Electrification of Railways

Electrification systems can be classified:

• by type of contact network :
  • with air contact suspension (most railways and tram systems)
  • with contact rail ( metro )
• by voltage
• by type of current :
  • D.C.
  • alternating current
    • current frequency
    • number of phases

Usually use direct or single-phase alternating current. Moreover, 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 be in contact under any conditions (like a trolley bus ), air arrows and current collectors have a complex device. It was used in the late XIX - early XX centuries, this system did not take root, first of all, due to the complexity of current collection at high speeds. In the 21st century, electrification by three-phase current was preserved as a technical relic on some rack and pinion railways carrying tourists, for example, the Jungfrau railway .

When using direct current, the voltage in the network is made quite low (up to 3 kV) to turn on the motors directly. When using alternating current, a much higher voltage is selected (from 10 to 25 kV), since it can be easily reduced with an electric locomotive using a transformer .

The simplicity of electrical equipment on a locomotive with a hyperbolic traction characteristic, low specific gravity and high efficiency led to the widespread use of this system in the early period of electrification.

The disadvantage of direct current electrification is the relatively low voltage in the contact network, therefore, for the transmission of the same power, a much higher current is required compared to higher voltage alternating current systems. ^{[note 1]} High currents limit the possible maximum power of DC locomotives and their number in the area. This forces:

• use a larger total cross-section of contact wires and lead cables;
• increase the area of ​​contact with the current collector of an electric locomotive by increasing the number of wires in the suspension of the contact network to two or even three (for example, on lifts) and the number of simultaneously used current collectors (up to three on electric locomotives ChS200 and VL15 );
• reduce the distance between traction substations to minimize current losses in the wires, which additionally leads to an increase in the cost of the electrification and maintenance of the system (although the substations are automated, but require maintenance). The distance between DC substations in heavy-duty sections or a line with high-speed communication, especially in difficult mountain conditions, can be only a few kilometers (for example, at the main course of the October Railway - in the suburban areas of Moscow and St. Petersburg, it is only 2-3 km).

Polarity

On railways, electrified with direct current, as well as on trams and in the subway, the positive polarity of the contact network is adopted: “plus”${\displaystyle <span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">(</span></span><span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">+</span></span><span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">)</span></span>}$ {\ displaystyle (+)}   moves on a contact wire ( contact rail ) , and "minus"${\displaystyle <span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">(</span></span><span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">-</span></span><span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">)</span></span>}$ {\ displaystyle (-)}   on the rails . Positive polarity is adopted in order to reduce electrochemical corrosion of pipelines and other metal structures located near railway lines.

Since the rails are the return wire, and it is almost impossible to isolate them from the ground, part of the traction current branches off. These currents are called stray currents . The direction of stray currents is almost impossible to predict. Stray currents flow not only in the ground, but also along the metal parts of various underground structures encountered on their way.

Zones where stray currents flow from rails or from other underground structures into the earth are called anode zones , and zones where stray currents enter from rails or other underground structures from the earth are called cathode zones . Since there is a potential difference between the metal (rail, pipeline) and earth, electrolysis occurs in these zones and electrochemical corrosion of the metal occurs.

The illustration shows an electrified railway with positive polarity.

An anode zone is formed under the wheels of an electric locomotive, and a cathode zone (the left part of the figure) is formed on a nearby pipeline. The zones at the junctions of the anode and cathode zones are called alternating , the potentials in them can change their polarity. Also, the anode and cathode zones are formed near the traction substation (right side of the figure). Rails corrode most intensely under the wheels of an electric locomotive, and underground structures at traction substations.

However, the anodic and cathodic zones depicted on the left side of the picture are “moving”, that is, in fact alternating, and the electrolysis in these zones is of a short-term nature. The anodic and cathodic zones depicted on the right side of the picture are “non-moving”, located near traction substations , and there electrochemical corrosion is observed to the greatest extent. There, respectively, are the cathodic protection stations.

