RU2658675C1 - Method and three-wire dc power supply system (options) - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: invention relates to the field of electrical engineering, in particular, to three-wire systems for the supply of DC power networks. In the three-wire DC power supply system, the first and second DC power sources located at station (1), set of three lines, common line (7) is connected to the common output of both sources of DC voltage at the station, wherein this output is obtained by combining one pair of outputs with opposite polarities of the output voltage. Non-ordinary line (6) is connected to an unused output of the first constant voltage source. Power line (8) is connected to the device and connected to a separate output of the second constant voltage source. In addition, polarity converters (4.1) and (4.2) have been added. Above polarity converters are connected to common line (7) and supply line (8) in accordance with their polarities. Outputs of the polarity converter are connected to the common and non-common lines according to their polarities. In the common line, the currents are compensated from the non-common and supply lines. DC loads (11) can be connected to the power supply system via the group line directly, AC loads can be connected via inverter (12).

EFFECT: group line allows you to connect loads that are located off the main lines of the power supply system.

23 cl, 27 dwg

Description

Technical field

The invention relates, in General, to DC power supply systems, stationary and mobile, mainly distributed along power supply lines, designed, in particular, for lighting roads, traction power supply.

State of the art

Known methods of power supply and their implementing systems are that they transfer energy from voltage sources to a reference station through electric lines to a load. Along these lines, loads are distributed in the form of stationary power consumers, for example, lighting, industrial. These systems are made on alternating current, as the most universal form of current. Their disadvantage is the presence of the inductive component of the current of the line itself, which limits the current load on the line and the possible length of the line, often requiring reactive power compensation devices. With the growth of current loads, there are limitations in the transfer of energy.

Known methods of DC power supply for long-distance power lines and for transport loads. These systems do not have an inductive component of current in stationary modes and therefore there are no drawbacks characteristic of AC power lines.

A known method of a two-wire DC power supply system for electric transport (VV Shevchenko, NV Arzamastsev, SS Bodrukhina "Power supply of urban terrestrial electric transport" Moscow "Transport" 1987, p. 10 Fig. 1.2b), consisting in that the loads are fed through the contact lines of both paths, and these lines are periodically connected by jumpers, that is, the contact lines of both paths are connected in parallel. With uneven movement on both paths, this gives the effect of reducing the voltage drop and energy loss in the contact lines, with a uniform load this effect is not. In addition, this method does not affect currents in the rail circuit.

Long-distance DC power lines are two-wire and three-wire. A three-wire line uses one line with a positive voltage relative to the common line, another line with a negative voltage relative to the common line. The common line is often formed by connecting to the ground the common conclusions of the sources of constant voltage of both signs. The voltages of the DC voltage sources are equal in magnitude. Such lines are also called bipolar. These power lines have more bandwidth than two-wire lines. At the initial station of the bipolar lines there are sources of constant voltage of both signs, to which one and the other line is connected. At the end station of the bipolar lines, there are two DC-to-DC converters that are convenient for further use, each for its own voltage polarity (http://lib.rosenergoservis.ru/sovremennaya-elektroenergetika?start=78 Fig. 11.5b) With unbalanced loads bipolar lines cause stray currents, with known consequences for conductive structures in the ground in the form of corrosion. The long-term ecological consequences of the flow of large currents in the earth for thousands of kilometers have not been investigated.

In bipolar power lines, intermediate power take-offs are possible. For this, parallel connection of intermediate substations to both lines with opposite voltages is used. A mandatory requirement is a symmetrical load at the end of the line. (http://lib.rosenergoservis.ru/sovremennaya-elektroenergetika?start=78, Fig. 11.6). This connection of the intermediate substation ensures the symmetry of the loads of both bipolar lines, in this case there is no current in the common line, i.e. in the ground. The connection of intermediate substations is not widespread. Their disadvantage is the obligatory symmetry of the loads along the lines, as well as the connection of the loads to the full voltage between both lines, which is twice as much as the voltage of one line. This makes it difficult to connect multiple loads. Such lines are unique.

Known methods and devices of three-wire traction power supply systems. They have a relatively low voltage, compared with long-distance power lines, which allows you to connect to the line a lot of loads distributed along the line.

A known method of power supply to the DC traction network (TP Tretyak, "Power supply system for electric railways of direct current", AS USSR No. 152 894, 1963), consisting in the fact that the power of the electric rolling stock of direct current is carried out from DC traction stations directly through the contact line, powered by the positive output of the DC voltage source of the traction station. This food is supplemented with energy from another line laid along the path with a contact line. The other line receives a DC voltage from a second DC voltage source at the traction station, with a positive polarity, the negative terminal of an individual rectifier can be connected to a contact line or to a rail circuit. Additional energy from the supply line to the contact line is supplied through the supply points located on the line, the supply points themselves include between the supply and contact lines. This method uses a three-wire power supply system with two direct current lines of the same polarity, but of different voltage relative to the common line - the rail circuit. In this method, the amount of added energy depends on voltage fluctuations in the contact line and it is difficult to achieve rational energy transfer through individual elements of the power supply system. In addition, this method does not reduce the current in the rail circuit, which is a common line.

A known method of enhancing the power supply of the DC traction network (S.N. Zasorin and A.P. Sukhoguzov "Power supply system for electric railways of direct current", AS USSR No. 488736, 1976), which consists in the fact that the load power carried out from the traction stations with direct current directly through the contact line, fed from the positive output of the rectifier of the traction station, supplemented by energy from the supply line, laid along the path from the contact line, received from a separate rectifier on the traction station, The 1st wire receives positive polarity from a separate rectifier, the negative terminal of a separate rectifier feeds the contact line. The contact line receives additional energy from the supply line through pulse converters located on the line, the pulse converters themselves are connected between the supply and contact lines. The disadvantage of the circuit is the lack of galvanic isolation between the contact and supply lines, which can lead to the contact line getting high voltage from the supply line, in case of breakdown in the pulse converter. This method does not reduce the current in the rail circuit, and therefore the loss in them and stray currents.

There is a method of enhancing the power supply of the DC traction network (Marikin A.N., Burkov A.T., Power supply system of direct current railways, PM of the Russian Federation No. 34905, 2003), which consists in that the DC load is supplied from traction stations directly through the contact line and supplement with energy from the supply line laid along the path with the contact line received from a separate rectifier on the traction station, and the supply line receives voltage from a separate rectifier with a positive polarity, from regarding rail chains. The energy from the supply line to the contact line is transmitted through the supply points with a transformer and an inverter located along the path, the supply points themselves at the inputs include between the supply line and the rail circuit. This method also used a three-wire power supply system with two direct current lines of the same voltage polarity relative to the common line - the rail circuit. This method does not reduce the current in the common line.

A known method of a three-wire trolleybus power supply system of direct current (VN Popelyash "Three-wire power supply system of trolleybuses", "Electricity", 1951, No. 12, p. 20) for distributed loads - trolleybuses. In this method of a three-wire DC power supply system, consisting in the fact that the loads are supplied from the first constant voltage source through a non-common line relative to the common line, the loads from the second constant voltage source are supplied to another line relative to the common line so that the voltage in the other line opposite in sign to the voltage in a non-common line, the unlike outputs of both DC voltage sources remaining free are combined and connected to a common line. A common line is formed by connecting each other with jumpers of contact lines, which have not become non-general and another lines.

Note on the terms. By a non-general line in the description is meant a contact line of the first path connected to the output of the first DC voltage source, by a common line is meant contact lines of the first and second path combined with each other and with the common output of both DC voltage sources. Another line in the prototype is a contact line of the second path connected to the unconnected output of the second DC voltage source. The voltage in the other line is opposite in sign to the voltage in the non-common line.

If the primary energy comes from an external power supply system, then an object with DC voltage sources is a substation. If the primary energy comes from an external energy supply system, for example in the form of gas, and is converted by the generators at the station into electrical energy, then the object with DC voltage sources is a traction power station. Traction power plants existed at the first tram systems and today are possible (“Traction power plant”, RF application for invention No. 2016132167 of 08/04/2016). To combine these two similar objects in the claims into one object, the term station is introduced.

The three-wire power supply system according to the method comprises a common line, a non-common and another line, a first and second DC voltage sources, a common line is connected to a common terminal of both DC voltage sources, formed by a combination of opposite terminals of a DC voltage source, a non-common line is connected to a non-general terminal of a first constant voltage source , the other line is connected to the other terminal of the second constant voltage source, the voltage of the constant voltage sources are equal in abs value. Moreover, the voltage values of both sources of constant voltage are the same, since they feed a load of the same type, with the same supply voltage.

A known method and device for powering a three-wire tram system for power supply of direct current (Tarnizhevsky MV, Tomlyanovich DK "Designing power supply devices for the tram and trolleybus" - Moscow .: "Transport", 1986, p. 145 Fig. 526) . In it, the power of the loads is carried out similarly to a three-wire trolleybus system. The difference in the execution of the common line, which is a rail circuit, as a result of which stray currents appear.

In this method of a three-wire DC power supply system, the loads are supplied from the first constant voltage source through a non-common line relative to the common line, the loads are supplied from the second constant voltage source from another line relative to the common line so that the voltage in the other line is opposite in sign to the voltage in non-common lines, the remaining unlike outputs of both sources of constant voltage are combined and connected to a common line. A common line is created by connecting jumpers of contact lines connected to a common output of DC voltage sources.

The power supply system according to the method comprises a common line, a non-common and another line, the first and second DC voltage sources at the traction substation, and one pair of their opposite outputs in polarity is combined, namely, the negative output of the first DC voltage source is combined with the positive output of the second DC voltage source, thereby forming a common exit. A non-common line is connected to the positive output of the first DC voltage source. The other line is connected to the negative output of the second DC voltage source. A common line is connected to the common output of the DC voltage sources.

