Electrified railways. Notes on railway transport: about the electrification of railways in the USSR and the types of currents in contact networks - yelkz

One of the features of railway transport in Russia is the high proportion of electrified roads. In terms of the length of electrified highways at the end of 2014, Russia ranks 1st in the world - 43.4 thousand km (2nd place China - 38.5 thousand km) - somewhere around half of public roads. Well, the fact that many highways are electrified is generally no secret to anyone, but many people are surprised to learn that contact networks use currents of various kinds. Nevertheless, it is a fact: contact networks use either permanent electricity rated voltage 3 kV or alternating single-phase current of industrial frequency 50 Hz rated voltage 25 kV. I'm talking about this myself for a long time I didn’t think about it - I found out when I received the third electrical safety group (working in an office associated with Russian Railways somehow obliged me to delve into and understand). Well, in general, for a long time I took this fact (“there is a constant 3 kV, there is a variable 25 kV / 50 Hz”) for granted - “because this is what has been accepted historically.” But for some time I still wanted to delve into the question and somehow figure out why it was so.

I want to make a reservation right away - I won’t dig very deeply into the physics of power supply, limiting myself to some general phrases and somewhere specifically exaggerating. Sometimes people tell me that I’m simplifying, but experts read and understand that “everything is wrong.” I am aware of this, but the specialists already know what I am writing and thinking about - and they are unlikely to learn anything new for themselves.

So, in fact, we should start with the fact that for the first time the use of electricity as an energy source for traction of trains was demonstrated at an industrial exhibition in Berlin in 1879, where a model of an electric railway was presented. A train consisting of a 2.2 kW locomotive and three carriages, each of which could accommodate up to 6 passengers, moved along a section less than 300 m long at a speed of 7 km/h. The creators of the new type of traction were the famous German scientist, inventor and industrialist Ernst Werner von Siemens (Werner von Siemens, 1816-1892) and engineer Halske. By the beginning of the 20th century, there was no doubt about the effectiveness of electric traction. IN short term Several railway electrification projects have been implemented in various countries. At the first stage, electrification was used in mountainous areas on lines with a heavy profile, with big amount tunnels, as well as in suburban areas, i.e. in those areas where the advantages of electric traction were obvious.

The first electrified railway in the USSR was opened on July 6, 1926 on the Baku - Sabunchi - Surakhani section

Accordingly, there are two main areas of application of electrification: suburban traffic and mountain highways. I would like to talk about suburban traffic (the essence of electric trains) separately, but now it should only be noted that it was suburban railway traffic that was a priority in terms of electrification in the USSR (in Russian Empire We didn’t have time to bring this project to fruition - the first one got in the way World War and revolution), in the USSR they took up this on a grand scale (here the GOELRO plan, of course, greatly contributed) - electric trains began to replace commuter trains with steam traction.

The power supply system was a direct current system with a nominal voltage of 1500 V. The direct current system was chosen because single-phase alternating current would require heavier and more expensive motor cars due to the need to install transformers on them. In addition, DC traction motors, other things being equal, have a higher torque and are more suitable for starting compared to single-phase motors. This is especially important for motor cars operating in suburban areas with a large number stopping points where high acceleration is required when starting off. The voltage of 1500 V was chosen due to the fact that significantly less copper is required for the contact network compared to the 600-800 V system (used for the electrification of tram-trolleybuses). At the same time, it became possible to create reliable electrical equipment for a motor car, which at that time could not be counted on at a voltage of 3000 V (the first commuter lines electrified with a direct current of 3000 V appeared only in 1937, but later all already built lines were transferred to this voltage) .

Electric trains S - the first family of Soviet trains, produced since 1929

In parallel with the development of suburban traffic in 1932-1933. electric traction was introduced on the Khashuri-Zestafoni main railway (63 km) at the difficult Suram pass. Here, unlike Moscow and Baku, electric traction was used for freight and passenger transportation. For the first time, electric locomotives began to operate on the railway lines of the USSR (in fact, according to the place of application, they began to be called “Suram electric locomotives” or “or Suram type electric locomotives”):

electric locomotive S (Suramsky) - the founder of the group of Suram electric locomotives built by the Americans General Electric for the USSR