If the contact network had a negative polarity (that is, the “minus” would be supplied to the contact wire), then the pipelines passing near the railway would represent an almost continuous anode zone, and protective measures for underground structures would have to be taken along the entire railway, which would be incomparably more expensive.

Application

On the railways of Russia and in the countries of the former USSR , voltage of 3000 V is used in sections electrified by a direct current system. In the 1930s - 1950s in the USSR, some suburban areas were electrified at 1500 V, then they were transferred to 3000 V. In the early 1970s, practical studies were conducted in the USSR on the Transcaucasian Railway with the possibility of electrification on direct current with a voltage of 6000 V , but this system was considered unpromising. in the future, all new sections were electrified with an alternating current of 25 kilovolts.

Trams and trolleybuses in the CIS operate on direct current with a voltage of 550 V, metro in the CIS - operate with direct current with a voltage of 750 ^[1] V.

Industrial DC electric locomotives operate at a voltage of less than 3 kV, for example, EL21 electric locomotive - 1.5 kV, and the II-KP4 electric locomotive was produced in various designs - 220, 550 or 600 volts.

Locomotive Systems

Resistor-contactor control system

In this system, DC traction motors are powered directly from the contact network. Start and regulation is carried out by connecting rheostats , rearrangement of engines (serial, series-parallel and parallel) and weakening the excitation.

On all Soviet electric locomotives and electric trains, traction motors are designed for a voltage of 1500 V, so they are always connected in pairs in series (the voltage in the contact network is 3000 V). The fact is, if you try to make a 3000 V electric motor with a power equal to a 1500 V electric motor, then the mass and dimensions of the high-voltage motor will be greater than that of the low-voltage motor.

Auxiliary electric motors (compressor drive, 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, a motor generator is used on electric trains ER2T , ED4M , ET2M , which converts a direct current of 3000 V into a three-phase 220 V 50 Hz).

Pulse Regulation

In recent decades, pulse regulation has begun to spread, which avoids energy losses in rheostats.

Inverter circuit

In 2010, the production of freight electric locomotives of direct current 2ES10 - 3ES10 Granit was launched in Russia. Asynchronous traction motors are powered by three-phase alternating current from inverters .

In a number of 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 collector motors . The motors are powered by the secondary winding of the transformer directly, without any converters. Auxiliary motors (for compressor, fans, etc.) are also usually collector, powered by a separate transformer winding. Collector motors powered by low frequency alternating current have better commutation compared to industrial frequency power supply.

The advantage of the system is the complete isolation of the contact network from the power supply, as the transformers are used for frequency conversion. The second advantage comes from here - there is no danger of phase imbalance (the umformer motor is powered by a three-phase current, and the generator produces a single-phase current). The third advantage is noticeably smaller inductive losses.

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

This system appeared in the 1910s forcibly, since the direct current losses were great , and the technical level of that time did not allow the implementation of an alternating current system of industrial frequency.

In Europe, the frequency of 16⅔ Hz was chosen, since it is 1/3 of 50 Hz, which allows the use of conventional three-phase machines at 50 Hz with modified winding connections in the generators of the scramblers .

In the USA, the frequency of 25 Hz is a technical relic: such was the frequency of the alternating current before the transition of the networks to 60 Hz at the beginning of the 20th century.

The development of semiconductor technology has led to the use of DC ( pulsating ) current collector motors powered by a semiconductor rectifier on low-frequency AC electric locomotives, and from the end of the 20th century traction asynchronous motors, for example, IORE electric locomotives, have been used . Thus, modern AC electric locomotives of reduced frequency do not have fundamental differences from AC electric locomotives of industrial frequency.

The use of industrial frequency current is the most economical, but its implementation met many difficulties. Initially, AC collector electric motors were used, converting motor generators (single-phase synchronous electric motor plus a direct current traction generator, from which direct current traction motors were operated), rotating frequency converters (giving current for asynchronous traction electric motors). Industrial-frequency commutator motors did not work well, and rotary inverters were too heavy and uneconomical.