The stresses in these contact lines are opposite in sign to each other with respect to the rail chain. The voltages of both sources of constant voltage are the same, since they feed a load of the same type - trams, with one voltage supply. The contact lines of both paths in conjunction with a common line - the rail circuit represent a three-wire line. In the common line there is a partial compensation of the current in the common line, with many loads. This leads to a decrease in stray currents, as shown in the indicated book of M. Tarnizhevsky, on p. 149, 3rd paragraph above. There is no such solution in analogues.

In this method and device of a three-wire DC power supply system, the greatest coincidence of the signs and features of the work, characterizing the prototype and the present invention.

The disadvantages of the prototype

1. Compensation of the currents of the common line is possible only with simultaneous loads on the non-common and other lines, which is difficult to implement. Loads on different paths are not interconnected. Counter currents in a common line are created by loads independent of each other in magnitude, simultaneity and location of application. The compensation effect is random and therefore has a small value. With a small number of line loads, there is no compensation.

2. Uneven loading of both sources of constant voltage of the station. Their loads are not interconnected in time and magnitude, since they are determined by the loads on the non-general and other lines belonging to different directions of the movements of the loads. The uneven loading worsens the temperature conditions of the equipment and, thereby, reduces the life cycle of the equipment of the station.

3. Difficult operational switching at the station to go to work on the classic two-wire circuit in emergency conditions.

4. The introduction of a second contact line with the opposite voltage, with respect to the first contact line, slightly reduces the load on the common line, thereby reducing the loss of energy and voltage in it. However, it is impossible to increase the number of loads or introduce new types of loads with increased power consumption due to an unacceptable voltage drop at the end of the lines or in the middle of the lines with two-way power. It is required to increase the number of stations and / or introduce reinforcing wires.

5. It is impossible to increase the energy load on the power supply system, and with a simple increase in voltage. The non-general and other lines are directly connected with the loads and this requires the complete replacement of all loads on devices with a high voltage level, an increase in the insulation level of the non-common and other lines, and a complete reconstruction of the stations.

6. Inability to compensate currents on single-track lines.

7. It is not possible to compensate for currents in a common line with bilateral supply of loads of non-common lines in double-track sections, when the loads "travel" in different directions, when there is no synchronism in time and place of their application.

8. Significant electromagnetic influence of lines.

9. The lack of reliability of the other line, because in the prototype, in addition to the function of the supply line, it also performs the function of current collection, and experiences great mechanical stresses, being a contact wire, it is also limited in the number of ways - it only feeds its own path.

10. Inability to transfer energy for loads in another line using another line with an increased voltage.

11. At a low traffic intensity, the voltage drop on a non-common line from the station to the place of application of the load may exceed the norm. This is due to the fact that large currents from the load of another line can create a voltage drop in the common line with a sign that reduces the voltage at the load in the line with small movement.

12. Lack of reliability due to false disconnection of feeders from overloads, overheating of wires of a non-common line.

13. Insufficient in magnitude and unstable in time reduction of stray currents, if the common line is made in the form of a rail circuit.

14. There is a need for powerful zero cables for connecting a common line, to reduce the voltage drop in them for tram systems.

The implemented three-wire power supply systems for the trolleybus and tram were abandoned (Tarnizhevsky MV, Tomlyanovich DK “Designing power supply devices for the tram and trolleybus” - Moscow: “Transport”, 1986, p. 145, first paragraph from above, with . 150, 2nd paragraph above).

SUMMARY OF THE INVENTION

The aim of the invention is to eliminate, at least partially, the above disadvantages of devices from the prior art.

The method of a three-wire DC power supply system, which consists in the fact that the loads are supplied from the first constant voltage source through a non-common line relative to the common line, the loads are supplied from the second constant voltage source from another line relative to the common line so that the voltage in the other line is opposite in the sign of the voltage in a non-common line, the unlike outputs of both DC voltage sources remaining free are combined and connected to a common line, the energy received by the load from a non-common line is supplemented with energy from another line, and when energy is transferred from another line to a non-common line, the polarity of the transmitted current is converted using the introduced DC polarity converter, at least one located in the zone between both DC voltage sources and the end of the non-common power zones lines, from the outputs of the DC-polarity converter, supply voltage to the non-common line relative to the common line, in the same polarity as the non-common line receives from of a DC voltage source, that the output current of the DC-polarity converter is summed in the load with current from a non-common line, with its inputs, the DC-polarity converter is connected between the other line and the common line so that the current passes between its inputs according to their polarities from the other and common lines .

A three-wire DC power supply system contains a common line, a non-common and another line, the first and second DC voltage sources, and one pair of their outputs opposite in polarity of the output voltage is combined, thereby forming a common output of DC voltage sources, the common line is connected to the common output of DC sources voltage. The non-common line is connected to the non-common output of the first constant voltage source. The other line is connected to the non-common output of the second DC voltage source. In addition, at least one DC polarity converter has been added. The common line is connected to the common output of both DC voltage sources. DC-polarity converters with inputs connected to a common line and another line, according to their polarities. The outputs of the DC polarity converter are connected to common and non-common lines, respectively, to their polarities. The positive output of the DC-polarity converter is connected to the line with positive potential, the negative output of the DC-polarity converter is connected to the line with negative potential. The first and second DC voltage sources are located at the station, DC-polarity converters are placed on the line.

Note on the terms. The voltage polarity of a non-common line relative to a common line in one embodiment can be positive, in another embodiment it can be negative. The terms general and non-general lines allow both possible embodiments to be given in the same claims. The efficiency of the device is not related to the polarity of the non-common outputs of the first and second DC voltage sources relative to the common outputs of both DC voltage sources. The terms common and non-common line characterize the connection of lines to the common and non-common outputs of constant voltage sources.

Further in the descriptions of examples of embodiments, another line for convenience of presentation is called the feed line for its new function. In the claims, the term other line for the supply line is retained. The dc polarity converter for short can be called a polarity converter.

The voltage of the second constant voltage source may be large in voltage of the first constant voltage source. This allows you to add energy to the non-common line with less loss than its transmission along the non-common line. This property is inherent in the method and device according to the method.

In cases with a high voltage of the second DC voltage source with respect to the voltage of the non-common line specified by the first DC voltage source, the voltage value is also transformed using the polarity converter, the conversion coefficient being related to the ratio of the input voltage of the polarity converter determined by the voltage of the supply line relative to the common line to the output voltage of the polarity converter, determined by the voltage of the non-common line relative to the common line.

The resistance of the supply line, reduced to the voltage of the common line, may be equal to the resistance of the common line. The resistances of both lines are determined from the station to the point of connection of the considered polarity converter, or from the nearest other polarity converter located closer to the traction station than the considered polarity converter. Equal resistance of both lines allows more fully compensate for currents in the common line. The resistance of the non-common line includes the resistance of the first voltage source, the resistance of the supply line includes the resistance of the second constant voltage source. This issue is considered in more detail below in the Example calculation of current distribution. Compensation of currents in the common line reduces the energy loss in it, which reduces the energy loss from the station to the loads and improves the load voltage mode.

Losses in the dc polarity converter can also be taken into account by slightly increasing the conversion coefficient. A similar increase in conversion factor is often used in power transformers. This loss compensation reduces the resistance introduced by the DC polarity converter into the line resistance.

There may be embodiments of a method and a power supply system when rectifier-inverter units are used as direct voltage sources, for example, for receiving recovery energy.

In another embodiment of the method and the power supply system, another polarity converter is used as the second constant voltage source, connected by its inputs to the output of the first constant voltage source, with the polarity of the connected inputs of the polarity converter and the outputs of the first constant voltage source being connected the same polarity.

In the power supply method, energy can be stored, for which the power supply system may comprise an energy storage device connected in parallel with the output of the polarity converter. An energy storage device smooths out peaks in energy consumption.

As a polarity converter, a DC-voltage converter can be used, containing a self-contained inverter in series, a transformer to provide galvanic isolation of the outputs from the inputs, in some embodiments and to lower the voltage level, and a rectifier. To pass current in the opposite direction, the rectifier may have inverting properties.

The method and device may include DC voltage sources and / or polarity converters with the function of regulating the output voltage.

The supply line can be made in the form of an insulated self-supporting wire, and the wire can be embodied in the form of an electro-optical wire.

The supply line connected to the negative output of the second DC voltage source, together with the rail circuit or with the contact line can be used to generate energy for non-traction consumers.

The method and system of three-wire power supply can be used when transferring energy from constant voltage sources of one station in different geographical directions from it, with its combination of non-common, common and different lines for each direction of energy transfer. The station in this way can be nodal. Such stations are characteristic of urban electric vehicles.

For multi-track sections with separate power supply for each path, a three-wire DC power supply system contains a common line of all paths, non-common lines of all paths, other lines of all paths, the first and second DC voltage sources, and the common line of both paths is connected to the common output of both DC voltage sources, obtained by combining one pair of their outputs, opposite in polarity of the output voltage. Non-common lines of each path are connected to non-common outputs of the first constant voltage source. Other lines of each path are connected to the non-common output of the second DC voltage source. In addition, at least one DC polarity converter has been added for each path. The common line is connected to the common output of both DC voltage sources. The direct current polarity converters of each path with inputs are connected to a common line and another line of its path, corresponding to their polarities. The outputs of the direct current polarity transducers of each path are connected to a common line and non-common lines of their path, corresponding to their polarities, namely, the positive output of the direct current polarity converter is connected to the line with positive potential, the negative output of the direct current polarity converters is connected to the line with negative potential. The first and second DC voltage sources are located at the beginning of the lines, DC-polarity converters are located on the line, between the station and the end of the lines. Multi-track sections with a common rail chain as a common line are typical for railways.

The resistance of the other line of each path, reduced to the voltage of the non-common line, is equal to or at least close to the resistance of the non-common line of its path, both resistances are determined from both sources of constant voltage to the point of connection of the considered converter of polarity of direct current of its path, or from the nearest other converter of polarity of direct the current of its path, which is closer to both sources of constant voltage than the considered converter of polarity of direct current.

