A rotary converter plant is a facility at which

rotary converter A rotary converter is a type of electrical machine which acts as a mechanical rectifier, inverter or frequency converter. Rotary converters were used to convert alternating current (AC) to direct current (DC), or DC to AC power, before the adv ...

s convert one form of electricity to another form of electricity. The installed combinations of motors and generators at a plant determine the possible type(s) of conversion. Such facilities also allow the setting of voltages and frequencies, if appropriate equipment is installed. Rotary converter plants were commonplace in railway electrification before the invention of

mercury arc rectifier Mercury commonly refers to: * Mercury (planet), the nearest planet to the Sun * Mercury (element), a metallic chemical element with the symbol Hg * Mercury (mythology), a Roman god Mercury or The Mercury may also refer to: Companies * Mercury ...

s in the 1920s. At each facility, power from an AC power grid was converted to DC to feed into an

overhead line An overhead line or overhead wire is an electrical cable that is used to transmit electrical energy to electric locomotives, trolleybuses or trams. It is known variously as: * Overhead catenary * Overhead contact system (OCS) * Overhead equipm ...

or a

third rail A third rail, also known as a live rail, electric rail or conductor rail, is a method of providing electric power to a railway locomotive or train, through a semi-continuous rigid conductor placed alongside or between the rails of a railway ...

of a railway. Rotary converter plants were also used for coupling power grids of different frequencies and operation modes. The former Neuhof Substation was an example of the latter. Former machinery transmitters like the Alexanderson alternator were, strictly speaking, rotary converter plants. In spite of modern power

semiconductor A semiconductor is a material which has an electrical conductivity value falling between that of a conductor, such as copper, and an insulator, such as glass. Its resistivity falls as its temperature rises; metals behave in the opposite way. ...

technology, rotary converters are still common for feeding railway systems with AC of a different frequency from that of the main electricity grid. In Europe, this would typically be for

15 kV AC railway electrification Railway electrification systems using at are used on transport railways in Germany, Austria, Switzerland, Sweden, and Norway. The high voltage enables high power transmission with the lower frequency reducing the losses of the traction mo ...

References

See also