Flexible power supply device of electrified railway substation

Abstract

The utility model provides a flexible power supply device for an electrified railway substation, and relates to the technical field of electrified railway power supply. The output end of the high-voltage bus circuit is connected with the input ends of the first transformer circuit, the second transformer circuit, the third transformer circuit and the fourth transformer circuit, and the output ends of the first transformer circuit and the fourth transformer circuit are connected with a medium-voltage common bus. The output ends of the second transformer circuit and the third transformer circuit are respectively connected with the input end of a medium-voltage bus distribution circuit, the medium-voltage bus distribution circuit is connected with an electric energy router, the output end of the electric energy router is connected with a medium-voltage common bus, and the output ends of the medium-voltage bus distribution circuit and the electric energy router are also connected with a power distribution load. According to the utility model, substation traction power supply and power distribution system cooperative operation and resource sharing are realized, the medium-voltage distribution network structure is enhanced, the regulation and control capability is improved, and new energy access requirements are effectively met.

Description

Technical Field

[0001] This utility model relates to the technical field of power supply for electrified railways, and in particular to a flexible power supply device for electrified railway substations. Background Technology

[0002] The railway power supply system mainly consists of two parts: the traction power supply system and the power distribution system. The traction power supply system realizes power conversion through traction substations. The railway traction power supply system is a single-phase AC 25kV system. Because the single-phase AC traction power supply system adopts a phase / zone power supply structure with alternating phase sequence, electrical phase separation areas will be formed in the traction power supply system, resulting in power supply islands, affecting line operation, and restricting the energy transfer within the power supply system, thereby reducing the power supply efficiency and the utilization rate of power supply equipment. On the other hand, the traditional single-phase AC traction power supply system is a passive power supply system, which cannot flexibly control the power supply energy and has obvious limitations in adapting to the needs of new energy access and emergency power supply.

[0003] In railway power distribution systems, there are currently two main power supply methods for power distribution loads within traction substations and along railway lines: one is to use independent power through-line power supply. This method cannot utilize the regenerative braking energy in the traction power supply system and requires separate power supply equipment, resulting in poor overall economic efficiency. If power is drawn from the traction network to supply power distribution loads through transformers with special wiring configurations, the power quality cannot be guaranteed, often resulting in serious power quality problems such as large voltage fluctuations and complex harmonic content. The other method is to build new substations to supply power distribution loads along the railway line, especially in intercity and urban / suburban railways. Typically, the newly built substations supplying power distribution loads are combined with the traction power supply equipment to form the main substation. However, in reality, the design of the traction power supply and power distribution systems is relatively independent, making resource sharing impossible. The existing railway medium-voltage distribution network has a radial grid structure. To limit short-circuit capacity and avoid electromagnetic loop problems, the interconnection switches between busbars are usually not closed during normal operation, resulting in an open-loop operation of the distribution network. The power flow is naturally distributed according to circuit parameters and load demand, with very limited regulation capabilities. The weak grid structure, outdated open-loop operation mode, and limited control methods hinder the improvement of the distribution network's operational flexibility and power supply reliability, easily causing problems such as unbalanced feeder loads, deterioration of power quality, and prolonged power outage time. Furthermore, it is unable to undertake the task of absorbing a large number of distributed power sources. In addition, with the increasing global emphasis on environmental protection and the maturity of renewable energy technologies, railway traction power supply systems need to gradually introduce renewable energy sources such as solar and wind power to reduce dependence on traditional energy sources, lower operating costs, and reduce environmental pollution. However, the passive power supply mode of traditional traction power supply systems is not suitable for the access needs of distributed new energy sources such as wind, solar, and energy storage. Utility Model Content

[0004] To address the problems of existing technologies, such as independent system operation, inability to share resources, weak medium-voltage distribution network structure, limited control capabilities, and difficulty in adapting to the needs of new energy access, this utility model proposes a flexible power supply device for electrified railway substations. This device enables coordinated operation and resource sharing between the substation's traction power supply and power distribution systems, enhances the structure of the medium-voltage distribution network, improves control capabilities, and effectively adapts to the needs of new energy access.

[0005] To achieve the above-mentioned technical effects, the technical solution of this utility model is as follows:

[0006] A flexible power supply device for an electrified railway substation includes: a three-phase high-voltage incoming line circuit, a high-voltage busbar circuit, a first transformer circuit, a second transformer circuit, a third transformer circuit, a fourth transformer circuit, a medium-voltage busbar distribution circuit, a power router, and a medium-voltage common busbar for supplying power to the contact network of the train traction load.

