As the alternator main shaft rotates, the exciter stator creates a current in the exciter rotor. The AVR supplies power to the exciter stator while monitoring the voltage from the main stator at the generator terminals. If less voltage is detected at the generator terminals than expected, the AVR signals the VSC to activate more coils on the exciter stator to increase electricity production.
The AVR controls how much voltage is applied to the exciter stator by using two circuits. One circuit controls the amount of voltage applied to the exciter stator when the engine is not running (off-cycle voltage). The other circuit controls the amount of voltage applied to the exciter stator while the engine is running (on-cycle voltage).
When the engine is off, no voltage is applied to the exciter stator because the main field coil is not energized. However, some voltage may be present on the output of the regulator due to stored charge on internal capacitors. This voltage comes from the battery and is normally around 12 volts. It can only source a small amount of current so it isn't enough to run anything else but the AVR itself. The AVR uses this voltage to keep its internal components alive so it can control the voltage applied to the exciter stator when the engine starts up again.
The exciter output is controlled by adjusting the exciter's field current. The exiter output then regulates the magnetic field of the rotor, resulting in a constant voltage output. This direct current feeds the rotor through slip rings. The exciters in current generators are static. That is, they do not rotate with the generator.
The stator of an exciter is usually made up of multiple strands of wire that are wound around iron cores. These wires are connected to terminals on the end of the generator case. When current is applied to these terminals, a magnetic field is created by the windings of the stator. This magnetic field causes the aluminum rotor to spin, providing power to anything that uses electricity: lights, heaters, fans, and so on. Excited-mode transformers are used instead when high voltages need to be brought down to residential electrical systems.
Excited mode operation allows for smaller, more efficient generators because there is no mechanical connection between rotor and stator. This means that there is no need for any kind of drive mechanism such as a belt or gearbox to connect them together. An excited-mode generator will always produce power as long as current is being applied to its terminals, even if some other part of the circuit is broken. This makes them very safe generators to use since they will continue to supply power even if something goes wrong with the machine body.
An exciter is a tiny generator installed on the same shaft as the main generator that generates direct current (DC) power for the main generator field winding. This reduces the voltage of the main generator's field coil when electric power is not being drawn from the main generator, thus preventing excessive magnetic flux in the main generator. This also reduces the size of the field coil required for the main generator, reducing its mass and cost. The exciter coil can be either an aluminum or steel wire wrapped around the outside of the main generator's shaft or placed within the hub of a gear attached to the shaft.
Generators used in aircraft usually have two exciters: one drives a dynamo that produces electricity for use by the aircraft, and the other provides extra torque for starting the engine. Generators used in boats usually have only one exciter because they are normally driven by a motor which can start their engines automatically if needed. Generators used in industrial applications may have many more than two exciters because they need much less DC voltage to run machinery than do household generators. For example, a commercial generator used in a factory might have eight exciters that each produce 120 volts at 40 Hz, for 480 volts and 10 kilohours of energy per day.
Previously, the exciter was a tiny DC generator that was connected to the same shaft as the rotor. As a result, as the rotor turns, this exciter generates power for the magnetic. This is how exciters have always worked.
Today, electric motors are used instead. They work on the same principle as the old exciter, but they use electromagnets rather than permanent magnets. Thus, electric motors can generate electricity too, and there are two ways this can be done: automatically or manually. Automatic generation means that the motor will continue to rotate even when not being driven, while manual generation requires that you stop the motor by either removing the power or by changing its direction. In other words, automatic generation allows the motor to function as a generator too.
So, an exciter is an electrical device that produces a continuous current without any external force being applied to it. It works on the same principle as a motor but uses a generator instead. Therefore, an exciter can also generate electricity automatically if it's a synchronous machine. Exciters are often used in combination with inverters to provide continuous power for loads such as lighting and heating systems during outages. They can also be used as standalone devices for emergency power supply.
The word "exciter" comes from the Latin excipere meaning to jump out.
Exciter Static The exciters in current generators are static. The electromagnet receives DC electricity from the main generator output. A series of high-power thyristors correct the alternating current to generate a direct current that flows into the rotor through slip rings. This type of exciter is used on large generators where space is limited and speed regulation is not required.
An example of an exciter used with a generator can be found in an electric power station where several hundred thousand watts are needed for operation of some large industrial plants or pumping stations. The generator will have a capacity of at least 100 kilowatts, but it may be as high as 400 kilowatts or more. It would normally be driven by a diesel engine or turbine, but it can also be powered by an electric motor driving a dynamo if control of voltage and frequency is necessary.
The generator itself consists of a steel housing within which is mounted a laminated iron core upon which is wound the electrical winding. The armature terminals are attached to this winding, and the field is supplied from a separate coil outside the case. An exciter has an additional set of windings called the "exciting coils" which are connected to the positive terminal of the D.C. supply bus. These exciting coils are part of the magnetic circuit which produces a magnetic field when current is passed through them. This magnetic field causes the armature to rotate.