ER2R

As far back as the 1950s, the Riga Carriage Building Plant was developing equipment allowing the use of electric braking on electric trains. The use of engine braking would increase the efficiency of electric trains and reduce the wear of friction elements and pneumatic equipment (pads, discs, compressor, etc.). But until the end of the 1970s, these attempts ended mainly with the construction of prototypes and compositions of small series. In 1979 , RVZ built the first electric train ER2R-7001 (factory designation 62-259), equipped with regenerative-rheostatic braking. The wagons were built on the basis of ER2 wagons with the installation of electrical equipment from the wagons of the ER22 series of the latest options (that is, ER22V). Initially, they even planned to designate the new electric train ER22K (that is, as a modification of ER22; the letter K indicated short wagons) and assign it number 71 (that is, continue the numbering of the ER22 series, the last representative of which was ER22V-70).

In 1982 , RVZ produced two more ER2R electric trains, and since 1984 began to mass-produce them, simultaneously discontinuing the production of ER2R. Their construction continued until September 1987. In total, 89 ER2R electric trains were produced, of which 57 10-car and 32 12-car. Also in 1986-1987. the plant produced 8 separate head and 27 separate intermediate electrical sections. Thus, a total of 512 electric sections, or 1,024 wagons, were built (see table below).

Composition

The main composition of the electric train - 2Pg + 5Mp + 3Pp (10 cars) - fully corresponds to the composition of ER1. An electric train during operation could be formed in compositions according to the general formula (PG + MP) + 0..4 × (MP + PP) + (MP + PG), that is, coupling sections from a motor and trailer car. Thus, it was also possible operation in the compositions:

• 2Pg + 4Mp + 2Pp (8 cars);
• 2Pg + 3Mp + 1Pp (6 cars);
• 2Pg + 2Mp (4 cars).

Specifications

The main parameters for the 10-car electric train ER2R: ^[2]

• tare weight:
  • MP car: - 58.5 t;
  • wagon PP: - 42.0 t;
  • Wagon PG: - 40.5 t;
• number of seats:
  • wagon MP: - 110;
  • wagon PP: - 107;
  • Wagon PG: - 84;
• total hourly power of TED: - 240 × 5 × 4 = 4800 kW.

Mechanical equipment

Compared to ER2, no changes were made to the mechanical part of the new composition. However, the mass of wagons increased (motor - up to 58.5 tons, head - up to 42.0 tons, trailed - up to 40.5 tons) due to the installation of heavier electrical equipment. Compared to the ER2 of the ten-car version, the similar ER2R composition is heavier by about 30 tons. Therefore, TUR-01 trolleys designed for higher loads were used.

Electrical equipment

Traction electric motors ( TED ) model 1DT-003.1 were inherited from the train ER22V. The power of the TED clock mode was 240 kW at a consumption current of 350 A. The shaft rotation frequency was:

• at 100% excitation (enhanced) - 570 rpm;
• at 50% excitation (normal) - 740 rpm;
• at 18% excitation (attenuated) - 740 rpm.

The train used support frame suspension TED. Regenerative braking on the ER2R is possible with a decrease in speed from 130 to 55 km / h. Further inclusion of the regenerative mode would be inefficient, and therefore in the speed range from 55 to 10 km / h, the rheostatic braking mode was activated. When reducing speed from 10 km / h to a complete stop, a pneumatic brake system was used.

Recuperative braking on electric trains ER2R, as well as electric trains ER2T up to number 7194 was carried out without a direct entrance to the recovery. In other words, it did not occur by a valve (diode) method, but by a different method. The essence of this method was to pre-increase the voltage at the anchors and compare it with the mains voltage. With this method, recovery occurs as follows. First, the contactor T is turned on, which connects the armature of the motors with starting braking resistances (PTS). In this case, the field windings are powered by a thyristor bridge, which is controlled by a block of the automatic current holding system (SAUT). The SAUT block, sending pulses to thyristors with a certain opening angle, regulates the current in the circuit of the field windings (OH). The voltage at the TED anchors directly depends on the current on the OB and the rotation speed of the anchors. By increasing the OV current, SAUT increases the voltage at the TED anchors. Thus, there is an increase in voltage at the TED anchors. This is the so-called preliminary rheostatic braking with independent excitation of TED. To control the modes, four relays are involved - a reed switch for voltage balance (RBN), a relay for switching on the recovery (PBR), a relay for maximum voltage (RMN) and a self-excitation relay (RSV). The RBN is normally closed and shorts the RVR coil with its contacts, preventing it from turning on. As soon as the voltage at the TED anchors approaches the mains voltage (voltage difference from 90 to 200 V) or becomes equal to the mains voltage, the RBN will open its contacts and turn on the PBP. The latter will turn on the linear contactor LK and disconnect the contactor T, as well as connect the TED anchors to the contact network, disconnecting them from the TCP. At this moment, there is a transition from rheostatic to regenerative braking. If the voltage of the TED exceeds a threshold value, then the maximum voltage relay (RMN) will turn on and turn off the LC and turn on T, that is, it will transfer the circuit back to rheostatic braking with independent excitation. The threshold (maximum) value of the voltage during switching is in the range from 3950 to 4000 V. With a decrease in the speed of movement, the current on the OB will increase. When it reaches a threshold value that lies in the range from 230 to 250 A, the SAUT will turn on the RSV, and thereby transfer the circuit to self-excitation.

