CN213007710U - Rail transit power supply system - Google Patents

Abstract

The utility model discloses a track traffic power supply system, it is arranged in supplying power for a plurality of stations, has the charging station in a plurality of charging stations at least, and the load of charging station includes charging circuit and awards the flow ware, and power supply system includes: the transformer substation comprises a transformer and a first AC/DC converter, wherein a primary coil of the transformer is connected with a mains supply inlet wire through a high-voltage alternating current bus, and a first secondary coil is connected with an alternating current end of the first AC/DC converter; the direct current ring network is connected with the direct current end of the first AC/DC converter and comprises station direct current buses and direct current cables connected between the station direct current buses of two adjacent stations; the power supply and distribution station comprises a low-voltage direct current bus and a low-voltage alternating current bus which are connected with corresponding loads of the stations. The power supply system can reduce the voltage level, reduce the equipment quantity and the equipment volume, reduce the equipment investment, improve the electric energy utilization efficiency and realize the diversity of power supply.

Description

Rail transit power supply system

Technical Field

The utility model relates to a track traffic technical field especially relates to a track traffic power supply system.

Background

The modern rail transit power supply system mainly uses alternating voltage, adopts a medium-voltage alternating current ring network technology, independently arranges a substation at each station, and converts the medium-voltage alternating current into low-voltage alternating current to supply power to station loads. The scheme has the following defects:

on one hand, the alternating current medium voltage ring network has high voltage level, high requirement on power supply and distribution equipment and large equipment volume, and the transformer substations are arranged in each station, so that the investment is large; on the other hand, with the development of new energy technology, more and more distributed energy sources are incorporated into a power grid, the composition of a power supply and a load in the power grid is obviously changed, and equipment adopting direct current power supply is widely applied, for example, a photovoltaic power generation system and an energy storage system are supplied with power in a direct current mode; moreover, when the alternating current power grid supplies power to the direct current load, a rectifier is needed, and when an alternating current power supply system is adopted for supplying power, a large number of inverters are needed at a load end, so that the electric energy loss in the process of converting the electric energy by the inverters is large, the investment is large, and the power supply reliability is low.

SUMMERY OF THE UTILITY MODEL

The present invention aims at solving at least one of the technical problems in the related art to a certain extent. Therefore, an object of the utility model is to provide a rail transit power supply system to adopt the mode that direct current looped netowrk power supply, alternating current-direct current distribution combined together to provide the electric energy for the station, can reduce the voltage level, reduce equipment quantity and equipment volume, reduce the equipment investment, improve the electric energy utilization efficiency.

In order to achieve the above object, the utility model provides a rail transit power supply system, it is used for supplying power for a plurality of stations, power supply system includes: the transformer comprises a primary coil and at least one secondary coil, the primary coil is connected with a mains supply inlet wire through a high-voltage alternating current bus, one of the at least one secondary coil is a first secondary coil, the first secondary coil is connected with an alternating current end of the first AC/DC converter, and the transformer is a step-down transformer; the direct current ring network is connected with the direct current end of the first AC/DC converter and comprises station direct current buses arranged at each station and a direct current cable connected between the station direct current buses of two adjacent stations; the power supply and distribution station comprises a low-voltage direct-current bus and a low-voltage alternating-current bus, the low-voltage direct-current bus is used for connecting direct-current loads of corresponding stations, the low-voltage alternating-current bus is used for connecting alternating-current loads of corresponding stations, a first voltage conversion unit is connected between the low-voltage direct-current bus and the station direct-current bus of the corresponding station, and/or the transformer comprises at least two secondary coils, the other secondary coil is a second secondary coil, and a second voltage conversion unit is connected between the low-voltage direct-current bus and the second secondary coil; a third voltage conversion unit is connected between the low-voltage direct-alternating current bus and a station direct-current bus of a corresponding station, and/or the low-voltage direct-alternating current bus is connected with the second secondary coil; the charging station comprises a plurality of stations, wherein at least one charging station exists in the stations, the load of the charging station further comprises a charging circuit and a current supplier, and the current supplier is connected with a station direct current bus or a low-voltage direct current bus of the corresponding charging station through the charging circuit.

