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A railway electrification system is a way of supplying electric power to electric locomotives or multiple units. An electric multiple unit pulling into Tile Hill station on the West Coast Main Line in Coventry, England. ...
An electric multiple unit pulling into Tile Hill station on the West Coast Main Line in Coventry, England. ...
For alternative meanings see: Coventry (disambiguation) Coventry is a city and metropolitan borough in the West Midlands of England. ...
Lightning strikes during a night-time thunderstorm. ...
East German E 18 electric locomotives of the Deutsche Reichsbahn An electric locomotive is a locomotive powered by electric motors which draws current from an overhead wire, a third rail, or an on-board storage device such as a battery or a flywheel energy storage system. ...
A classic Belgian multiple unit of type 74 A multiple unit is a passenger train whose carriages have their own motors, either diesel (DMUs) or electric (EMUs), and do not need to be hauled by a locomotive. ...
Such systems can be classified by:
Third rail at the West Falls Church Metro stop in the Washington, D.C. area, electrified to 750 volts. ...
An electric multiple unit pulling into Tile Hill station; Coventry, England. ...
Direct current (DC or continuous current) is the continuous flow of electricity through a conductor such as a wire from high to low potential. ...
It has been suggested that this article or section be merged with AC power. ...
This article may be too technical for most readers to understand. ...
Sine waves of various frequencies; the lower waves have higher frequencies than those above. ...
The generation of AC electric power is commonly three phase, in which the waveforms of three supply conductors are offset from one another by 120°. These three conductors are commonly housed in a single conduit (e. ...
Three-phase power transformer which is the sole transfer point for electricity to a suburban shopping mall in Canada. ...
Direct current
 Third rail in Amsterdam Metro Early electric systems used relatively low-voltage DC. Electric motors were fed directly from mains, and were controlled by using a combination of resistors and relays that connected the motors in parallel or series. Image File history File links en Third rail at the Amsterdam Metro (station Zuid / WTC) de Stromschiene der Amsterdamer Metro (station Zuid / WTC) nl Derde rail te Amsterdam Zuid/WTC by LennartBolks File links The following pages link to this file: Railway electrification system ...
Image File history File links en Third rail at the Amsterdam Metro (station Zuid / WTC) de Stromschiene der Amsterdamer Metro (station Zuid / WTC) nl Derde rail te Amsterdam Zuid/WTC by LennartBolks File links The following pages link to this file: Railway electrification system ...
DC or dc may stand for: Axiom of dependent choice, in set theory (mathematics) Da capo, a musical term Dawsons Creek Democrazia Cristiana, a political party in Italy Destinys Child Detective Conan a. ...
Electric motors of various sizes. ...
Resistor symbols A resistor is a two-terminal electrical or electronic component that passes a current that is proportional to the potential difference between its terminals in accordance with Ohms law. ...
Relay is also the name of a series of medium-altitude satellites; the first of which was launched in 1962. ...
Left: Series / Right: Parallel Arrows indicate direction of current flow. ...
Left: Series / Right: Parallel Arrows indicate direction of current flow. ...
The common voltages are 600 V and 750 V for trams and metros, and 1500 V and 3000 V for railways. In the past, Rotary converters or mercury arc rectifiers were used to convert utility (mains) AC power to the required DC voltage. Today, this is usually done by semiconductor rectifiers. A modern tram in the Töölö district of Helsinki, Finland Volkswagen Cargo-Tram in Dresden. ...
This page refers to urban rail mass transit systems. ...
Rotary Converter refers to a class of electrical machinery that was used to convert one form of electrical power into another form. ...
A mercury arc valve is a type of electrical rectifier which converts alternating current into direct current. ...
It has been suggested that this article or section be merged with AC power. ...
DC or dc may stand for: Axiom of dependent choice, in set theory (mathematics) Da capo, a musical term Dawsons Creek Democrazia Cristiana, a political party in Italy Destinys Child Detective Conan a. ...
