Multi-system power supply traction substation
By introducing a power fusion device and a DC bus into the multi-mode power supply traction substation, the problem of limited medium-voltage power supply capacity was solved, negative sequence compensation and three-phase balance were achieved, operating costs were reduced and power quality was improved.
Patent Information
- Application Number
- CN202422553498.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-22
- Publication Date
- 2025-12-09
- Estimated Expiration
- 2034-10-22
AI Technical Summary
In existing traction substations with multiple power supply systems, the utilization of medium-voltage power supply capacity is limited, resulting in high operating costs and poor power quality of the power supply system, especially when single-phase AC traction power supply generates negative sequence power and three-phase imbalance.
Design a multi-mode power supply traction substation, including a power sharing device, an AC bus, a DC bus, an AC incoming power supply, and a DC traction branch. By setting up a power sharing device between the AC bus and the DC bus, negative sequence compensation and three-phase balance are achieved, and power support is provided through the DC bus when the AC power supply capacity is limited.
It improves power quality, reduces the operating costs of the power supply system, and optimizes the utilization of power resources through negative sequence compensation and three-phase balancing.
Smart Images
Figure CN223651966U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of traction power supply system technology, and more specifically, to a multi-system power supply traction substation. Background Technology
[0002] In existing traction substations employing multiple power supply systems, external AC medium-voltage power is typically supplied from the grid. However, in actual operation, the severely limited utilization of medium-voltage power supply capacity and high operating costs of the power supply system are prominent issues. The supply capacity of medium-voltage power supplies is usually limited, and power companies impose very strict restrictions on it. Furthermore, during single-phase AC traction power supply, the single-phase AC traction load generates significant negative-sequence power in the three-phase medium-voltage system, causing severe three-phase imbalance. This results in only a portion of the power supply capacity being used for traction power supply, while also degrading the power quality of the medium-voltage system, leading to high operating costs. Utility Model Content
[0003] The purpose of this utility model is to provide a multi-system power supply traction substation to improve the above-mentioned problems. To achieve the above objective, the technical solution adopted by this utility model is as follows:
[0004] This application provides a multi-system power supply traction substation, including a power fusion device, an AC bus, a DC bus, an AC incoming power supply, an AC traction branch, and a first DC traction branch; the AC bus is electrically connected to the AC end of the power fusion device; the DC bus is electrically connected to the DC end of the power fusion device; at least two AC incoming power supplies are provided, and the AC incoming power supplies are electrically connected to the AC bus; the AC traction branch is electrically connected to the AC bus; the first DC traction branch is used for negative sequence compensation, and its two ends are electrically connected to the DC traction power supply system and the AC bus, respectively.
[0005] Optionally, a first switch is provided between the AC bus and the power fusion device, and a second switch is provided between the DC bus and the power fusion device.
[0006] Optionally, an AC energy storage branch is electrically connected to the AC bus, the AC energy storage branch including a first AC / DC bidirectional converter and a first energy storage device, the two ends of the first AC / DC bidirectional converter being electrically connected to the first energy storage device and the AC bus, respectively.
[0007] Optionally, a DC energy storage branch is electrically connected to the DC bus. The DC energy storage branch includes a first DC / DC bidirectional converter and a second energy storage device. The two ends of the first DC / DC bidirectional converter are electrically connected to the second energy storage device and the DC bus, respectively.
[0008] Optionally, the first DC traction branch includes a first sub-branch and a second sub-branch, and a third switch is provided between the first sub-branch and the second sub-branch.
[0009] Optionally, the first sub-branch includes a second AC / DC bidirectional converter, one end of which is electrically connected to the positive bus and negative bus of the DC traction power supply system, and the other end of which is electrically connected to the AC bus.
[0010] Optionally, a fourth switch is provided between the second AC / DC bidirectional converter and the positive bus of the DC traction power supply system, and a fifth switch is provided between the second AC / DC bidirectional converter and the negative bus of the DC traction power supply system.
[0011] Optionally, a first new energy branch is provided on one side of the AC bus, and a second new energy branch is provided on one side of the DC bus.