However, in the late 1920s. in the USSR , when they were just starting to electrify the Suram pass, many experts ^{[ who? ]} well understood that in the future, direct current electric traction with a rated voltage of 3 kV would not rationally solve the issue of increasing the carrying capacity of lines by increasing the weight of trains and their speed. The simplest calculations showed that when driving a train weighing 10,000 tons at a lift of 10 ‰ at a speed of 50 km / h, the traction current of electric locomotives would be more than 6,000 A, which would require an increase in the cross-section of contact wires, as well as the very frequent location of traction substations. After comparing about two hundred variants of combinations of current type and voltage values, it was decided that the best option is electrification with direct or alternating (50 Hz) current of 20 kV. The first system at that time in the world was not tested anywhere, and the second was studied very little, therefore, at the first All-Union Conference on Electrification of Railways, it was decided to construct an experimental section electrified by alternating current (50 Hz ) voltage of 20 kV. In 1938, an OR22 electric locomotive was built with an ignitron rectifier and non-contact stepless phase regulation by changing the ignition moment of the ignitron . His tests were completed in connection with the outbreak of war in 1941, but the results were very positive, and the circuit diagram (with voltage regulation on the low side) turned out to be so successful that they began to use it when designing the vast majority of Soviet AC electric locomotives.

The single-phase system of industrial frequency (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 with more modern silicon rectifiers - for environmental and economic reasons); then this system spread to many other countries.

When the driver and assistant occupied a place in the cab of an electric locomotive VL60 (or VL80 , F , VL41 , VL61 ) with mercury rectifiers , they always had gas masks with a special filter box that absorbed mercury vapor . In the event of an accident (burnout of the ignitron case), you should put on a gas mask, open the side vents in the cockpit, turn off the faulty ignitron and drive the train to the nearest station in the gas mask.

When rectifying a single-phase current, it is not pulsating direct current, but pulsating , that is why special pulsating current motors are used, and smoothing reactors (chokes) are introduced into the circuit, which reduce current ripples, and constant field weakening resistors connected in parallel to the motor excitation windings 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 powered from a separate winding of the traction transformer (auxiliary winding) through a rectifier, or industrial asynchronous electric motors powered by a phase splitter (such a scheme was used on the OP22, and later spread to French, American and Soviet electric locomotives) 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 the uneven load of the phases of the external power system. To increase the uniformity of the phase load in the contact network , sections with different phases alternate ; neutral inserts are arranged between them - short, several meters long, sections of the contact network that the rolling stock passes with the pantographs lowered, on the coast , so that the pantograph does not cross the gap between the sections under high linear (interphase) voltage at the moment of transition from the wire to the wire. When stopping at the neutral insert, voltage can be supplied to it from the front-side section of the contact network.

Railways in Russia and the countries of the former Soviet Union, electrified with alternating current, use a voltage of ~ 25 kV with a frequency of 50 Hz . Some sources indicate a voltage of 27.5 kV, which creates confusion. In fact, traction substations give out voltage of 27.5 kV, but due to the voltage drop due to the high inductive resistance of the "contact wire - rail" circuit, electric locomotives are designed to operate at a voltage of 25 kV.

2 × 25 kV system

For sparsely populated areas, a 2 × 25 kV electrification system (two of twenty-five kilovolts) was developed. There, as a rule, there is often no possibility to locate traction substations (in addition, it can be difficult to find qualified personnel to service them, as well as create proper living conditions for people).

On the supports of the contact network (on the side of the railway track and the contact wire), a special supply wire is pulled into which a voltage of 50 kV from the traction substation is supplied. Low-maintenance step-down autotransformers are installed at railway stations (or on stages), one output of the winding is connected to the supply wire, and the other to the contact wire. The common (return) wire is the rail. Half voltage from 50 kV, i.e. 25 kV, is applied to the contact wire. As a rule, slightly higher than 50 kilovolts is fed, usually 55; taking into account losses, that on the contact wire was 27.5 kV.

This system allows you to build traction substations less often, as well as reduce heat loss . Electric locomotives and AC electric trains do not need alteration.

Industrial AC electric locomotives operate at a voltage of less than 25 kV, for example, a traction unit OPE1 - 10 kV 50 Hz.

