if this happened it will be due to residual magentism and as soon as this magentism vanishes no voltage will be available , what iam saying can be interpreted mathematically
first the generated emf across the armature is given by
E= k* flux* speed
it is clear due to this equation the emf is directly prportional to the flux which means if the flux is reduced so does the emf and the revers is true, the reduction may be lead to zero flux value and thus the emf (zero field current)
secondly this emf covers the terminal voltage and the drop in armature winding if other possiple drops are ignored as
E= terminal voltage + armature drop
in this equation as E drops down as a result of reducing the flux and which in turn because of reduction in the field current , then right hand components will also drop down until both get zero values , so theoreyically no voltage will be exist at generator terminals when the field current comes to zero value, so the persistance of voltage is due to the residual field and will not last long
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.
The working principle of a turbo generator is that of forcing extremely hot condensed air into the piston chamber. The hot condensed air reduces the need for fuel.
There are several different types of generators. I'll explain how a "large" 3 phase synchronous generator works - the type that most likely is generating the power you're using at work or home. The generator is only a small part of a power plant. It is composed of two sets of windings, one on the stator, or stationary part of the generator, and the other mounted on the rotor, or rotating part of the generator. Usually the rotor windings have voltage applied to them by an outside source that is controllable by the power plant operators through what is called the "voltage regulator". A power source is used to spin the rotor. This can be a steam turbine, a wind turbine, and many others. As the rotor spins, it induces current in the stator windings in proportion to the amount of power applied to the rotor windings by the voltage regulator (VR). This current flows out of the stator windings, which are connected to a load through the transmission system. This current, in turn, induces a reverse force (called "back emf") on the rotor winding. The back emf causes the rotor to slow down. As the rotor slows down, the governor (a system that monitors the generator's speed, and keeps it within a certain range) kicks in to speed the generator back up.
IF answer is yes . please explain how we can measure in primary side ??
due to commutation the current in the coil reverses
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.
when the dc generator is loaded current will be drawn from it, therefore a back emf Will be generated, which opposes the motion of a generator, and hence, that opposition loads the three phase generator
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A generator is tool that converts kinetic energy into electricity, through the use of magnets which is surrounded by magnetic fields. As a magnet starts turning its magnetic fields collide with a coil that surrounds the magnet. Which induces current, which is electricity.
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This question is not understandable. You can use a step up transformer to increase voltage; you can't increase voltage by producing electricity at a lower voltage; this will result in current flow into your generator, not current flow out (similar to operating a generator in the leading mode). Please explain further under "discuss question".
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In its simplest form, the starter of a dc motor is a variable resistance in series with the armature circuit of dc motor to reduce the high starting current so that the armature winding does not get overheated and burnt while the motor isgetting started. As the rotating armature of dc motor picks up speed, the starter resistance is gradually reduced so that the motor is able to attain its full speed when the starter is not expected to offer any additional resistance in series with the armature winding of the dc motor. At full speed the motor starts running normally, of course, without the help of starter. In other words, the starter offers resistance to armature current during starting of dc motor only. Under normal working condition of dc motor , the starter is electrically out of armature circuit of the motor. The starter protects the armature of dc motor from getting damaged. The electromotive force (emf) induced in the armature winding during starting builds up from zero value to max value to restrict the armature current within the permissible value at full speed. As the speed of armature/motor build up, armature induced emf also starts building thus reducing the role resistance offered by the starter, hence requiring it to gradually reduce as the motor picks up full speed.