Question: A 60-Hz synchronous generator having inertia constant H~4 MJ/MVA and a direct axis transient reactance X₂-0.2 per unit is connected to an infinite bus through a purely reactive circuit as shown in following circuit. Reactance are marked on the diagram on a common system base. The generator is delivering real power P₂=0.7 per unit and Q=0.05 per unit to the infinite bus at a voltage of V=1 per unit. (a) A temporary three-phase fault occurs at the sending end of the line at point F. When the fault is cleared, both lines are intact. Determine the critical clearing angle and the critical fault clearing time. (b) A three-phase fault occurs at the middle of one of the lines, the fault is cleared, and the faulted line is isolated. Determine the critical clearing angle. XL1-0.5 XL2-0.6 V- 1 pu X'd-0.2 Xt-0.1 (c) A three-phase fault occurs at a point on one of the lines that are twice as far from one side as the other. After the fault is cleared, the faulted line is isolated. Determine the critical clearing angle.

Question: A 60-Hz synchronous generator having inertia constant H~4 MJ/MVA and a direct axis transient reactance X₂-0.2 per unit is connected to an infinite bus through a purely reactive circuit as shown in following circuit. Reactance are marked on the diagram on a common system base. The generator is delivering real power P₂=0.7 per unit and Q=0.05 per unit to the infinite bus at a voltage of V=1 per unit. (a) A temporary three-phase fault occurs at the sending end of the line at point F. When the fault is cleared, both lines are intact. Determine the critical clearing angle and the critical fault clearing time. (b) A three-phase fault occurs at the middle of one of the lines, the fault is cleared, and the faulted line is isolated. Determine the critical clearing angle. XL1-0.5 XL2-0.6 V- 1 pu X'd-0.2 Xt-0.1 (c) A three-phase fault occurs at a point on one of the lines that are twice as far from one side as the other. After the fault is cleared, the faulted line is isolated. Determine the critical clearing angle.

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

Chapter12: Power System Controls

Section: Chapter Questions

Problem 12.5P

See similar textbooks

Similar questions

Consider a three-phase generator rated 300MVA,23kV, supplying a system load of 240 MA and 0.9 power factor lagging at 230 kV through a 330MVA,23/230Y-kV step-up transformer with a leakage reactance of 0.11 per unit. (a) Neglecting the exciting current and choosing base values at the load of 100 MVL and 230 kV. Find the phasor currents IA,IB, and IC supplied to the load in per unit. (b) By choosing the load terminal voltage IA as reference, specify the proper base for the generator circuit and determine the generator voltage V as well as the phasor currents IA,IB, and IC, from the generator. (Note: Take into account the phase shift of the transformer.) (C) Find the generator terminal voltage in kV and the real power supplied by the generator in MW. (d) By omitting the transformer phase shift altogether, check to see whether you get the same magnitude of generator terminal voltage and real power delivered by the generator.
For Problem 3.18, the motor operates at full load, at 0.8 power factor leading, and at a terminal voltage of 10.45 kV. Determine (a) the voltage at bus 1, which is the generator bus, and (b) the generator and motor internal EMFs.
With the same transformer banks as in Problem 3.47, Figure 3.41 shows the oneline diagram of a generator, a step-up transformer bank, a transmission line, a stepown transformer bank, and an impedan load. The generator terminal voltage is 15 kV (line-to-line). (a) Draw the per-phase equivalent circuit, aounting for phase shifts for positive-sequence operation. (b) By choosing the line-to-neutral generator terminal voltage as the reference, determine the magnitudes of the generator current, transmiss ion-line current, load current, and line-to-line load voltage. Also, find the three-phase complex power delivered to the load.
Three-phase, 60-Hz synchronous generator is connected through a transformer and paralleltransmission lines to an infinite bus. All reactances are given in per-unit on a common systembase. If the infinite bus receives 1.0 per unit real power at 0.95 p.f. lagging, determinea) the internal voltage of the generator andb) the equation for the electrical power delivered by the generator versus its power angle δ.
A 24,000 kVA, 17.32 kV, three-phase, 60 Hz synchronous reactance of 5 Ω/phase and negligible armature resistance. At a certain excitation, the generator delivers rated load, 0.8 pf lagging to an infinite bus bar at a line the line voltage of 17.32 kV. Determine the excitation voltage per phase
A 100KVA, 6.6 kV 3 PHASE star connected cylindrical pole synchronous generator has 20-ohm as synchronous reactance and the armature resistance is negligible and the generator is working at the full load and unity power factor then find the value of the induced emf voltage(line to line). 10 points
a single-phase, 10-kVA, 200-V, generator has an internal impedance Z, of 2 Q. Using the ratings of the generator as base values, determine the generated per-unit voltage that is required to produce full-load current under the short-circuit condition.
Question 1: Figure 1 shows a single-line diagram of a three-phase, 60-Hz synchronous generator, connected through a transformer and parallel transmission lines to an infinite bus. All reactances are given in per-unit on a common system base. If the infinite bus receives 1.0 per unit real power at 0.95 p.f. lagging, determine (a) the internal voltage of the generator and (b) the equation for the electrical power delivered by the generator versus its power angle δ.
why nutral gas based combined cycle power plants are more efficint comparing to open cycle natral gas based power plant
Discuss system demand and generator loading
Determine the per unit impedance of a three-phase generator rated at 900 KVA and 33 KV, given that its armature resistance and synchronous reactance are 40 Ohms per phase and 140 Ohms per phase, respectively.
A three-phase, 250 MVA, 16 kV rated synchronous generator is feeding into an infinite bus bar at 15 kV. The generator has a synchronous reactance of 1.62 pu. It is found that the machine excitation and mechanical power input are adjusted to give E = 24 kV and power angle δ = 30◦. a) Determine the line current and active and reactive power fed to the generator terminal. b) With reference to part (a) current is to be reduced by 20% at the same power factor by adjusting mechanical power input to the generator and its excitation. Determine E, angle δ and mechanical power input. c) With the reduced current as in part (c), the power is to be delivered to generator terminal at unity power factor, what are the corresponding values of E and δ and also the mechanical power input to the generator. Per-unit values are given on machine rating as the base.