Derka semiconductor is a material with an electrical conductance that is intermediate between that of an insulator and a conductor. ...
It has been suggested that this article or section be merged with rectification (electricity). ...
The DC system is quite simple, but requires thick wires and short distances between feeder stations; additionally, there are significant resistive losses. Electrical resistance is a measure of the degree to which an electrical component opposes the passage of current. ...
Auxiliary machinery, such as fans and compressors, are also powered by motors fed directly from mains. Consequently, these motors are often unusually bulky. Household Electric Fan A fan has two purposes – to move air for creature comfort or for ventilation and to move air or gas from one location to another for industrial purposes. ...
Compressor has several meanings: A gas compressor is a mechanical device that takes in a gas and increases its pressure by squeezing a volume of it into a smaller volume. ...
The 1500 V DC system is used in The Netherlands, Japan, parts of Australia and partially in France. In the United States, 1500 V DC is used in the Chicago area on the Metra (formerly Illinois Central) Electric district and the Chicago, South Shore and South Bend interurban streetcar line. The Netherlands (Dutch: Nederland) is the European part of the Kingdom of the Netherlands (Dutch: Koninkrijk der Nederlanden). ...
Chicago (officially named the City of Chicago) is the third largest city in the United States (after New York City and Los Angeles), with an official population of 2,896,016, as of the 2000 census. ...
Metra system schematic Metra (officially known as the Northeastern Illinois Regional Commuter Railroad Corporation) is Chicagolands commuter rail system, serving over 200 stations on eleven lines across the Regional Transportation Authoritys (RTAs) six-county service area. ...
The Illinois Central (AAR reporting mark IC) was a railroad carrier in the central United States, with its primary routes from Chicago to New Orleans and Sioux Falls. ...
The Chicago South Shore & South Bend Railroad (CSS&SB, reporting mark CSS) (more commonly known as the South Shore Line) was an electric-powered interurban passenger railroad which operated between downtown Chicago, Illinois and suburban areas along the south shore of Lake Michigan in Illinois and northern Indiana. ...
Interurban was the name used to describe a streetcar line connecting urban areas, primarily during the early 1900s. ...
In the United Kingdom, 1500 V DC was used in 1954 for electrifying the trans-Pennine route (now closed) through the Woodhead Tunnel; the system used regenerative braking, allowing for transfer of energy between up and down trains on the steep approach-inclines to the tunnel. The only UK system now using this voltage is the Tyne and Wear Metro. The western portals of the Woodhead Tunnels in 2004, from the former Woodhead Station. ...
The Tyne and Wear Metro is a light rail metro system in and around Newcastle, in the Tyne and Wear county of north-east England. ...
The 3000 V DC system is used in Belgium, Italy, Poland, the northern Czech Republic, Slovakia, former Yugoslavia and in the former Soviet Union. 3000 V DC was also formerly used by the Delaware, Lackawanna & Western Railroad (now NJ Transit, and converted to 25 kV AC). The Socialist Federal Republic of Yugoslavia was the Yugoslav state that existed from 1945 to 1992. ...
Delaware, Lackawanna and Western Railroad External links DL&W pages by the Erie Lackawanna Historical Society Employees Thomas Patrick Norton 1906 to 1960, Hoboken Terminus, Yardmaster Categories: Stub | Delaware, Lackawanna and Western Railroad ...
New Jersey Transit Arrow III at West Windsor, NJ Hudson-Bergen Light Rail vehicle at 2nd Street station New Jersey Transit (NJ Transit) is a statewide public transportation system serving the U.S. state of New Jersey. ...
Note that voltages such as 1500 V DC are nominal voltage which fluctuate up and down from say 1300 V to 1800 V depending on:
- number of trains drawing current,
- distance from substations.