According to the embodiment of the utility model provides a track traffic power supply system need not to set up the electric substation at every station, also need not to exchange the middling pressure looped netowrk, but passes through the electric substation, the power supply of direct current looped netowrk realization to the supply and distribution substation of station, then passes through DC/AC converter or first, the conversion that DC/DC converter realized voltage at the supply and distribution substation to supply power for alternating load, the direct current load power supply of corresponding station. From this, this system adopts the mode that direct current looped netowrk power supply, alternating current-direct current distribution combined together to provide the electric energy for the station, can reduce the voltage class, reduces equipment quantity and equipment volume, reduces the equipment investment, improves the electric energy utilization efficiency, and can supply power for the alternating current-direct current load at station simultaneously, has realized the variety of power supply.

In addition, according to the utility model discloses foretell track traffic power supply system can also have following additional technical characterstic:

in some examples, the first voltage conversion unit includes: a first DC/DC converter, wherein a first DC end of the first DC/DC converter is connected with a station DC bus of a corresponding station, and a second DC end of the first DC/DC converter is connected with the low-voltage DC bus; or, the direct current end of the first DC/AC converter is connected to a station direct current bus of a corresponding station, the alternating current end of the first DC/AC converter is connected to the alternating current end of the second AC/DC converter, and the direct current end of the second AC/DC converter is connected to the low-voltage direct current bus.

In some examples, the second voltage conversion unit includes: and the alternating current end of the third AC/DC converter is connected with the second secondary coil, and the direct current end of the third AC/DC converter is connected with the low-voltage direct current bus.

In some examples, the third voltage conversion unit includes: the direct current end of the second DC/AC converter is connected with a station direct current bus of a corresponding station, and the alternating current end of the second DC/AC converter is connected with the low-voltage alternating current bus; or, the first direct current end of the second DC/DC converter is connected to a station direct current bus of a corresponding station, the second direct current end of the second DC/DC converter is connected to the direct current end of the third DC/AC converter, and the alternating current end of the third DC/AC converter is connected to the low-voltage alternating current bus.

In some examples, the power supply system further comprises: the alternating current ring network is connected with the second secondary coil, the alternating current ring network comprises station alternating current buses arranged at each station and alternating current cables connected between the station alternating current buses of two adjacent stations, and the station alternating current buses are connected with the low-voltage alternating current buses corresponding to the stations.

In some examples, the substation further comprises a first switch connected between a mains inlet line and the high voltage AC bus, a second switch connected between the high voltage AC bus and the transformer, and a third switch connected between the first AC/DC converter and a DC ring network.

In some examples, a fourth switch is connected between the station dc bus and the dc cable.

In some examples, the power supply and distribution station further includes a fifth switch connected between the station direct current bus of the corresponding station and the second DC/AC converter, a sixth switch connected between the second DC/AC converter and the low voltage alternating current bus of the corresponding station, and a plurality of seventh switches each connected between the low voltage alternating current bus and a corresponding alternating current load.

In some examples, the power supply and distribution station further comprises a distributed direct current power supply, and the distributed direct current power supply is connected with a station direct current bus or a low-voltage direct current bus of a corresponding station.

In some examples, the number of the power substations is 2, and the power substations are respectively marked as a first power substation and a second power substation, and the second power substation is used for working when the first power substation fails.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

Fig. 1 is a schematic view of a rail transit power supply system according to a first example of the present invention;

fig. 2 is a schematic view of a rail transit power supply system according to a second example of the present invention;

fig. 3 is a schematic diagram of a rail transit power supply system according to a third example of the present invention;

fig. 4 is a schematic view of a rail transit power supply system according to a fourth example of the present invention;

fig. 5 is a schematic view of a rail transit power supply system according to a fifth example of the present invention;

fig. 6 is a schematic view of a rail transit power supply system according to a sixth example of the present invention;

fig. 7 is a schematic diagram of a rail transit power supply system according to a seventh example of the present invention;

fig. 8 is a schematic view of a rail transit power supply system according to an eighth example of the present invention;

fig. 9 is a schematic diagram of a rail transit power supply system according to a ninth example of the present invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary and intended to be used for explaining the present invention, and should not be construed as limiting the present invention.

The rail transit power supply system according to the embodiment of the present invention will be described below with reference to fig. 1 to 8.

