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For a 3 phase alternator why there is an AC voltage generated in the absence DC excitation?
Wiki User
∙ 10y ago
due to residual magnetism
Wiki User
∙ 10y 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.
Where does the voltage that is necessary for field excitation on the rotor originates from?
The excitation current is provided by a small self-excited pilot generator, attached to the same shaft as the alternator's rotor.
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 is exitation voltage?
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What is characteristics of LVDT?
1.Null Voltage 2.Resolution 3.Linearity 4.Sensitivity 5.Excitation voltage and excitation frequency 6.Dynamic response
How do you calculate the excitation voltage and current of an alternator?
formals to calculate exciation voltage of alternator
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.
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.
Where does the voltage that is necessary for field excitation on the rotor originates from?
The excitation current is provided by a small self-excited pilot generator, attached to the same shaft as the alternator's rotor.
In what situation is the generated voltage at its maximum?
On auto alternator 1000 rpm
What is meant by regulation or an alternator?
Regulation of an alternator is varying or adjusting the d.c. current flow (excitation current) in the revolving field coil to control the output voltage. When an alternator is subject to varying load conditions, and therefore changing load resistance at the output, the output voltage will vary in response. When output voltage is reduced in response to increased load (reduced output resistance), the "voltage regulator" will respond by increasing the excitation current to increase the voltage output. If load is reduced, the generator will momentarily become over-excited and the ouput voltage will increase. The voltage regulator responds by decreasing excitation current, returning the generator output voltage to its nominal level.
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.
Generator excitation voltage?
the voltage which is given for creating magnetic field in a generator is known as excitation voltage.
Why the rotor of an alternator at rated power dissipates more heat at a low power factor load?
In an alternator, the load current is supplied by the stator and the excitation is applied to the rotor. When the power factor is low (lagging), more excitation is required to maintain rated output voltage at rated current. More excitation is also required to maintain rated output voltage with increased output current. Increased excitation current means increased rotor losses that must be dissipated as heat. (akash)
How do you derive alternating current from car alternator?
The car's alternator is a three phase generating system. Inside the alternator is a three phase full wave diode bridge that changes the AC generated voltage to a DC voltage.
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 voltage is generated at lower value?
Are you are asking why an alternator's terminal voltage needs to be increased, using a transformer, for transmission? The answer is that the voltage supplied by an alternator is determined by how many conductors can be inserted into its stator slots and this, in turn, is limited by the physical size of the alternator. So the output of alternators is limited to around 300 kV.