Note also that the common voltages are simple multiples of each other: - 1500VDC = 2 x 750VDC
- 3000VDC = 2 x 1500VDC
- 1200VDC = 2 x 600VDC
Third Rail Most electrification systems use overhead wires, but third rail is an option for low voltages systems up to about 1200V. While use of a third-rail does not imply the use of direct current, in practice, systems using third rail have all used dc because it can carry 41% more power than an ac system operating at the same peak voltage. Third rail is more compact than overhead wires and can be used in smaller diameter tunnels, an important factor for subway systems.
Third rail systems can be designed to use top contact, side contact, or bottom contact. Top contact is less safe as the live rail is exposed to people treading on the rail unless an insulating hood of some sort is provided. Side and bottom contact third rail can easily have safety shields incorporated, carried bythe rail itself. Uncovered top contact third rails are also vulnerable to disruption caused by ice and snow, and possibly fallen leaves.
Since third rail and DC systems are limited to relatively low voltages, this can limit the size and speed of trains and the amount of air-conditioning the trains can provide; this may be a factor favoring overhead wires and high voltage AC even for urban usage.
Low-frequency alternating current Common commutating electric motors can also be fed alternating current ( universal motor), because reversing current in both stator and rotor does not change the direction of torque. However, inductance of the windings makes large moters impractical at standard AC distribution frequencies. Many European countries, including Germany, Austria, Switzerland, Norway, and Sweden have standardised on 15 kV 16-2/3 Hz (one-third the normal mains frequency) single-phase alternating current (earlier, 6 kV and 7.5 kV systems have been in use). In the United States (with its 60 Hz distribution system), 25 Hz (an older, now-obsolete standard mains frequency) is used at 11 kV between Washington, DC and New York City. A 12.5 kV 25 Hz section between New York City and New Haven, Connecticut was converted to 60 Hz in the last third of the 20th century. A commutator is an electrical switch that periodically reverses the current in an electric motor or electrical generator. ...
Electric motors of various sizes. ...
The stator is the fixed part of a rotating machine. ...
R0t0r is from efnet ...
The concept of torque in physics, also called moment or couple, originated with the work of Archimedes on levers. ...
Inductance is a physical characteristic of any system of conductors (including an inductor), which creates a voltage proportional to the instantaneous rate of change in current flowing through it. ...
Aerial photo (looking NW) of the Washington Monument and the White House in Washington, DC. Washington, D.C., officially the District of Columbia (also known as D.C.; Washington; the Nations Capital; the District; and, historically, the Federal City) is the capital city and administrative district of the United...
Midtown Manhattan, looking north from the Empire State Building, 2005 New York City (officially named the City of New York) is the most populous city in the United States, the most densely populated major city in North America, and is at the center of international finance, politics, entertainment, and culture. ...
City nickname: The Elm City Location in the state of Connecticut Founded April 24, 1638 County New Haven County Mayor John DeStefano, Jr. ...
Motors are fed through a switching transformer that allows voltage change, so no resistors are required. Auxiliary machinery is driven by low voltage commutating motors, powered from a separate winding of the main transformer, and are reasonably small. Transformers - Typical electrical configurations. ...
The unusual frequency means that electricity has to be converted from utility power by motor-generators or static inverters at the feeding substations, or generated at altogether separate electric power stations. A motor-generator (an M-G set) is a device for converting one form of electrical power to another form. ...
A static inverter station is the terminal equipment for a high voltage direct current transmission line, in which direct current is converted to three-phase alternating current, and, usually, the reverse. ...
Standard frequency alternating current The first attempts to use standard-frequency (50 Hz) single-phase alternating current were made in Hungary in 1930s. However, only in 1950s did this system become widespread. // Events and trends The 1930s were spent struggling for a solution to the global depression. ...
// Events and trends The 1950s in Western society was marked with a sharp rise in the economy for the first time in almost 30 years and return to the 1920s-type consumer society built on credit and boom-times, as well as the height of the baby-boom from returning...