The utility model discloses an in the embodiment, track traffic power supply system is used for supplying power for a plurality of stations. As shown in fig. 1, the rail transit power supply system 100 includes: the power substation 10, the direct current looped network 20 and the power supply and distribution station 30 arranged at each station.

Referring to fig. 1, a substation 10 includes a transformer T and a first AC/DC converter 11, where the transformer T includes a primary coil and at least one secondary coil, the primary coil is connected to a mains supply inlet wire through a high-voltage AC bus, one of the at least one secondary coil is a first secondary coil, the first secondary coil is connected to an AC terminal of the first AC/DC converter 11, and the transformer T is a step-down transformer; the direct current ring network 20 is connected with the direct current end of the first AC/DC converter 11, and the direct current ring network 20 includes station direct current buses arranged at each station and a direct current cable connected between the station direct current buses of two adjacent stations. The power supply and distribution station 30 comprises a low-voltage direct-current bus and a low-voltage alternating-current bus, the low-voltage direct-current bus is used for connecting a direct-current load 2 of a corresponding station, the low-voltage alternating-current bus is used for connecting an alternating-current load 2 of the corresponding station, a first voltage conversion unit is connected between the low-voltage direct-current bus and the station direct-current bus of the corresponding station, and/or the transformer comprises at least two secondary coils, the other secondary coil is recorded as a second secondary coil, and a second voltage conversion unit is connected between the low-voltage direct-current bus and the second secondary coil; and a third voltage conversion unit is connected between the low-voltage direct-current bus and the station direct-current bus corresponding to the station, and/or the low-voltage direct-current bus is connected with the second secondary coil.

Further, as shown in fig. 2, at least one charging station exists in the plurality of stations, and the load of the charging station further includes a charging circuit and a current provider, where one end of the charging circuit is connected to the station dc bus or the low voltage dc bus of the corresponding charging station (the charging circuit is shown to be connected to the low voltage dc bus in fig. 2), and the other end of the charging circuit is connected to the current provider. In this embodiment, when the rail vehicle stops at a specific position of the charging station, the charging interface of the rail vehicle is correspondingly connected with the current provider, so that the rail vehicle can be charged through the charging circuit. The current supplier may be configured in structure, shape, and the like according to actual charging needs, for example, the current supplier may be a charging bow, a charging slot, a charging rail, and the like, which may not be limited herein.

In this embodiment, the ac voltage input by the mains inlet is 10kV or 35kV, and the dc voltage in the dc ring network 20 is 1500V or 7500V.

Specifically, the commercial power incoming line transmits 10kV or 35kV medium-voltage alternating current to the high-voltage alternating current bus, the high-voltage alternating current bus outputs alternating current to the transformer T, and then the alternating current is converted into direct current with 1500V or 7500V through the transformer T and the first AC/DC converter 11, and the direct current is transmitted to the direct current ring network 20, so that the direct current ring network 20 provides electric energy to the power supply and distribution station 30 of the corresponding station through the station direct current bus of each station.

In an example of the present invention, referring to fig. 1, the first voltage conversion unit includes: and a first DC/DC converter 32, wherein a first DC end of the first DC/DC converter 32 is connected with a station DC bus of a corresponding station, and a second DC end of the first DC/DC converter 32 is connected with a low-voltage DC bus. The third voltage conversion unit includes: and a second DC/AC converter 31, wherein a DC end of the second DC/AC converter 31 is connected to a station DC bus of a corresponding station, and an AC end of the second DC/AC converter 31 is connected to a low-voltage AC bus.

Specifically, referring to fig. 1, on one hand, the direct current ring network 20 outputs direct current to the second DC/AC converter 31 of each station through the station direct current bus of each station, and then the second DC/AC converter 31 converts the direct current into low-voltage alternating current and outputs the low-voltage alternating current to the low-voltage alternating current bus of the corresponding station, so as to supply power to the alternating current load 1 of the corresponding station, and meet the power consumption requirement of the alternating current load 1; on the other hand, the direct current ring network 20 outputs direct current to the first DC/DC converter 32 of the corresponding station through the station direct current bus of each station, and then the first DC/DC converter 32 converts the direct current into low-voltage direct current and outputs the low-voltage direct current to the low-voltage direct current bus, so as to supply power to the direct current load 2 of the corresponding station, and meet the power consumption requirement of the direct current load 2.