[0012] Optionally, a second DC traction branch is provided on one side of the DC bus, and the two ends of the second DC traction branch are electrically connected to the DC traction power supply system and the DC bus, respectively.
[0013] Optionally, the second DC traction branch includes a second DC / DC bidirectional converter, a sixth switch, and a seventh switch. One end of the second DC / DC bidirectional converter is electrically connected to the DC bus, and the other end of the second DC / DC bidirectional converter is electrically connected to the positive bus and the negative bus of the DC traction power supply system, respectively. The sixth switch is disposed between the second DC / DC bidirectional converter and the positive bus of the DC traction power supply system, and the seventh switch is disposed between the second DC / DC bidirectional converter and the negative bus of the DC traction power supply system.
[0014] The beneficial effects of this utility model are as follows:
[0015] This invention improves power quality by electrically connecting the first DC traction branch to the AC bus, enabling negative sequence compensation for the phase AC load and three-phase balance of the AC bus in AC traction power supply mode. Furthermore, a power sharing device is installed between the AC bus and the DC bus, so that when the AC power supply capacity is limited, power can be supplied through the DC bus to meet the energy requirements of AC traction power supply.
[0016] Other features and advantages of this invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing embodiments of the invention. The objects and other advantages of this invention can be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings. Attached Figure Description
[0017] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 This is a schematic diagram of the multi-system power supply traction substation structure described in the embodiments of this utility model.
[0019] The diagram is labeled as follows: 1. Power fusion device; 2. AC bus; 3. DC bus; 4. AC incoming power supply; 5. AC traction branch; 6. First switch; 7. Second switch; 8. First AC / DC bidirectional converter; 9. First energy storage device; 10. First DC / DC bidirectional converter; 11. Second energy storage device; 12. Third switch; 13. Second AC / DC bidirectional converter; 14. Fourth switch; 15. Fifth switch; 16. Positive bus; 17. Negative bus; 18. Second DC / DC bidirectional converter; 19. Sixth switch; 20. Seventh switch; 21. First new energy branch; 22. Second new energy branch. Detailed Implementation
[0020] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. The components of the embodiments of this utility model described and shown in the accompanying drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this utility model provided in the accompanying drawings is not intended to limit the scope of the claimed utility model, but merely to illustrate selected embodiments of the utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.
[0021] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this utility model, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.
[0022] like Figure 1As shown, this embodiment provides a multi-system power supply traction substation, including a power fusion device 1, an AC bus 2, a DC bus 3, an AC incoming power supply 4, an AC traction branch 5, and a first DC traction branch. The AC bus 2 is electrically connected to the AC terminal of the power fusion device 1; the DC bus 3 is electrically connected to the DC terminal of the power fusion device 1; at least two AC incoming power supplies 4 are provided, and the AC incoming power supplies 4 are electrically connected to the AC bus 2; the AC traction branch 5 is electrically connected to the AC bus 2; the first DC traction branch is used for negative sequence compensation, and its two ends are electrically connected to the DC traction power supply system and the AC bus 2, respectively; the AC traction branch 5 generally includes a transformer as an AC / AC conversion device, connecting the AC traction load. It can obtain power from the AC bus to supply power to the AC traction load, and can also convert and feed back the regenerative braking energy of the AC traction load to the AC bus. The AC incoming power supply 4 is an AC incoming power supply branch of medium-voltage power source introduced from the nearby power system. When the AC incoming power supply 4, AC traction branch 5 and the first DC traction branch are put into operation, the AC traction power supply mode is entered to realize negative sequence compensation for the AC 27.5kV (and / or 2×27.5kV) single-phase AC load and realize the three-phase balance of the AC bus. When the AC traction power supply mode is entered, the power fusion device 1 and DC bus 3 are introduced at the same time. When the AC power supply capacity is limited, power can be provided through the DC bus to meet the energy needs of AC traction power supply.