A variety of power supply systems caused the appearance of docking points (current systems, voltages, current frequencies). In this case, several options arose for solving the issue of organizing traffic through such points. Three main areas emerged:

1. The equipment of the docking station with switches, allowing to supply this or that type of current to separate sections of the contact network. For example, a train arrives with a direct current electric locomotive, then this electric locomotive disengages and leaves for a revolving depot or dead end for the sludge of locomotives. The contact network on this path is switched to alternating current, an alternating current electric locomotive drives in and leads the train further. The disadvantage of this method is the increase in the cost of electrification and the maintenance of power supply devices, and also requires a change in the locomotive and the associated additional material, organizational and time costs (see the list of stations linking the genera of the Russian Railways traction and the list of stations docking the genera of the UZ rod ) At the same time, it takes not so much a change in the electric locomotive as much as testing the brakes . ^{[ specify ]}

2. The use of multi-system rolling stock. At the same time, docking on the contact network is done outside the station. This method allows you to pass docking points without stopping (although, as a rule, on 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 in operation. In addition, multi-system electric locomotives have more weight (which, however, is of little relevance on the railroad, where frequent ballasting of locomotives to increase traction weight is not uncommon). In the USSR and CIS countries such types of rolling stock were produced in small series as electric locomotives VL61 ^d , VL82 and VL82 ^m (direct current voltage of 3 kV and single-phase 25 kV), VL19 and electric train C ^r(direct current voltage of 3 kV and 1.5 kV). Two-system electric locomotives operated on the Mineralnye Vody section (~ 25 kV and = 3 kV) - Kislovodsk (= 3 kV) (this section was switched to alternating current in the 2000s), operate on the border of the Leningrad Region (= 3 kV) with Finland (~ 25 kV) and in Ukraine (see docking stations with neutral inserts ).

In Western Europe, there is a four-system electric rolling stock (direct current 1500 V, direct current 3000 V, alternating current 25 kV 50 Hz, alternating current 15 kV 16⅔ Hz).

At present, Russia has launched production of two-system passenger electric locomotives EP20 (direct current 3 kV and alternating current 25 kV 50 Hz), which are produced by NEVZ (a small batch of electric locomotives EP10 was produced there in 1998-2007). A two-system freight project (direct current 3 kV and alternating current 25 kV 50 Hz) of the 2ES20 electric locomotive was also developed , but the project is currently virtually frozen.

Two-system high-speed electric trains EVS2 “Sapsan” are operated on the route Moscow (= 3 kV) - Nizhny Novgorod (~ 25 kV), two-system electric trains Allegro are operated on the high-speed route St. Petersburg - Helsinki .

Several types of electric locomotives are several types:

• based on the scheme of a DC electric locomotive - always used rheostat start and rearrangement of motors; when powered by an AC mains, an unregulated transformer with a rectifier is connected (example - VL82 );
• separate circuits are used when powered by direct and alternating current: rheostat starting and rearrangement of motors when powered by a direct current network and switching transformer windings when powered by an alternating current network;
• based on the scheme of an electric locomotive of alternating current; when powered by a DC network, the transformer is connected through an inverter .

3. The use of a diesel insert - leaving between sections with different power supply systems a small traction arm serviced by diesel locomotives. In practice, it is used in the Kostroma – Galich section of a length of 126 km: in Kostroma direct current (= 3 kV), in Galich - alternating current (~ 25 kV). Trains Moscow - Khabarovsk and Moscow - Sharya , as well as Samara - Kinel - Orenburg, run in transit (the diesel locomotive is hitched to passenger trains in Samara, and to freight trains in Kinel). In Samara and in Kinel, direct current (= 3 kV), in Orenburg - alternating current (~ 25 kV), trains to Orsk , Alma-Ata , Bishkek pass in transit. With this “docking” method, the operating conditions of the line are significantly worsened: the parking time of trains is doubled, the efficiency of electrification is reduced due to the content and reduced speed of diesel locomotives. Other examples of diesel inserts are Necklace / Tula — Yelets, Red Knot — Kanash, Red Knot — Arzamas, Sarajevka — Stary Oskol, Tatarskaya — Karasuk, Ryazhsk — Penza, Syzran — Albaba — Kazan.