An energy storage device is connected between the non-common line and the common line, this is conveniently done at the point of connection of the polarity converter to these lines.

Another line and / or non-common line in the embodiment without the function of the contact wire can be made in the form of an insulated self-supporting wire. This improves the performance of the lines.

The DC polarity converter together with switching equipment, buses of other lines and non-common lines, as well as control equipment can be placed in one unit / room, thereby forming a supply point. These tires are divided into sections of each path at the power point of the tire section of the same lines of multi-track sections. For multi-track sections, starting from a three-track section, sections of the same busbars, non-common and supply lines are interconnected via the first outputs of their switching devices in a nodal scheme, and the second conclusions of the switching devices are interconnected into a node separate for bus sections of the same name.

Brief Description of the Drawings

The figure 1 shows the principle of operation of the three-wire power supply system according to the invention.

1 - station with constant voltage sources;

2 - the first source of constant voltage;

3 - the second source of constant voltage;

4 - converter polarity DC;

5 - DC load;

6 - non-general line;

7 - common line;

8 - other / supply line.

The figure 2 shows the equivalent circuit of the power supply system of figure 1.

The figure 3 shows the location of the objects of the method and the power supply system and the change of currents along the power zone, one station 1, one polarity converter 4 and one load 5, located to the right of the connection of the polarity converter.

In figures 4 shows the location of station 1, three transducers of polarity 4 and three loads 5, in addition, presents the change in currents and voltages along the lines.

параметры по изобретению;

parameters of the invention;

параметры по прототипу.

parameters of the prototype.

Figure 4.1 shows the location of these objects, and loads 5.2 and 5.3 are located at the connection point of the transducers of polarity 4.2 and 4.3, the load 5.1 is located between station 1 and the transducers of polarity 4.1. Figure 4.2 shows the change in currents along the non-common line according to the prototype and according to the invention, figure 4.3 shows the change in voltage along the non-common line according to the invention and according to the prototype.

Figure 5 shows an example embodiment of a three-wire power supply system for power lines with connecting intermediate loads.

9 - output DC-DC converter at the output station.

Figure 6 shows an example of a three-wire power supply system for stationary loads located along a three-wire line, with the connection of two load groups 11 and 14.

10 - disconnectors between non-common and common lines and group lines of loads;

11 - the first group line of loads;

12 - the first load;

13 - Converter DC to AC;

14 - the second group line of loads;

15 - second load.

The figure 7 shows the location of the objects of the method and device of a three-wire power supply system for powering non-traction consumers near the railway, using a constant voltage used as a voltage for the supply line used for traction of trains. Two transformers of polarity 4.1, 4.2 and two loads 5.1 and 5.2 are shown.

Figures 8.1 and 8.2 show the location of the objects of the method and device of the three-wire power supply system, the change in voltage along the power supply zone under loads evenly distributed along the lines, using the example of a trolleybus load on the feeder zone with one-way power supply.

In figures 9 shows the location of the objects of the method and device of a three-wire power supply system with a common line in the form of a rail chain, typical for rail modes of transport: tram, metro and railways. The change in voltages and currents along the supply zone is shown.

Figure 9.1 shows the location of station 1, one polarity converter 4 and one load 5, with a graph of currents in the rail circuit and stray currents, with one-way power supply.

Figure 9.2 shows the location of stations 1.1 and 1.2, three transducers of polarity 4.1, 4.2 and 4.3, on a feeder zone with two-sided power supply, under loads uniformly distributed along the rail circuit. Figure 9.3 shows the change in the magnitude of the voltage in non-common line 8.

Figure 9.4 shows the flow of stray currents.

The figure 10 shows a diagram of a three-wire power supply system of the traction network for a double-track line with separate power supply paths. This may apply to railways, subways and tram lines with separate track power.

8 'is the supply line of the first path;

8 '' is the supply line of the second path;

6 'is a non-general line of the first path;

6 '' is a non-general line of the second path;

4.1 and 4.3 - direct current polarity converters of the first path;

4.3 and 4.4 are second-way direct current polarity converters.

In figures 11.1 and 11.2, embodiments of the second 3 and first DC voltage source 2 are shown in the form of DC / DC converters.

Figure 11.3 shows the inclusion of an energy storage device in the installation area of the polarity converter.

16 - energy storage.

Figure 11.4 shows the possible inclusion of a DC-voltage converter for supplying consumers in the installation area of the DC-polarity converter; voltage for a non-common line is a supply line.

Figure 11.5 shows the inclusion of the Converter for voltage non-common line - rail circuit and energy storage 16.

17 - Converter DC to single phase.

Figure 12.1 shows the possible location of the supply line 8 in space, together with non-common 6 and common 7 lines of the trolleybus contact network. Figure 12.2 shows the possible location of the supply line 8 on the support of the contact network of the main railway.

The figure 13 shows the main elements of a possible embodiment of a DC polarity converter in the form of a sequence of an autonomous inverter, a galvanically isolated transformer and a rectifier.

18 - autonomous inverter;

19 - transformer with galvanic isolation;

20 - rectifier output keys.

Figure 14 shows the main elements of a possible embodiment of a stand-alone inverter, and a rectifier-inverter, the keys of which are made on IGBT - transistors with a reverse diode.

21 - IGBT - transistors of input keys;

22 - IGBT - transistors of the output keys;

23 - control system;

24 - input capacitor;

25 - output capacitor.

Figure 15 shows a possible embodiment of a supply point for double-track railways.

26 - feeding point;

27 - optical line with protective shells;

28 - transceivers of the optical line;

29 - the first section of the supply line bus, for the 1st path;

30 - the second section of the supply line bus, for the 2nd path;

31 - sectional switching device bus supply line;

32 - the first section of the bus non-common lines for the 1st path;

33 - the second section of the bus non-common lines for the 2nd path;

34 - sectional switching device bus non-common lines;

35 - switching apparatus connecting the first section of the bus supply line to the supply line of the 1st path to the left;

36 - switching apparatus connecting the first section of the bus supply line to the supply line of the 1st path to the right;

37 - switching apparatus for connecting the second section of the bus supply line to the supply line of the 2nd path;

38 - switching apparatus for connecting the first section of the bus non-common line to the non-common line of the 1st path;

39 is a switching apparatus for connecting a second section of a bus of a non-common line to a non-common line of the 2nd path;

40 — first polarity converter;

41 - second polarity converter;

42 - backup polarity converter;

43 - switching apparatus for connecting the negative input of the first polarity converter to the busbar section of the supply line, for the 1st path;

44 - switching apparatus for connecting the negative input of the second polarity converter to the section of the supply line bus, for the 2nd path;

45 - switching devices for connecting the positive inputs of the polarity converters to a common line;

46 - switching device for connecting the positive output of the first polarity converter to the first section of the bus common lines, for the 1st path;

47 - switching apparatus for connecting the positive output of the second polarity converter to the second section of the bus common lines, for the 2nd path;

48 - switching apparatus for connecting the negative input of the backup polarity converter to the section of the supply line bus, for the 1st path;

49 - switching apparatus for connecting the negative input of the backup polarity converter to the section of the supply line bus, for the 2nd path;

50 - switching apparatus for connecting the positive output of the backup polarity converter to the first section of the non-common line bus, for the 1st path;

51 - switching device for connecting the positive output of the backup polarity converter to the second section of the bus of a non-common line, for the 2nd path;

52 - output reactors of polarity converters;

53 - switching devices for connecting the negative output of energy storage devices to a common line;

54 - switching devices for connecting the positive output of energy stores to bus sections of the required lines.

ШНЛ 1, ШНЛ 2 - the first and second sections of the bus common line;

ШПЛ 1, ШПЛ 2 - the first and second sections of the supply line bus.

Figure 16 shows a possible embodiment of a feeding station for three-track railways.

55 - third polarity converter;

56 - the third section of the supply line bus, for the 3rd path;

57 - the third section of the bus non-common lines for the 3rd path;

58 is a switching apparatus for connecting a third section of a supply line bus to a supply line of a third path on the left;

59 is a switching apparatus for connecting a third section of a supply line bus to a supply line of a third path on the right;

60 — switching apparatus for connecting the third section of the non-common line to the non-common line of the 3rd path;

61 - switching device for connecting the second section of the bus supply line to the first and / or third sections of the same bus;

62 - switching device for connecting the third section of the bus of the supply line to the first and / or second sections of the same bus;

63 is a switching apparatus for connecting a second section of a bus of a non-common line to the first and / or third sections of the same bus;

64 is a switching apparatus for connecting a third section of a bus of a non-common line to the first and / or second sections of the same bus;

65 is a switching apparatus for connecting the positive terminal of the backup polarity converter to the third section of the non-common bus line;

ШНЛ 3 - the third section of the bus common line;

ШПЛ 3 - the third section of the supply line bus.

Description of preferred embodiments

The figure 1 on the example of an embodiment shows the principle of operation of the method and the power supply system, in which at station 1 there are first 2 and second 3 DC voltage sources, one DC polarity converter 4 and one load 5. The load is not part of the power supply system, but it is important to understand the operation of the system. The load is connected between non-common line 6 and common line 7. In the example, a three-wire power supply method is implemented in which the first constant voltage source 2 is connected by its positive output to the non-common line, and thereby supply power to load 5, the first constant voltage source 2 is connected by its negative output with a positive output of the second constant voltage source 3 and connected to a common line 7. The negative output of the second constant voltage source 3 is connected to another line 8, which plays the role of a pit line, additionally supplying the load through the DC polarity converter 4. To match the directions of the supply currents from two lines in load 5, and thereby summing these currents in it, the polarity is converted so that the non-common line receives voltage from the polarity converter 4 in that the same polarity as the non-common line receives from the first source of constant voltage. Therefore, voltage is supplied to the non-common line 6 from the positive output of the polarity converter 4, and voltage is supplied to the common line 7 from the negative output of the polarity converter. The polarity converter 4 is connected with its inputs so that the positive input is connected to the common line 7, the negative input is connected to the supply line 8, which has a negative voltage relative to the common line 7. The input current of the polarity converter appears from the positive output of the second voltage source, passes through the common line 7 , then, through the polarity converter itself, it enters the supply line 8 and returns to the second constant voltage source. The output current passes through non-common line 6 to load 5, returning via common line 7 to polarity converter 4.