The main feature of all electric locomotives of the Suram type was the presence of transition platforms at the ends of the body, which, according to the standards that existed at that time, was mandatory for all electric locomotives with electrical equipment for working under CME. The crew part of the locomotive consists of two articulated three-axle bogies (axial formula 0- 3 0 -0 + 0-3 0 -0). Car body with a supporting main frame. Spring suspension is carried out mainly on leaf springs. The suspension of the traction electric motor is support-axial.

electric locomotive S S (Suramsky Soviet) - the first direct current electric locomotive built in the USSR under license from GE

And here we need to make an important note. In contrast to steam locomotives, the engine of which is a steam engine, the next generations of railway transport began to be driven by electric motors: the so-called TEDs (traction electric motors) - for many, by the way, it is not obvious that TEDs are used both in electric locomotives/electric trains and in diesel locomotives (the latter simply power the TEDs with a diesel generator located in the locomotive). So, at the dawn of the electrification of railways, exclusively direct current electric motors were used. This is due to their design features, the ability to regulate speed and torque over a wide range using fairly simple means, the ability to work with overload, etc. Technically speaking, the electromechanical characteristics of DC motors are ideal for traction purposes. The engines are alternating current(asynchronous, synchronous) have such characteristics that without special means of regulation their use for electric traction becomes impossible. Such means of regulation on initial stage There was no electrification yet and therefore, naturally, direct current was used in traction power supply systems. Traction substations were built, the purpose of which is to reduce the alternating voltage of the supply network to the required value and straighten it, i.e. conversion to permanent.

VL19 is the first serial electric locomotive, the design of which was created in the Soviet Union

But the use of a direct current contact network created another problem - the high consumption of copper in the contact network (compared to alternating current), because in order to transmit high power (power is equal to the product of current and voltage) at a constant voltage, it is necessary to provide a large current strength, that is, you need more wire and a larger cross-section (the voltage is constant - you need to lower the resistance).

VL22 M - the first Soviet large-scale electric locomotive and the last representative of Surami locomotives

Back in the late 1920s, when they were just beginning to electrify the Suram Pass, many experts were well aware that in the future, direct current electric traction with a nominal voltage of 3 kV would not allow a rational solution to the issue of increasing the carrying capacity of lines by increasing the weight of trains and their speed. movements. The simplest calculations showed that when driving a train weighing 10,000 tons on a rise of 10 ‰ at a speed of 50 km/h, the traction current of electric locomotives would be more than 6000 A. This would require an increase in the cross-section of the contact wires, as well as a more frequent location of traction substations. After comparing about two hundred options for combinations of the type of current and voltage values, it was decided that the best option is electrification on direct or alternating (50 Hz) current with a voltage of 20 kV. The first system had not been tested anywhere in the world at that time, and the second was, although very little, studied. Therefore, at the first All-Union Conference on Electrification railways it was decided to build a pilot section electrified with alternating current (50 Hz) with a voltage of 20 kV. It was necessary to create an electric locomotive for testing that would reveal the advantages and disadvantages of AC electric locomotives under normal operating conditions.

Electric locomotive OR22 - the first AC electric locomotive in the USSR

In 1938, the electric locomotive OR22 was created (single-phase with a mercury rectifier, 22 - load from wheelsets per rail, in tons). Schematic diagram electric locomotive (transformer-rectifier-TED, that is, with voltage regulation on the low side) turned out to be so successful that it began to be used in the design of the vast majority of Soviet AC electric locomotives. Many other ideas were tested on this model, which were later embodied in later projects, but unfortunately the war intervened. The experimental machine was disassembled, its rectifier was used at a DC traction substation. And they returned to the ideas of AC electric locomotives only in 1954 with the NO (or VL61) series, already at the Novocherkassk Electric Locomotive Plant.

VL61 (until January 1963 - N-O - Novocherkassk Single-phase) - the first Soviet serial AC electric locomotive

The first experimental section Ozherelye - Mikhailov - Pavelets was electrified using alternating current (voltage 20 kV) in 1955-1956. After testing, it was decided to increase the voltage to 25 kV. The results of the operation of the experimental section of electric traction on alternating current Ozherelye - Pavelets of the Moscow Railway made it possible to recommend this alternating current system for widespread implementation on the railways of the USSR (Resolution of the Council of Ministers of the USSR No. 1106 of October 3, 1958). From 1959, 25 kV alternating current began to be introduced on long stretches where electrification was required, but there were no direct current test sites nearby.