Plans for the creation of the first domestic electric railway appeared in 1898. The Oranienbaum Electric Line ( St. Petersburg - Krasnaya Gorka ) began to be built in 1913, but World War I prevented the implementation of plans. As a result, the road began to be used in limited areas as tram route No. 36 to Strelna , which operates to date ^[2] .

The first electrified line in the territory of the former USSR (hereinafter the borders of 1945-1991 are considered) was the suburban line Tallinn - Päeskyla with a length of 11.2 km in independent Estonia . Electric trailers with trailed cars began work in 1924. Significant reconstruction of the site and expansion of the electrification range was carried out in the 1950s.

In 1926, electric traction was introduced on suburban lines in Baku .

Since 1929, electrification began to be introduced on the main railways, mainly for suburban traffic, where steam trains replaced commuter trains . The first section was the Moscow - Mytishchi line with a length of 18 km. In the 1930s Yaroslavl (Moscow - Aleksandrov , Mytishchi - Monino ), Gorkovskoe (Moscow - Obiralovka , Reutovo - Balashikha ), Ryazan (Moscow - Ramenskoe ), Kursk (Moscow - Podolsk ) directions were electrified at the Moscow junction. A direct current of 1500 V was used . The Zagorsk - Aleksandrov section in 1937 was electrified with a direct current of 3000 V , electric trains coming from Moscow switched groups of engines at the Zagorsk station and continued on. The electrification of the unit continued during the Great Patriotic War and in the second half of the 1940s (Moscow - Nakhabino , Moscow - Domodedovo , Podolsk - Lvov , Moscow - Golitsyno ).

In 1932-1933 electric traction was introduced on the Khashuri - Zestafoni trunk railway (63 km) on the heavy 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 USSR railway lines.

Since 1933, a course has been outlined for the priority introduction of electrification in three cases:

1. Intensive suburban traffic, in which the use of locomotive traction is extremely inefficient. So, electric traction appeared in Leningrad (Baltic direction), in the resorts of the Caucasian Mineral Waters ( Mineralnye Vody - Kislovodsk ), Kuibyshev ( Samara - Bezymyanka ), some branches from the main electrified railway in Georgia ( Surami , Borjomi , Kutaisi , Gardabani , etc.). n.), where due to the availability of electrification for freight traffic, it was unprofitable to keep steam locomotives for suburban and local traffic. In such cases, as a rule, electrification was carried out at a direct current voltage of 1500 V (in Georgia immediately 3000 V).
2. On railway crossings, where electric traction allowed to significantly increase the throughput and carrying capacity of the lines. So it was in Georgia, in the Urals ( Kizel - Chusovskaya and the further development of electric traction in a growing industrial region, in 1945 Chelyabinsk - Zlatoust ). Electrification was carried out at a direct current voltage of 3000 V.
3. On tense railway lines in new industrial areas ( Perm - Sverdlovsk region, Zaporozhye - Krivbass , Louhi - Murmansk , Novokuznetsk - Belovo ).

Such a course persisted until about 1950. During the war, on many electrified lines, the contact network was dismantled, and the electric rolling stock was evacuated. The Louhi – Murmansk line , despite passing the front line nearby, continued to operate. During the war, electric traction was developed on the Moscow hub and in the Urals , and after the war it was completely restored to all previous sites.

In 1950-1955 The first, still cautious expansion of the electrification range began. The transition has begun from a voltage of 1500 V to 3000 V at all suburban nodes, further development of suburban nodes, lengthening of electrified lines to neighboring regional centers with the introduction of electric traction for passenger and freight trains. Electrification "islands" appeared in Riga , in Kuibyshev , in Western Siberia , Kiev .

