What is an electrified railway

2024 Author: Howard Calhoun | [email protected]. Last modified: 2023-12-17 10:16

The increase in the volume of transported goods and the intensity of train traffic on the main transport routes has led to the emergence of electrified railways. Such objects are quite difficult to implement technically. Unlike the first electrified railways, modern highways are complex infrastructure facilities from an engineering point of view and perform a number of important tasks for the population and the economy of the state. This article describes the history of the emergence and development of electric railway transport, gives the main technical characteristics and an idea of the substation system and locomotive fleet.

Early history of the electrified railroad

The first electric locomotive in history owes its appearance to the world-famous German inventor and businessmanWerner Siemens. This sample was presented to the whole world at the exhibition of achievements of industry and science in Berlin on May 31, 1879. An electrified railway with a contact network was built especially to demonstrate the capabilities of an electric locomotive. The length of this experimental path was a little over 300 meters. The device, which was demonstrated to the public, can hardly be attributed to locomotives by modern standards. Rather, it was his model. The vehicle weighed only 250 kilograms, had a power of three horsepower and could reach a speed of no more than 7 kilometers per hour. An additional rail was used to supply voltage. The rolling stock consisted of three wagons. In total, they could accommodate no more than 18 people.

This novelty aroused great interest from business representatives. Already in the same 1879, a 2-kilometer road was built to deliver workers and raw materials to the territory of one of the French clothing factories.

Thus, initially electric rail transport was used in industrial enterprises and for the transport of passengers within the city (tram lines). However, after only a few years, traffic on the route Likterfelzh - Berlin opens. The red ribbon cutting ceremony took place on May 16, 1881.

Electrification of railways in Soviet Russia and the USSR

In tsarist Russia, due attention was not paid to the development of electric railwaytransport. Tram lines were built in major cities. The main railway lines connecting the largest cities of the empire were not electrified. In 1880, a scientist named Pirotsky managed to move a heavy railway car from its place with the help of electricity. But this experiment did not interest anyone. Only with the advent of Soviet power did a discussion of the prospects for the development of this industry begin. At that time, electric locomotives were actively introduced in most countries of the world. Electrified railways were simply vital to develop. Already in 1921, a strategic plan for the electrification of all territories of the country was approved. In accordance with the announced plan, the contact network of electrified railways was to stretch over the most important highways that connect large industrial regions and cities.

Already in 1926, a twenty-kilometer section of the road with a contact electrical network was put into operation. It connected the capital of the Azerbaijan SSR with the oil fields of Surakhani. In this section, a direct current of 1200 volts was used. 1929 was marked by the solemn launch of the first electric train from Moscow to Mytishchi. These events marked, without exaggeration, the beginning of a new era in the history of the development and industrialization of our country.

After a few decades, alternating current comes to replace the constant. On December 19, 1955, the Mikhailov-Ozherelye section of the railway was put into operation. Its length is 85 kilometers. Locomotives in this section were powered by alternating currentindustrial frequency (50 Hertz) with a voltage of 22,000 volts. A year later, contact power lines were extended to Pavelets 1 station. Thus, the total length of this route was about 140 kilometers.

General information about the Russian railway

The railway of the Russian Federation is a huge organism. It is divided into 17 separate departments. According to the latest data, the total length of operated roads reaches 86 thousand kilometers. At the same time, the length of electrified railways is slightly more than half of this value (51%). Not every country can boast of such an indicator. It should be noted that the share of electrified railways in Russia accounts for more than eighty percent of the total freight and passenger traffic. This is quite understandable. After all, first of all, highly loaded transport highways are electrified. Moreover, electrifying roads with little traffic is not economically viable and will incur losses. Such indicators can only be achieved through the united work of the entire people. At the same time, it is necessary to have a very developed mechanical engineering and instrument making, a developed electrical industry and scientific potential.

The total length of the electrified sections of the railway in our country is approximately 43 thousand kilometers. At the same time, 18 thousand kilometers are powered by direct current. Accordingly, the remaining 25 thousand kilometers run on alternating current.

