This document discusses the components and operation of an AC generator. It describes the key parts including the field, armature, prime mover, rotor, stator and slip rings. The field and magnetic flux produce voltage in the armature. The rotor is driven by the prime mover and its rotation through the magnetic field induces current in the armature coils. Slip rings allow current to flow in and out of the rotating component. AC generators have advantages over DC generators for applications such as power generation.

1. NAME
MUHAMMAD AKRAM BIN IDRISS
MUHAMAD AIMAN BIN ABD AZIZ
JAGADESS SIVAMOORTHY
COURSE : MARINE ELECTRICAL PRATICE
BATCH : WATCHKEEPING ENGINERRING 05

2. INTRODUCTION
COMPENEN

3. A generator is a device which convert mechanical
energy to electrical energy.
Most of Electrical Power use in ship and Aircraft.
Ac Generator most important means of producing
electrical power.

4. Field
Armature
Prime mover
Rotor
Stator
Slip rings

5. The field in an AC generator consists of coils of
conductors within the generator that receive a voltage
from a source (called excitation) and produce a
magnetic flux.
 The magnetic flux in the field cuts the armature to
produce a voltage. This voltage is ultimately the
output voltage of the AC generator.

6. The armature is the part of an AC generator in which
voltage is produced.
This component consists of many coils of wire that
are large enough to carry the full-load current of the
generator.

7. The prime mover is the component that is used to
drive the AC generator.
 The prime mover may be any type of rotating
machine, such as a diesel engine, a steam turbine, or a
motor.

8. The rotor is the rotating component of the generator,
as shown in Figure 1.
The rotor is driven by the generator’s prime mover,
which may be a steam turbine, gas turbine, or diesel
engine.
Depending on the type of generator, this component
may be the armature or the field.
The rotor will be the armature if the voltage output is
generated there; the rotor will be the field if the field
excitation is applied there

10. The stator of an AC generator is the part that is
stationary (refer to Figure 1).
Like the rotor, this component may be the armature
or the field, depending on the type of generator.
The stator will be the armature if the voltage output is
generated there; the stator will be the field if the field
excitation is applied there.

11. Slip rings are electrical connections that are used to
transfer power to and from the rotor of an AC generator
Slip rings are used in AC generators because the desired
output of the generator is a sine wave.
In a DC generator, used to provide an output whose
current always flowed in the positive direction, as shown
in Figure 2.
This is not need for an AC generator. Therefore, an AC
generator may use slip rings, allow the output current and
voltage to positive and negative values.

12. These Generators are generally maintenance free,
because of absence of brushes.
Easily step up and step down through transformers.
Transmission link size might be thinner because of
step up feature
Size of the generator relatively smaller than DC
machine
Losses are relatively less than DC machine
These Generator breakers are relatively smaller than
DC breakers

13. Hybrid electric vehicle (HEV) drive systems,
automotive starter generators,
aircraft auxiliary power generation,
wind generators,
high speed gas turbine generators.

14. The basic principle of ac generator is electromagnetic
induction when a coil of a conductor moves in a
magnetic field the electrons in it starts moving
because of attraction and repulsion of magnetic field.
Thus, an emf is induced in it.

15. When the coil is in the vertical
position, no magnetic field
line are cut by ab and dc; no emf is
include and no current flow.
While the coil rotate it cut the
filed lines and cause a change in
magnetic flux, an emf is induced
which cause an electric current flow
in the circuit.

17. A 400/230-V three-phase generator hase three line
terminals, together with a neutral terminal.
 The line voltage (i.e. the voltage between any pair of
line terminals) is 400 V, while the phase voltage (i.e.
the voltage between any line terminal and the neutral
terminal) is 230 V.