Energy flows along non-common 6 and supplying 8 lines go from station 1 to load 5. Energy through non-common line 6 in the form of current I _1.2 passes from the station to the load, and along the supply line in the form of current I _1.3 , which flows physically from load 5 to stations 1. Energy, and passes along a common line in the form of these currents. They are directed towards each other in a common line. To implement the passage of current through the common line in this way, the voltage to the supply line is applied negatively relative to the common line. This implements bipolar energy transfer to the load via three wires. The DC-polarity converter provides the summation of the additional energy received by the load from the non-common line with the energy received from the supply line.

Load 5 is located at the connection point of the DC-polarity converter. The current in the load goes from top to bottom in the figure and has two components. One component I _1.2 comes from the traction station 1 from the first direct current source 2 along the non-common line 6. Current I _1.2 returns along the common line 7. The second component of the load current 5 - I _4out comes from the polarity converter 4, in the direction according to the current I _1.2 .

Current I _1.3 is the input current of a polarity converter I _4in . It returns to the second DC source 3 along the supply line 8.

In the diagram, the potential of the common line 7 is taken to be zero, then on the non-common line 6 there will be a positive potential relative to it, and on the supply line 8 there will be a negative potential.

In the common line 7, the currents flowing from the load to the station and from the station to the polarity converter are counter-directed and cancel each other out. These currents are caused by the same load, always simultaneous, even at a single load. If the transmitted energies are equal using the non-common line 6 and the supply line 8, and the voltages are equal in them, there will be no current at all in the common line 7. There will be no voltage drop and energy loss in it. The case of voltage inequality is considered below in the example of calculating the current distribution.

If the common line 7 is represented by a rail circuit, then due to the lack of current in it, a stray current will not branch into it from the ground.

In another embodiment, the first constant voltage source 2 can be connected by its positive output to the negative output of the second constant voltage source 3. In this case, the polarity of the inputs and outputs of the transformer of the polarity to the supply, common and non-common lines will change, in accordance with the connection rule specified in the formula of the method. The polarity of a non-common line will not affect the ratios of currents in lines and transmitted energies, positive effects arising from this.

Approximate calculation of current distribution

Figure 2 presents the equivalent circuit of the electrical circuit of figure 1. It is used to determine the currents in the system.

The equivalent circuit in figure 2 is based on the reduction of the resistance of the supply line to the voltage at the load, that is, to the voltage of the source E1. R _pl = R _nl / K _pp . To _pp is the voltage conversion coefficient of the polarity converter. The resistance of the non-common line includes the resistance of the first voltage source, the resistance of the supply line includes the resistance of the second constant voltage source. We take the current in the load depending only on the mode of its operation, not depending on the voltage on it. This is a feature of most motor loads, including traction loads. We assume that the voltage across the loads corresponds to the rated voltage within the limits of permissible deviations. The load resistance in such cases is always greater than the resistance of the power lines.

The passage of currents is as follows. Current I _nl (non-common line current 6). From the first DC voltage source E1 via non-common line 6, then by load 5 (R _nl ) with return via common line 7.

Current I _PL (current supply line 7). From the second DC voltage source E2 through the common line 7, the polarity converter 4, then return to E2 via the supply line 8. This current is the input current of the polarity converter.

The common line current is formed from currents flowing towards each other from non-common and supply lines. I _ol = I _nl -I _pl .

The output current of the polarity converter 4 - I _4out . The current exits the polarity converter 4, passes through the load 5 and returns to the polarity converter 4. The source of energy for this current is the input current of the converter, obtained through the supply line I _pl .

Since the voltage at the input and output of the polarity inverter taken equal to the equivalent circuit, the input and the output of polarity inverter currents are equal in magnitude I _sq = I _4vyh but oppositely directed.

The current in load 5 has two components: I _nl and I _4out , passing through the load according to.

The currents received by the load 5 from the non-common line 6 I _nl and from the supply line 8 through the polarity converter _I4out will be divided between the indicated lines in inverse proportion to their resistances.

We assume that the wires of the non-common line 6 and the supply wire 7 have the same resistance R _nl = R _pl , then the load current will be divided between them in half. That is, I _4out = I _PL = I _nl . This is possible when the wire cross sections of these lines are equal in copper equivalent and the same length.

Then the current in the common line I _ol = I _PL -I _nl = 0. This line will not affect the current distribution between the non-common line and the supply line.

In another case, with a voltage in the supply line of 1200 V and in a non-common line of 600 V K _pp = 2. The current received by the load from the polarity converter will be 2 times greater than the current from the non-common line I _nl , since the resistance R _PL = R _nl / K _pp .

This means that in a real circuit, the current flowing along the supply line I _PL turns out to be 2 times less than the output current of the _I4out converter due to K _pp = 2. That is, it is equal to the current I _nl . Both of these currents are subtracted from each other in a common line. As a result, physically the current in the common line I ₇ will be absent, and this line will not affect the current distribution between the non-common line and the supply line.

An example of calculating current distribution with different voltages shows that the current in the load is 1/3 received from the non-common line and 2/3 received from the supply line through the polarity converter. Compared to a conventional two-wire power circuit, the current in a non-common line is reduced by a factor of three. Accordingly, the voltage drop in it will decrease by three times. There is no voltage drop in the common line, since there is no current in it and therefore it does not increase the voltage drop in lines 6 and 7 to load 5. The total voltage drop to the load, defined as the sum of the voltage drops in the non-common and common lines, decreases. With full compensation of currents in a common line, for example, this voltage drop decreases six times in total, compared with a two-wire power supply system.

If the stresses are equal, the total voltage drop in lines 6 and 7 to load 5 will decrease by 4 times. This is due to a 2-fold decrease in the current in the non-common line and the absence of a voltage drop in the common line 7, due to the compensation of currents in it. If the supply voltage is equal and the common line, the supply line unloads the non-common line in current only 2 times.

The resistance of the current path circuit between the station and the load along the common line is “decreasing”, as a result of current compensation from non-common and supply lines. Currents, "passing" along a common line, as shown above, do not create a voltage drop and energy loss in it from compensated currents. This reduces the overall voltage drop in the traction network and the energy loss in the traction network as a whole. There will be no energy losses in the common line from the passage of load currents along it.

This effect is physically similar to the effect of the "disappearance" of the current in the neutral wire of a three-phase load with symmetry of the loads of three phases. "Balancing", namely, the alignment of the currents of the common and supply lines, is carried out by turning on the DC polarity converter with the described circuit for its inclusion and the voltage conversion coefficient determined by the ratio of input and output voltages. In the invention and the three-phase power supply system, a widely used technique is used in the technique of compensating for some manifestations of physical effects with similar effects, but in a different direction, giving, in geometric form, in the general case, zero manifestation of the effect. The combination of features of a method and a device similar to the invention is unknown from the prior art, giving the same effect as the invention for solving the specific problems of energy transfer described as examples here and below.

The figure 3 presents a diagram with great approximation to practical cases, when the load 5 is applied to the common and non-common lines at some distance from the polarity converter, away from the station. This case is possible for loads that are not combined at the place of application with the installation site of the polarity converter or for non-stationary loads at the place of application, namely, traction loads. In this case, currents flow along the common line, flowing locally to the load from the nearest energy source - the polarity converter. Compensation of currents in the common line will appear between station 1 and the polarity converter 4. In the part of the common line, between the polarity converter and the load, there will be no current compensation. The effect in the zone between station 1 and the polarity converter 4 is saved. To reduce the flow zones of such local load currents, it is possible to increase the number of polarity converters in excess of one.

In figures 4 presents a diagram of a three-wire power supply system with several transducers of polarity and several loads, which differs from the schemes in the previous figures even closer to practical cases.

The figure 4.1 shows a diagram of a three-wire power supply system with three loads and three polarity converters. Load 5.1 is located between station 1 by a polarity converter 4.1. Loads 5.2 and 5.3 are included at the connection point of the converters 4.2 and 4.3, respectively.

Figure 4.2 shows the distribution of currents: I _ol total, I _nl non-common and I _pl supply lines. The direction of the current in the supply line to the station is taken to be positive, the direction of the current in the non-common line from the station is taken to be positive, the direction of the current in the common line to the station is taken to be positive. The dotted line shows the currents of the prototype. In this case, currents in the common line are everywhere, increasing with approach to the station.

In sections 4.1-4.2 and 4.2-4.3, there will be no current in the common line, since thanks to the polarity converters in the common line there will be compensation for currents received by the loads through the non-common and supply lines. On the head section 1-4.1 of the common line, the currents from the loads 5.2 and 5.3 will also be compensated. At the head section, local currents I _ol from load 5.1 to station 1 and to the polarity converter 4.1 are directed in different directions with respect to each other and they cannot be compensated. However, the total voltage drop from the load currents 5.1 cancel each other, facilitating the flow of currents of other loads.

By local currents we mean the currents created by the load and flowing along the common and non-common lines between two voltage sources, namely between the station and the polarity converter or two polarity converters. Outside the specified section, these currents are distributed between the supply and non-common lines using polarity converters and are summed with the same currents from other loads, flowing through the entire power supply system. The currents passing through the polarity converters determine the main parameters of the system and act globally, in contrast to the load currents in local areas.

The currents in the common and non-general lines according to the invention are reduced compared with the prototype. In the non-common line, the currents decrease, since the supply line supplements with its energy the load energy received from the non-common line. In addition, at the head section, the load current 5.1 coming from the polarity converter partially compensates the current of other loads 5.2 and 5.3. In the example, the voltage of the supply line is taken equal to the voltage of the non-common line. The current in the supply line increases when approaching the station. The current in the common line decreases, as indicated above, due to compensation. It is always valid for all loads. Even for local loads in the part that passed through the polarity converter.