[0023] In one specific embodiment of this disclosure, a first switch 6 is provided between the AC bus 2 and the power switching device 1, and a second switch 7 is provided between the DC bus 3 and the power switching device 1. The connection between the DC bus 3 and the AC bus 2 can be controlled by providing the first switch 6 and the second switch 7.
[0024] In one specific embodiment of this disclosure, an AC energy storage branch is electrically connected to the AC bus 2. The AC energy storage branch includes a first AC / DC bidirectional converter 8 and a first energy storage device 9. The two ends of the first AC / DC bidirectional converter 8 are electrically connected to the first energy storage device 9 and the AC bus 2, respectively. When entering the AC traction power supply mode, when the power flow control device detects that the AC traction load regeneration causes the voltage of the AC bus 2 to rise, it absorbs and stores the regenerated braking energy in the first energy storage device 9 by connecting to the AC energy storage branch, or obtains electrical energy from the AC incoming power supply 4 and stores it in the first energy storage device 9 when the electricity price is low at night. When the power flow control device detects that the power of the AC traction branch 5 exceeds the limit, it releases the electrical energy stored in the first energy storage device 9 to the AC bus 2 to supply power to the AC traction power supply load, thereby reducing the capacity requirement of the AC power supply line, reducing electricity expenses, and reducing operating costs.
[0025] In one specific embodiment of this disclosure, a DC energy storage branch is electrically connected to the DC bus 3. The DC energy storage branch includes a first DC / DC bidirectional converter 10 and a second energy storage device 11. The two ends of the first DC / DC bidirectional converter 10 are electrically connected to the second energy storage device 11 and the DC bus 3, respectively.
[0026] In one specific embodiment of this disclosure, the first DC traction branch includes a first sub-branch and a second sub-branch. A third switch 12 is provided between the first sub-branch and the second sub-branch. The first sub-branch includes a second AC / DC bidirectional converter 13. One end of the second AC / DC bidirectional converter 13 is electrically connected to the positive bus 16 and the negative bus 17 of the DC traction power supply system, respectively. The other end of the second AC / DC bidirectional converter 13 is electrically connected to the AC bus 2. A switch is provided between the second AC / DC bidirectional converter 13 and the positive bus 16 of the DC traction power supply system. A fifth switch 15 is installed between the fourth switch 14, the second AC / DC bidirectional converter 13, and the negative bus 17 of the DC traction power supply system. When the third switch 12 is in the open position, and the fourth switch 14, the fifth switch 15, and all switches on the second sub-branch are in the closed position, a DC 750V voltage is output to the DC bus 3. When the third switch 12 is in the closed position, the fourth switch 14 is in the closed position, the switch on the second sub-branch connected to the negative bus 17 is in the closed position, and the fifth switch and the switch on the second sub-branch connected to the positive bus 16 are all in the open position, a DC 1500V voltage is output to the DC bus 3.
[0027] In one specific embodiment of this disclosure, a first new energy branch 21 is provided on one side of the AC bus 2, a second new energy branch 22 is provided on one side of the DC bus 3, and a second DC traction branch is provided on one side of the DC bus 3. The two ends of the second DC traction branch are electrically connected to the DC traction power supply system and the DC bus 3, respectively. The second DC traction branch includes a second DC / DC bidirectional converter 18, a sixth switch 19, and a seventh switch 20. One end of the second DC / DC bidirectional converter 18 is electrically connected to the DC bus 3, and the other end is electrically connected to the positive bus 16 and the negative bus 17 of the DC traction power supply system, respectively. The sixth switch 19 is located between the second DC / DC bidirectional converter 18 and the positive bus 16 of the DC traction power supply system, and the seventh switch 20 is located between the second DC / DC bidirectional converter 18 and the negative bus 17 of the DC traction power supply system. In the operation mode where the power supply system outputs DC 750V / DC 1500V, the sixth switch 19 and the seventh switch 20 are closed, and the second DC traction branch is introduced. When the AC power supply capacity is limited, power is obtained from the second new energy branch 22 via the DC bus and supplemented to the DC traction power supply system through the second DC traction branch. In the operation mode where the power supply system outputs DC 750V / DC 1500V, the sixth switch 19 and the seventh switch 20 are closed, and the second DC traction branch and the DC energy storage branch are introduced. When the DC traction load regenerates and brakes, the regenerative braking energy is sent to the second energy storage device 11 of the DC energy storage branch via the second DC traction branch and stored therein. When the voltage of the DC traction power supply system drops, the energy stored in the second energy storage device 11 is released to the DC bus 3 and supplied to the DC traction power supply system via the second DC traction branch, reducing electricity costs and lowering operating costs.