In this example, a power supply and distribution station 30 is provided at each station, and the power supply and distribution station 30 is provided with a second DC/AC converter 31 and a first DC/DC converter 32, so that the direct current output by the direct current ring network 20 can supply power to the alternating current load 1 and the direct current load 2 of each station at the same time. From this, compare in traditional track traffic power supply system, the utility model discloses a power supply system 100 need not to set up the electric substation at every station, also need not the medium voltage ring network of exchanging, but adopt an electric substation 10 (this electric substation 10 can be close to certain station setting) and direct current looped netowrk 20, and supply the distribution in the power supply and distribution station 30 at every station, save a large amount of middle conversion links, the equipment quantity and the equipment volume that significantly reduce, reduce the equipment investment, and need not to consider power supply system 100's frequency, the power factor, the harmonic, a great deal of factors such as circuit impedance, need not a large amount of dc-to-ac converters, and then can reduce the electric energy loss in the electric energy conversion process, improve the electric energy utilization efficiency. Meanwhile, the power supply system of the embodiment can also supply power for the alternating current load and the direct current load of the same station, and the diversity of power supply is realized.

Alternatively, as shown in fig. 2, the ac load 1 may comprise a switch and the dc load 2 may comprise a lighting, ac or dc power source. The alternating current and direct current power supply can supply power for a control loop and secondary equipment of each equipment in a station, a battery can be arranged in the alternating current and direct current power supply, specific direct current can be output, specific alternating current can also be output, and the alternating current and direct current power supply is specifically determined according to the specification of the equipment.

In an example of the present invention, as shown in fig. 3, the first voltage conversion unit includes: and a first DC/DC converter 32, wherein a first DC end of the first DC/DC converter 32 is connected with a station DC bus of a corresponding station, and a second DC end of the first DC/DC converter 32 is connected with a low-voltage DC bus. The third voltage conversion unit includes: the direct current end of the second DC/AC converter 32 is connected with a station direct current bus of a corresponding station, and the alternating current end of the second DC/AC converter 32 is connected with a low-voltage alternating current bus; the first direct current end of the second DC/DC converter is connected with a station direct current bus of a corresponding station, the second direct current end of the second DC/DC converter is connected with the direct current end of the third DC/AC converter 33, and the alternating current end of the third DC/AC converter 33 is connected with the low-voltage alternating current bus. In this example, the second DC/DC converter and the first DC/DC converter 32 may be common.

Alternatively, the second DC/AC converter 33 may be a bidirectional converter. At this time, the example shown in fig. 3 may also be: the first voltage conversion unit includes a first DC/DC converter 32, a first DC/AC converter, and a second AC/DC converter, and the third voltage conversion unit includes a second DC/AC converter 31. The second AC/DC converter and the second DC/AC converter 33 may be shared, and the first DC/AC converter and the second DC/AC converter 31 may be shared.

Specifically, referring to fig. 3, when power is supplied, the first DC/DC converter 32 may convert the direct current provided by the station direct current bus to provide the converted direct current to the low-voltage direct current bus. On one hand, the electric energy is supplied to a direct current load through a low-voltage direct current bus; on the other hand, the electric energy is transmitted to the DC end of the second DC/AC converter 33 through the low-voltage DC bus, and after being converted by the second DC/AC converter 33, the electric energy outputs AC power to the low-voltage AC bus to supply power to the AC load.

During power supply, the second DC/AC converter 31 may also convert the direct current provided by the station direct current bus to provide the converted alternating current to the low voltage alternating current bus. On one hand, the electric energy is supplied to an alternating current load through a low-voltage alternating current bus; on the other hand, the electric energy is transmitted to the AC end of the second DC/AC converter 33 through the low-voltage AC bus, and is converted by the second DC/AC converter 33, and then the DC power is output to the low-voltage DC bus to supply power to the DC load.

In an example of the present invention, as shown in fig. 4, the first voltage conversion unit includes: and a first DC/DC converter 32, wherein a first DC end of the first DC/DC converter 32 is connected with a station DC bus of a corresponding station, and a second DC end of the first DC/DC converter 32 is connected with a low-voltage DC bus. The transformer comprises at least two secondary coils, wherein the other of the at least two secondary coils is taken as a second secondary coil, and the low-voltage direct current bus is connected with the second secondary coil.