Electrification benefits

Against the backdrop of a huge number of advantages and disadvantages of electrified railways, all the disadvantages are simply lost. Firstly, the amount of harmful emissions is much less than from diesel locomotives. This has a positive effect on the environment. Secondly, the efficiency of an electric locomotive is much higher. Thus, the cost of transporting goods is reduced.

Among other things, electrified railways solve the problem of providing electricity to industrial enterprises and settlements that are located along the railway line and not far from it. According to statistics for 1975, more than half of the total electricity of the contact network of the railways of the USSR was spent on the power supply of these facilities that are not included in the transport infrastructure.

And this is not an exhaustive list of benefits. It should also be said that the electrified railway has a much greater capacity, reliability, and allows you to create comfortable conditions for the transportation of passengers.

Traction substations: general concepts

If we simplify to a minimum, then the traction substation can be given the following definition: an installation designed for the distribution and conversion of electricity. In other words, the traction substation is a step-down transformer. If the locomotive runs on direct current, then the substation acts as a rectifier. For networkselectrified roads on alternating current, it is necessary to equip traction substations at a distance of 50 to 80 kilometers throughout the entire section of the track. The transition to direct current requires the construction of substations every 15-20 kilometers. In some exceptional cases, this distance may be reduced to 5 kilometers (on especially busy highways).

The metro uses a special type of traction substations. Devices of this type do not convert AC to DC, but only lower the DC voltage.

Design of blocks of traction substations

Traction substation units are a complex of cells, panels and cabinets. These elements are mounted on frames and connected by a network of wires (both power and control wires).

There are two types of blocks. In some blocks, all elements are mounted on a frame, in others, each element is placed in a sealed container. Blocks of the first type are intended for installation in buildings. Blocks of the second type are installed along the open-air railway line.

Contact network

The contact network is a very complex engineering structure. It includes many elements: the wire itself, the cable (carrier), power transmission poles, rigid and flexible crossbars … Very stringent requirements are imposed on the suspension. If it does not correspond to them, then the current will be taken intermittently, which will not allow the locomotive to operate in normal mode and may lead to an emergency. Strictly regulated height and tension forcewires, maximum allowable curvature, spans and so on. In our country, locomotives operate both on direct current and on alternating current. This, of course, somewhat complicates the power supply of electrified railways. Each of these systems has its own advantages and disadvantages.

Construction of a simple catenary

In fact, a simple contact suspension is a wire attached to supports. The distance between these supports is usually 30-40 meters. Such a design is acceptable only on sections of roads where high-speed traffic is not allowed (bridges, tunnels), as well as in trolleybus and tram power lines.

Advantages of direct current contact network

Compared to the contact network on alternating current, the contact network on direct current has a number of advantages. Among them, it is especially necessary to cancel the possibility of using it for locomotives with a relatively simple design and low weight. In addition, in such systems there is no influence of the voltage applied to the contact network. The most important advantage is the higher level of operational safety compared to AC systems.

Disadvantages of DC contact network

The main disadvantage of such power supply systems for electrified railways is their high cost. After all, their construction requires a more complex and expensive suspension. Copper pull wirehas a much larger cross section, which also significantly increases the cost of the project. An important disadvantage is the rather insignificant distance between traction substations on electrified railways compared to contact networks on alternating current. On average, it ranges from 15 (in areas with maximum train traffic) to 20 kilometers. Among other things, direct currents cause the emergence of so-called stray currents, which lead to the emergence and rapid corrosion destruction of steel structures and supports.

Training requirements for personnel servicing power supply systems

Before a worker is allowed to repair and maintain transmission lines of an electrified railway, he must undergo special training. And this applies not only to people who work directly with the electrical part, but also to locksmiths and installers who service the entire structure of transmission lines and their supports. All personnel are required to pass a knowledge test and confirm their qualification level.

Conclusion

The advent of electrified railways marked the rapid growth of industry due to the intensification of traffic and an increase in freight turnover. It became possible to significantly increase the mass of goods transported by one locomotive.

In addition, it solved a number of problems. So, conventional diesel locomotives often fail at low temperatures. The electric locomotive works reliably in all weather conditions. This, in turn, created the prerequisites for the active development of the northern and Far Eastern regions of our country.