WO2024050981A1 - Train power supply system, train power supply method, and train - Google Patents

Abstract

A train power supply system, a train power supply method, and a train. The power supply system comprises a plurality of direct-current auxiliary converters, a first direct-current bus, and a rectifying load which are connected in sequence; the rectifying load comprises a variable-frequency air conditioner, a variable-frequency motor, and direct-current loads; the plurality of direct-current auxiliary converters are used for decreasing the voltage of a high-voltage direct current, and thus outputting a low-voltage direct current to the first direct-current bus; the first direct-current bus is used for transmitting the low-voltage direct current to the rectifying load; the power supply system does not comprise an alternating-current bus, so that the problems of reactive power transmission and frequency stability necessarily associated with an alternating-current system, and the alternating-current voltage distortion problem when a rectifying load is connected would not occur; the rectifying load is used for converting the low-voltage direct current into an alternating current so as to drive the rectifying load to work. The rectifying load can be driven to work by directly inputting a direct current to the rectifying load, and the rectifying load does not need to rectify an alternating current into a direct current, so that the electric energy loss and the capacity requirement are reduced, and the power supply capacity and the electric energy quality are improved.

Description

A train power supply system, a train power supply method and a train

This application requires the priority of the Chinese patent application submitted to the State Intellectual Property Office of China on September 9, 2022, with the application number 202211103259.X and the invention title "A train power supply system, a train power supply method and a train", all of which The contents are incorporated into this application by reference.

Technical field

The present application relates to the field of vehicles, for example, to a train power supply system, a train power supply method and a train.

Background technique

At present, the power dispersion architecture has become the mainstream solution for EMUs around the world. In the existing technology, the train power supply system using the power dispersion architecture includes the AC bus. In this way, there are reactive power transmission and Frequency stability issues, AC voltage distortion when connected to a rectified load, large power loss and capacity requirements make it impossible to improve the lightweight level.

Contents of the invention

In view of this, the purpose of this application is to provide a train power supply system, a train power supply method and a train, which reduce power loss and capacity requirements, effectively improve power supply capacity and power quality, and fundamentally improve the lightweight level.

In order to achieve the above purpose, this application has the following technical solutions:

In a first aspect, embodiments of the present application provide a train power supply system, including a plurality of DC auxiliary converters, a first DC bus and a rectifying load connected in sequence; the rectifying load includes a variable frequency air conditioner, a variable frequency motor and a Various DC loads;

The plurality of DC auxiliary converters are used to step down high-voltage DC power and output low-voltage DC power to the first DC bus;

The first DC bus is used to transmit the low-voltage direct current to the rectifying load;

The rectifying load is used to convert the low-voltage direct current into alternating current to drive the rectifying load to work.

In the second aspect, embodiments of the present application provide a train power supply method, using a train power supply system to provide power to the train.

In a third aspect, embodiments of the present application also provide a train, which includes a train power supply system.

Compared with the existing technology, the embodiments of the present application have the following advantages:

Embodiments of the present application provide a train power supply system, a train power supply method and a train. The power supply system includes a plurality of DC auxiliary converters, a first DC bus and a rectifying load connected in sequence; the rectifying load includes a variable frequency air conditioner, a variable frequency air conditioner and a rectifying load. Motors and various DC loads, multiple DC auxiliary converters, used to step down high-voltage DC power, so that low-voltage DC power can be output to the first DC bus. The first DC bus is used to transmit low-voltage DC power to rectifying loads. , in this way, the power supply system does not include the AC bus, and there are no problems such as reactive power transmission, frequency stability, and AC voltage distortion when connected to a rectifier load that are inevitably associated with the AC system. The rectifier load is used to convert low-voltage DC power into AC power. It works by driving the rectifying load. In this way, DC power is directly input to the rectifying load. The rectifying load can drive the rectifying load without rectifying the AC power into DC power, thereby reducing the power loss and capacity requirements, and effectively improving the power supply capacity and Power quality, fundamentally improve the level of lightweight.

Description of the drawings

In order to more clearly explain the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are: For some embodiments of the present application, those of ordinary skill in the art can also obtain other drawings based on these drawings without exerting creative efforts.