In an example of the present invention, as shown in fig. 5, the first voltage conversion unit includes: and a first DC/DC converter 32, wherein a first DC end of the first DC/DC converter 32 is connected with a station DC bus of a corresponding station, and a second DC end of the first DC/DC converter 32 is connected with a low-voltage DC bus. The transformer comprises at least two secondary coils, wherein the other of the at least two secondary coils is taken as a second secondary coil, and the low-voltage direct current bus is connected with the second secondary coil. The third voltage conversion unit includes: and a second DC/AC converter 31, wherein a DC end of the second DC/AC converter 31 is connected to a station DC bus of a corresponding station, and an AC end of the second DC/AC converter 31 is connected to a low-voltage AC bus.

In an example of the present invention, as shown in fig. 6, the power supply system 100 may further include an ac ring network, the ac ring network is connected to the second secondary coil, the ac ring network includes a station ac bus provided at each station and an ac cable connected between the station ac buses at two adjacent stations, and the station ac bus is connected to the low voltage ac bus corresponding to the station.

It should be noted that, in the examples shown in fig. 4 and 5, the second secondary coil may be connected to a low-voltage ac bus of at least one station; in the example shown in fig. 6, the ac ring network can supply power to a plurality of stations. For example, for a station on the travel line near the substation 10, the second secondary winding of the substation 10 is directly connected to the low voltage ac bus of the station, thereby powering an ac load (e.g., a switch). Referring to fig. 5, the second DC/AC converter 31 and the second secondary winding are simultaneously arranged, so that the reliability of power supply of the switch can be ensured.

Based on the example shown in fig. 6, in an example of the present invention, as shown in fig. 7, the second secondary coil is connected to the low-voltage AC bus of each station through an AC looped network, and for the station on the left side of fig. 7, the first voltage conversion unit includes a first DC/DC converter 32, and the third voltage conversion unit includes a second DC/DC converter and a third DC/AC converter 33. In this example, the second DC/DC converter and the first DC/DC converter 32 may be common.

Alternatively, when the transformer T includes two secondary windings, both secondary windings are connected to the AC terminal of the first AC/DC converter, as shown in fig. 3.

Referring to fig. 5 and 6, the substation 10 may further include a first switch K1, a second switch K2, and a third switch K3, where the first switch K1 is connected between the utility power inlet and the high-voltage AC bus, the second switch K2 is connected between the high-voltage AC bus and the transformer T, and the third switch K3 is connected between the first AC/DC converter 31 and the DC ring network 20. Referring to fig. 6, a switch K31 may be connected between the second secondary winding and the ac loop network. The first switch K1, the second switch K2, the third switch K3 and the switch K31 may be circuit breakers, and the third switch K3 may also be referred to as a dc feeder circuit breaker.

Referring to fig. 5 and 6, a fourth switch K4 may be connected between the station dc bus and the dc cable. Referring to fig. 6, a switch K41 may be connected between the station ac bus and the ac cable. Wherein, the switch K4 and the switch K41 can be breakers.

Referring to fig. 5 and 6, when the power distribution station 30 is provided with the second DC/AC converter 31, the power distribution station 30 further includes a fifth switch K5, a sixth switch K6 and a plurality of seventh switches K7, the fifth switch K5 is connected between the corresponding station DC bus and the second DC/AC converter 31, the sixth switch K6 is connected between the second DC/AC converter 31 and the corresponding low-voltage AC bus, and each seventh switch K7 is connected between the low-voltage AC bus and the corresponding AC load. Referring to fig. 6, a switch K71 may be connected between the station ac bus and the low voltage ac bus.

Referring to fig. 5 and 6, when the power distribution station is provided with the first DC/DC converter 32, the power distribution station further includes an eighth switch K8, a ninth switch K9 and a plurality of tenth switches K10, the eighth switch K8 is connected between the corresponding station DC bus and the first DC/DC converter 32, the ninth switch K9 is connected between the first DC/DC converter 32 and the corresponding low-voltage DC bus, and each tenth switch K10 is connected between the low-voltage DC bus and the corresponding DC load.