According to this method, regenerative-rheostatic braking was carried out on all ER2R electric trains, as well as on ER2T to the number 7194. This method has three drawbacks. Firstly, it is at least four switching in the power circuit for one braking. Secondly, a negligible percentage of recovery. Thirdly, the likelihood of the inclusion of the so-called "motor mode", which is the most important drawback. This will happen if during recovery the voltage at the TED anchors becomes much lower than the voltage of the contact network. In this case, the TED will instantly switch from the generator mode to the motor mode, and instead of braking, the traction will turn on. To prevent this from happening, a protection element is introduced into the circuit - a motor current relay (PMT). When this mode appears, it will turn on the contactor T and turn off the LC, which will transfer the circuit back to rheostatic braking. But, unlike RMN, the relay will not rise to self-pickup, and it is possible to turn on the recovery in a new cycle. Because of this number of shortcomings, it was necessary to switch to a new scheme, which was implemented on ER2T trains from number 7194 onwards. This is the so-called direct recovery input circuit when diode switching is used. Later, on some ER2R electric trains (the numbers are not exactly known), in the conditions of repair in the depot, the standard circuit was replaced by a diode one. A similar diode circuit began to be used on many other DC trains.

Numbering and marking ^{[1] [3]}

The numbering and marking system used on ER2R trains generally corresponds to that adopted for other RVZ electric trains (for the first time a similar system was used for the ER1 series). The compositions received four-digit spelling numbers (from 7001 to 7089). Marking on the front of the head cars was carried out in the ER2R-XXXX format, where XXXX is the train number (without indicating the car number). Marking was carried out under the windshields in the center. Each carriage of the train received its own number, in which the first digits denoted the train number, the last two - the number of the train car. Marking with wagon numbers was carried out under the windows in the middle of the wagon and differed from marking on the frontal part by adding two digits of the wagon number in the same format. Motor cars got even numbers (02, 04, 06, 08, 10 and 12), head ones - 01 and 09, intermediate trailers - the rest odd ones (03, 05, 07 and 11). For example, the marking of the first head car of the ER2R-7046 electric train will be ER2R-704601 ; one of the motor cars of the same train will be ER2R-704604 , etc. Also, under the windshields in the center (above the number) the RVZ logo of that time was fixed (the letters "RVR").

The electric train ER2R, due to numerous complaints from the operating depots, was not certified. Instead of ER2R, the plant switched to the production of ER2T electric trains, which differed from ER2R, mainly, with more reliable electrical equipment ^[4] .

The prototype (ER2R-7001) was tested at the Zasulauks depot in Latvia; from the plant was transferred to the depot ТЧ-17 Nakhabino of the Moscow railway (Riga direction). On February 8, 1983, the train arrived for operation at the PM-4 depot Zheleznodorozhnaya of the Moscow Road (to Gorky direction) ^{[1] [3]} . Since March 1983, all other electric trains began to be transferred to operation also at the depot ТЧ-4 Zheleznodorozhny, and then to other sections

As of 2018, all remaining electric trains and additional ER2R wagons are operated in Russia on the Moscow Railway (most of the electric trains and additional wagons of this series are located in the PM-14 Lobnya ) and in Ukraine on the Southern Railway ( RPC-1 Kharkov ); at the same time, individual wagons can be found on the October Railway ^{[1] [3]} .

In the 1980s, an electric train ER24 was developed at RVZ, in which they planned to realize the idea of ​​rearrangement of engines. It was planned to carry out these regroupings, combining two motor cars in one power circuit. At the same time, eight motors were to be switched on in series, and 2 × 4 groups of engines on series-parallel. Because of this, the composition of the electric train was assumed to be sectional, moreover, from four-car sections (8 or 12 cars). Each section would consist of two trailed and two motor cars (PP + MP + MP + PP or PG + MP + MP + MP) ^[5] .

It was possible to implement such a scheme only in 1995 by MPEI specialists on the ER2R-7066 electric train during overhaul. In some documents, the train was even designated as ER2S , although the marking on the cars did not change ^{[5] [1] [3]} .

The MPEI experts announced for the new scheme an estimated energy savings of 35%. During testing, only 15 ... 20% savings were confirmed. Moreover, the composition showed insufficient reliability, besides, acceleration and braking performance deteriorated. The following year, the composition was transferred to the Zheleznodorozhnaya depot, where it was operated and debugged during daily monitoring by representatives of MPEI. Operation has confirmed that the layout of the four sections does not allow you to sometimes create the desired composition. Then, changes were made to the control circuit, which made it possible to quickly switch each motor car to work in the new mode (for the four-car section) or in normal mode (for the two-car section). Thanks to this, it became possible to complete a train of ten cars. But in the latter case, since the characteristics of the sections turned out to be different, longitudinal blows to the train in traction and during electric braking began to be observed, which could negatively affect the comfort of passengers ^[5] .

The electric train ER2R-7001 did not pass the KR-1 and was decommissioned in 1987. Its head carriage No. 700109 was for a long time in Shcherbinka in an abandoned state (further fate is unknown). The head car cabin No. 700101 was installed in PTU-129 in Moscow (after merging with other institutions - railway college No. 52) as a teaching aid. Motor car number 700110 is cut into scrap. The fate of the remaining cars is unknown; probably most of them are cut into scrap metal. All other electric trains of the series continued to operate on Moscow and other railways ^{[1] [3]} .

Starting in 2010, ER2R electric trains began to be decommissioned in connection with the replacement of the inventory fleet with new ED4M electric trains .

• Nazarov O.N., Belokrylin A. Yu. Electric train of direct current ER2R (neopr.) . Professionally about electric trains . The EMU pages. Date of treatment June 19, 2016.