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Where does the voltage that is necessary for field excitation on the rotor originates from?
Wiki User
∙ 11y ago
The excitation current is provided by a small self-excited pilot generator, attached to the same shaft as the alternator's rotor.
Wiki User
∙ 11y ago
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What is excitation and why is it needed for start up in an AC generator?
An alternator is just another name for a synchronous generator. Excitation is needed to create a magnetic field in the rotor. When to rotor is spun with excitation the magnetic field will cut through the stator field and produce an AC voltage in the stator field. In terms of an alternator with built in rectifier the stators AC voltage in the rectified to DC. The strength of excitation will determine the alternators output voltage. The AVR Automatic Voltage Regulator built into almost every alternator controls field current to maintain a constant output voltage.
What is exitation voltage?
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What effects causes the difference in terminal voltage between the increasing and decreasing field excitation current?
sdrg
When you rotate the handle of the electric generator faster does it deliver more less or the same voltage?
The speed of a generator only effects the frequency. Most generators operate at 1800 RPM. The output voltage is controlled by varying the field excitation voltage.
What is Short circuit maintenance current transformer in automatic voltage regulator?
the SCT is used to provide excitation during short circuit conditions. under Short Circuit the voltage may drop below threshold level causing field current to drop, to avoid over excitation by the AVR, the short circuit provides the excitation energy required to maintain a voltage that allows protective devices to operate and isolate the fault. the SCT is open under normal operating condition
Generator excitation voltage?
the voltage which is given for creating magnetic field in a generator is known as excitation voltage.
What is excitation and why is it needed for start up in an AC generator?
An alternator is just another name for a synchronous generator. Excitation is needed to create a magnetic field in the rotor. When to rotor is spun with excitation the magnetic field will cut through the stator field and produce an AC voltage in the stator field. In terms of an alternator with built in rectifier the stators AC voltage in the rectified to DC. The strength of excitation will determine the alternators output voltage. The AVR Automatic Voltage Regulator built into almost every alternator controls field current to maintain a constant output voltage.
What is exitation voltage?
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Why 3 phase diesel generators run undervoltage?
The excitation voltage is too low. Turn the field voltage "pot" to raise the field voltage while watching the output generator voltage.
Difference between static excitation system?
It is called static excitation when you make use of solid state components like diode and thyristors to convert to pure dc and to use this dc for field excitation of synchronous generators. The field winding of synchronous generators can be excited by dc source only. It is called brushless excitation because use of carbon brushes are not made here.It is called dynamic excitation is when you make use of rotating brushes. Excitation is necessary to produce reactive power and also to regulate the voltage of synchronous generators.
What effects causes the difference in terminal voltage between the increasing and decreasing field excitation current?
sdrg
Discuss on the losses of generator power output?
The field excitation could have been lost. Check the output from the voltage regulator.
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.
What is the excitation of the generator?
The rotor must have a magnetic field in order to generator voltage in stator winding. The exciter circuit generates this DC filed in the rotor.
What voltage is generally used for field excitation?
For a small generator like the 125 Watt Alternator/Generator in your car, 12 Volts at a couple Amps. For a large 1,200,000,000 Power Plant Generator typical excitation is 600V at 8000A.
Why does the no-load characteristic differ for increasing and decreasing excitation current?
No-load characteristic knows as magnetic characteristic or open circuit Characteristic (O.C.C). It shows the relation between the no-load generated e.m.f in armature, E and the field or exciting current Im at a given fixed speed. The excitation voltage is directly proportional with excitation current. When excitation voltages increase so do excitation currents also increase.
When you rotate the handle of the electric generator faster does it deliver more less or the same voltage?
The speed of a generator only effects the frequency. Most generators operate at 1800 RPM. The output voltage is controlled by varying the field excitation voltage.
