Question

A 4- pole, 50 Hz,
Y-connected, 3-phase generator has a phase voltage of 260 V ∠0°, a
synchronous reactance of 0.06 Ω, a stator resistance of 0.003 Ω,
and Lsf= 0.02 H. The generator is directly connected to a balanced
3-phase load that draws 2 MW at a lagging 0.8 power
factor.

Sketch the
equivalent circuit annotating all the components, currents and
voltages on the diagram

Calculate the
3-phase apparent power of the load in rectangular form

Calculate the
generator phase current in polar form

Calculate the
required field current.

Calculate the
necessary speed of the prime mover in RPM

Answer #1

A submarine has a 3-phase, Y-connected, 2- pole, 60Hz
synchronous generator rated to deliver 1687.5 kVA at a FP = 0.8
lagging with a line voltage of 450-V. The machine stator resistance
RS = 0.004 ?. The synchronous reactance is Xs=0.08 ?. The actual
system load on the machine draws 900 kW at FP = 0.6 lagging. Assume
that a voltage regulator has automatically adjusted the field
current so that the terminal voltage is its rated value. Mechanical
losses are...

A synchronous generator 480-V, 50-Hz, Y-connected, six-pole has
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to the 45 kW steam turbine. The friction loss and the core
generators are respectively 1.5 kW and 1.0 kW.
Question : Draw a Capability curves!

A 3-phase, 1.2 MVA, Y-connected, 6.6 KV, 6-poles, 60 HZ,
synchronous generator has a synchronous reactance of 30W and
negligible resistance. The generator is connected to an infinite
bus at 6.6 KV and 60 Hz.
a)Determine the excitation voltage (Ea) when the machine is
delivering rated power at o.8 PF lagging.
b)The field excitation current is increased by 10% without
changing the power input from the prime mover. Find the stator
current (Ia), the power factor and the reactive power...

A three-phase, 9,375 kVA, 13.8 kV, 4-pole, 60 Hz, Y-connected
synchronous generator has a synchronous reactance, Xs = 17.9, and
is connected to an infinite bus at rated voltage. If the rotational
and electrical losses are negligivle, what is Ia, Ef, delta, theta,
Tdrive, Phasor diagram, and power flow diagram (label completely
with numerical values for,
A) the machine as a generator; the prime-throttle is opened and
If is adjusted so that the machine delivers rated kVA, 0.8 pf
lagging,...

The no-load (line) voltage of a 6-pole, 72-slot, 1200-rpm,
three-phase, Y-connected, synchronous generator is 1732 V. There
are 10 conductors per slot. For a series connection, determine (a)
the frequency of the induced emf and (b) the flux per pole.

3) A three-phase, nozzle, 4-pole cylindrical pole synchronous
generator feeds a 400 Volt, 50Hz conversion center. The synchronous
reactance of the synchronous generator is 0.72 Ove armature
resistance is neglected. The relation between the pole voltage E
'induced in the induction of the synchronous generator and the
excitation current, is selected as E, = 824. In this working
environment of the synchronous generator,
a.) On the consumer screen, find the excitation current (U),
load values, internal phase values, the moment...

A 1200 kVA, 2.3 kV, 3-phase, star - connected alternator has a
resistance of 0.401 /phase and a synchronous reactance of 3.21
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at the output terminals of the generator if the load is suddenly
disconnected. Assume the speed and the excitation current is to
remain unchanged.

A two-pole Y-connected generator rated at 13.8 kV, 20 MVA, 0.8
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synchronous reac- tance of 8 Ω per phase (at 60 Hz) and a
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following:
(i) What is the torque angle of the generator at rated
conditions?
(ii) How many MW of power this generator can deliver?

A 42 kVA three-phase synchronous generator with line voltage
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A three-phase wye-connected (Y) synchronous generator is
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rated secondary of 2.0 kV and a per-unit series reactance of...

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