Электропоезда Реферат

Keywords: electric train, electric locomotive, freight train, mobility, transportation, DC system, railway, electrical equipment, AC locomotive, electricity.

Summary includes material of the basic part 18 787 symbols (11 pages), the list of literature – 13 sources.

The work purpose – look through the literature and highlight the development and use of electric trains.

The electric train is a kind of motorcar rolling stock that receives energy fr om the external contact main by means of pantograph.

Electric trains are widely used in suburban communications. Unlike other types of trains, they can quickly accelerate on short distances between stations, create a low noise level and do not pollute the environment, which is very important in densely populated areas. In addition, electric trains are used in high-speed passenger traffic.

The main feature of AC trains in comparison with DC trains is the use on each motor car of a semiconductor rectifier unit that converts a single-phase alternating current of an industrial frequency into a constant frequency.

Besides the railway, electric trains are used in the metro, as well as on monorail transport.

Electric trains are the most есоnomical to operate, if traffic is heavy enough to repay electrification of the railway. Where trains run less frequently over long distances the cost of electrification is prohibitive. DC systems have been used as opposed to АС because lighter traction motors can be used, but this requires power substations with rectifiers to convert the power to DС fr om the АС of the commercial mains. The latest development of electric trains has been the installation of rectifiers in the cars themselves and the use of the same АС frequency as the commercial mains, which means that fewer substations are necessary.

Mobility is a central aspect of our lives and activities. Whether we are commuting to work, travelling for business or taking a vacation, we depend on a reliable and affordable means of locomotion. Furthermore, transportation does not just affect us as individuals: The mechanized movement of goods has permitted the concentration of industry and hence modern manufacturing methods. Similarly, the existence of large cities depends on the ability reliably and continuously supply them with food and other necessities.

An electric locomotive is a type of train that is powered by electricity. This source of electricity usually comes from an external area such as a third rail, a battery, or overhead electrical lines. Locomotives that also include a diesel or gas motor are classified as diesel-electric locomotives.

Today, the electric locomotive is quite popular throughout the globe. Many countries in Europe still rely upon the electric locomotive, and many commuter rails within the United States are powered by electricity. The main difference between the original electric trains and the trains that can be seen today is the speed at which today's train travel.

Electric trains are the most есоnomical to operate, if traffic is heavy enough to repay electrification of the railway. Wh ere trains run less frequently over long distances the cost of electrification is prohibitive. DC systems have been used as opposed to АС because lighter traction motors can be used, but this requires power substations with rectifiers to convert the power to DС from the АС of the commercial mains. The latest development of electric trains has been the installation of rectifiers in the cars themselves and the use of the same АС frequency as the commercial mains, which means that fewer substations are necessary.

The first known electric locomotive was built by a Scotsman, Robert Davidson of Aberdeen in 1837 and was powered by galvanic cells batteries. Davidson later built a larger locomotive named Galvani, which was exhibited at the Royal Scottish Society of Arts Exhibition in 1841. It was tested on the Edinburgh and Glasgow Railway in September of the following year but the limited electric power available from batteries prevented its general use. Werner von Siemens at Berlin presented the first electric passenger train in 1879. A 2.2 kW motor drove the locomotive and the train, consisting of the locomotive and three cars, reached a maximum speed of 13 km/h. During four months, the train carried 90,000 passengers on a 300 meters long circular track. The electricity was supplied through a third, insulated rail situated between the tracks. A stationary dynamo nearby provided the electricity. The world's first electric tramline opened in Lichterfelde near Berlin, Germany, in 1881. Werner von Siemens built it. In Britain, Volk's electric railway was opened in 1883 in Brighton. In the US, electric trolleys were pioneered in 1888 on the Richmond Union Passenger Railway, using equipment designed by Frank J. Sprague.

Much of the early development of electric locomotion was driven by the increasing use of tunnels, particularly in urban areas. Smoke from steam locomotives was noxious and municipalities were increasingly inclined to prohibit their use within their limits. Thus the first successful working, the City and South London Railway underground line in the UK, was prompted by a clause in its enabling act prohibiting use of steam power. This line opened in 1890, using electric locomotives built by Mather and Platt. Electricity quickly became the power supply of choice for subways, abetted by the Sprague's invention of multiple-unit train control in 1897. Surface and elevated rapid transit systems generally used steam until forced to convert by ordinance.