In 1956, a new stage in the mass electrification of the USSR railways began, which promptly brought electric traction and diesel traction from a 15% share in transportation in 1955 to an 85% share in 1965. Over the course of ten years, the longest electrified roads were introduced:

Moscow - Kuibyshev - Chelyabinsk - Novosibirsk - Krasnoyarsk - Irkutsk ;

Leningrad - Moscow - Kharkov - Rostov-on-Don - Sochi - Tbilisi - Yerevan ;

Moscow - Gorky - Kirov - Perm ;

Moscow - Ryazan - Voronezh - Rostov-on-Don - Mineralnye Vody .

This period also includes the construction of the first in the USSR new railway, electrified immediately during construction - the Abakan - Taishet road . Local electric traction ranges in Eastern Ukraine, Azerbaijan , and Gorky increased significantly, new “islands” appeared in Minsk , Volgograd , Vladivostok , and Western Ukraine; electrification in Georgia was basically completed (1969). On average, about 2,000 km of electrified railways were introduced every year of this decade. During these years, electrification continued both on the already well-established direct current with a voltage of 3,000 V and in alternating current of a frequency of 50 Hz with a voltage of 25 kV.

The first on alternating current (voltage 20 kV) was the electrified experimental section Ozherelye - Mikhailov - Pavelets in 1955-1956. After testing, it was decided to increase the voltage to 25 kV. Since 1959, alternating current with a voltage of 25 kV began to be introduced in long sections where electrification was required, but there were no direct current landfills nearby ( Krasnoyarsk and East-Siberian railways, Gorky junction and further to Kirov , Ryazan - Voronezh - North Caucasus , nodes in Barnaul , in Central and Western Ukraine ). In parallel with the development of a network of AC lines, the development of AC rolling stock was carried out.

The first electric trains ER7 and ER9 began to work only in 1962. For the Krasnoyarsk railway , French type F locomotives were purchased in 1959, since the production of Soviet alternating current electric locomotives ( VL60 and VL80 ) was delayed.

Since 1966, there has been a decline in the extent of electrification. In the five-year period of 1966-1970, an average of 1,700 km of new electrification was introduced per year, and from 1971 to 1990, 900–1,000 km per year, and such stable indicators were maintained in each of the four five-year periods of this period. If in 1966-1970 the transfer of lines from steam to electric traction continued, then after 1970 the most strained diesel mains switched to electric traction. In addition, electrification continued to be introduced at large suburban hubs - in Kazan , Saratov , Lviv , Vilnius , Kaliningrad ; previously electrified suburban systems developed in Minsk , Riga , Leningrad , Moscow , Volgograd , Yaroslavl , Kostroma , etc. In the 1980s, electrified few of extended roads: Trans-Siberian Railway from Chita to Khabarovsk , the BAM from Ust-Kut to Taksimo , line Vyazma - Minsk - Brest , line Cherusti - Kazan - Druzhinino , transkazahskaya road Karaganda - Tashkent with sequels to Alma-Ata and C Markand .

In 1991-2005, the size of electrification in the countries of the former USSR fell to 450 km per year, with “falls” in some years to 150 km per year and “take-offs” to 700 km per year as part of the work on the electrification of long lines. Electrification continued mainly on highways previously planned in the USSR, where electric locomotive traction was more advantageous than diesel traction. In addition, during this period there was a large-scale transfer of a number of lines from DC to AC . In 1995, the 377-kilometer line Zima - Irkutsk - Slyudyanka was switched to alternating current, in 2001 the 450-kilometer line Louhi - Murmansk , in 2003 - 90 km of the suburban-urban lines of the Volgograd junction as part of the electrification of the Volga course Syzran - Volgograd - Tikhoretskaya with alternating current, and in 2006, the 70-km agglomeration dead end branch Mineralnye Vody - Kislovodsk and Beshtau - Zheleznovodsk was switched to alternating current. A similar transition was on the Ukrainian railways . In 1950-1959, the Brovary - Kiev - Fastov section was electrified with direct current, but in connection with the electrification of the Znamenka - Mironovka - Fastov sections in 1963 and Brovary - Konotop - Zernovo in 1967, an alternating current line in the first section in 1967 was converted to alternating current.

