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 (??).

Q: The symmetrical fault occurs in the terminals of the synchronous generator. Find the direct axis…

A: Find the direct axis transient Reactance of the symmetrical generator?  If the leakage Reactance Xl=…

Q: The positive, Negative and Zeroes sequence per unit impedance of two generators connected in…

A:

Q: A 50 MVA, 11 kV synchronous generator has internal reactance of 0.8 Q. The generator is connected to…

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Q: Question-9 The positive, Negative and Zeroes sequence per unit impedance of two generators connected…

A: Given- Impedance- X1=0.12 p.u.X2=0.096 p.u.X3=0.036 p.u. Voltage E=1 p.u. To Find- The positive…

Q: Q6/ A 3-phase, 50Hz synchronous generator having H=6 MJ/MVA is delivering power of 1.0 P.U to…

A: Critical clearing angle:- It is load angle at which fault is clear and system will stable, without…

Q: A fault occurs at bus 4 of the network shown in Figure Q3. Pre-fault nodal voltages throughout the…

A: x=1y=7Note: reactance of element right to bus 4 is not given. Hence we will not consider that in…

Q: The sum of the armature reactance  and.............reactance  is the reactance of the synchronous…

A: ARMATURE REACTANCE AND LEAKAGE REACTANCE   The armature reaction reactance and the leakage reactance…

Q: Figure shows a sample power system network and Zpus Matrix elements. For a solid three phase fault…

A:

Q: cance is X = ault occurs at the generator terminals. 0.20 pu. The generator is operating at rated…

A: In this question we will find magnitude of the steady state per phase fault current ...

Q: A three-phase, Y-connected, 75-MVA, 27-kV synchronous generator has a synchronous reactance of 9.0 2…

A: The given data is shown below:

Q: Q5 An 11 kV three-phase 5 MVA, star-connected generator is protected by an earth- fault relay having…

A:

Q: jX, (1) 2 3x. iX; E, O E. Figure 1

A: Three phase short circuit occur at bus 2 a) Calculating sub transient generator current Ig…

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Q: The symmetrical fault occurs in the terminals of the synchronous generator. Find the direct axis…

A:

Q: Q6. Q7. Q8. Q9. When identical partially loaded AC generating units are operating in parallel on…

A: Power system:- It is an interconnection of electrical equipment which is used for power generation,…

Q: 2. for the system shown in figure. When Three phase to ground bolted Short Circuit Occurs on line 2.…

A: Step 1: Step 2: Step 3: Step 4:

Q: Find, for a symmetrical three-phase symmetrical three-phase fault at node 2 the values during the…

A: Motor load rating SM3ϕ=150kVApf=0.8 lagV2ph=3k3VV2ph=1kV Before fault,…

Q: The symmetrical fault occurs in the terminals of the synchronous generator. Find the direct axis…

A: Given: Leakage reactance, Xl=7.9 Ω Armature reactance, Xad=7.7 Ω Field reactance, Xf=6.4 Ω

Q: b) A fault occurs at bus 2 of the network shown in Figure Q3. Pre-fault nodal voltages throughout…

A:

Q: A 20-MVA, 13.8-kV generator has a direct-axis subtransient reactance (X") of 0.25 per unit. The…

A: Given Data:A generator with,Power rating Voltage rating Direct-axis sub-transient reactance Negative…

Q: For the following single line diagram of a three-phase system, a three-phase fault occurs at point P…

A: The fault occurs at P. Transient reactance of the motor, Xm'(pu)=1.7*0.14              =0.238

Q: In a 7-bus system, the double line fault is occurred at bus -5. During fault the positive sequence…

A: Correct option is B  Given V01= 0.0175 I =  -j0.148

Q: It is required to keep L-G fault current with zero fault impedance to rated line current. Determine…

A: In this question we need to find a reactance need to be placed in neutral of genrator to limit the…

Q: It is required to keep L-G fault current with zero fault impedance to rated line current. Determine…