Today, some locomotives in this system use a transformer and rectifier that provide low-voltage pulsating DC current to motors. Speed is controlled by switching windings in the transformer. More sophisticated locomotives use thyristor or IGBT transistor circuitry to generate chopped or even variable-frequency ac that is then directly consumed by ac traction motors. A locomotive is a railway vehicle that provides the motive power for a train, and has no payload capacity of its own; its sole purpose is to move the train along the tracks. ...
Transformers - Typical electrical configurations. ...
It has been suggested that this article or section be merged with rectification (electricity). ...
Pulse-width modulation of a signal or power source involves the modulation of its duty cycle to either convey information over a communications channel or control the amount of power sent to a load. ...
Circuit symbol for a thyristor The thypissor is a solid-state semiconductor device similar to a diode, with an extra terminal which is used to turn it on. ...
The Insulated (or sometimes called Isolated) Gate Bipolar Transistor combines the simple gate drive characteristics of the MOSFET with the high current and low saturation voltage capability of bipolar transistors by combining an isolated gate FET for the control input, and a bipolar power transistor as a switch, in a...
It has been suggested that this article or section be merged with AC power. ...
Traction motor typically refers to those motors that are used to power the driving wheels of a railroad locomotive, electrical multi-unit train (such as a subway or light rail vehicle train), or a tram. ...
This system is quite economical, but it has its drawbacks: the phases of the external power system are loaded unequally, and there is significant electromagnetic interference generated. Radio Frequency Interference (RFI) is electromagnetic radiation which is emitted by electrical circuits carrying rapidly changing signals, as a by-product of their normal operation, and which causes unwanted signals (interference or noise) to be induced in other circuits. ...
The 25 kV 50 Hz single-phase AC system is used in France, Great Britain, Finland, Denmark, the former Soviet Union, the former Yugoslavia, Japan and parts of Australia (namely, all electrification in Queensland and Western Australia), while USA commonly uses 12.5 and 25 kV at 60 Hz. The Socialist Federal Republic of Yugoslavia was the Yugoslav state that existed from 1945 to 1992. ...
QR, formerly known as Queensland Rail and Queensland Railways, is the corporation responsible for the operation and maintenance of the railway system in the State of Queensland, Australia. ...
Motto: Cygnis Insignis (Distinguished by its swans) Nickname: Wildflower State Other Australian states and territories Capital Perth Government Governor Premier Const. ...
Multisystem locomotives Because of the variety of railway electrification systems, which can vary even within a country, trains often have to pass from one system to another. One way this is accomplished is by changing locomotives at the switching stations. These stations have overhead wires that can be switched from one voltage to another, and so the train arrives with one locomotive, and then departs with another. Often however, this is inconvenient and time-consuming.
Another way is to use multisystem locomotives that can operate under several different voltages and current types. In Europe, it is common to use four-system locomotives (DC 1.5 kV, DC 3 kV, AC 15 kV 16-2/3 Hz, AC 25 kV 50 Hz). These locomotives do not have to stop when passing from one electrification system to another.
Eurostar trains through the Channel Tunnel are multisystem because a significant part of the route near London is over the old UK 'third rail' system, and the route into Brussels is electrified at 3000 V DC. Channel Tunnel The British terminal at Cheriton, from the Pilgrims Way The Channel Tunnel, (French: le tunnel sous la Manche; once popularly nicknamed the Chunnel in English) is a 50-km-long rail tunnel beneath the English Channel at the Straits of Dover, connecting Cheriton in Kent, the United Kingdom...
In the United States New Jersey Transit uses multisystem ALP-44 locomotives for its Midtown Direct service into New York. New Jersey Transit Arrow III at West Windsor, NJ Hudson-Bergen Light Rail vehicle at 2nd Street station New Jersey Transit (NJ Transit) is a statewide public transportation system serving the U.S. state of New Jersey. ...
State nickname: Empire State Other U.S. States Capital Albany Largest city New York City Governor George Pataki (R) Official languages None (English is de facto) Area 141,205 km² (27th) - Land 122,409 km² - Water 18,795 km² (13. ...
See also List of current systems for electric rail traction This a list of the voltages, etc. ...
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