there is problem in AVR and magnetic strength.
You have a seperately excited generator and then you have a shunt generator which has the field winding in parallel with the armature terminals. In DC machines a separately excited generator could be run as a shunt generator provided the field winding is designed to work on the generated voltage. A separately excited alternator needs a DC supply for the field winding. In car alternators that is taken from the main winding via a rectifier and a voltage regulator.
A generator excites it self due to a high power thyristors feeding to a rotor through slip rings. Once excited it lessons maintenance and operational requirements.
If a self-excited generator lost all its residual magnetism, can it build up an output voltage?
Residual magnetism in a self-excited generator refers to the small amount of magnetism that remains in the magnetic core after the generator has been de-energized. This residual magnetism is crucial for the initial excitation of the generator because it provides the necessary magnetic field to induce voltage when the generator is started. As the rotor turns, the residual magnetism induces a small voltage in the stator windings, which, when connected to the field windings, enhances the magnetic field and leads to self-excitation, allowing the generator to generate power. Without sufficient residual magnetism, the generator may fail to start or produce voltage.
Either or both can be separately excited. To generate voltage you need a big magnet( the field). Most generators use an electro-magnet. Now the electro-magnet needs a source of power (electricity). We could use the generators own output to excite the field (magnet), this is called self excitation. The problem with self excitation is that we have to wait for the generator to turn and start generating, also to start generating (Building up) there must be some left over magnetism from the last time it was run (called residual magnetism) or not even a little voltage will be generated to start the field current flowing. To solve these problems we could use separately excited. This means we must have a separate source of power to excite the field to produce the magnetism. Sometimes a battery or gasoline driven generator is used to excite the field of a very large generator to get it generating and then we can use some of the generated output to either recharge the battery or switch over to from the battery. In any case we have adjustable control of the generator all the time. This is why most generators are designed to be separately excited. And that is why you car has a voltage regulator. It wakes up the alternator when the engine is started by separately exciting it (the field) with the battery and then regulates the output voltage of the alternator as the engine changes speed with the driver's commands from the gas pedal.
There are two types me dc generator 1 separately excited dc generator 2 self excited dc generator
It is self excited generator, no external excitation circuit.
in a separately excited generator the field coils are excited from a separate source like a dc battery may be or any other small generator. They are self starting generators.
Excitation is the phenomenon by which you control the excitation of field winding of a generator. In DC generator field winding is placed on stator and this field winding can be self excited or seperately excited depending upon the type on generator used. AC generators can also be self excited or seperately excited type but field winding is placed on rotor nad armature winding on stator.
Easy. By controlling the speed of the motor or whatever is turning the generator's shaft.
when the current is passing through the winding then it is called "Excitation". Types of excitation (1)seperately excited generator. (2)self excited generator. self generator is classified into 3 types. 1.shunt generator. 2.series generator. 3.compound generator. compoud generator is again classified into 2 types. 1.short shunt generator. 2.long shunt generator.
when the current is passing through the winding then it is called "Excitation". Types of excitation (1)seperately excited generator. (2)self excited generator. self generator is classified into 3 types. 1.shunt generator. 2.series generator. 3.compound generator. compoud generator is again classified into 2 types. 1.short shunt generator. 2.long shunt generator.
You have a seperately excited generator and then you have a shunt generator which has the field winding in parallel with the armature terminals. In DC machines a separately excited generator could be run as a shunt generator provided the field winding is designed to work on the generated voltage. A separately excited alternator needs a DC supply for the field winding. In car alternators that is taken from the main winding via a rectifier and a voltage regulator.
A generator excites it self due to a high power thyristors feeding to a rotor through slip rings. Once excited it lessons maintenance and operational requirements.
If a self-excited generator lost all its residual magnetism, can it build up an output voltage?
What can usually happen is the permanent magnets in the generator will become energized, and like static shocks, will store energy in them.
Residual magnetism in a self-excited generator refers to the small amount of magnetism that remains in the magnetic core after the generator has been de-energized. This residual magnetism is crucial for the initial excitation of the generator because it provides the necessary magnetic field to induce voltage when the generator is started. As the rotor turns, the residual magnetism induces a small voltage in the stator windings, which, when connected to the field windings, enhances the magnetic field and leads to self-excitation, allowing the generator to generate power. Without sufficient residual magnetism, the generator may fail to start or produce voltage.