A voltage generator is a device that converts potential and kinetic energy into electrical energy. This is most commonly achieved by moving a conductor through a magnetic field to build up voltage. The generator operates very similarly to a water pump in which the electric charge is moved into an external circuit much like water is pushed into a pipe. The potential and kinetic energy that begins the process can come from a variety of sources such as steam or wind.
The origins of the concept of a voltage generator comes from the studies of an English physicist named Michael Faraday in 1831. He wrapped coils of insulated wire around an iron ring. When he passed a current through one coil ring, he discovered that the other coil was also induced. Using this concept he constructed an electromagnetic rotary device. This was essentially the first electric motor and worked as the principle opposite of a voltage generator by producing kinetic energy using electrical energy.
In 1832, Hipployte Pixii built an electrical generator for industry. Called the Dynamo, it converted rotating kinetic energy into electricity. This early invention was a direct current (DC) device and needed an additional part not found on modern voltage generators: a commutator. The commutator was designed to alternate the current in the Dynamo. This helps distribute the power throughout the generator to the best location.
A voltage generator is comprised of two different mechanical parts: a rotor and a stator. The rotor is the rotating part of the generator, while the stator is the stationary portion. The electrical components are connected to each of these pieces. The armature is the power-producing component and can be located on either the rotor or the stator. A magnetic field component must be placed on the opposite mechanical part.
Either permanent magnets or field coils can be used on the generator. While magnets create their own electric charge during the process, field coils need to be charged in order to produce power. This is accomplished using smaller generators to excite the coils. In the event of power outage, these field coils need to be stimulated again in a process known as a “black start.”
Voltage generators are a necessary portion of modern industry. Large power plants across the world use potential and kinetic energy converted into electricity. No matter the initial state the potential energy takes, it ultimately is converted using a high voltage generator. Wind, geothermal, nuclear, oil and coal are all converted to an electrical charge.