From figure below, if 3 phase bolted fault occurs. Using Zbus method to choose asuitable rating of C.B's.Data are as follows:Gl: 100 MVA, 22 Kv,Xgi" = 0.2 puG2: 100 MVA, 22 KV, X2"=0.15 puTR1: 100 MVA, 22/220 KV, XTr1 =0.1 puTR2: 100 MVA, 22/220 KV, XTR2 =0.1 puCBTR11ZTL-J50 ohmTR2свсвG23Zload =(0.2 + j0.1) puCB

From figure below, if 3 phase bolted fault occurs. Using Zbus method to choose a suitable rating of C.B’s. Data are as follows: GI: 100 MVA, 22 Kv,Xgı" = 0.2 pu G2: 100 MVA, 22 KV, X2¯=0.15 pu TRI: 100 MVA, 22/220 KV, XTR1 =0.1 pu TR2: 100 MVA, 22/220 KV, XTR2 =0.1 pu CB TR1 2 ZTL-J50 ohm TR2 св св 3 Zload =(0.2 + j0.1) pu CB

From figure below, if 3 phase bolted fault occurs. Using Zbus method to choose a suitable rating of C.B’s. Data are as follows: GI: 100 MVA, 22 Kv,Xgı" = 0.2 pu G2: 100 MVA, 22 KV, X2¯=0.15 pu TRI: 100 MVA, 22/220 KV, XTR1 =0.1 pu TR2: 100 MVA, 22/220 KV, XTR2 =0.1 pu CB TR1 2 ZTL-J50 ohm TR2 св св 3 Zload =(0.2 + j0.1) pu CB

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

Chapter7: Symmetrical Faults

Section: Chapter Questions

Problem 7.15P

See similar textbooks

Similar questions

Consider the single-Line diagram of a power system shown in Figure 3.42 with equipment ratings given: Generator G1: 50MVA,13.2kV,x=0.15p.u. Generator G2: 20MVA,13.8kV,x=0.15p.u. Three-phase -Y transformer T1: 80MVA,13.2/165YkV,X=0.1p.u. Three-phase Y- transformer T2: 40MVA,165Y/13.8kV,X=0.1p.u. Load: 40MVA,0.8PFlagging,operatingat150kV Choose a base of 100 MVA for the system and 132-kV base in the transmission-line circuit. Let the load be modeled as a parallel combination of resistance and inductance. Neglect transformer phase shifts. Draw a per-phase equivalent circuit of the system showing all impedances in per unit.
Determine the positive- and negative-sequence phase shifts for the three- phase transformers shown in Figure 3.36.
Figure 3.39 shows a oneline diagram of a system in which the three-phase generator is rated 300 MVA, 20 kV with a subtransient reactance of 0.2 per unit and with its neutral grounded through a 0.4- reactor. The transmission line is 64km long with a cries reactance of 0.5-/km. The three-phase transformer T1 is rated 350MVA.230/20kV with a leakage reactance of 0.1 per unit. Transformer T2 is composed of three single-phase transformers, each rated 100 MVA, 127/13.2kV with a leakage reactance of 0.1 per unit. Two 13.2kV motors M1 and M2 with a subtransient reactance of 0.2 per unit for each motor represent the load. M1 has a rated input of 200 MVA with its neutral grounded through a 0.4- current-limiting reactor, M2 has a rated input of 100 MVA with its neutral not connected to ground. Neglect phase shifts associated with the transformers. Choose the generator rating as base in the generator circuit and draw the positive-sequence reactance diagram showing all reactances in per unit.
A generator rated 100 MVA, 20 kV has X1=X2=20% and X0 =5% Its neutral is grounded through reactor of 0.32 ohms. The generator is operating at rated voltage with load and is disconnected from the system when a single line to ground fault occurs at its terminals. Find the subtransient current in the faulted phase and line to line voltage.
Figure 2 shows the circuit of a simple power system. The ratings of the generators, transformers and the motors are as shown in the figure. The reactance of lines 1 and 2 are 40 ohms and 50 ohms respectively. Assume that system is unloaded, and the generators are generating their rated voltage. Select the generator G₁ ratings as base values. Choose the fault location in bus 1 And give the below answers For a symmetrical three phase fault on the bus (a).Determine the Thevenin's equivalent circuit which can be used to calculate the fault current. (b) Calculate the fault current contribution from the generator connected to the bus on which you have selected for fault calculation
In a short circuit test on 132 kV, 3-phase system, the breaker gives the following results: Power factor of the fault = 0.45. Recovery voltage 0.9 time of full line voltage. The breaking current is symmetrical. The restriking transient has a natural frequency of 15 kHz. Calculate the rate of rise of restriking voltage (RRRV) in the following types of faults: (1) Grounded fault (2) Undergrounded fault.
b) A fault occurs at bus 4 of the network shown in Figure Q3. Pre-fault nodal voltages throughout the network are of 1 + j0 p.u, and the impedance of the electric arc is neglected (Zf = 0 + j0 p.u.). The positive, negative and zero sequence impedance parameters of the generator, transmission lines and transformer are given in Figure Q3. (i) Determine the positive sequence fault current for the case when a three-phase-to-ground fault occurs at bus 4 of the network (ii) Determine the short-circuit fault current for the case when a one-phase- to-ground fault occurs at bus 4. Recall that phasors can be expressed in terms of their symmetrical components as shown in the picture attached. where F stands for any three-phase quantity (e.g., current, voltage) (iii) Determine the short-circuit fault current for the case when a phase-to-phase fault occurs at bus 4 ReplyForward
In the shown below power system, both generators G1 and G2 emf’s are equal.All the system data are shown on the system diagram.a) Draw the system diagram in per unit using (MVA)base = 75 and (KV)base =20 KV in the generators side.b) Calculate the three-phase balanced short circuit current (If) at busbar 3 inAmpere and the fault level (MVA)sc in MVA.c) If the fault at busbar 3 is a line-to-line fault, calculate the fault current inAmpere and the fault level (MVA)sc in MVA.
At a 220 kV substation of a power system, it is given that the three-phase fault level is 4000 MVA and single-line to ground fault level is 5000 MVA. Neglecting the resistance and the shunt susceptances of the system, (B) And the zero sequence driving point reactance at the bus is: (@)2.2Q (b) 4.84Q (€)18.18 Q (d)22.72Q
8.In a line-by-line failure we can expect Immersive reader A) Currents exist in the ground connections. B) The current values at the ground connections are zero. C) Short-circuit currents exist in all three phases. D) The voltages at the fault point with respect to ground are zero in the faulted phases. E) N. A.
A 30kV, 50MVA generator having a solidly grounded neutral and Z1 = 0.25pu, Z2=0.15pu and Z0=0.05pu. a. Calculate the fault current and voltages for a single line to ground fault. b. Sketch the phasor diagram for the fault voltages.
4.In a double line-to-ground fault we can expect thatImmersive reader A) There are currents in the ground connections. B) The current values in the ground connections are zero. C) Short-circuit currents exist in all three phases. D) The currents in the faulted phases are equal. E) N. A.