answersLogoWhite

0

What else can I help you with?

Related Questions

What is the excitation system in a generator used for?

The excitation system is used to control the excitation of the rotating field in the armature. By increasing the armature current, it in turn increases the magnetic flux in the armature coil. This has the effect of increasing the voltage output of the generator. By lowering the armature current this in turn lowers the generator output voltage. The generator's voltage regulator automatically adjusts the output voltage continuously as the applied load on the generator changes.


Why does the no-load characteristic differ for increasing and decreasing excitation current?

The no-load characteristic of a generator differs for increasing and decreasing excitation current due to magnetic hysteresis, residual magnetism, and core saturation effects. When the excitation current increases, the magnetic domains in the iron core gradually align with the applied magnetic field, resulting in a higher generated electromotive force (EMF). However, as the excitation current decreases, these magnetic domains do not immediately return to their original unaligned state. This lag in realignment causes the generated voltage to remain higher during the decreasing phase of excitation than during the increasing phase at the same level of excitation current. This phenomenon is known as magnetic hysteresis. Even when the excitation current is zero, the magnetic core retains some level of magnetisation, known as residual magnetism. This residual magnetic field means that when the excitation current starts increasing again, it takes additional current to overcome this residual alignment before the generated voltage rises significantly. As a result, the voltage is initially lower when increasing the excitation current from zero. Conversely, during the decreasing phase, the residual magnetism keeps the voltage higher than it would be if the core were fully demagnetised, further contributing to the difference between the increasing and decreasing curves. As the excitation current increases, the magnetic core of the generator approaches saturation. Near saturation, any further increase in excitation current results in only a small increase in generated voltage because the core's magnetic domains are almost fully aligned. When the excitation current decreases from this saturated state, the magnetic domains gradually return to a less aligned state. This gradual realignment causes the generated voltage to decrease differently than it increased, contributing to the asymmetry between the increasing and decreasing excitation phases.


What effects causes the difference in terminal voltage between the increasing and decreasing field excitation current?

sdrg


How do you explain excitation?

by increasing the terminal voltage


What is transformer turns ratio excitation current?

This is the current level needed to energize a transformer to its rated voltageThe clue is in the name! 'Excitation' means to create a magnetic field. So the excitation current is the current drawn from the supply which sets up the magnetic field around the core.


Why does the no-load characteristic differ for increasing and decreasing excitation current in dc generator?

cari diri r. aku pun selok ugop ni


What components compose the excitation current of transformer how the are modeled in the transformer's equivalent circuit?

Excitation current Io = Iw + Iu


What is the difference between generator over excitation versus under excitation when attached to the grid?

Over Excitation is a condition when the Excitation System is providing too much field current and as a result, the rotor of the generator will over heat. The Excitation System is equipped with an Over Excitation Limiter. This limiter acts to reduce the Excitation Current if this condition exists Underexcitation is a condition when the generator is not getting enough Excitation Current. If the generator does not get enough Excitation Current, it can be un-synchronized with the grid. We call this slipping a pole. If this occurs, the generator can be severely damaged. Kelly Thompson Engineering Lead Siemens Energy Alpharetta GA


Why The Excitation current is non-sinusoidal when applied voltage is sinusoidal?

excitation voltage is sinusoidal because it is taken from the terminal of alternator but excitation current is non-sinusoidal because it always dc.


If the excitation of generator changes what happens to the terminal voltage?

By Decreasing the excitation voltage the terminal voltage will decrease and similarly by increasing the excitation voltages the terminal voltage will also increases.


What effect does increasing the current have on solenoid?

it will produce a stronger magnetic field.


In synchronous motor theory is excitation current the same as field current?

Yes, in synchronous motor theory, excitation current is the same as field current. This current is used to produce the magnetic field in the rotor that interacts with the stator current to generate torque and make the motor operate synchronously.