A: Given:Z1=0.35p.uZ2=0.5p.uZ0=0.05p.uWe need  to find the value of reactance that need to be placed in…

Q: Figure below shows a power system where load at bus 5 is fed by generators at bus 1 and bus 4. The…

A: When line L1 has length =100 km, fault current for fault at bus 5 is =2530 A When line L1 reduced to…

Q: When identical partially loaded AC generating units are operating in parallel on governor control,…

A: Since you have posted multiple different questions, we will solve the first question for you. To get…

Q: Three 11 kV; 20 MVA 3 plase synchronous generators are connected to common set of bus bars. Each…

A: Given V=11 kV S=20 MVA X1 =20 % X2=15 % X3 =30 %

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A:

Q: Q14. In paralleling of synchronous generators, the machines that are to be paralleled must have the…

A: Conditions for  parallel operation of alternators (synchronous generators) : -Bus bar voltage of the…

Q: Calculate the fault AC and DC components current in 2.5sec instant

A: Given- Sub transient reactance =0.15 pu Transient reactance =0.25 pu Synchronous reactance = 1.5 pu…

Q: Under short circuit, the reactance’s of the synchronous generator during the  steady state condition…

A: when a fault occurs in the power system network, the currents flowing is determined by the internal…

Q: Given the 4 bus network shown below, assume that there are no loads and all buses are at the rated…

A: In given 4 bus system, there are 3 generators at three buses and fault is occurred at 4th bus Zf =j…

Q: The 3-φ generator is rated 25 MVA, 13.8 kV. The positive, negative and zero sequence reactances are…

A: Among the various types of unsymmetrical fault, LG fault is the most severe fault.

Q: Figure 1 shows a three-bus power system network of an electric utility company with each generator…

A: The one-line diagram of a three-bus power system network is given. The parameters (reactances) are…

Q: For the following single line diagram of a three-phase system, a three-phase fault occurs at point P…

A: G1=20 MVA1=6.9 kVis taken as base valueXg1=0.15 pu Xg2(at new base)=0.08×2025×6.96.92…

Q: A 600 KVA generator with X"a = 0.22 per unit is connected to a bus through a circuit breaker, as…

A: For Generation(here the line volatge is zero)600 KVA 2.5 KVX"d=0.22 pulet base MVA =200 KVA =0.2…

Q: A 3-phase generator (30 MVA, 13.8 KV, 0.15) supplies two motors (rated at 20 MVA, 12.8 KV, 20%, and…

A: The one line diagram is shown below voltage in transmission line circuit=13.8×11513.2=120.23 kV…

Q: Q. Line impedances for the power system shown in Figure. In this system, the impedance distance…

A: It is given that: Relay setting :ZsetGH=0.5ZGHZsetHR=0.8ZHRZsetHS=0.8ZHS

Q: The symmetrical fault occurs in the terminals of the synchronous generator. Find the direct axis…

A: When a symmetrical fault occurs in the terminals of a synchronous generator, then during the…

Fault Analysis

In an electrical engineering system, a fault is an abnormal electric current flowing through the system, and fault analysis is the study of these faults. For instance, a short-circuit is a fault where the live wire touches the ground or neutral wire. If a circuit is interrupted by a failure of a current-carrying wire then an open circuit fault occurs. The open-circuit faults are also called series faults. One or more phases or ground may be involved in a three-phase fault or may occur only between two phases. Current flows into the earth in case of a ground fault or earth fault. For most situations, the prospective short circuit current of a fault that is predictable can be calculated. To limit the loss of service because of a failure, the protective devices can detect fault conditions and operate circuit breakers and also other devices. All phases equally can be affected in a poly-phase system which is known as symmetric electrical fault. The asymmetric fault becomes more complicated to analyze if only some phases are affected. By using methods such as symmetrical components, the power system analysis of these types of faults is often simplified. The main objective of power system protection is to design, detect, and interrupt power system faults.