Two identical 2,000 kW alternator operates in parallel. The governor of the first machine is such that the frequency drops uniformly from 50 Hz at no-load to 48 Hz at full-load. The corresponding uniform speed drop of the second machine is 50 Hz to 47.5 Hz. What is the maximum load that can be delivered without overloading either machine?

Two identical 2,000 kW alternator operates in parallel. The governor of the first machine is such that the frequency drops uniformly from 50 Hz at no-load to 48 Hz at full-load. The corresponding uniform speed drop of the second machine is 50 Hz to 47.5 Hz. What is the maximum load that can be delivered without overloading either machine?

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 12.4P

See similar textbooks

Similar questions

Name three factors that determine the torque produced by an induction motor.
Two identical 2000 kW alternator operates in parallel. The governor of the first machine is such that the frequency drops uniformly from 50 Hz at no-load to 48 Hz at full-load. The corresponding uniform speed drop of the second machine is 50 Hz to 47.5 Hz, What is the maximum load that the second generator can be delivered without overloading the first machine?
Two identical 2000 kw alternator operates in parallel. The governor of the first machine is such that the frequency drops uniformly from 50 Hz at no-load to 48 Hz at full-load. The corresponding uniform speed drop of the second machine is 50 Hz to 47.5 Hz, What is the system frequency such that maximum load that can be delivered without overloading either machine?
At a location in Europe, it is necessary to supply 300 kW of 60-Hz power. The only power sources available operate at 50 Hz. It is decided to generate the power by means of a motor-generator set consisting of a synchronous motor driving a synchronous generator. How many poles should each of the two machines have in order to convert 50-Hz power to 60-Hz power?
Show that an alternator running in parallel on constant-voltage and frequency bus-bars has a natural time period of oscillation. Deduce a formula for the time of one complete oscillation and calculate its value for a 5000-kVA, 3-phase, 10,000-V machine running at 1500 r.p.m. on constant 50-Hz bus-bars. The moment of inertia of the whole moving system is 14,112 kg-m2 and the steady short-circuit is five times the normal full-load value. ANSWER IS [1.33 second]
The armature of a 6-pole separately excited dc generator is triplex wave wound with 534 conductors. This machine delivers power to the load at 200V while being driven at 900rpm. At this load, the armature circuit dissipates 640W. If the flux of this generator is 180-mWb, determine the kW rating of the load served. Assume a total brush drop of 2V.
Find the synchronous impedance and reactance of an alternator in which a given field current produces an armature current of 300A on short-circuit and generated emf of 40V on an open-circuit. The armature resistance is 0.1 ohm. To what induced voltage must the alternator be excited if it is to deliver a load of 100A at pf of lagging, with a terminal voltage of 300V.
In the load characteristic of a separately-excited DC generator, its output voltage decreases with increasing load current (decreasing load resistance). What possible fix or action can you take to offset this decrease in voltage and maintain the output voltage at a constant level as the load current increases? .....
In the load characteristics of a separately-excited DC generator, its output voltage decreases with increasing load current (decreasing load resistance). What possible fix or action can you take to offset this decrease in voltage and maintain the output voltage at a constant level as the load current increases?
1. i)What are the different ways to supply DC power to rotor of an alternator? Which method is superior and why? ii)How do you define ‘static stability limit’ of an alternator?
The armature and field resistances of a series machine are 0.2 ohm and 0.3 ohms respectively. While running as a generator, the generated emf is 250V at 1200rpm. If the machine is run as motor, it takes 4A at220V. At a certain load, the motor takes 30A at 220V. However, on load, the armature reaction weakens the field by 4%. Find the motor speed at this load.
111/ The armature reaction of the DC generator reduces the generated EMF. Select one: True False