Electric locomotive F - AC electric locomotive, built in France by order of the USSR

In 1950-1955 The first, still cautious expansion of the electrification site began. The transition from a voltage of 1500 V to 3000 V began at all suburban nodes, further development of suburban nodes, extension of electrified lines to neighboring regional centers with the introduction of electric locomotive traction for passenger and freight trains. “Islands” of electrification appeared in Riga, Kuibyshev, Western Siberia, and Kyiv. Since 1956 (which) began a new stage of mass electrification of the railways of the USSR, which rapidly brought electric and diesel traction from a 15% share in transportation in 1955 to an 85% share in 1965. Mass electrification was carried out mainly on the already well-proven direct current with a voltage of 3000 V, although somewhere alternating current with a frequency of 50 Hz and a voltage of 25 kV was already beginning to be introduced. In parallel with the development of the network of AC lines, the development of AC rolling stock was carried out. Thus, the first AC electric trains ER7 and ER9 began operation in 1962, and for the Krasnoyarsk Railway in 1959, French F-type electric locomotives were purchased, since the production of Soviet AC electric locomotives (VL60 and VL80) was delayed.

VL60 (before January 1963 - N6O, - Novocherkassk 6-axle Single-phase) - the first Soviet mainline AC electric locomotive launched into large-scale production.

In general, lines that were put into operation earlier were electrified with direct current; later lines were electrified with alternating current. Also in the 90s/2000s, there was a large-scale transfer of a number of lines from direct current to alternating current. The debate about the advantages of the systems has not stopped to this day. At the dawn of the introduction of alternating current, it was believed that this power supply system was more economical, but now there is no clear solution:
- DC rolling stock is one and a half times cheaper
- specific consumption the EPS on a hilly profile, typical for most of our country, is 30% lower.
One way or another, new electrification lines are now being built only on alternating current, and some old ones are also being converted from direct to alternating current. The only case in the history of electrification of Soviet and Russian railways when a section was transferred from alternating current to direct current occurred in 1989 on the Paveletsky direction of the Moscow Railway. After the direct current electrification of the Rybnoye - Uzunovo section, the Ozherelye - Uzunovo section (historically the first alternating current main line) was transferred from alternating current to direct current:

twin brothers: locomotive VL10 (DC) and VL80 (AC)

By the way, now there is a tendency towards the introduction of more reliable and economical asynchronous electric motors (they are installed on the new generation locomotives EP20, ES10, 2TE25A). So in the very distant future, due to the transition to such TEDs, it will be possible to abandon direct current completely. So far, both types of current are being used perfectly:

4ES5K "Ermak" (alternating current) and 3ES4K "Donchak" (direct current)

It remains to clarify the last question. The variety of power supply systems has caused the emergence of connection points (current systems, voltage systems, current frequency systems). At the same time, several options arose for solving the issue of organizing traffic through such points. Three main directions emerged:
1) Equipping the docking station with switches that allow one or another type of current to be supplied to individual sections of the contact network. For example, a train arrives with a DC electric locomotive, then this electric locomotive is uncoupled and goes to a turnaround depot or dead end for locomotive storage. The contact network on this track is switched to alternating current, an alternating current electric locomotive comes here and drives the train further. The disadvantage of this method is that electrification and maintenance of power supply devices become more expensive, and it also requires a change of locomotive and associated additional material, organizational and time costs. At the same time, it takes a significant amount of time not so much to change the electric locomotive as to test the brakes

EP2K (direct current) and behind EP1M (alternating current) at the Uzunovo docking station

2) 2. The use of multi-system rolling stock (in this case, two-system - although in Europe, for example, there are also four-system locomotives). In this case, connecting via the contact network can be done outside the station. This method allows you to pass docking points without stopping (albeit, as a rule, on the coast). The use of dual-system passenger electric locomotives reduces the travel time of passenger trains and does not require changing the locomotive. But the cost of such electric locomotives is higher. Such electric locomotives are also more expensive to operate. In addition, multi-system electric locomotives have more weight (which, however, is of little relevance on the railway, where additional ballasting of locomotives to increase the adhesion weight is not uncommon).

