An 11-kV, 1000-kVA, 3-phase, Y-connected alternator has a resistance of 2 Q per phase. The open-circuit and full-load zero power factor characteristics are given below. Find the voltage regulation of the alternator for full load current at 0.8 p.f. lagging by Potier method ? Field current 40 50 110 140 180 (A) O.C.C. 3350 4000 7200 7900 8650 voltage(V/ph) zero p.f. load voltage(V/ph) 860 4900 6000 7200

An 11-kV, 1000-kVA, 3-phase, Y-connected alternator has a resistance of 2 Q per phase. The open-circuit and full-load zero power factor characteristics are given below. Find the voltage regulation of the alternator for full load current at 0.8 p.f. lagging by Potier method ? Field current 40 50 110 140 180 (A) O.C.C. 3350 4000 7200 7900 8650 voltage(V/ph) zero p.f. load voltage(V/ph) 860 4900 6000 7200

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

Chapter2: Fundamentals

Section: Chapter Questions

Problem 2.32MCQ: While the instantaneous electric power delivered by a single-phase generator under balanced...

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.
While the instantaneous electric power delivered by a single-phase generator under balanced steady-state conditions is a function of time havi ng two components of a constant and a double-frequency sinusoid, the total instantaneous electric power delivered by a three-phase generator under balanced steady-state conditions is a constant. (a) True (b) False
Two alternators rated 400 MW and 600 MW are operating in parallel. The droop characteristics of their governors are 3% and 4% respectively from no load to full load. Assuming that the alternators are operating at 50 Hz at no load, how would a load of 1000 MW be shared between them? What will be the system frequency at this load? [Ans. G1 = 468.132 MW, G2 = 531.669 MW, f= 48.296 Hz]
An 11 kV, three-phase, turbo alternator has a synchronous impedance per phase of(0,4 + j0,8) Ω and it supplies 2 kA at unity power factor to an infinite bus. Theexcitation is increased so that the emf is increased by 20%. Sketch a general loaddiagram and determine the following from this diagram: the armature current for maximum power output, the actual maximum power output
The effective resistance of a 2200 V, 50 Hz, 440 KVA, 1 -phase alternator is 0.5 ohm. On short-circuit, a field current of 40 A gives the full load current of 200 AS. The electromotive force on open-circuits with same field excitation is 1160 V. Then the synchronous impedance and reactance is _______ ohm and _______ ohm respectively.
If, in a 3-φ alternator, a field current of 50Aproduces a full-load armature current of 200 Aon short-circuit and 1730 V on open circuit, then its synchronous impedance is ....... ohm.
Two 50-MVA, 3-phase alternators operate in parallel. The settings of the governors are such that the rise in speed from full-load to no-load is 2 percent in one machine and 3 percent in the other, the characteristics being straight lines in both cases. If each machine is fully loaded when the total load is 100 MW, what would be the load on each machine when the total load is 60 MW? (Req'd) Draw an appropriate diagram.
A 3-Phase 10Kva, 400 V, 50Hz star connected alternator supplies a rated load at 0.8 power factor lagging. If the armature resistance per phase is 0.5Ჲ and the synchronous reactance is 10Ჲ, using the e.m.f method, estimate the alternator’s voltage regulation
Two alternators rated 400 MW and 600 MW are operating in parallel. The droopcharacteristics of their governors are 3% and 4% respectively from no loadto full load. Assuming that the alternators are operating at 50 Hz at noload, how would a load of 1000 MW be shared between them? What will be thesystem frequency at this load?
A 3-phase, star -connected turbo-alternator, having a synchronous reactance of 10 Ω per phase and negligible armatureresistance, has an armature current of 220 A at unity p.f. The supply voltageis constant at 11 kV at constant frequency. If the steam admission is unchangedand the e.m.f. raised by 25%, determine the current and power factor.
An 11 kV, three-phase, star-connected alternator has a synchronous impedance of10∟80° Ω/phase and operates at unity power factor on infinite bus bars. It supplies acurrent of 300 A by using a general load diagram. Determine: the full-load current for normal excitation ( motor mode), the current and power factor for 100% excitation on 25% overload (generatormode), the maximum power that the machine can develop in the generator mode for50% excitation
Two 60MVA, alternators operate in parallel. The setting of the governor are such that the rise in speed from full load to no load is 2% in one machine and 3% in the other, the characteristics being straight lines in both cases. If each machine is fully loaded when the total load is 120MW, what will be the load on the first machine (with 2% speed regulation) when the total load is reduced to 80MW?