The first use of electrification on a mainline was on a four-mile stretch of the Baltimore Belt Line of the Baltimore and Ohio Railroad (B&O) in 1895. This track

The electric freight train try to replace the diesel truck on a national scale. Few people realize that the implications of doing this would truly be a game changer. The electric train has amazing efficiency and versatility. The ultra – low rolling resistance of steel wheels on steel rails, combined with the high efficiency of the electric motor, allow electric trains to be up to 3 times as efficient as diesels.

They can offer a fuel economy of up to 1500 ton-miles per gallon equivalent. Trains equipped with regenerative braking can also frugally feed electricity back into the grid with minimal losses – a train descending a mountain, for example, can generate enough energy in this manner to almost pull another train up that mountain.

Unlike a diesel, the electric can get its propulsive power from many sources, most importantly clean and renewable sources. It offers clean operation in cities, reduces smog, and generates no emissions at the point of use.

Such a system would be enormously expensive to build, but it would be one of the best investments. It would start saving us vast amounts of money and over the course of its operational life; it would pay for itself many times over. These savings could then be passed on to the average American, which would put a noticeable amount of money back into people’s pockets, and help stimulate the economy. This would be a very direct, and effective, type of economic stimulus.

Think of a gallon of milk or a head of lettuce shipped from California to the East Coast for example. A considerable portion of its price is just the fuel cost needed to transport it across this long distance. You see this reflected in the price of food every time oil prices spike. Transporting food via electric freight trains could potentially reduce this fuel cost by 70%, and considerably reduce the overall price of food. The savings could then be passed right back on to the people.

Millions of our working class and lower to middle-income families would benefit from this the most. Not just food could be shipped this way, but

Electric locomotive is a locomotive driven by traction motors that may receive their power from a contact system or, less often, from both a contact system and storage batteries that are mounted in the locomotive. In the latter case, the locomotive may be termed a contact-storage-battery locomotive. Other electric locomotives are powered by storage batteries alone and are called storage-battery locomotives.

According to the type of duty performed, electric locomotives may be classified as switching, industrial, mining, and main line locomotives. Main-line locomotives may haul freight, passengers, or both. Electric locomotives may use direct current, alternating current, or a combination of the two. In order to increase hauling capacity and to improve the turnaround cycle, several electric locomotives controlled from one cab may be used at one time.

In addition to the current systems mentioned above, electric locomotives abroad use older systems, such as 1.5-kV direct current or single-phase alternating current at a voltage of 11–16 kV, the frequencies employed being 16 2/3 Hz and 25 Hz. For straight-through express service in Western European countries that have differing current systems (such countries include France, Belgium, and the Federal Republic of Germany), passenger locomotives use one of four supply systems: 1.5-kV direct current, 3-kV direct current, 25-kV single-phase alternating current at 50 Hz, and 15-kV alternating current at 16 2/3 Hz.

An electric locomotive consists of mechanical components and electrical and pneumatic equipment. The mechanical components include the body (in which most of the equipment is located), the running gear, and the automatic coupling. The locomotive’s all-metal body usually rests on two- or three-axle trucks, which consist of welded, cast, or bar frames that are made of steel and in which the wheel pairs and journal boxes are mounted. The trucks have spring suspension, a brake lever gear, and traction drive.

Electric locomotives are locomotives that are completely powered by electricity. Electric locomotives can be faster than other types of locomotives, but are less contained since they rely on connections to a power-grid for energy. In other words, electric locomotives do not have their fuel source on-board. This often makes them more expensive to build than diesel locomotives.

This type of locomotive is often preferred over diesel locomotives for commuter trains, because they often have better acceleration, are usually quieter, and do not produce any steam or exhaust like steam and diesel locomotives.

The first electrics date back to 1879 when Werner Von Siemens successfully demonstrated the technology on a small railway in Berlin, Germany.

Electric locomotives define efficiency. Even today, no other type can match their low operating costs, high tractive efforts, and swift acceleration. However, they do carry a substantial downside; the implementation capital is so high railroads find the justification to do so difficult. This sticking point has caused electrification to remain elusive more than a century after it was first employed despite talk it would one day reign supreme.

It has been a long time since train velocities first surpassed the 100 km per hour lim it and they are now approaching 200 km per hour and even higher velocities in some countries. Is it possible to increase the speed with the help of the traditional wheel at the present stage in the development of transport facilities? Scientists and engineers in various countries have concluded that a new leap in velocity is possible only if the wheel is replaced with an air or magnetic cushion.

The future trains must be ecologically clean and noiseless. It has been estimated that the cost of high-speed ground transport will be recouped three times faster than with the railways.