Figure 4.3 shows the change in voltage on a non-common line relative to a common line U _nl , that is, the voltage applied to the loads. This voltage characterizes the quality of energy supplied to the loads. Figure 4.3 shows that the voltage drop for loads along the lines of the three-wire power supply system according to the invention is much less than that of the prototype. This is caused by a decrease in currents that physically flow along non-common and common lines, as shown in figure 4.2.

The currents at local sections in the common line are reduced significantly, due to the exclusion of the influence of loads on the remaining sections of the power supply system. The currents at local sites in the non-general line are also sharply reduced, due to the adoption of half the load or more by the supply line. The total voltage drop in the local sections of the common line, taking into account the sign of the flow of local currents from the load, will be partially or fully compensated. The total voltage drop in the local sections of the non-common line, taking into account the sign of the flow of local currents from the load, will also be partially or fully compensated. Both last circumstances, taking into account also the general decrease in currents in the common and non-common line, reduce the voltage drop between the non-common and common line, which is applied to the load. Thus, the voltage level at the load increases.

The figure 5 presents the embodiment of the method and three-wire power supply system for power lines. The power supply system has, for example, two DC polarity converters 4.1 and 4.2. Loads that are not included in the system are connected at the connection point of the converters via disconnectors 9. The loads themselves are not shown in the figure.

In this power supply system, the loads are supplied from the positive (non-common) output of the first constant voltage source, which in the example has a positive voltage, relative to a common line that is connected to the unified outputs of both constant voltage sources at the station. From the non-common output of the second constant voltage source having a negative voltage in the example, the loads are supplied with power to the supply line, so that the voltage in the supply line is negative with respect to the voltage in the non-common line. Both voltages are obtained relative to the common line. The energy received by the load from the non-common line is supplemented with energy from the supply line through a DC current polarity converter, at least one, and when the energy is transferred from the supply line to the non-common line, the polarity of the transmitted direct current is converted, so the polarity of the output current becomes positive relative to the common line . The polarity of the input current of the polarity converter connected to the supply line is negative. The load receives current from the polarity converter in positive polarity, as does the current received by it along a non-common line from the first direct current source with positive polarity.

The load is connected at the points where the DC-polarity converters are connected. This connection allows you to select power from a three-wire power supply system at intermediate points between the transmitting and receiving stations, without breaking the symmetry of the currents in the non-common and common lines. This allows you to have a common line of small cross section, necessary for the system to operate in emergency conditions with less power or to work with a certain number of local loads.

At a lower voltage in a non-common line compared to the supply line, the input load nodes are simplified. Polarity converters take voltage reduction from the main, according to the transmitted power, supply line. This simplifies such connections and can increase the number of connected loads having an operating voltage corresponding to a common line voltage.

When using a polarity converter 4.3 at the receiving station, a single DC-voltage converter 15 will be enough to supply the loads and there is no need to balance the load of the two converters, as is necessary in the analogue. The number of converters of one insulation class at the receiving station remains the same.

Grounding the common line is useful for fixing on the non-common and supply lines the voltage level of insulators relative to the ground, and on the common line of voltage close to the voltage of the earth. This simplifies the insulation design of all lines of the three-wire system. Grounding of relatively short lines can be made at one point. In long lines, it is advisable to ground at several points. With this grounding of the common line, it will not create stray currents in normal conditions, since the returning currents of the non-common and supply lines will mutually cancel each other in the common line due to the polarity converter.

Figure 6 shows a possible embodiment of a three-wire power supply system for loads located along extended objects, for example, road lighting, loads located along railways that are difficult to connect to public networks, for example, due to their remoteness from loads.

The power supply system has, in the example on the track, two polarity converters and load groups 11 and 14 powered by the power supply system. To power the load group 11, at the point of connection of the polarity converter, the voltage was removed from the non-common line and the common lines through the disconnector 9 to the group line 10. The last one is used to power the loads 11. This connection is convenient when the power supply to the loads 11 corresponds to the voltage of the non-common line relative to the common line.

If the loads are AC power receivers, then between the three-wire power supply system and the load groups, after the disconnectors 9, they include DC-to-AC converters 12 (inverters) having the required number of phases and voltage value at the output.

The main lighting energy is transmitted to the track along the supply line, which has a significantly higher voltage than the voltage of a non-common line. Both voltages are taken relative to the common line. The energy losses in the supply line will be small due to the indicated conditions and it is possible to supply the loads at a considerable distance from station 1. The purpose of the non-common line is to fix a small voltage, compared with the voltage of the supply line, convenient for connecting a large number of loads and inverters. The group line allows you to power loads that go not only along the lines of the power supply system, but away from it. The system can perform the function of linear power supply, such as, for example, longitudinal power supply to non-traction railway consumers.

In this embodiment of the power supply system, the load power, as in the previous embodiment of FIG. 5, is supplied from the positive (non-common) output of the first DC voltage source, which in the example has a positive voltage, relative to a common line that is connected to the unified opposite outputs of both DC voltage sources at the station. From the non-common output of the second constant voltage source having a negative voltage in the example, the loads are supplied with power to the supply line, so that the voltage in the supply line is negative with respect to the voltage in the non-common line. Both voltages are obtained relative to the common line. The energy received by the load from the non-common line is supplemented with energy from the supply line through a DC current polarity converter, at least one, and when the energy is transferred from the supply line to the non-common line, the polarity of the transmitted direct current is converted, so the polarity of the output current becomes positive relative to the common line . The polarity of the input current of the polarity converter connected to the supply line is negative. The load receives current from the polarity converter in positive polarity, as does the current received by it along a non-common line from the first direct current source with positive polarity.

The figure 7 presents a three-wire power supply system for powering non-traction loads for an electrified railway. These loads are located along the railway, as in the case of figure 6. The difference is that as the second source of constant voltage 3, a converter of the traction station for constant voltage, for example 3.3 kV, is used to power the traction load. Its voltage is positive relative to the common line, which is used as a rail circuit. As a second source of constant voltage, a special converter is used with a relatively small voltage, convenient for supplying loads, for example, 300-500 V. This voltage is supplied to a non-common line with a negative voltage relative to a common line - a rail circuit.

It also uses the method according to the invention, in the implementation of which from the previous embodiments there are the following differences. In the supply line, the voltage relative to the common line is positive; in the non-common line, the voltage relative to the common line is negative. That is, these voltages are inverse to the corresponding voltages of other implementations. However, the energy flows in the same directions and in the same proportions. The DC polarity converter is also current when transferring it from the supply line to the non-common line. There are also exactly the same decrease in currents in the common and non-common lines, compensation of voltages in these lines, improvement of the voltage mode at loads, caused by the same reasons that are listed above. By using the terms of the lines without indicating their polarity, all of the above embodiments are described by one formula of the method and one formula of the power supply system.

In this embodiment, it is advisable to make a non-general line in the form of an insulated self-supporting wire, so that high voltage from the supply line or contact line does not hit the load in case of accidents. To control the operation of the DC-polarity converter and other equipment, a self-supporting insulated wire must be made in the form of an electro-optical wire.

Figure 8.1 shows a three-wire power supply system with direct current polarity converters 4.1, 4.2 and 4.3, and evenly distributed loads along the lines of the power supply system. The load of trolleybus and tram power supply systems with parallel connection of contact lines is close to this case. The voltage in the non-common line relative to the common line is shown in figure 8.2. The connection of unipolar contact lines of two paths between each other increases the number of loads and brings them closer to a uniform distribution along the feeder zone. In fact, this is a single track section. It is enough to have in this case one reinforcing line.

The voltage in the non-common line is reduced much less than in the prototype, due to the energization through the polarity converter and current compensation in the common line, as well as the partial compensation of voltage drops from the load in the non-common line, as well as in the above examples of embodiments of the method and power supply system.

The available compensation allows for a reduction in the cross section of the common line wire for the trolley bus. It should be designed only for local currents. The resistance value of this line practically does not affect the current distribution between the supply and non-common lines. Due to compensation of currents in it, there are no losses of energy and voltage in it, which halves these indicators of losses in the contact network of the trolley bus.

In a tram system, the distribution of currents and voltages corresponds to figure 8.2, the difference is only in the appearance of stray currents, described below.

The features of the method and the three-wire DC power supply system with a common line made in the form of rails are considered in figures 9.

The circuit in figure 9.1 is similar to the circuit in figure 3. The execution of a common line in the form of a rail circuit generates a stray current. The passage of current along the rail circuit creates a voltage drop along the rail. Since there are transition resistances in the form of sleepers between the rails and the ground, so part of the current from the common line has the ability to branch into the ground. The part of the common line where local load currents are present will correspond to voltage drops in the rail circuit and stray currents. This local part of the common line creates stray currents only from local currents. Therefore, the section of the common line between the load 5 and the connection point of the transformer of polarity 4 will correspond to stray current. There is no current in the rail circuit between the connection point of the polarity converter 4 and station 1. This section does not serve for the appearance of stray current. There is nothing to branch out and there is no potential difference.

The potential difference along the rails from the passage of the local current I _rc will be significantly less than in the absence of a polarity converter, therefore, the value of the stray current will be less. The covered area of the earth by stray current will also be less, since the area of the rail chain generating it is smaller.

Two-way power does not introduce significant differences in the use of the method and power supply system according to the invention. If the power is on the one hand, for example, from the side of station 1.1, the operation of this circuit will be reduced to the operation of the circuit of figure 8.1. Having imposed its symmetrical reflection on this circuit, the power supply only from the station 1.2, we obtain the voltage distribution according to figure 9.3. With a symmetrical load of the section relative to the DC-polarity converter 4.2, it will receive equal currents from both stations.