Figure 1 shows a schematic structural diagram of a train power supply system provided by an embodiment of the present application;

Figure 2 shows a schematic structural diagram of yet another train power supply system provided by an embodiment of the present application.

Detailed ways

In order to make the above objects, features and advantages of the present application more obvious and easy to understand, the specific implementation modes of the present application will be described in detail below with reference to the accompanying drawings.

Many specific details are set forth in the following description to fully understand the present application. However, the present application can also be implemented in other ways different from those described here. Those skilled in the art can do so without violating the connotation of the present application. Similar generalizations are made, and therefore the present application is not limited to the specific embodiments disclosed below.

The inventor found that the traditional train power supply system using a power decentralized architecture includes a high-voltage DC bus, an AC auxiliary converter, a medium-voltage AC bus and a rectifying load connected in sequence. The AC auxiliary converter converts DC power into three-phase AC power 380V. , three-phase AC power is transmitted to the rectifying load through the medium voltage AC bus. With the development of technology and the demand for energy saving and consumption reduction, rectifier loads such as variable frequency air conditioners and speed-adjustable fans are increasingly widely used. The rectifying load receives three-phase AC power. The rectifying load first converts the three-phase AC power supply into DC power supply through the rectifier, and then drives the air conditioning compressor, fan and other motor loads through the inverter. This has the inevitable problems of reactive power transmission and frequency stability associated with AC systems, as well as the problem of AC voltage distortion when connected to a rectified load. The power loss and capacity requirements are large, making it impossible to improve the lightweight level.

In order to solve the above technical problems, embodiments of the present application provide a train power supply system, a train power supply method and a train. The power supply system includes a plurality of DC auxiliary converters, a first DC bus and a rectifying load connected in sequence; Loads include variable frequency air conditioners, variable frequency motors and various DC loads. Multiple DC auxiliary converters are used to step down high-voltage DC power, so that low-voltage DC power can be output to the first DC bus. The first DC bus is used to The rectifying load transmits low-voltage direct current, so that the power supply system does not include the AC bus, and there are no problems such as reactive power transmission, frequency stability, and AC voltage distortion that are inevitably associated with the AC system. The rectifying load is used to Low-voltage DC power is converted into AC power to drive the rectifying load. In this way, DC power is directly input to the rectifying load. The rectifying load can drive the rectifying load without rectifying the AC power into DC power, thereby reducing power loss and capacity requirements. It effectively improves the power supply capacity and power quality, and fundamentally improves the lightweight level.

Exemplary device

Refer to Figure 1, which is a schematic structural diagram of a train power supply system provided by an embodiment of the present application. The train power supply system includes a plurality of DC auxiliary converters, a first DC bus and a rectifying load connected in sequence. Each DC auxiliary converter can be located in different compartments, and the rectifying loads include variable frequency air conditioners, variable frequency motors and various DC loads.

In the embodiment of this application, multiple DC auxiliary converters are used to step down high-voltage DC power and output low-voltage DC power to the first DC bus. The first DC bus is used to transmit low-voltage DC power to the rectifying load, so that The power supply system does not include an AC bus, and there are no issues such as reactive power transmission, frequency stability, and AC voltage distortion when connected to a rectified load that are inevitably associated with the AC system.

In the embodiment of the present application, the rectifying load is used to convert low-voltage direct current into alternating current to drive the rectifying load to work. Compared with the existing technology, AC power is connected from the AC bus, and the rectifying load needs to convert the AC power into DC power in order to drive the load. In this application, DC power can be directly input to the rectifying load, and the rectifying load does not need to convert the AC power into the load. The rectified power can be used to drive the rectified load. The auxiliary converter and electrical load can eliminate the inversion and rectification links. The overall efficiency is expected to increase by more than 5%. As the proportion of such speed-regulated loads gradually increases in the future, , the above characteristics will be more prominent, thereby reducing power loss and capacity requirements, effectively improving power supply capacity and power quality; in addition, the power conversion process is simplified from the DC-AC-DC mode in the existing technology to a DC-DC mode. It can save the rectifier module and inverter module of all levels of load and auxiliary converter of the power supply, and the weight of the vehicle power supply system can be reduced by 20% to 30%, fundamentally improving the lightweight level.

