Vbase Bus 3 = 15kV Vbase Lines = 345kV Neutral Reactance (pu) Xd' (per unit) Solidly grounded 0.45 0.20 0.40

Power System Analysis and Design (MindTap Course List)

6th Edition

ISBN:9781305632134

Author:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Publisher:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Chapter5: Transmission Lines: Steady-state Operation

Section: Chapter Questions

Problem 5.3P

See similar textbooks

Similar questions

Equipment ratings for the four-bus power system shown in Figure 7.14 are as follows: Generator G1: 500 MVA, 13.8 kV, X=0.20 per unit Generator G2: 750 MVA, 18 kV, X=0.18 per unit Generator G3: 1000 MVA, 20 kV, X=0.17 per unit Transformer T1: 500 MVA, 13.8/500YkV,X=0.12 per unit Transformer T2: 750 MVA, 18/500YkV,X=0.10 per unit Transformer T3: 1000Â MVA, 20/500YkV,X=0.10 per unit A three-phase short circuit occurs at bus 1, where the prefault voltage is 525 kV. Prefault load current is neglected. Draw the positive-sequence reactance diagram in per unit on a 1000-MVA, 20-kV base in the zone of generator G3. Determine (a) the ThĂ©venin reactance in per unit at the fault, (b) the subtransient fault current in per unit and in kA rms, and (c) contributions to the fault current from generator G1 and from line 1-2.
Equipment ratings for the five-bus power system shown in Figure 7.15 are as follows: Generator G1:Â Â Â Â 50Â MVA,Â 12kV,Â X=0.2 per unit Generator G2: 100Â MVA, 15 kV, X=0.2 per unit Transformer T1: 50 MVA, 10 kV Y/138kVY,X=0.10 per unit Transformer T2: 100 MVA, 15 kV /138kVY,X=0.10 per unit Each 138-kV line: X1=40 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 unit on a 100-MVA, 15-kV base in the zone of generator G2. Determine (b) the ThĂ©venin equivalent at the fault, (c) the subtransient fault current in per unit and in kA rms, and (d) contributions to the fault from generator G2 and from transformer T2.
Given the 4 bus network shown below, assume that there are no loads and all buses are at the rated voltage and all have the same phase angles. Assume that shunt capacitances are neglected. The relevant transient reactances for the generators and the reactances for the transformers are shown. Solve for the fault current through the fault impedance for a fault at bus 4 with a fault impedance of j0.1 pu. HINT: Use Delta to Wye conversion.
A single-line diagram of a four-bus system is shown in fiugre. Equipment ratings and per-unit reactances are given as follows.Machines 1 and 2: 100 MVA 20 kV; X1= X2 = 0.2; X0= 0.04 Xn= 0.05 Transformers T1 and T2: 100 MVA 20Y/345Y kV; X1 = X2 = X0 = 0.08. On a base of 100 MVA and 345 kV in the zone of the transmission line, the series reactances of the transmission line are X1 = X2 = 0.15 and X0=0.5 per unit. (a) Determine the bus impedance matrix for each of the three sequence networks. (b) Assume the system to be operating at nominal system voltage without prefault currents when a bolted single-line-toground fault occurs on phase A at bus 3. Compute the fault current, the current out of phase C of machine 2 during the fault, and the line-toground voltages at the terminals of machine 2 during the fault. Total detailed answer is needed. The figure is attached.
As shown in Figure 1, a synchronous generator and motor are rated 100MVA, 13.8 kV. Xm" = 0.2 per unit, Xg" = 0.15 per unit, and XT = 0.305 per unit. The synchronous generator is operating at 100 MVA, 0.95 p.f. lagging and at 1.05 per unit voltage when a three-phase short circuit occurs at bus 2. Please use the superposition method to calculate the per-unit values of (a) subtransient generator current (Ig"); (b) subtransient motor current (Im"); and (c) subtransient fault current (If).
Figure 1 shows a three-bus power system network of an electric utility company with each generator is represented by an electromotive force (e.m.f.) behind the transient reactance. All impedances are expressed in per unit on a common MVA base. The pre-fault system is on noload condition with 1.0 per unit voltage, and pre-fault currents are zero. All answer must be given in FOUR (4) decimal points. (a) Construct the bus impedance matrix for the system using building algorithm method.
The one line diagram of a simple three bus power system is shown in figure Each generator is represented by an emf behind the subtraction reactance. All impedances are expressed in per unit on a common MVA base. All resistances and shunt capacitances are neglected. The generators are operating on no load at their rated voltage with their emfs in phase. Athree phase fault occurs at bus 3 through a fault impedance of Zf=j0.19 per unit. a-using thevenin’s theorem obtain the impedance to the point of fault and the fault current in per unit. b-determine the bus voltage and line currents during fault
As shown in Figure 1, a synchronous generator and motor are rated 100 MVA, 13.8 kV.??"=0.2per unit, ??"=0.15per unit, and ??=0.305per unit. The synchronous generator is operating at 100 MVA, 0.95 p.f. lagging and at 1.05 per unit voltage when a three-phase short circuit occurs atbus 2. Please use the direct method to calculate the per-unit values of (a)subtransient generator current (??"); (b)subtransient motor current (??"); and (c)subtransient fault current (??). Please use the superposition method to calculate the per-unit values of (d)subtransient generator current (??"); (e)subtransient motor current (??"); and (f)subtransient fault current (??).
For the radial power system shown in Figure 3, calculate the line-to-ground fault current flowing in each of the circuit breakers for faults at bus 1, bus 2 and bus 3. Also determine the corresponding faulted phase voltage, assuming that the generator is ideal, with a terminal voltage of 1.0 pu. *positive sequence impedance = negative sequence impedance