[0028] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this utility model is in use. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.
[0029] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0030] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.
[0031] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.
Claims
1. A multi-system power supply traction substation, characterized in that, include: Power fusion device (1); AC bus (2), which is electrically connected to the AC terminal of the power fusion device (1); DC bus (3), which is electrically connected to the DC end of the power fusion device (1); An AC power supply (4) is provided, and at least two AC power supplies (4) are provided. The AC power supply (4) is electrically connected to the AC bus (2). AC traction branch (5), which is electrically connected to the AC bus (2); The first DC traction branch is used for negative sequence compensation. The two ends of the first DC traction branch are electrically connected to the DC traction power supply system and the AC bus (2), respectively.
2. The multi-system power supply traction substation according to claim 1, characterized in that: A first switch (6) is provided between the AC bus (2) and the power fusion device (1), and a second switch (7) is provided between the DC bus (3) and the power fusion device (1).
3. The multi-system power supply traction substation according to claim 1, characterized in that: An AC energy storage branch is electrically connected to the AC bus (2). The AC energy storage branch includes a first AC / DC bidirectional converter (8) and a first energy storage device (9). The two ends of the first AC / DC bidirectional converter (8) are electrically connected to the first energy storage device (9) and the AC bus (2), respectively.
4. The multi-system power supply traction substation according to claim 1, characterized in that: The DC bus (3) is electrically connected to a DC energy storage branch, which includes a first DC / DC bidirectional converter (10) and a second energy storage device (11). The two ends of the first DC / DC bidirectional converter (10) are electrically connected to the second energy storage device (11) and the DC bus (3), respectively.
5. The multi-system power supply traction substation according to claim 1, characterized in that: The first DC traction branch includes a first sub-branch and a second sub-branch, and a third switch (12) is provided between the first sub-branch and the second sub-branch.
6. The multi-system power supply traction substation according to claim 5, characterized in that: The first sub-branch includes a second AC / DC bidirectional converter (13), one end of which is electrically connected to the positive bus (16) and negative bus (17) of the DC traction power supply system, and the other end of which is electrically connected to the AC bus (2).
7. The multi-system power supply traction substation according to claim 6, characterized in that: A fourth switch (14) is provided between the second AC / DC bidirectional converter (13) and the positive bus (16) of the DC traction power supply system, and a fifth switch (15) is provided between the second AC / DC bidirectional converter (13) and the negative bus (17) of the DC traction power supply system.
8. The multi-system power supply traction substation according to claim 1, characterized in that: A first new energy branch (21) is provided on one side of the AC bus (2), and a second new energy branch (22) is provided on one side of the DC bus (3).
9. The multi-system power supply traction substation according to claim 1, characterized in that: A second DC traction branch is provided on one side of the DC bus (3), and the two ends of the second DC traction branch are electrically connected to the DC traction power supply system and the DC bus (3), respectively.
10. The multi-system power supply traction substation according to claim 9, characterized in that: The second DC traction branch includes a second DC / DC bidirectional converter (18), a sixth switch (19), and a seventh switch (20). One end of the second DC / DC bidirectional converter (18) is electrically connected to the DC bus (3), and the other end of the second DC / DC bidirectional converter (18) is electrically connected to the positive bus (16) and the negative bus (17) of the DC traction power supply system, respectively. The sixth switch (19) is located between the second DC / DC bidirectional converter (18) and the positive bus (16) of the DC traction power supply system, and the seventh switch (20) is located between the second DC / DC bidirectional converter (18) and the negative bus (17) of the DC traction power supply system.