In the embodiment of the present application, the power supply system may also include multiple four-quadrant rectifiers and a second DC bus. Refer to Figure 2, which is a schematic structural diagram of another train power supply system provided by the embodiment of the present application. Multiple four-quadrant rectifiers The rectifiers are located in power car 02, power car 04, power car 05 and power car 07 respectively. Multiple DC auxiliary converters are located in head car 01, transformer car 03, transformer car 06 and head car 08 respectively. Multiple four-quadrant rectifiers, It is used to convert high-voltage alternating current into high-voltage direct current. The high-voltage direct current output by multiple four-quadrant rectifiers is connected in parallel to power the second DC bus. The voltage of the second DC bus is higher than the voltage of the first DC bus.

Compared with the existing technology, the four-quadrant rectifier in the power car 02 only supplies power to the DC auxiliary converter in the lead car 01, and the four-quadrant rectifier in the power car 04 only supplies power to the DC auxiliary converter in the transformer car 03. power supply, this will easily lead to the failure of the four-quadrant rectifier in the power car 02, and the DC auxiliary converter in the lead car 01 will also stop working. The four-quadrant rectifiers are independent of each other and lack the ability to support each other. When one of them When a component fails, it often also causes other equipment connected to it to shut down.

In this application, the high-voltage DC output from multiple four-quadrant rectifiers is connected in parallel to power the second DC bus, and multiple DC auxiliary converters are connected to the second DC bus. In this way, the four-quadrant rectifier in the power vehicle 02 When a fault occurs, the outputs of multiple high-voltage DC power supplies are connected in parallel to supply power to the high-voltage DC bus. The four-quadrant rectifiers in Power Car 04, Power Car 05 and Power Car 07 all supply power to the second DC bus, and the one connected to the second DC bus is located at the head The DC auxiliary converter in Car 01 can still work normally, increasing the redundancy of the power supply system.

Specifically, the first DC bus may be a medium voltage DC bus, the second DC bus may be a high voltage DC bus, and the third DC bus may be a low voltage DC bus. As a high-voltage DC power source, a four-quadrant rectifier can convert the output of the traction transformer into DC power.

In this embodiment of the present application, the power supply system may further include an energy storage device, which is connected to the first DC bus and used to supply power to the first DC bus and provide energy thereto.

In the embodiment of the present application, the power supply system may also include a charger. The charger is connected to the first DC bus. The energy storage device supplies power to the third DC bus through the charger. The voltage of the third DC bus is lower than that of the second DC bus. voltage, the charger is a low-voltage DC power supply. The charger is a load on the medium-voltage DC bus, responsible for charging the battery and providing 110V control power for the train. The 110V low-voltage DC bus on the train runs through the train, and various network control equipment, brake controllers, traction controllers and other loads are connected to the 110V low-voltage DC bus.

In this embodiment of the present application, the energy storage device can supply power to the second DC bus through the DC auxiliary converter. As a medium-voltage DC power supply, the DC auxiliary converter steps down the voltage of the high-voltage DC bus and achieves electrical isolation. It can also control the bidirectional flow of energy.

In this embodiment of the present application, the voltage of the first DC bus may be 600V, the voltage of the second DC bus may be 1800V or 3600V, and the voltage of the third DC bus may be 110V. Specifically, the voltage level of the high-voltage DC bus can be 1800V or 3600V, the voltage level of the medium-voltage DC bus can be 600V, and the voltage level of the low-voltage DC bus can be 110V.

In the embodiment of the present application, the system also includes multiple traction inverters connected to the second DC bus for converting high-voltage DC power into AC power to control the operation of the motor. Specifically, all traction inverters and DC auxiliary converters serve as loads and draw power from the high-voltage DC bus; the traction inverter converts DC power into AC power and controls the motor to convert electrical energy into mechanical energy.

In the embodiment of the present application, the system also includes a traction transformer connected to multiple four-quadrant rectifiers for isolating and reducing single-phase AC power and outputting high-voltage AC power to multiple four-quadrant rectifiers. Specifically, the traction transformer isolates and steps down the 25kV/50Hz single-phase AC power and outputs it to the four-quadrant rectifier. The four-quadrant rectifier rectifies the AC power output from the traction transformer into DC power and transmits it to the high-voltage DC bus. The traction inverter converts the high-voltage DC power into DC power. It is alternating current with variable voltage and frequency, which is used to drive the traction motor for traction or braking.