Locomotives of alternating (EP1M) and direct (ChS7) currents in the return depot of Uzunovo station

3) The use of a diesel locomotive insert - leaving between areas with different power supply systems a small traction arm, serviced by diesel locomotives. In practice, it is used on the Kostroma - Galich section with a length of 126 km: in Kostroma direct current (=3 kV), in Galich - alternating current (~25 kV). The Moscow-Khabarovsk and Moscow-Sharya trains, as well as the Samara-Kinel-Orenburg trains run in transit (the diesel locomotive is coupled to passenger trains in Samara, and to freight trains in Kinel). In Samara and Kinel there is direct current (=3 kV), in Orenburg - alternating current (~25 kV), trains pass through in transit to Orsk, Alma-Ata, Bishkek. With this method of “docking,” the operating conditions of the line are significantly worsened: the parking time of trains is doubled, and the efficiency of electrification is reduced due to the maintenance and reduced speed of diesel locomotives.

Soviet dual-system freight electric locomotive VL82 M

In practice, we mainly encounter the first method - with docking stations for traction types. Let’s say, if I’m traveling from Saratov to Moscow, such a station will be Uzunovo, if to St. Petersburg - Ryazan-2, if to Samara - Syzran-1, but if to Sochi or Adler - Goryachiy Klyuch (by the way, I was always surprised by the fact that in Sochi still uses direct current, although all the North Caucasus railways are on a break - but they say there it is necessary to expand the tunnels somewhere in order to switch to a break, there are generally problems).

The newest Russian two-system passenger electric locomotive EP20

P.S. Small clarification. In addition to my own photographs (color), the post also used material from Wikipedia!

Electrification of railways

Railway electrification- a set of activities carried out on a railway section to make it possible to use electric rolling stock on it: electric locomotives, electric sections or electric trains.

Electric locomotives are used to pull trains on electrified sections of railways. Electric sections or electric trains are used as commuter transport.

Electrification systems

Electrification systems can be classified:

• by type of conductors:
  • with contact suspension
  • with contact rail
• by voltage
• by type of current:
  • alternating current
    • current frequency
    • number of phases

Typically, direct (=) or single-phase alternating (~) current is used. In this case, the rail track acts as one of the conductors.

The use of three-phase current requires the suspension of at least two contact wires, which should not touch under any circumstances (like a trolleybus), so this system did not take root, primarily due to the complexity of current collection at high speeds.

When using direct current, the voltage in the network is kept low enough to turn on electric motors directly. When using alternating current, a much higher voltage is chosen because on an electric locomotive the voltage can be easily stepped down using a transformer.

DC system

In this system, DC traction motors are powered directly from the contact network. Regulation is carried out by connecting resistors, rearranging the motors and weakening the excitation. In recent decades, pulse regulation has become widespread, allowing to avoid energy losses in resistors.

Auxiliary electric motors (drive of a compressor, fans, etc.) are usually also powered directly from the contact network, so they are very large and heavy. In some cases, rotating or static converters are used to power them (for example, electric trains ER2T, ED4M, ET2M use a motor-generator that converts direct current 3000 V into three-phase 220 V 50 Hz).

On Railways of Russia and countries of the former Soviet Union areas electrified by DC system, now they mainly use voltage = 3000 V (in old sections - = 1500 V). In the early 70s in the USSR, on the Transcaucasian Railway, practical research with the possibility of electrification at direct current with a voltage of = 6000 V, but subsequently all new sections were electrified with alternating current of a higher voltage.

Simplicity of electrical equipment on the locomotive, low specific gravity and high efficiency led to the widespread use of this system in the early period of electrification.

The disadvantage of this system is the relatively low voltage of the contact network, so more current is required to transmit the same power compared to higher voltage systems. This forces:

• use a larger total cross-section of contact wires and supply cables;
• increase the contact area with the pantograph of an electric locomotive by increasing the number of wires in the overhead contact network to 2 or even 3 (for example, on inclines);
• reduce the distances between traction substations to minimize current losses in the wires, which additionally leads to an increase in the cost of electrification itself and system maintenance (although the substations are automated, they require maintenance). The distance between substations in heavily loaded areas, especially in difficult mountain conditions, can be only a few kilometers.

