11. A 20 kW, 440-V, short-shunt, compound d.c. generator has a full-load efficiency of 87%. If the esistance of the armature and interpoles is 0.4 2 and that of the series and shunt fields 0.25 2 and 240 2 espectively, calculate the combined bearing friction, windage and core-loss of the machine. (725 W)

11. A 20 kW, 440-V, short-shunt, compound d.c. generator has a full-load efficiency of 87%. If the esistance of the armature and interpoles is 0.4 2 and that of the series and shunt fields 0.25 2 and 240 2 espectively, calculate the combined bearing friction, windage and core-loss of the machine. (725 W)

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

Chapter11: Transient Stability

Section: Chapter Questions

Problem 11.3P

See similar textbooks

Similar questions

A long-shunt, four pole, 1500-W, 250-V, duplex wave-wound DC compound generator with the rated speed of 500 r.p.m., has a shunt field resistance of 100 Ω, a series field resistance of 0.05 Ω and an armature resistance of 0.2 Ω. If the flux per pole is 48.798 mWb and a total of 620 conductors, calculate the following: (a) the generated voltage, (b) the field currents, (c) the power generated in the armature.
A 20KW, 440V, short shunt compound dc generator has full load efficiency of 87%. If the resistance of the armature and interpoles is 0.4ohm and that of the series and shunt fields 0.25ohm and 240ohms respectively, calculate the combined bearing friction, windage and core loss of the machine A 10 kW 250 volts self-excited generator, when delivering rated load, has an armature-circuit voltage drop of 5% of the terminal voltage and a shunt field current equal to 5% of the rated load current. The resistance of the armature is 0.02 ohm. Calculate the voltage generated and power output.
A 20 kW, 440-V, short-shunt, compound d.c. generator has a full-loade fficiency of 87%. If the resistance of the armature and interpoles is 0.4Ω and that of the series and shunt fields 0.25 Ω and 240 Ω respectively, calculate the combined bearing friction, windage and core-loss of the machine. [Ans. 725 W]
A 20 kW, 440-V, short-shunt, compound d.c. generator has a full-load efficiency of 87%. If the esistance of the armature and interpoles is 0.4 ohms and that of the series and shunt fields 0.25 ohms and 240 ohms respectively, calculate the combined bearing friction, windage and core-loss of the machine.
1. A 20 Kw , 440 V, short-shunt compound dc generator has a full-load efficiency of 87%. If the resistance of the armature and interpoles is 0.4 ohm and that of the series and shunt fields 0.25 ohm and 240 ohms respectively. Calculate the combined bearing friction, windage and core loss of the machine.
A 10 kW shunt generator having an armature circuit resistance of 0.75 ohm and a field resistance of 125 ohm, generates a terminal voltage of 250V at full load. Determine the efficiency of the generator at full load, assuming the iron, friction and windage losses amount to 600W.
Q/ dc shunt generator 4 pole with 500 condcutor , wave running at speed 1000 r.p.m the resistance of armature and field are 0.02 , 55 ohm and delivering load 43.12kwatt at terminal voltage 220 volt, the iron losses is 750 watt 1-Torque developed by the prime mover .........and The torque developed by the armature ........... when running at 1000 r.p.m * 2-The load current ,,,,,,,,,,,,when the speed drops to 800 r.p.m. if If is unchanged ? * 3-Output of the prime motor…….kwatt * 4-Mechanical , electrical and overall efficiency …….. * 5-Flux per pole is......... wb *
A 70-MVA, 69.3-kV, three-phase round-rotor synchronous generator has a synchronous reactance of 14 ohm per phase and negligible armature resistance. 1) The generator is delivering rated power at 0.87 power factor lagging at the rated terminal voltage to an infinite bus bar (Fig. 1). Determine the magnitude of the generated emf per phase and the power angle δ. 2) The generator is delivering 53.5 MW to the bus bar at the rated voltage with its field current adjusted for a generated emf of 46 kV per phase. Determine the armature current and the power factor. Is the power factor is lagging or leading? 3) Given that the generator is operating at the excitation voltage of Part (1), determine the maximum steady-state power which the machine can deliver without losing synchronism. Find the armature current corresponding to this maximum power.
4. A short shunt compound generator supplies a load of 10 kW at 200 V through a pair of feeder resistance of 0.10 ohm. Armature, shunt field resistance and series field resistance are 0.10 ohm, 52.5 ohms and 0.10 ohm, respectively. If the core, friction, and windage losses amount to 631 watts, determine (a) HP of driving engine (b) commercial, electrical and mechanical efficiencies.
An A 20kW DC shunt generator having an armature circuit resistance of 0.8Ω and a field resistance of 140 Ω, generates a terminal voltage of 230V at full load. Determine the total iron, friction and windage losses if the efficiency of the generator at full load= 83%.
In a three-phase, Y-connected, 750-kVA, 1732-V, synchronous generator afield current of 20 A at the rated speed produces a current of 300 A onshort circuit and a voltage of 1732 V on open circuit. The resistance betweenany two terminals of the generator is 0.8 R. Determine the synchronousreactance of the generator. The rotational loss is 20 kW. Using the per-unitsystem, determine the voltage regulation and the efficiency of the generatorwhen it delivers the rated load at its rated voltage and unity power factor.
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.