The embodiment of the present application provides a train power supply system. The power supply system includes a plurality of DC auxiliary converters, a first DC bus and a rectifying load connected in sequence; the rectifying load includes a variable frequency air conditioner, a variable frequency motor and various DC loads. , multiple DC auxiliary converters, used to step down high-voltage DC, so that low-voltage DC can be output to the first DC bus. The first DC bus is used to transmit low-voltage DC to rectifying loads, so that the power supply system does not include The AC bus does not have the problems of reactive power transmission, frequency stability, and AC voltage distortion that are inevitably associated with the AC system, as well as AC voltage distortion when connected to a rectified load. The rectified load is used to convert low-voltage DC power into AC power to drive the rectified load. , in this way, direct current is input to the rectifying load, and the rectifying load can drive the rectifying load without rectifying the alternating current into direct current, thus reducing the power loss and capacity requirements, effectively improving the power supply capacity and power quality, and fundamentally Improve the level of lightweight.

Based on the above train power supply system, embodiments of the present application also provide a train power supply method, using the train power supply system as described above to supply power to the train.

Based on the above train power supply system, embodiments of the present application also provide a train, which includes the train power supply system as described above.

Each embodiment in this specification is described in a progressive manner. The same and similar parts between the various embodiments can be referred to each other. Each embodiment focuses on its differences from other embodiments.

The above are only the preferred embodiments of the present application. Although the present application has been disclosed above with preferred embodiments, they are not intended to limit the present application. Any person familiar with the art can make many possible changes and modifications to the technical solution of the present application by using the methods and technical content disclosed above, or modify it to equivalent changes without departing from the scope of the technical solution of the present application. Example. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present application that do not deviate from the content of the technical solution of the present application still fall within the scope of protection of the technical solution of the present application.

Claims (10)

1. A train power supply system, characterized in that it includes a plurality of DC auxiliary converters, a first DC bus and a rectifying load connected in sequence; the rectifying load includes a variable frequency air conditioner, a variable frequency motor and various DC loads;

   The plurality of DC auxiliary converters are used to step down high-voltage DC power and output low-voltage DC power to the first DC bus;

   The first DC bus is used to transmit the low-voltage direct current to the rectifying load;

   The rectifying load is used to convert the low-voltage direct current into alternating current to drive the rectifying load to work.
2. The system according to claim 1, wherein the system further includes a plurality of four-quadrant rectifiers and a second DC bus;

   The plurality of four-quadrant rectifiers are used to convert high-voltage alternating current into the high-voltage direct current. The high-voltage direct current output by the plurality of four-quadrant rectifiers is connected in parallel to power the second DC bus. The voltage of the second DC bus is high. at the voltage of the first DC bus.
3. The system according to claim 2, characterized in that the system further includes an energy storage device, the energy storage device is connected to the first DC bus and is used to supply power to the first DC bus.
4. The system according to claim 3, characterized in that the system further includes a charger, the charger is connected to the first DC bus, and the energy storage device is a third DC bus through the charger. To supply power, the voltage of the third DC bus is lower than the voltage of the second DC bus.
5. The system according to claim 3, wherein the energy storage device supplies power to the second DC bus through the DC auxiliary converter.
6. The system according to claim 4, wherein the voltage of the first DC bus is 600V, the voltage of the second DC bus is 1800V or 3600V, and the voltage of the third DC bus is 110V.
7. The system according to claim 1, characterized in that the system further includes a plurality of traction inverters connected to the second DC bus for converting the high-voltage DC power into alternating current to control the operation of the motor.
8. The system according to claim 2, characterized in that the system further includes a traction transformer connected to the plurality of four-quadrant rectifiers for isolating and reducing single-phase AC power and outputting the high-voltage AC power to The plurality of four-quadrant rectifiers.
9. A train power supply method, characterized in that the train power supply system according to any one of claims 1 to 8 is used to supply power to the train.
10. A train, characterized in that the train includes the train power supply system according to any one of claims 1-8.

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