Figure 9.2 shows the location of two traction stations 1.1 and 1.2 and three transducers of polarity 4.1, 4.2 and 4.3 on the feeder zone between these two stations, with two-way power and single-track movement.

The embodiment of FIG. 9.2 is no different from previous embodiments in the method and system of power supply. In this power supply system, the loads are supplied from the positive (non-common) output of the first constant voltage source, which in the example has a positive voltage, relative to a common line that is connected to the unified outputs of both constant voltage sources at the station. From the non-common output of the second constant voltage source having a negative voltage in the example, the loads are supplied with power to the supply line, so that the voltage in the supply line is negative with respect to the voltage in the non-common line. Both voltages are obtained relative to the common line. The energy received by the load from the non-common line is supplemented with energy from the supply line through a DC current polarity converter, at least one, and when the energy is transferred from the supply line to the non-common line, the polarity of the transmitted direct current is converted, so the polarity of the output current becomes positive relative to the common line . The polarity of the input current of the polarity converter connected to the supply line is negative. The load receives current from the polarity converter in positive polarity, as does the current received by it along a non-common line from the first direct current source with positive polarity.

The graphs are based on a uniformly distributed load along the feeder zone, and the same resistance values of the common and supply lines. To plot the current in the rail circuit, it was taken into account that at the connection point of the polarity 4 converters, the current in the rail circuit will be zero, due to the leveling properties of the polarity converters.

If the voltage in the supply line 8 is equal to the voltage in the non-common line 6, the current in the non-common line at the traction station to the left of the loads located near the polarity converter in section A and then it will decrease by half, and the voltage drop in the non-common line will be reduced by half from these currents . Local currents from loads between station 1.1 and polarity converter 4.1 will be added to the remaining current. The local load currents received from neighboring polarity converters are directed in different directions, the voltage drops generated by them are directed opposite each other, as shown in Figure 4. These local voltage drops reduce the total voltage drop in such a section of the non-common line.

The voltage of the non-general line of the prototype, represented by a dotted line, represents one curve over the entire feeder zone with a larger value of the minimum of the curve, compared with local minima of the same voltage according to the invention. In the general line, the voltage drops will become smaller than in the prototype, since the physically flowing current will significantly decrease, the algebraic sum of the voltage drops in the local sections of the non-common line will also decrease due to the mutual compensation from different directions of local currents along the non-common line.

Stray currents will acquire a local character, since they will be a manifestation of local currents in the rail circuit, flowing in local sections of a non-common line, between energy sources connected to it. Local currents themselves are much smaller than the global currents of the prototype, determined by all the loads of the entire feeder zone. Stray currents are created by local currents in a common line, flowing in opposite directions to each other in local areas. This sharply reduces the coverage of the earth, increases the resistance of the earth to the flow of stray current and further reduces stray currents.

The reduction of currents in the common and non-common lines for any combination of loads, in comparison with the prototype, reduces the requirements for the cross-section of the cable supplying the common line from the station, energy loss and voltage drop, and reduces the protection settings.

The disadvantages of the prototype

The disadvantage number 1. Compensation of currents in the common line occurs at any number of loads located in the area of connection of the DC polarity converter and then the polarity converter to the side of the DC voltage sources at the station. Compensation is generated automatically by turning on the DC polarity converter.

Drawback number 2. Both DC voltage sources are simultaneously loaded, due to the equalization of currents created by the polarity converter, regardless of the number of loads. A small additional load will be at the constant voltage source supplying the non-common line from local loads located near the stations in the initial part of the zone between the station and the first polarity converters. It can be taken into account when determining the installed power of the specified constant voltage source. The power of the DC voltage sources is selected taking into account their output voltages. The uneven loading of DC voltage sources relative to their installed capacities at the stations is practically absent.

Drawback number 3. Operational switching at the station for switching to work according to the classical two-wire circuit is easily carried out by disconnecting the supply line and polarity converters.

Drawback number 4. In the invention, amplification is achieved by introducing one line - the supply line, which unloads the non-common line, from which the loads are directly fed. The reduction of energy and voltage losses occurs not only in the non-common line, but also in the common line, due to the significant and constant compensation of the current in it, unlike the prototype, due to the introduction of a supply line with a different polarity than in the non-shared line, in conjunction with polarity converter.

In the case of rail execution of a common line, its resistance is less than that of a non-common line, therefore, the main effect of reducing voltage losses is brought by a non-common line, the contribution of the rail circuit is less. However, a significant decrease in currents in the rail circuit - a common line, leads to another important effect - a decrease in stray currents.

Drawback number 5. As shown in the application examples, when the voltage in the supply line is greater than in the non-common line, the standard voltage for them received from the non-common line remains at the loads. Polarity converters take over voltage of the supply line. Since most of the energy is supplied through the supply line, this allows you to increase the number of loads, or introduce new types of loads with increased power consumption, you can also increase the distance between stations, with a decrease in their number.

Drawback number 6. Compensation is possible on single-track sections of traction three-wire power supply systems. Current compensation in a common line is not related to the number of paths.

Drawback number 7. It is possible to work with two-way power supply of non-common lines at double-track sections. Compensation of currents in the common line, outside the local sections with loads, occurs at any number of loads, in the local sections there is compensation for the voltage drop across the entire local section, which improves the voltage mode on the non-common line.

Drawback number 8. The electromagnetic influence of the lines will decrease, since in the circuit a non-common line - a common line, the value of the affecting current will decrease, and the value of the influence current in the circuit will decrease the common line - the supply line. The geometry of the contours, which creates influences, will decrease, for the most part there is no current in the common line, it is reduced in local areas.

Drawback number 9. Another line in the prototype has two functions: current collector and power only its path, it is made as a contact wire. In the invention, it is deprived of the function of current collection, which simplifies its design and increases reliability, since there is no retraction and constant mechanical loads, and the power function is extended to any number of paths. This is the supply line.

Drawback number 10. The other line has the main function of transferring energy to loads connected to non-common lines.

Drawback number 11. Compensation of currents in the common line occurs at any number of loads located in the area of connection of the DC polarity converter and then the polarity converter to the side of the DC voltage sources at the station. Compensation from loads near the station may not be, but there are no problems with the voltage drop on the load due to the small distance from the station and, accordingly, the low resistance of live lines.

Drawback number 12. Due to the distribution of traction currents along two lines, the traction currents are reduced on each line, and short-circuit currents remain the same. Therefore, the number of false positives of overload protection will be significantly reduced. This will reduce interruptions in the supply of electricity. The overheating of the line wires will also decrease with a decrease in load currents. Reducing the number of false shutdowns that cause interruptions in movement, eliminates current overloads from repeated starts of loads, reduces wear of circuit breakers, their maintenance, reduces aging of insulation, which significantly increase the reliability of the power supply system (Tarnizhevsky MV, Tomlyanovich DK “Design power supply devices for trams and trolleybuses ”- Moscow:“ Transport ”, 1986, p. 164-165).

Drawback number 13. If the common line is made in the form of a rail circuit, then the polarity converters equalize the currents in the lines, compensating for them in the common line, significantly reducing stray currents, regardless of the number of loads, their size and location. Local currents in a common line producing stray currents are substantially smaller in magnitude than currents in a common line without using polarity converters. Alignment is performed continuously and it is not associated with the movement of loads.

Drawback number 14. The currents in the common line are reduced, due to compensation, on a regular basis, and not by chance, as in the prototype, the need for a large cross section of the zero cable is reduced.

Continued Description of Preferred Embodiments

The following are additional embodiments of the method and the three-wire power supply system.

The figure 10 shows a diagram of a three-wire power supply system of the traction network for a double-track line with separate power supply paths. This may apply to railways, subways and tram lines with separate track power. Separate power supply of the tracks increases the reliability of the functioning of the system as a whole, makes the movement on different paths independent of each other. Therefore, the supply lines and polarity converters for each path should be their own.

Common elements of the power supply system are constant voltage sources 2 and 3 at station 1 and a common line 7 in the form of a rail circuit. Adopted rail chains of all paths to interconnect in parallel. Both non-common lines 6 'and 6' 'of the first and second paths are connected at the station to the non-common output of the first constant voltage source. Both supply lines 8 'and 8' 'of the first and second paths are connected at station 1 to the non-common output of the second DC voltage source 3. The rail circuit is connected to the common output of both DC voltage sources 2 and 3.

The direct current polarity converters of the first and second paths 4 'and 4' 'are connected by positive inputs to the common line and negative inputs to the supply lines of their paths, respectively.

To evaluate the operation of such a two-track three-wire power supply system, we use the overlay method. Let the load be only on the first path in the zone between the station and the first from the polarity converter. Then the operation of such a power supply system will not be different from the operation of the power supply system according to figure 4.3. There will be no current along the rail circuit between the polarity converters 4.2 and 4.4, and a local current from the load in this zone will flow in the area between the station and the polarity converter 4.2, as indicated in the explanation to figure 4.3. In another case, when the load is only on the second track, in the same zone of the rail chain, the current flow pattern will be reflected symmetrically. A local current will appear in the rail circuit in the area between the station and the polarity converter 4.1.

When loads appear on both paths, polarity converters connected only to their supply lines and non-common lines will work independently of each other. In view of the low resistance of the rail circuit and, accordingly, the small value of the voltage drop across the rail circuit, in comparison with the voltages of the first and second sources of constant voltage 2 and 3, this voltage drop will practically not affect the distribution of currents in the lines. Current converters equalize currents in the supply and non-common lines only in the lines of their paths, regardless of the location and magnitude of the loads on the adjacent path. Compensation of currents in the common rail circuit will be made for each track independently from each other, under any loads and directions of movement.

One supply line and common polarity converters for both paths can somewhat reduce the effect of current compensation in the common line. Full compensation of the global load currents will be with the equality of the reduced resistance of the supply line and the resistance of the non-common line, as shown above. With changes in power supply circuits in forced operation modes, this ratio will change, therefore, the compensating effect will also slightly change. The effect of adding energy to the loads through the supply line will continue.