Trams and trolleybuses use a constant voltage = 550 (600) V, metro = 750 (825) V.

Reduced Frequency AC System

In a number European countries(Germany, Switzerland, etc.) a single-phase alternating current system of 15 kV 16⅔ Hz is used, and in the USA on old lines 11 kV 25 Hz. The reduced frequency allows the use of AC brushed motors. The motors are powered from the secondary winding of the transformer without any converters. Auxiliary electric motors (for compressors, fans, etc.) are also usually commutator motors, powered from a separate winding of the transformer.

The disadvantage of the system is the need to convert the current frequency at substations or build separate power plants for railways.

Power Frequency AC System

The use of industrial frequency current is the most economical, but its implementation has encountered many difficulties. At first, they used commutator AC motors, converting motor-generators (a single-phase synchronous electric motor plus a DC traction generator, from which DC traction motors operated), and rotating frequency converters (providing current for asynchronous traction motors). Commutator electric motors operated poorly at industrial frequency current, and rotating converters were too heavy and uneconomical.

The system of single-phase power frequency current (25 kV 50 Hz) began to be widely used only after the creation in France in the 1950s of electric locomotives with static mercury rectifiers (ignitrons; later they were replaced by more modern silicon rectifiers - for environmental and economic reasons); then this system spread to many other countries (including the USSR).

When rectifying a single-phase current, the result is not a direct current, but a pulsating one, therefore special pulsating current motors are used, and the circuit contains smoothing reactors (choke) that reduce current ripples, and constant excitation attenuation resistors connected in parallel with the excitation windings of the motors and passing the alternating component of the pulsating current , which only causes unnecessary heating of the winding.

To drive auxiliary machines, either pulsating current motors are used, powered from a separate winding of the transformer (own winding) through a rectifier, or industrial asynchronous electric motors, powered by a phase splitter (this scheme was common on French and American electric locomotives, and from them was transferred to Soviet ones) or phase-shifting capacitors (used, in particular, on Russian electric locomotives VL65, EP1, 2ES5K).

The disadvantages of the system are significant electromagnetic interference for communication lines, as well as uneven load on the phases of the external power system. To increase the uniformity of the phase load in the contact network, sections with different phases; Between them, neutral inserts are arranged - short, several hundred meters long, sections of the contact network, which the rolling stock passes with the engines turned off, by inertia. They are made so that the pantograph does not bridge the gap between sections under high linear (phase-to-phase) voltage at the moment of transition from wire to wire. When stopping on the neutral insert, voltage can be supplied to it from the forward section of the contact network.

Russian Railways and countries of the former Soviet Union, electrified by AC system use voltage ~25 kV(i.e. ~25000 V) frequency 50 Hz.

Connection of power supply systems

Electric locomotives different systems current at the docking station

Dual-system electric locomotive VL82M

The variety of power supply systems has caused the emergence of connection points (current systems, voltage systems, current frequency systems). At the same time, several options arose for solving the issue of organizing traffic through such points. 3 main directions have emerged.

Railway network Russian Federation quite extensive. It consists of several sections of highways, which are owned by Russian Railways OJSC. Moreover, all regional roads are formally branches of JSC Russian Railways, while the company itself acts as a monopolist in Russia:

The road runs through the territory of the Irkutsk and Chita regions and the republics of Buryatia and Sakha-Yakutia. The length of the highway is 3848 km.

The road runs along two parallel latitudinal directions: Moscow - Nizhny Novgorod- Kirov and Moscow - Kazan - Yekaterinburg, which are connected by roads. The road connects the Central, North-Western and Northern regions of Russia with the Volga region, the Urals and Siberia. The Gorky road borders on the following railways: Moscow (Petushki and Cherusti stations), Sverdlovsk (Cheptsa, Druzhinino stations), Northern (Novki, Susolovka, Svecha stations), Kuibyshevskaya (Krasny Uzel, Tsilna stations). The total developed length of the road is 12066 km. Length of main railway tracks- 7987 km.

The railway passes through the territory of five constituent entities of the Russian Federation - Primorsky and Khabarovsk territories, Amur and Jewish autonomous regions, Republic of Sakha (Yakutia). Its service area also includes the Magadan, Sakhalin, Kamchatka regions and Chukotka - over 40% of the territory of Russia. Operating length - 5986 km.