[0007] The three-phase high-voltage incoming line circuit is connected to the input terminal of the high-voltage bus circuit. The output terminal of the high-voltage bus circuit is connected to the input terminals of the first transformer circuit, the second transformer circuit, the third transformer circuit, and the fourth transformer circuit, respectively. The output terminals of the first transformer circuit and the fourth transformer circuit are respectively connected to the medium-voltage common bus. The output terminals of the second transformer circuit and the third transformer circuit are respectively connected to the input terminal of the medium-voltage bus distribution circuit. The output terminal of the medium-voltage bus distribution circuit is connected to the input terminal of the power router. The output terminal of the power router is connected to the medium-voltage common bus. The output terminals of the medium-voltage bus distribution circuit and the power router are also connected to the power distribution load.

[0008] Preferably, the three-phase high-voltage incoming line circuit includes a first three-phase high-voltage incoming line, a second three-phase high-voltage incoming line, a first high-voltage circuit breaker QFA, and a second high-voltage circuit breaker QFB. The first three-phase high-voltage incoming line is connected to one end of the first high-voltage circuit breaker QFA, the second three-phase high-voltage incoming line is connected to one end of the second high-voltage circuit breaker QFB, and the other ends of the first high-voltage circuit breaker QFA and the second high-voltage circuit breaker QFB are respectively connected to the high-voltage bus circuit.

[0009] Preferably, the high-voltage bus circuit includes a first high-voltage bus, a third high-voltage circuit breaker QFAB, and a second high-voltage bus. The first high-voltage bus is connected to the output terminal of the first high-voltage circuit breaker QFA, the input terminal of the first transformer circuit, the input terminal of the second transformer circuit, and one end of the third high-voltage circuit breaker QFAB. The second high-voltage bus is connected to the output terminal of the second high-voltage circuit breaker QFB, the input terminal of the third transformer circuit, the input terminal of the fourth transformer circuit, and the other end of the third high-voltage circuit breaker QFAB.

[0010] Preferably, the first transformer circuit includes a fifth high-voltage circuit breaker QF1, a first single-phase transformer T1, and a sixth high-voltage circuit breaker QF12. The first high-voltage busbar is connected to one end of the fifth high-voltage circuit breaker QF1, the other end of the fifth high-voltage circuit breaker QF1 is connected to the input end of the first single-phase transformer T1, the output end of the first single-phase transformer T1 is connected to one end of the sixth high-voltage circuit breaker QF12, and the other end of the sixth high-voltage circuit breaker QF12 is connected to the medium-voltage common busbar.

[0011] Preferably, the fourth transformer circuit includes a seventh high-voltage circuit breaker QF4, a second single-phase transformer T4, and an eighth high-voltage circuit breaker QF15. The second high-voltage busbar is connected to one end of the seventh high-voltage circuit breaker QF4, the other end of the seventh high-voltage circuit breaker QF4 is connected to the input end of the second single-phase transformer T4, the output end of the second single-phase transformer T4 is connected to one end of the eighth high-voltage circuit breaker QF15, and the other end of the eighth high-voltage circuit breaker QF15 is connected to the medium-voltage common busbar.

[0012] Preferably, the second transformer circuit includes a ninth high-voltage circuit breaker QF2, a first three-phase transformer T2, and a tenth high-voltage circuit breaker QF5. The first high-voltage busbar is connected to one end of the ninth high-voltage circuit breaker QF2, the other end of the ninth high-voltage circuit breaker QF2 is connected to the input end of the first three-phase transformer T2, the output end of the first three-phase transformer T2 is connected to one end of the tenth high-voltage circuit breaker QF5, and the other end of the tenth high-voltage circuit breaker QF5 is connected to the medium-voltage busbar distribution circuit.

[0013] Preferably, the third transformer circuit includes an eleventh high-voltage circuit breaker QF3, a second three-phase transformer T3, and a twelfth high-voltage circuit breaker QF6. The second high-voltage busbar is connected to one end of the eleventh high-voltage circuit breaker QF3, the other end of the eleventh high-voltage circuit breaker QF3 is connected to the input end of the second three-phase transformer T3, the output end of the second three-phase transformer T3 is connected to one end of the twelfth high-voltage circuit breaker QF6, and the other end of the twelfth high-voltage circuit breaker QF6 is connected to the medium-voltage busbar distribution circuit.

[0014] Preferably, the medium-voltage busbar power distribution circuit includes a thirteenth high-voltage circuit breaker QF10, a first medium-voltage busbar, a fourteenth high-voltage circuit breaker QF7, a second medium-voltage busbar, and a fifteenth high-voltage circuit breaker QF11. One end of the fourteenth high-voltage circuit breaker QF7 is connected to the other end of the tenth high-voltage circuit breaker QF5, the input terminal of the power router, and one end of the thirteenth high-voltage circuit breaker QF10. The other end of the fourteenth high-voltage circuit breaker QF7 is connected to the other end of the twelfth high-voltage circuit breaker QF6, the input terminal of the power router, and one end of the fifteenth high-voltage circuit breaker QF11. The other ends of the thirteenth high-voltage circuit breaker QF10 and the fifteenth high-voltage circuit breaker QF11 are respectively connected to the power distribution load.

