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Residual flux is not strictly necessary for separately excited generators to operate, but it is often beneficial. It provides an initial magnetic field that helps establish the output voltage when the generator is started. Without residual flux, the generator may require additional time or an external source to build up the magnetic field and achieve stable operation. Overall, while not essential, residual flux aids in the generator's performance and efficiency during startup.

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What is dc separately excited shunt generator?

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.


Are tachogenerator always separately excited?

Tachogenerators are not always separately excited; they can be self-excited or separately excited depending on their design and application. In separately excited tachogenerators, an external power source provides the excitation current, allowing for better control and stability. Self-excited tachogenerators generate their own excitation voltage through the interaction of the rotor's movement and the magnetic field. The choice between the two types depends on specific operational requirements and system configurations.


Can a shunt generator build up its voltage without residual magnetism?

no...because before producing voltage needed to connect the generator to the grid then after it will produced voltage.AnswerYes, but only if you have an external d.c. supply to supply the field windings. Such machines are called, 'separately-excited'.


How residual magnetism present inside the self excited generator?

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.


Can you use the separately excited shunt generator machine as self excited 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.

Related Questions

What is separately-excited generator?

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.


Application of separately excited dc generators?

As a separate supply is required to excite field, the use is restricted to some special applications like electro-plating, electro-refining of materials etc. But what is the difference between self excited and separately excited?


What is dc separately excited shunt generator?

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.


Are tachogenerator always separately excited?

Tachogenerators are not always separately excited; they can be self-excited or separately excited depending on their design and application. In separately excited tachogenerators, an external power source provides the excitation current, allowing for better control and stability. Self-excited tachogenerators generate their own excitation voltage through the interaction of the rotor's movement and the magnetic field. The choice between the two types depends on specific operational requirements and system configurations.


Can a shunt generator build up its voltage without residual magnetism?

no...because before producing voltage needed to connect the generator to the grid then after it will produced voltage.AnswerYes, but only if you have an external d.c. supply to supply the field windings. Such machines are called, 'separately-excited'.


What are the Applications of differential compound?

Differential compounded generators are used in Ward Lenard motor generator loops. The shunt fields on these generators are separately excited and when the shunt field polarity is reversed by the controller the series field helps drive the generator voltage to zero thus aiding in the reversal of current.


Discuss the curves of separately excited and self excited machine?

it is normally in the age above 14


What is separately excited motor?

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Answering Which one is a separately excited generator - ac generator or dc generator?

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.


What are the application of differential compound generator?

Differential compounded generators are used in Ward Lenard motor generator loops. The shunt fields on these generators are separately excited and when the shunt field polarity is reversed by the controller the series field helps drive the generator voltage to zero thus aiding in the reversal of current.


How residual magnetism present inside the self excited generator?

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.


Can you use the separately excited shunt generator machine as self excited 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.