The fifth switch K5, the sixth switch K6, the seventh switch K7, the eighth switch K8, the ninth switch K9, the tenth switch K10 and the switch K71 may be breakers, and the fifth switch K5 and the eighth switch K8 may also be referred to as station incoming line breakers.

In an example of the present invention, as shown in fig. 8, the number of the substations 10 may be 2, which are respectively recorded as a first substation 10-a and a second substation 10-B, and the second substation 10-B is configured to operate when the first substation 10-a fails.

Specifically, each power supply section can be provided with 2 substations, namely a first substation 10-A and a second substation 10-B, wherein the first substation 10-A can be a main substation, and the second substation 10-B can be a standby substation. When the main substation can normally supply power, the first substation 10-A supplies power to each station through the direct current ring network 20; when the main substation fails, the unimportant loads of each station in the power supply section can be disconnected to reduce the line load, and the second substation 10-B can be used for power supply support to supply power to each station in the power supply section through the direct current ring network 20.

Referring to fig. 8, when the commercial power incoming line in any power supply section fails or the transformer T fails, that is, the main substation cannot supply power normally, the third switch K3 may be opened until the failure is removed, and the normal power supply is recovered. When the third switch K3 is opened, the fourth switch K4 can be closed, and the standby substation supplies power to the station in the power supply interval through the direct current ring network 20. Therefore, the reliability of power supply and distribution of the station can be ensured.

Referring to fig. 8, when the incoming line in any station breaks down, the station incoming line breakers K5 and K8 can be disconnected, so that the station with the fault has power failure until the line fault is eliminated, and the normal power supply is recovered. It should be understood that in this example, when any of the station internal distribution lines or loads fails, the failed section may be disconnected and the remaining normal lines remain operational until the failure is cleared, restoring the energization of the failed section.

In an example of the present invention, the power distribution station 30 may further include a distributed dc power supply 34, wherein the distributed dc power supply 34 may be connected with a corresponding station dc bus. As shown in fig. 9, when the power distribution station 30 is provided with the first DC/DC converter 32, the distributed DC power supply 34 is connected to the corresponding low-voltage DC bus or station DC bus (fig. 9 shows that the distributed DC power supply 34 is connected to the corresponding low-voltage DC bus).

The distributed dc power supply 34 may supply power to a secondary control line and a primary switching device in a station, and the distributed dc power supply 34 may include an energy storage system (e.g., a storage battery, a super capacitor, etc.), a photovoltaic power generation system, and the like. The utility model discloses an adopt distributed DC power supply to supply power among the track traffic power supply system, have the control of being convenient for, the high characteristics that are showing of electric energy quality.

It should be noted that the power supply and distribution stations at each station on one operation line may be arranged identically or differently, and the structures of the voltage conversion units are not limited to those shown in fig. 1 to 8, as long as the corresponding ac/dc power supply can be realized.

To sum up, the rail transit power supply system of the embodiment of the utility model provides electric energy for the station by adopting the mode of combining direct current single ring network power supply and alternating current-direct current power distribution, so that the voltage level can be reduced, the equipment number and the equipment volume are reduced, the equipment investment is reduced, and the electric energy utilization efficiency is improved; the direct current provided by the direct current loop network is converted into alternating current and direct current at each station, so that the normal use of alternating current and direct current loads at each station can be ensured, and the reliability is high; can realize multiple power supply and distribution scheme, and then according to the actual conditions at a plurality of stations, adopt different power supply and distribution schemes to supply power to the load at station, simple easy realization.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like, indicate the orientation or positional relationship indicated based on the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," and "fixed" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In the present application, unless expressly stated or limited otherwise, the first feature may be directly on or directly under the second feature or indirectly via intermediate members. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

Although embodiments of the present invention have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art without departing from the scope of the present invention.