Since 2006, the size of electrification has been further reduced, and less than 200 km of electric lines are introduced every year. Basically, these works are carried out in Ukraine, where there is a surplus of cheap electricity from nuclear power plants . Only four major projects are being implemented in Russia: electrification of lines to the port of Ust-Luga in the Leningrad Region, complex reconstruction of the Karymskaya - Zabaikalsk line in the Zabaykalsky Territory , complex reconstruction of lines on the Taman Peninsula as part of the construction of the new deep-water port of Taman, and electrification of the Moscow Central Ring (former MK MZD) with all stations and transmission branches. In addition to them, in Russia some short lines for the movement of electric trains to airports were electrified and partially completed; The Adler-Rosa Khutor line , designed to serve the 2014 Winter Olympics, was immediately electrified. A railway electrification program has been adopted in Belarus , during which Osipovichi - Gomel and Molodechno - Nauoyoi-Vilnya (together with Lithuania ) were electrified by 2018, and the electrification of the Zhlobin - Kalinkovichi line was launched.

• Some industrial electric locomotives can receive power not only from the upper contact wire , but also from the side or cable (in open pits , where the extracted minerals are loaded into gondola cars ). The cable is wound on a drum mounted on an electric locomotive.
• A direct current of 3 kV or an alternating current of 25 kV can be supplied to the contact network of the Belorechenskaya - Maykop line ( North Caucasian Railway ), which is the test site of Russian Railways .
• The only case in the history of the electrification of Soviet and Russian railways that a section was transferred from AC to DC took place in 1989 on the Paveletsky direction of the Moscow Railway . The newly built Uzunovo - Rybnoye section was electrified with direct current, and the Ozherelye -Uzunovo section was switched from alternating current to direct. Instead of the Necklace, the docking station was Uzunovo ^[3] .
• According to electrical safety conditions, inside the buildings of locomotive depots, the contact wire is not suspended, electric locomotives are driven into the workshop with the current collector lowered, supplying power to one of the traction motors from an internal workshop DC source with a voltage of about 90 volts. On the back of the electric locomotive there is a socket, electric current is supplied via cable. In the same way, electric locomotives are driven into the workshop (the diesel engine is stopped at the same time). In the same way, locomotives roll out onto the street.
• Powerful DC electric locomotives when moving the train lift two, or even all current collectors. The amperage is so great that contact wire can burn out.

• The introduction of asynchronous three-phase traction motors can increase the power of an electric locomotive by about 1.5 times. The fact is that the traction motor is a machine of maximum performance. Its power is determined by the overall dimensions due to the gauge , more precisely, the distance between the wheels . “Forcing” the collector electric motor, increasing the current strength, is very difficult, since this causes saturation of the magnetic system , and further it is useless to increase the current. Three-phase asynchronous traction electric motors have lower metal consumption in comparison with collector ones at the same power. For example, the collector electric motor of the ChS200 electric locomotive has an hourly power of 1050 kW, and the three-phase asynchronous electric motor of the BR 185 electric locomotive has 1400 kW.

• Current collector
• Electric locomotive
• Electric train
• Linear motor
• Traction substation
• Detachable tower
• Electrification of the railways of the Karelian Isthmus

Comments

Sources

• Moody, G T. "Part One". Southern Electric. - 3rd edition ed. - London : Ian Allan Ltd., 1960.
• Voinarovsky P. D .,. Electric Railways // Brockhaus and Efron Encyclopedic Dictionary : 86 tons (82 tons and 4 additional). - SPb. , 1890-1907.
• V.A. Crayfish . Experienced electric locomotive AC22-01 // Locomotives of domestic railways 1845-1955. - 2nd, revised and supplemented. - Moscow: "Transport", 1995. - S. 426-429. - ISBN 5-277-00821-7 .

• The history of the electrification of the railways of the USSR on the site Steam locomotive IP (neopr.) . Archived July 14, 2012.
• What is the difference between alternating current railway electrification systems: 25 kV, 50 Hz and 2 × 25 kV, 50 Hz?
• Features of the application of direct and alternating current.