Electric generators can transform the energy into an electrical form from a mechanical stage.
FREMONT, CA : There are dozens of essential terms and definitions when developers speak about the power system. For sure, one of the most significant is that any AC power system begins with a source of generation. Electric generators are devices that transform energy into an electrical form from a mechanical structure. The process, referred to as the conversion of electromechanical energy, involves magnetic fields that function as an intermediate medium. From several energy sources, the input to the generating machine can be derived.
In the generation of large-scale electric power, coal can produce steam that drives the machine's shaft. Generally, only about 1/3 of the raw energy (that is, from coal) is converted into mechanical energy for such a thermal process. With efficiency close to 100 percent, the final step of the energy conversion is quite useful.
The governor's job is to regulate the input of mechanical power to the generator. The monitoring is achieved through a feedback loop where the rotor speed is continuously controlled. For example, the intake is insufficient and must be increased if the speed falls behind the synchronous speed. It is achieved by opening the valve to increase the turbogenerator steam volume or hydro generator water flow through the penstock. Compared to other electromagnetic parameters associated with the unit, governors are mechanical systems and typically have substantial time lags (many seconds).
Damper windings (armortisseur windings)
Such windings are unique conducting bars on the rotor surface embedded in notches (the rotor resembles a squirrel-cage-rotor induction machine). During operation, the damper windings offer an extra stabilizing force for the system. The stator field rotates at the same speed as the rotor if the unit is steady, and no currents in the damper windings are caused. When (due to a load disturbance) the speeds of the stator field and the rotor varies, currents are generated in the damper windings in such a way as to prevent the two rates from separating.
Excitation control system
There are quick and powerful modern excitation systems. A feedback loop is required to ensure the machine terminals' voltage is an excitation control device at a fixed level.
A reliable electric power supply ensures the loads are supplied at a constant voltage and frequency. A dedicated power system is one in which, if interrupted, the synchronous machines will return to their original state if there is no net power shift or stabilize without loss of synchronization in a new form.