Claims (10)

1. A rail transit power supply system for supplying power to a plurality of stations, the power supply system comprising:

the transformer comprises a primary coil and at least one secondary coil, the primary coil is connected with a mains supply inlet wire through a high-voltage alternating current bus, one of the at least one secondary coil is a first secondary coil, the first secondary coil is connected with an alternating current end of the first AC/DC converter, and the transformer is a step-down transformer;

the direct current ring network is connected with the direct current end of the first AC/DC converter and comprises station direct current buses arranged at each station and a direct current cable connected between the station direct current buses of two adjacent stations;

the power supply and distribution station comprises a low-voltage direct current bus and a low-voltage alternating current bus, the low-voltage direct current bus is used for connecting direct current loads of corresponding stations, the low-voltage alternating current bus is used for connecting alternating current loads of corresponding stations, wherein,

a first voltage transformation unit is connected between the low-voltage direct-current bus and a station direct-current bus of a corresponding station, and/or the transformer comprises at least two secondary coils, the other of the at least two secondary coils is recorded as a second secondary coil, and a second voltage transformation unit is connected between the low-voltage direct-current bus and the second secondary coil;

a third voltage transformation unit is connected between the low-voltage alternating-current bus and a station direct-current bus of a corresponding station, and/or the low-voltage alternating-current bus is connected with the second secondary coil;

the charging station comprises a plurality of stations, wherein at least one charging station exists in the stations, the load of the charging station further comprises a charging circuit and a current supplier, and the current supplier is connected with a station direct current bus or a low-voltage direct current bus of the corresponding charging station through the charging circuit.

2. The rail transit power supply system of claim 1, wherein the first voltage conversion unit comprises:

a first DC/DC converter, wherein a first DC end of the first DC/DC converter is connected with a station DC bus of a corresponding station, and a second DC end of the first DC/DC converter is connected with the low-voltage DC bus; and/or the presence of a gas in the gas,

the direct current end of the first DC/AC converter is connected with a station direct current bus of a corresponding station, the alternating current end of the first DC/AC converter is connected with the alternating current end of the second AC/DC converter, and the direct current end of the second AC/DC converter is connected with the low-voltage direct current bus.

3. The rail transit power supply system of claim 1, wherein the second voltage conversion unit comprises:

and the alternating current end of the third AC/DC converter is connected with the second secondary coil, and the direct current end of the third AC/DC converter is connected with the low-voltage direct current bus.

4. The rail transit power supply system according to claim 1, wherein the third voltage conversion unit includes:

the direct current end of the second DC/AC converter is connected with a station direct current bus of a corresponding station, and the alternating current end of the second DC/AC converter is connected with the low-voltage alternating current bus; and/or the presence of a gas in the gas,

the first direct current end of the second DC/DC converter is connected with a station direct current bus of a corresponding station, the second direct current end of the second DC/DC converter is connected with the direct current end of the third DC/AC converter, and the alternating current end of the third DC/AC converter is connected with the low-voltage alternating current bus.

5. The rail transit power supply system of claim 1, wherein the power supply system further comprises:

the alternating current ring network is connected with the second secondary coil, the alternating current ring network comprises station alternating current buses arranged at each station and alternating current cables connected between the station alternating current buses of two adjacent stations, and the station alternating current buses are connected with the low-voltage alternating current buses corresponding to the stations.

6. The rail transit power supply system of claim 1, wherein the substation further comprises a first switch, a second switch, and a third switch, the first switch being connected between a utility line inlet and the high voltage AC bus, the second switch being connected between the high voltage AC bus and the transformer, and the third switch being connected between the first AC/DC converter and a DC ring network.

7. The rail transit power supply system according to claim 1, wherein a fourth switch is connected between the station dc bus and the dc cable.

8. The rail transit power supply system according to claim 4, wherein the power supply and distribution station further includes a fifth switch, a sixth switch, and a plurality of seventh switches, the fifth switch is connected between the station direct current bus of the corresponding station and the second DC/AC converter, the sixth switch is connected between the second DC/AC converter and the low voltage alternating current bus of the corresponding station, and each of the seventh switches is connected between the low voltage alternating current bus and the corresponding alternating current load.

9. The rail transit power supply system according to claim 1, wherein the power supply and distribution station further comprises a distributed direct current power supply, and the distributed direct current power supply is connected with a station direct current bus or a low voltage direct current bus of a corresponding station.

10. The rail transit power supply system according to claim 1, wherein the number of the power substations is 2, and the power substations are respectively marked as a first power substation and a second power substation, and the second power substation is configured to operate when a fault occurs in the first power substation.

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