Short circuitA short circuit (sometimes abbreviated to short or s/c) is an electrical circuit that allows a current to travel along an unintended path with no or very low electrical impedance. This results in an excessive current flowing through the circuit. The opposite of a short circuit is an open circuit, which is an infinite resistance (or very high impedance) between two nodes. A short circuit is an abnormal connection between two nodes of an electric circuit intended to be at different voltages.
AlstomAlstom is a French multinational rolling stock manufacturer which operates worldwide in rail transport markets. It is active in the fields of passenger transportation, signaling, and locomotives, producing high-speed, suburban, regional and urban trains along with trams. The company and its name (originally spelled Alsthom) was formed by a merger between the electric engineering division of Société Alsacienne de Constructions Mécaniques (Als) and Compagnie Française Thomson-Houston (thom) in 1928.
AutorackAn autorack, also known as an auto carrier (also car transporter outside the US), is a specialized piece of railroad rolling stock used to transport automobiles and light trucks. Autoracks are used to transport new vehicles from factories to automotive distributors, and to transport passengers' vehicles in car shuttles and motorail services, such as Amtrak's Auto Train route. In the early 20th century, when automobiles were still new technology, their production levels were low enough that they could be shipped in sufficient quantities in boxcars.
Lightning arresterA lightning arrester (alternative spelling lightning arrestor) (also called lightning isolator) is a device, essentially an air gap between an electric wire and ground, used on electric power transmission and telecommunication systems to protect the insulation and conductors of the system from the damaging effects of lightning. The typical lightning arrester has a high-voltage terminal and a ground terminal. When a lightning surge (or switching surge, which is very similar) travels along the power line to the arrester, the current from the surge is diverted through the arrester, in most cases to earth.
East Coast Main LineThe East Coast Main Line (ECML) is a electrified railway between its southern terminus at London King's Cross station and via , , , , and Newcastle. The line is a key transport artery on the eastern side of Great Britain running broadly parallel to the A1 road. The main line acts as a 'spine' for several diverging branches, serving destinations such as Cambridge, , , and , all with direct services to London. In addition, a few ECML services extend beyond Edinburgh to serve , although the principal London-Glasgow route is the West Coast Main Line (WCML).
Variable-frequency driveA variable-frequency drive (VFD, or adjustable-frequency drives, adjustable-speed drives), variable-speed drives, AC drives, micro drives, inverter drives, or drives) is a type of AC motor drive (system incorporating a motor) that controls speed and torque by varying the frequency of the input electricity. Depending on its topology, it controls the associated voltage or current variation. VFDs are used in applications ranging from small appliances to large compressors.
Electrical resistivity and conductivityElectrical resistivity (also called volume resistivity or specific electrical resistance) is a fundamental specific property of a material that measures its electrical resistance or how strongly it resists electric current. A low resistivity indicates a material that readily allows electric current. Resistivity is commonly represented by the Greek letter ρ (rho). The SI unit of electrical resistivity is the ohm-metre (Ω⋅m).
Indian RailwaysIndian Railways (IR) is a statutory body under the ownership of the Ministry of Railways, Government of India that operates India's national railway system. It manages the fourth largest national railway system in the world by size, with a total route length of , running track length of and track length of . of all the gauge routes are electrified with 25 kV 50 Hz AC electric traction . In 2020, Indian Railways carried 808.6 crore (8.086 billion) passengers and in 2022, Railways transported 1418.
Motor–generatorA motor–generator (an M–G set) is a device for converting electrical power to another form. Motor–generator sets are used to convert frequency, voltage, or phase of power. They may also be used to isolate electrical loads from the electrical power supply line. Large motor–generators were widely used to convert industrial amounts of power while smaller motor–generators (such as the one shown in the picture) were used to convert battery power to higher DC voltages.
Rotating magnetic fieldA rotating magnetic field is the resultant magnetic field produced by a system of coils symmetrically placed and supplied with polyphase currents. A rotating magnetic field can be produced by a poly-phase (two or more phases) current or by a single phase current provided that, in the latter case, two field windings are supplied and are so designed that the two resulting magnetic fields generated thereby are out of phase. Rotating magnetic fields are often utilized for electromechanical applications, such as induction motors, electric generators and induction regulators.
