What is electric generator

Electric Generator, also called dynamo, any machine that converts energy to electricity for transmission and distribution over power lines to domestic, commercial, and industrial customers. Generators also produce the electric power required for automobiles, aircraft, ships, and trains. The mechanical power for an electrical generator is typically obtained from a shaft and is adequate to the shaft torque multiplied by the rotational, or angular, velocity. The mechanical power may come from a number of sources: hydraulic turbines at dams or waterfalls; wind turbines; steam turbines using steam produced with heat from the combustion of fossil fuels or from nuclear fission; gas turbines burning gas directly in the turbine; or gasoline and diesel engines. The construction and therefore the speed of the generator may vary considerably counting on the characteristics of the mechanical first cause. Nearly all generators wont to supply electrical power networks generate AC, which reverses polarity at a hard and fast frequency (usually 50 or 60 cycles, or double reversals, per second). Since variety of generators are connected into an influence network, they need to operate at an equivalent frequency for simultaneous generation. They are therefore referred to as synchronous generators or, in some contexts, alternators. Synchronous Generators A major reason for choosing AC for power networks is that its continual variation with time allows the utilization of transformers. These devices convert electrical power at whatever voltage and current it is generated to high voltage and low current for long-distance transmission and then transform it down to a low voltage suitable for each individual consumer (typically 120 or 240 volts for domestic service). The particular sort of AC used may be a wave, which has the form shown in Figure 1. This has been chosen because it is the only repetitive shape for which two waves displaced from each other in time can be added or subtracted and have the same shape occur as the result. The ideal is then to have all voltages and currents of sine shape. The synchronous generator is meant to supply this shape as accurately as is practical. This will become apparent because the major components and characteristics of such a Generator are described below. Rotor An elementary synchronous generator is shown in cross section in Figure 2. The central shaft of the rotor is coupled to the mechanical first cause. The magnetic flux is produced by conductors, or coils, wound into slots cut within the surface of the cylindrical iron rotor. This set of coils, connected serial, is thus referred to as the sector winding. The position of the field coils is such that the outwardly directed or radial component of the magnetic field produced in the air gap to the stator is approximately sinusoidally distributed around the periphery of the rotor. In the sector density within the air gap is maximum outward at the highest, maximum inward at rock bottom, and 0 at the 2 sides, approximating a sinusoidal distribution. The construction and therefore the speed of the generator may vary considerably counting on the characteristics of the mechanical first cause. Nearly all generators wont to supply electrical power networks generate AC, which reverses polarity at a hard and fast frequency (usually 50 or 60 cycles, or double reversals, per second).