The power supply method of the three-wire power supply system of the double-track section also remains unchanged and is not related to the number of paths by the number. Due to the small voltage drop across the common elements of the power supply system - the rail circuit and direct voltage sources, the supply lines and the polarity converters of each path will not have a mutual influence on each other. The equalization of currents in non-general and supply lines of both paths will be made independently of each other, as in a single-track section. The same can be extended to multi-path sections, if each path has its own polarity converter and its own supply line.

In figures 11 shows variants of embodiments of the method and power supply system with a variation of the implementation of direct voltage sources at the stations - Fig. 11.1 and 11.2, connecting the energy storage devices at the connection point of the polarity converter - FIG. 11.3, AC inverters and their combination with energy storage - Fig. 11.4 and 11.5.

Figure 11.1 shows the possible implementation of the second DC voltage source 3 at station 1 in the form of a DC voltage converter, similar to the converter described below in Figures 13 and 14. Figure 11.2 shows the possible implementation of the first DC voltage source 3 at station 1 in the form of a DC voltage converter. The converters operate at frequencies higher than the industrial frequency of public networks at 50 Hz, so its internal transformer has lower overall dimensions than power converter transformers at 50 Hz. A possible polarity converter device is shown below in FIG. 13.

Figure 11.3 shows the connection of the energy storage device on the line, useful for removing peak current consumption, which will reduce the power of DC voltage sources and polarity converters. The drive 16 is charged from the station with a current of I _1.2-16 and from a polarity converter 4. When the voltage in the non-common line 6 is reduced due to the high inrush current of the load 5, the load is powered by currents coming from the supply line 8 through the polarity converter 4 with a current of I _{4out n} , from drive 11 current I ₁₆ and from the station through a non-common line 6 current I _1.2-5 . Since the drive has less internal resistance than other sources of load current 5, it takes up most of the peak current. Energy storage devices can also be installed at stations to reduce peak current consumption by loads located near the stations.

Figure 11.4 shows the wiring diagram of the inverter 12, useful for supplying AC loads, as previously shown in figure 5. The inverter is connected between the non-common line 6 and the supply line 8. The inverter can be either single-phase or three-phase, depending on the requirements of the loads. Figure 11.5 shows the simultaneous connection of the drive 16 and a single-phase inverter 17. The inverter in this figure is connected between the common line 7 and the supply line 8. In fact, it is connected to the DC loads 5.

Figure 12.1 shows the possible placement of the wire of the supply line near the wires of the common and common lines of trolleybus systems using the supporting devices of these lines. This simplifies the transmission of electricity to the trolleybus route to polarity converters. The feed line can be made in the form of an insulated self-supporting wire with an optical cable. External insulation is needed if the rod leaves the contact wire so that it does not get on the supply line wire with high voltage and damage to the electrical equipment of the trolley bus does not occur. Similar wires are used in power lines. (PM 80278 2009. Combined electro-optical self-supporting insulated wire).

Figure 12.2 shows the possible placement of the wire of the supply line on the support of the contact network of the main railway, on the console on the field side of the support. When making a wire of this line in the form of an insulated self-supporting wire, it can be placed also from the side of the path. Possible placement above the support. The specific location is determined by the presence of other lines on the supports of the contact network. For the lighting networks shown in FIG. 5, for supporting the wires of the common, non-common and supply lines, it is possible to use lighting poles, similar to the poles of a contact network.

About DC Polarity Converter and Regulation

The embodiment of a DC-polarity converter is possible based on a pulsed DC-DC converter (PTDC). Figure 13 schematically shows the embodiment of the DC polarity converter 4 in the form of a circuit, at the beginning of which there is an autonomous inverter 18, which is a controllable key that operates in opposite phases in pairs, supplying an alternating current in the primary winding of the transformer 19. A bridge rectifier on diodes 20, which are also voltage-controlled keys, is connected to the secondary winding of the transformer, this rectifier is the end of the circuit. The transformer provides galvanic isolation of the output and input circuits of the polarity converter, necessary to create the effect of changing polarity. When the positive terminal of the rectifier 20 is connected to the non-common line 6, the current of the polarity converter will flow in the load according to the current from the non-common line. The presence of the transformer 19 also allows you to change the ratio of the input and output voltages of the polarity converter. This makes it possible to increase the voltage in the supply line.

To transfer the energy of the load recovery in the line, the output keys must be controlled by an external signal. These keys can be thyristors or power transistors. An example of such a circuit is shown in Figure 14. The IGBT transistors in the input circuit 21 and the IGBT transistors in the output circuit 22 are used as controlled keys. The transformer of the polarity converter is also necessary for the galvanic isolation of the inputs and outputs of the polarity converter inside it.

Converter devices with such an internal structure are known (“Devices of power electronics of railway rolling stock” study guide / V.M. Antyukhin, A.A. Bogomyakov, Yu.A. Evseev, et al .; Edited by Yu.M. Inkov and F.I. Kovaleva. - M.: Federal State Budget Educational Establishment "Educational and Methodological Center for Education in Railway Transport", 2011. S. 232-233, Fig. 11.2.). Since the conversion frequency is usually much higher than the industrial frequency, the overall dimensions of the transformer of the polarity converter are much smaller than the classical converter transformer at a traction station powered by a network with an industrial frequency. This makes it possible to use a polarity converter as one of the DC voltage sources at the traction station, as described above.

A three-wire power supply system may include DC voltage sources and / or polarity converters with the function of regulating the output voltage. This, together with the electro-optical wire, will allow to organize intelligent control of the output voltage of traction stations and polarity converters on the line, to regulate the loads on stations and polarity converters, voltage modes on the lines. It is sometimes necessary to regulate the load in order to relieve the station overload due to unequal voltages coming to them from the supply centers. This will reduce heat loads, reduce energy losses, extend the life cycle of power supply devices.

In the above source on power electronics, in Sec. 10 describes methods of zone-phase regulation of the output voltage by switching sections of the secondary winding and regulating their voltage using its own separate rectifier. Voltage regulation is not a necessary property of a DC polarity converter, which is so named for its primary function in this invention. However, it can be useful for mutual control of the loads of DC voltage sources at stations and polarity converters in some operational situations.

About the supply point

The figure 15 presents an example embodiment of a feeding point of a double-track section, formed by the combined use of polarity converters and energy storage devices for a double-track feeder zone of the railway.

The supply point, in addition to connecting DC-polarity converters and other types of power equipment, such as energy storage devices, must ensure reliable operation, ease of maintenance and control. For this, in addition to feeders with switching equipment, bus sectioning, redundancy of polarity converters are provided, for individual cases of operation it is possible to use a supply point as a point of parallel connection of contact (non-common) lines, and / or supply lines, and use it as a point of longitudinal sectioning of supply lines.

Power cables of the supply line together with the optical communication line go to the supply point. Optical cables 27 are connected to the transceivers of the telemechanics system 28.

The power station contains bus power and non-common lines, divided into sections, for the first and second paths. The first section of the bus of the supply line 29 is connected via switching devices 35 and 36 to the supply line of the first path 8 '. Due to this, the supply line can be longitudinally partitioned. A second section of the supply line bus 30 is connected to the supply line of the second path through one switching device 37. The supply line of the second path is shown not to be partitioned. The busbar sections of the supply line can be interconnected by a switching apparatus 31, for parallel operation of the supply lines in unusual situations.

The first section of the bus of the non-shared line 32 is connected through the switching device 38 to the non-shared line of the first path 6 ', the second section of the bus of the shared line 33 is connected through the switching device 39 to the non-shared line of the second path 6' '. The bus sections of the non-common line can be interconnected by the switching apparatus 34, to ensure parallel operation of the non-common lines of both paths in non-standard situations.

The first polarity converter 40 serves the first path, the second polarity converter 41 serves the second path. The negative input of the first polarity converter 40 through the switching device 43 is connected to the first section of the bus of the supply line 29. The negative input of the second polarity converter 41 through the switching device 44 is connected to the second section of the bus of the supply line 30. Switching devices 45 connect the positive inputs of all the converter to non-common line 7 polarity 40, 41 and 42.

The positive output of the first polarity converter 40 through the switching device 46 is connected to the first section of the bus of the common line 32. The positive output of the second polarity converter 41 through the switching device 47 is connected to the second section of the bus of the common line 33. In series with the positive outputs of all polarity converters 40, 41 and 42 reactors 52 are included.

The negative input of the backup polarity converter 42 through the switching devices 48 and 49 is connected, if necessary, to the first 29 or second 30 sections of the supply line bus, respectively. The positive output of the backup polarity converter 42 through the switching devices 50 or 51 is connected to the first 32 or to the second section 33 of the bus common lines. Such a fork in the input and output connections, you can reserve the first or second polarity converters. Polarity converters are equipped with reactors, the functions of which are known in such applications: ensuring electromagnetic compatibility and facilitating the identification of emergency conditions and their shutdown.

It is possible to install energy storage devices 15 for each path, shown in FIG. 15. It is also possible to install DC / AC converters in the supply point for supplying non-traction consumers shown in FIG. 11.

The provided backup capabilities of equipment and lines are sometimes necessary in individual cases of operation, usually not long. The possible deterioration of certain properties of the system in such cases will slightly affect the general properties of the power supply system over a longer period of operation. All this increases the survivability of the power supply system in emergency situations.

Switching devices of the supply point can be high-speed switches and / or disconnectors. It is possible to disconnect the polarity converters by stopping the supply of opening signals to the controlled keys at the input and output.

Optical cables go into the transceiver for communication with telemechanics devices. Thanks to telemechanics, it is possible to control the operation of all elements of the supply point, input and output currents and voltages, to provide control of the voltage of the converters, when they are regulated.

For a tram line, a charging terminal can be included in the supply station for charging trams, autonomous trolley buses and electric buses on the battery line. For these terminals, the role of traction substation tires is played by buses of non-common lines. Such terminals are known (RF patent No. 2509667 from 2014).