[0015] Preferably, the power router includes a sixteenth high-voltage circuit breaker QF8, a third three-phase transformer T5, a first three-phase to single-phase converter Q1, a third single-phase transformer T7, a seventeenth high-voltage circuit breaker QF13, an eighteenth high-voltage circuit breaker QF9, a fourth three-phase transformer T6, a second three-phase to single-phase converter Q2, a fourth single-phase transformer T8, a nineteenth high-voltage circuit breaker QF14, a DC / DC converter, and a DC / AC converter;

[0016] The first medium-voltage busbar is connected to one end of the sixteenth high-voltage circuit breaker QF8. The other end of the sixteenth high-voltage circuit breaker QF8 is connected to the input end of the third three-phase transformer T5. The output end of the third three-phase transformer T5 is connected to the input end of the first three-phase to single-phase converter Q1. The output end of the first three-phase to single-phase converter Q1 is connected to the input end of the third single-phase transformer T7. The output end of the third single-phase transformer T7 is connected to one end of the seventeenth high-voltage circuit breaker QF13. The other end of the seventeenth high-voltage circuit breaker QF13 is connected to the medium-voltage common busbar.

[0017] The second medium-voltage busbar is connected to one end of the eighteenth high-voltage circuit breaker QF9. The other end of the eighteenth high-voltage circuit breaker QF9 is connected to the input end of the fourth three-phase transformer T6. The output end of the fourth three-phase transformer T6 is connected to the input end of the second three-phase to single-phase converter Q2. The output end of the second three-phase to single-phase converter Q2 is connected to the input end of the fourth single-phase transformer T8. The output end of the fourth single-phase transformer T8 is connected to one end of the nineteenth high-voltage circuit breaker QF14. The other end of the nineteenth high-voltage circuit breaker QF14 is connected to the medium-voltage common busbar.

[0018] The output terminals of the first three-phase to single-phase converter Q1, the output terminals of the second three-phase to single-phase converter Q2, the input terminals of the DC / DC converter and the DC / AC converter are interconnected through a common DC bus. The output terminals of the DC / DC converter and the DC / AC converter are respectively connected to the power distribution load.

[0019] Preferably, the medium-voltage common busbar is connected to the train traction load contact network via the twentieth high-voltage circuit breaker QF16 and the twentieth high-voltage circuit breaker QF17.

[0020] Compared with the prior art, the beneficial effects of this utility model's technical solution are:

[0021] This utility model proposes a flexible power supply device for electrified railway substations. Firstly, power is distributed to each transformer circuit via a three-phase high-voltage incoming circuit and a high-voltage busbar circuit. The first and fourth transformer circuits are connected to the medium-voltage common busbar to supply power to the train traction load contact network. Then, the second and third transformer circuits are connected to a power router via the medium-voltage busbar distribution circuit. The DC output of the medium-voltage busbar distribution circuit and the power router can be connected to the power distribution load, integrating the train traction load and the power distribution load into a single architecture, thereby constructing an integrated flexible intelligent system that combines traction power supply and power distribution. The power supply device can simultaneously supply power to railway traction loads and non-traction loads along the line, realizing flexible interconnection and resource sharing of traction power supply system and power distribution system; secondly, the medium-voltage bus distribution circuit realizes flexible interconnection power supply of different buses in the medium-voltage distribution network through power router, avoiding the formation of electromagnetic loop network, enhancing the structure of medium-voltage distribution network, and improving the control capability of medium-voltage distribution network; furthermore, the collaborative design of medium-voltage bus distribution circuit and power router provides access ports for distributed energy and energy storage units, realizing the coordinated control of clean energy and train traction load and power load, effectively adapting to the needs of new energy access; Attached Figure Description

[0022] Figure 1 This is a schematic diagram illustrating the structure of a flexible power supply device for an electrified railway substation as proposed in an embodiment of this utility model.

[0023] Figure 2 This is another structural schematic diagram of a flexible power supply device for an electrified railway substation proposed in an embodiment of this utility model.

[0024] Figure 3 This diagram illustrates the three-phase to single-phase converter topology proposed in this embodiment of the invention.

[0025] Figure 4 This diagram illustrates the power router-DC series network proposed in this embodiment of the invention.

[0026] Figure 5 This diagram illustrates the DC series / parallel network topology of the power router proposed in this embodiment of the present invention.

[0027] 1. Three-phase high-voltage incoming line circuit; 2. High-voltage bus circuit; 3. First transformer circuit; 4. Second transformer circuit; 5. Third transformer circuit; 6. Fourth transformer circuit; 7. Medium-voltage bus distribution circuit; 8. Power router; 9. Medium-voltage common bus. Detailed Implementation

[0028] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the scope of this patent.