The Trans-Baikal Railway runs in the south-east of Russia, through the territory of the Trans-Baikal Territory and the Amur Region, is located next to the border of the People's Republic of China and has the only direct land border railway crossing in Russia through the Zabaikalsk station. Operating length - 3370 km.

The West Siberian Railway passes through the territories of Omsk, Novosibirsk, Kemerovo, Tomsk regions, Altai Territory and partly the Republic of Kazakhstan. The developed length of the main tracks of the highway is 8986 km, the operational length is 5602 km.

The road operates in special geopolitical conditions. The shortest route from the center of Russia to the countries lies through Kaliningrad Western Europe. The road does not have common borders with Russian Railways. The total length of the highway is 1,100 km, the length of the main routes is over 900 kilometers.

The highway passes through four large regions - Kemerovo region, Khakassia, Irkutsk region and Krasnoyarsk Territory, connecting the Trans-Siberian and South Siberian railways. Figuratively speaking, it is a bridge between the European part of Russia, its Far East and Asia. The operational length of the Krasnoyarsk road is 3160 km. The total length is 4544 kilometers.

The railway stretches from the Moscow region to the Ural foothills, connecting the center and west of the Russian Federation with large socio-economic regions of the Urals, Siberia, Kazakhstan and Central Asia. The road consists of two almost parallel lines running from West to East: Kustarevka - Inza - Ulyanovsk and Ryazhsk - Samara, which connect at the Chishmy station, forming a double-track line ending at the spurs Ural mountains. Two other lines of the road Ruzaevka - Penza - Rtishchevo and Ulyanovsk - Syzran - Saratov run from North to South.

Within its current boundaries, the Moscow Railway was organized in 1959 as a result of the full and partial unification of six roads: Moscow-Ryazan, Moscow-Kursk-Donbass, Moscow-Okruzhnaya, Moscow-Kyiv, Kalinin and Northern. The deployed length is 13,000 km, the operational length is 8,800 km.

The Oktyabrskaya Mainline passes through the territory of eleven constituent entities of the Russian Federation - Leningrad, Pskov, Novgorod, Vologda, Murmansk, Tver, Moscow, Yaroslavl regions, the cities of Moscow and St. Petersburg and the Republic of Karelia. Operating length - 10143 km.

The Volga (Ryazan-Ural) railway is located in the southeast of the European part of Russia in the region of the Lower Volga and the middle reaches of the Don and covers the territories of the Saratov, Volgograd and Astrakhan regions, as well as several stations located within the Rostov, Samara regions and Kazakhstan. The length of the road is 4191 km.

The highway connects the European and Asian parts of Russia, stretches for one and a half thousand kilometers from west to east and crosses the Arctic Circle in a northern direction. Passes through Nizhny Tagil, Perm, Yekaterinburg, Surgut, Tyumen. Also serves Khanty-Mansi and Yamalo-Nenets autonomous okrugs. Operating length - 7154 km. The deployed length is 13,853 km.

The highway originates in the center of Russia and extends far to the north of the country. Most of The Northern Mainline is operated in the harsh conditions of the Far North and the Arctic. The unfolded length is 8500 kilometers.

In the service area of ​​the road there are 11 constituent entities of the Russian Federation Southern federal district, it directly borders Ukraine, Georgia and Azerbaijan. The operational length of the highway is 6358 km.

South Eastern Railway occupies a central position in the railway network and links eastern regions and the Urals with the Center, as well as the regions of the North, North-West and Center with the North Caucasus, Ukraine and the states of Transcaucasia. The South-Eastern Road borders on the Moscow, Kuibyshev, North Caucasus, and Southern Railways of Ukraine. Operating length - 4189 km.

The South Ural Railway is located in two parts of the world - at the junction of Europe and Asia. It includes Chelyabinsk, Kurgan, Orenburg and Kartalinsk branches. Several mainline railway lines pass through the territory of Kazakhstan. The South-Eastern Road borders on the Moscow, Kuibyshev, North Caucasus, and Southern Railways of Ukraine. Operating length - 4189 km. The developed length is over 8000 km.