The figure 16 presents an example embodiment of a feeding point of a multi-track section, using the example of a three-track section, formed by the combined use of polarity converters and energy storage devices. Unlike the feeding point of the double-track section, the point in question has tires with the number of sections, according to the number of tracks. Sections of different paths of the same name on the line are interconnected in the form of a node, with the number of branches of the node equal to the number of paths, through the switching devices of the sections of each path. This connection allows you to connect any of the same name lines in parallel, thereby reserving power on them in different operating situations. In addition, as in the double-track power point, redundancy of polarity converters and their mutual redundancy, longitudinal sectioning of the lines are provided.

The set of supply points with supply lines is essentially an internal system of distributed power to the traction network from base stations. Through them, external energy enters the three-wire power supply system. The point itself is much simpler than base stations of high power; to receive energy, it only needs one input cable of the supply line of each path.

List of sources used

1. V.V. Shevchenko, N.V. Arzamastsev, S.S. Bodrukhina "Power supply of urban terrestrial electric transport" Moscow "Transport" 1987, p. 10 pic. 1.2b.

2.http: //lib.rosenergoservis.ru/sovremennaya-elektroenergetika?start=78, Fig. 11.5b

3.http: //lib.rosenergoservis.ru/sovremennaya-elektroenergetika?start=78, Fig. 11.6.

4. T.P. Tretyak, “Power supply system for direct current electric railways”, A.S. USSR No. 152894, 1963

5. S.N. Zasorin and A.P., Sukhoguzov "Power supply system for direct current electric railways", A.S. USSR No. 488736, 1976

6. Marikin AN, Burkov AT, Power supply system for direct current railways, PM RF №34905, 2003

7. Tarnizhevsky M.V., Tomlyanovich D.K. “Designing power supply devices for trams and trolleybuses” - Moscow: “Transport”, 1986, p. 145 images 52b.

8. “Traction power plant”, RF application for invention No. 2016132167 of 08/04/2016.

9. PM 80278 2009. Combined electro-optical self-supporting insulated wire.

10. Tarnizhevsky M.V., Tomlyanovich D.K. “Designing power supply devices for trams and trolleybuses” - Moscow: “Transport”, 1986, p. 164-165.

11. "Devices of power electronics of railway rolling stock" textbook. allowance / V.M. Antyukhin, A.A. Bogomyakov, Yu.A. Evseev et al .; under the editorship of Yu.M. Inkova and F.I. Kovaleva. - M .: FSBEI "Educational and Methodological Center for Education in Railway Transport", 2011. p. 232-233, fig. 11.2.

12. Edigaryan T.A., Bolshakov A.V. Krikunov I.E., Osipov V.E. "Transformer substation of electric powered vehicles", RF patent No. 2509667 from 2014

Claims (23)

1. The method of a three-wire DC power supply system, which consists in the fact that the loads are supplied from the non-shared output of the first constant voltage source through a non-shared line relative to the common line, from the non-shared output of the second constant voltage source the loads are fed to another line, the remaining unlike outputs are combined both sources of constant voltage and connect them to a common line relative to the common line so that the voltage in the other line is opposite in sign to the voltage non-common line, characterized in that the energy received by the load from the non-common line is supplemented with energy from another line, and when transferring energy from another line to the non-common line, the polarity of the transmitted current is converted using the introduced DC polarity converter, at least one located in the area between both sources of constant voltage and the end of the power zones of the non-common line, from the outputs of the transformer of the polarity of the direct current supply voltage to the non-common line relative to the common in the same polarity as the non-common line receives from the first DC voltage source, so that the output current of the DC-polarity converter is summed in the load with the current from the non-common line, with its inputs, the DC-polarity converter is connected between the other line and the common line so, so that the current passes between its inputs according to their polarities from another and common lines. 2. The method according to p. 1, characterized in that the voltage value of the second constant voltage source can be larger than the voltage value in a non-common line, and in this case, using the DC polarity converter, the voltage value is also converted, and the conversion coefficient is related to the ratio output and input voltage of a DC polarity converter. 3. The method according to p. 1, characterized in that the resistance of the line connected to the negative terminal of the second constant voltage source, reduced to the voltage of the non-common line, is equal to or at least close to the resistance of the non-common line, both resistances are determined from the nearest traction station to the connection points of the considered DC-polarity converter or from the nearest other DC-polarity converter located closer to the traction station to the considered field converter Nost DC, in both the resistance includes resistance DC power supply sources that feed their lines. 4. The method according to p. 1 or 3, characterized in that the voltage conversion coefficient of the DC-polarity converter is selected so that the secondary voltage of the DC-polarity converter, correlated with the voltage of a non-common line, is greater taking into account the compensation for losses in the DC-polarity converter . 5. The method according to p. 1, characterized in that as the sources of constant voltage using a rectifier-inverter unit. 6. The method according to p. 1, characterized in that energy is supplied to the second constant voltage source from the first constant voltage source or vice versa. 7. The method according to p. 1, characterized in that in the place of connection of the transformer of the polarity of the direct current or near it accumulate energy using an energy storage device. 8. The method according to p. 1, characterized in that the DC voltage sources and / or DC-polarity converters perform with the regulation of the output voltage. 9. The method according to p. 1, characterized in that both sources of constant voltage are used to connect different sets of non-common, common and other lines when transmitting energy from one station in different geographic directions of energy transfer. 10. A three-wire DC power supply system containing a common line, non-common and other lines, the first and second DC voltage sources, and one pair of their opposite outputs in polarity is combined, thereby forming a common output of both DC voltage sources, the common line is connected to a common the output of both sources of constant voltage, the non-common line is connected to the non-common output of the first constant voltage source, the other line is connected to the non-common output of the second constant voltage source voltage, characterized in that at least one DC-polarity converter is inserted, located between both DC voltage sources and the end of the feeder zone, the inputs of the DC-polarity converter are connected to common and other lines, corresponding to their polarities, the positive input of the DC-polarity converter is connected to lines with a positive potential, the negative input of a DC-polarity converter is connected to a line with a negative potential, output One DC-polarity converter is connected to common and non-common lines, corresponding to its polarities, the positive output of the DC-polarity converter is connected to a line with a positive potential, the negative output of a DC-polarity converter is connected to a line with a negative potential. 11. The three-wire power supply system according to claim 10, characterized in that the resistance of the other line connected to the non-common terminal of the second constant voltage source, reduced to the voltage of the non-common line, is equal to or at least close to the resistance of the non-common line, both resistances are determined from both constant sources voltage to the point of connection of the considered converter of polarity of a direct current, or from the nearest other converter of polarity of a direct current, which is closer to both sources constant voltage than the considered DC-polarity converter, the resistances of the DC voltage sources supplying their lines respectively enter into both resistances. 12. The three-wire power supply system according to claim 10, characterized in that different sets of non-common, common and different lines are connected to both DC voltage sources, each for transferring energy from one station in different geographical directions. 13. The three-wire power supply system according to claim 10, characterized in that the second DC voltage source, made in the form of a DC-DC converter, is connected by inputs to the outputs of the first constant voltage source or vice versa. 14. The three-wire power supply system according to claim 10, characterized in that an energy storage device is connected between the non-common line and the common line. 15. The three-wire power supply system according to claim 10, characterized in that the other line and / or non-common line is made in the form of an insulated self-supporting wire. 16. A three-wire power supply system according to claim 10 or 14, characterized in that the self-supporting insulated wire is made in the form of an electro-optical wire. 17. The three-wire power supply system according to claim 10, characterized in that the line connected to the negative output of the second constant voltage source, together with a common line or with a non-common line, can be used to generate energy for non-traction consumers. 18. The three-wire power supply system according to claim 10, characterized in that the direct current polarity converter together with switching equipment, buses of other lines and non-common lines, as well as control equipment can be placed in one unit / room, thereby forming a supply point, tires are divided into sections of each path. 19. A three-wire DC power supply system of a multi-track section, containing a common line, non-common and other lines, first and second DC voltage sources, and one pair of their opposite terminals in polarity is combined, thereby forming a common terminal, the common line is connected to the common terminal of both DC voltage sources, a non-common line connected to a non-common output of a first DC voltage source, another line connected to a non-common output of a second DC voltage source, distinguishing By introducing at least one DC-polarity converter for each path located between both DC voltage sources and the end of the feeder zone, non-common lines of each path and other lines of each path are introduced, the inputs of the DC-polarity converters of each path are connected to the common line and to the other lines of their paths, corresponding to their polarities, and the polarity of the inputs of the transformer of the direct current polarity of each path corresponds to the polarity of the other line of its path and field Nost general line outputs polarity DC converter of each path are connected to a common line and nonshared line of its path according to their polarities, the polarity of the DC converter output polarity of each path corresponds to the polarity of another line of its path and the polarity of the common line. 20. The three-wire power supply system according to claim 19, characterized in that the resistance of the other line of each path, reduced to the voltage of the non-common line, is equal to or at least close to the resistance of the non-common line of its path, both resistances are determined from both sources of constant voltage to the point of connection of the considered the direct current polarity converter of its path, or from the nearest other direct current polarity converter of its path, which is closer to both DC voltage sources than assmatrivaemy polarity DC converter. 21. The three-wire power supply system according to claim 19, characterized in that an energy storage device is connected between the non-common line and the common path line. 22. The three-wire power supply system according to claim 19, characterized in that the other line and / or non-common line is made in the form of an insulated self-supporting wire. 23. The three-wire power supply system according to claim 19, characterized in that the direct current polarity converter together with switching equipment, buses of other lines and non-common lines, as well as control equipment can be placed in one unit / room, thereby forming a supply point, indicated the buses are divided into sections of each path at the power point, bus sections of the same lines of multi-track sections, non-common and other lines, starting from a three-track section, are interconnected through the first conclusions of their switching x units of the node circuit, the second terminals of the switching devices are interconnected in a node, separate sections for the tires of the same name and node number of branches equal to the number of ways.

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