0
1- can operate in generator/ motor mode for both sub/ super-synchronies speed mode with four possible operation conditions
2-A speed variation of ±30% around synchronous speed can be obtained by the use of power converter of 30% of nominal generated power
3-it has not necessarily to be magnetised from the power grid since it can be magnetised from the rotor circuit too
4- the size of the converter is not related to the total generator power but to the selected speed range and hence to the slip power
Wiki User
∙ 12y ago
Add your answer:
Earn +20 pts
What is the working principle of Doubly Fed Induction Generator?
The principle of the DFIG is that rotor windings are connected to the grid via slip rings and back-to-back voltage source converter that controls both the rotor and the grid currents. Thus rotor frequency can freely differ from the grid frequency (50 or 60 Hz). By using the converter to control the rotor currents, it is possible to adjust the active and reactive power fed to the grid from the stator independently of the generator's turning speed.
Explain the working principle of shunt generator?
A shunt generator is a machine with a rotating set of coils of wire embedded in the iron core in its armature (the spinning part), and a 'commutator' and brushes that carry the current from the (spinning) windings on the armature to the stationary external electrical load. It also has a 'field' winding that creates a stationary magnetic field inside the machine, that the armature coils are spun in. As the windings spin, they cut the stationary field and generate an alternating voltage. As well as providing a moving connection to the coils, the commutator and brushes act like a switch, reversing the connections from the coils to the external circuit each time the waveform changes polarity from positive to negative and vice versa. This creates direct current in the external circuit and load. In a shunt generator, the field windings are connected in parallel with the armature ('shunt' is a common term for 'in parallel') and the field gets its power ('excitation') from the armature - the machine is 'self-excited'. A self-excited generator needs a small 'residual field' in the field's iron core so it can generate a small output from the armature when starting, which is fed to the field, boosting the armature output, which is fed to the field.... and so on, until the field iron core saturates with flux, and the field stops strengthening. Shunt generators are the 'workhorse of the small generator market - they are cheap and simple, have an output voltage that 'droops' a little with increasing load, and most shunt generators can safely be short-circuited - this takes the electrical energy away from the field, and the armature can usually develop only a small output current - not enough to damage it.
How horn antenna is fed?
Horn antenna are typically fed by a section of a waveguide, the waveguide itself is often fed with a short dipole.
What is a synchronous generator?
Synchronous generators are the majority source of commercial electrical energy. They are commonly used to convert the mechanical power output of steam turbines, gas turbines, reciprocating engines and hydro turbines into electrical power for the grid. (OR) A "synchronous" generator runs at a constant speed and draws its excitation from a power source external or independent of the load or transmission network it is supplying. A synchronous generator has an exciter that enables the synchronous generator to produce its own " reactive" power and to also regulate its voltage. Synchronous generators can operate in parallel with the utility or in "stand-alone" or "island" mode. Synchronous generators require a speed reduction gear
Is the reverse effect of converting rotation to electrical energy is possible when the power is turned off in the ceiling fan?
The type of electric motor commonly used in ceiling fans does not make a good electrical generator. It is what is known as an AC (Alternating Current) Shaded-Pole Motor, a type of induction motor. An induction motor resembles a rotating transformer, because the stator (stationary part) is essentially the primary side of the transformer and the rotor (rotating part) is the secondary side. There are no brushes, and no direct electrical connection to the rotor windings. More specifically, these motors are often referred to as "squirrel cage" motors. Squirrel-cage motors have a relatively heavy winding made up of solid bars, usually aluminum or copper, joined at the ends of the rotor. Currents induced into this winding provide the rotor magnetic field. The alternating electromagnetic fields created by the current flowing in the stator windings induce the current into the rotor windings. It is the interaction between the rotor and stator fields that cause the motor to turn. Since power for the rotor is a result of the power fed to the stator, and there is no actual physical electrical connection between the two components, if no current is present when the motor is at rest, none will be produced if it is mechanically driven in an attempt to use it as a generator.
How the doubly fed induction generator build up voltage?
If a self-excited generator lost all its residual magnetism, can it build up an output voltage?
What is the function of ACtoAC convertor in doubly fed induction generator?
The Doubly Fed Indcution Generator (DFIG) is a very popular machine, since the output of the stator terminals is already at 60hz (no change in voltaje or frequency necessary). The matrix converter is used in the rotor side (wound rotor) in order to control the frequency and voltage magnitud to make the induction machine generate power at a wide range of speeds...
What has the author G Abad written?
G. Abad has written: 'Doubly fed induction machine' -- subject(s): TECHNOLOGY & ENGINEERING / Power Resources / General, Equipment and supplies, Automatic control, Wind turbines, Mathematical models, Induction generators
What is the working principle of Doubly Fed Induction Generator?
The principle of the DFIG is that rotor windings are connected to the grid via slip rings and back-to-back voltage source converter that controls both the rotor and the grid currents. Thus rotor frequency can freely differ from the grid frequency (50 or 60 Hz). By using the converter to control the rotor currents, it is possible to adjust the active and reactive power fed to the grid from the stator independently of the generator's turning speed.
What are the main difference between the sensor less induction motor and induction motor?
basically sensorless scheme estimated the speed using current signal or current sensor without considerartion speed sensor thats reduce the cost of machine and make it more efficient ..basically sensorless scheme can uses sensor only at current signal or sensor at dc link in doubly fed machine,.........................
What has the author Fahad H Al-Ghubari written?
Fahad H. Al-Ghubari has written: 'Voltage analysis of PWM inverter fed induction motors' -- subject(s): Computer simulation, Electric inverters, Electric motors, Induction, Induction Electric motors, Testing
When pool ozone generator goes bad?
Fit it. Then find out why it was fed air that was not very dry. The air dryer is usually the cause of generator failure, since the air can also make sticky gunk that will fail the generator.
What has the author Ashok Ramchandran written?
Ashok Ramchandran has written: 'Frequency-domain, parameter estimation for a brushless, doubly-fed machine' -- subject(s): Brushless Electric motors, Electric motors, Brushless
How does nuclear energy work simpyfied?
Nuclear fuel - uranium - gets hot and brings water to boil. The steam makes a turbine spin, and the turbine makes an electric generator spin. Electricity from the generator is fed out onto the grid and into peoples homes.
What produces electricity by spinning a magnet in a coil of wire?
A generator or alternator. If the magnetic field is permanent, the current produced from the coil will be alternating current. AC. Alternators usually work the other way round. The magnet is spun inside a coil of wire. The power is taken off from the stator. The rotor is an electromagnet, fed via slip rings on the shaft. The strength of the magnet can be varied and controlled externally, to control the output voltage.
What has the author Alson R Kemp written?
Alson R. Kemp has written: 'Use of multiple loop model for brushless doubly fed machine rotor design' -- subject(s): Brushless Electric motors, Computer simulation, Design and construction, Electric motors, Brushless
What are some of the advantages of solar post lights?
There are many different advantages surrounding the use of solar post lights. The most noted benefit would be that one would have a lower electricity bill as the lights are 'fed' by the sun.
