The excitation system
creates the electromagnetic field in the rotor
. The stator has the armature winding that has the electrical energy induced. The stronger the magnetic field created, the stronger the electrical power produced. The strength of the magnetic field is adjusted by controlling the current to the rotor.
How is excitation created?
An electric generator or electric motor consists of a rotor spinning in
a magnetic field
. The magnetic field may be produced by permanent magnets or by field coils. … The process of generating a magnetic field by means of an electric current is called excitation.
What is excitation effect?
A change in the excitation of an alternator running in parallel with other affects only its KVA output; it does not affect the KW output. A change in the excitation, thus, affects only
the power factor of its output
.
What is purpose of excitation?
The basic function of an excitation system is
to provide a continuous (DC) current to the field winding of a synchronous machine
. This is achieved through the use of closed-loop control (or feedback control).
How does alternator excitation work?
The main purpose of exciter in a generator(alternator) is
to provide stationary rotating magnetic field
. Which is used to induce the e.m.f in the armature coil. So, DC power is given to exciter and the exciter is nothing but a coil, and the exciter creates a magnetic field.
Why is excitation always DC?
In the alternator, as the rotor conductor changes its position as the rotor rotating so
constant flux
is to be produced in the rotor winding and it is possible only when the DC supply is given to the rotor winding. … As we need constant flux that is why DC is used instead of AC for excitation of Synchronous Alternator.
What does excitation mean?
:
excitement especially
: the disturbed or altered condition resulting from stimulation of an individual, organ, tissue, or cell.
Does alternator need excitation?
Without the excitation system the AC alternator would have no way of building its voltage as it starts to rotate, nor would not be able to regulate its voltage to the pre-set nominal level while running at its rated speed. So, without an excitation system, an AC
alternator would be useless for its purpose
.
What are the types of excitation system?
- Shunt excitation. …
- EBS excitation. …
- PMG excitation. …
- Auxiliary winding. …
- Auxiliary winding excitation. …
- SCR-controlled excitation system. …
- Sub-controlled excitation with distorted input voltage waveform. …
- Pulse width modulated (PWM) excitation system.
What is excitation in psychology?
n.
the electrical activity elicited in a neuron or muscle cell in response to an external stimulus
, specifically the propagation of an action potential.
What is the need of excitation control?
Excitation system, an integral part of the synchronous generator, performs control and protection functions that include
control of voltage and reactive power
. Power system stability can also be enhanced by supplying additional signal through the excitation system.
What are the characteristics of an excitation system?
The dynamic characteristic of the excitation control system refers to the
transient process when
, in response to an external disturbance (such as a sudden change in the reactive load) or a change in the setting value, the system transits from a stable state to another state at this moment.
What happens when generator loss excitation?
When a generator loses its excitation,
the rotor current gradually decreases and the field voltage decays by the field time constant as well
. In this case, the generator operates as an induction generator and draws reactive power from the power system instead of generating reactive power.
How much excite voltage is needed for alternator?
This voltage should be
approximately 12.5 with nothing
running. The battery light is critical for alternator operation. If this light does not work the alternator will not charge. This light is used as a resister to excite the alternator to charge.
What is self excitation in alternator?
a kind of excitation of generators
where the magnetic field of the main poles is excited by a current supplied to the windings of the main poles from
the armature (rotor) winding. … Self-excitation is made use of most often in DC generators.
What wires go to an alternator?
The brown wire goes to the ignition, the
blue
is the field wire and goes to the alternator, the red wire is the positive battery sensor and the white wire goes to alternator stator.