[0029] It is understandable to those skilled in the art that some well-known details may be omitted from the accompanying drawings;

[0030] To facilitate understanding of the following embodiments, the following explanations are provided for some of the technical terms involved:

[0031] Electromagnetic loop network: An electromagnetic loop network refers to two sets of lines with different voltage levels connected in parallel through the magnetic circuits of transformers at both ends. In high- and low-voltage electromagnetic loop networks, the load transfer caused by the disconnection of the high-voltage line is likely to cause the accident to escalate and the system to become unstable. Furthermore, the electromagnetic loop network will increase the system's short-circuit current.

[0032] Power Router: A multi-port intelligent power management device based on high-power converter and its control technology, used to efficiently distribute and control power flow among multiple nodes.

[0033] Train traction load contact network: an overhead conductor system that supplies electrical energy to the locomotive via pantograph, mainly composed of supports, foundations, supporting structures, and contact suspension.

[0034] Power transmission line: A power transmission line is a 10kV or 35kV power line that connects two adjacent substations along a railway line to supply power to the railway loads along the line. It is a power line that connects two adjacent substations along a railway line to supply power to the railway loads.

[0035] The technical solution of this utility model will be further described below with reference to the accompanying drawings and embodiments.

[0036] Example 1

[0037] like Figure 1 As shown, this embodiment proposes a flexible power supply device for an electrified railway substation, including: a three-phase high-voltage incoming line circuit 1, a high-voltage busbar circuit 2, a first transformer circuit 3, a second transformer circuit 4, a third transformer circuit 5, a fourth transformer circuit 6, a medium-voltage busbar distribution circuit 7, a power router 8, and a medium-voltage common busbar 9 for supplying power to the contact network of the train traction load.

[0038] The three-phase high-voltage incoming line circuit 1 is connected to the input terminal of the high-voltage bus circuit 2. The output terminal of the high-voltage bus circuit 2 is connected to the input terminals of the first transformer circuit 3, the second transformer circuit 4, the third transformer circuit 5, and the fourth transformer circuit 6, respectively. The output terminals of the first transformer circuit 3 and the fourth transformer circuit 6 are connected to the medium-voltage common bus 9, respectively. The output terminals of the second transformer circuit 4 and the third transformer circuit 5 are connected to the input terminal of the medium-voltage bus distribution circuit 7, respectively. The output terminal of the medium-voltage bus distribution circuit 7 is connected to the input terminal of the power router 8, and the output terminal of the power router 8 is connected to the medium-voltage common bus 9. The DC-side output terminals of the medium-voltage bus distribution circuit 7 and the power router 8 are also connected to the power distribution load.

[0039] First, power is distributed to each transformer circuit via the three-phase high-voltage incoming circuit and the high-voltage bus circuit. The first and fourth transformer circuits are connected to the medium-voltage common bus to supply power to the train traction load contact network. Then, the second and third transformer circuits are connected to the power router via the medium-voltage bus distribution circuit. Power distribution loads can also be connected to the DC output of the medium-voltage bus distribution circuit and the power router, integrating the train traction load and power distribution load into the same architecture. This constructs an integrated flexible intelligent power supply device that combines traction power supply and power distribution, capable of simultaneously supplying power to the train traction load and power distribution network. The system provides power to railway traction loads and non-traction loads along the line, enabling flexible interconnection and resource sharing between the traction power supply system and the power distribution system. Secondly, the medium-voltage busbar distribution circuit achieves flexible interconnection of different buses in the medium-voltage distribution network through an energy router, avoiding the formation of electromagnetic loops, enhancing the structure of the medium-voltage distribution network, and improving its regulation capabilities. Furthermore, the collaborative design of the medium-voltage busbar distribution circuit and the energy router provides access ports for distributed energy and energy storage units, enabling coordinated control of clean energy with train traction loads and power loads, effectively adapting to the needs of new energy access.

[0040] See Figure 2 The three-phase high-voltage incoming circuit 1 includes a first three-phase high-voltage incoming line, a second three-phase high-voltage incoming line, a first high-voltage circuit breaker QFA, and a second high-voltage circuit breaker QFB. The first three-phase high-voltage incoming line is connected to one end of the first high-voltage circuit breaker QFA, and the second three-phase high-voltage incoming line is connected to one end of the second high-voltage circuit breaker QFB. The other ends of the first high-voltage circuit breaker QFA and the second high-voltage circuit breaker QFB are respectively connected to the high-voltage bus circuit 2. The first three-phase high-voltage incoming line and the second three-phase high-voltage incoming line are 220kV or 110kV three-phase incoming lines.

[0041] The high-voltage bus circuit 2 includes a first high-voltage bus, a third high-voltage circuit breaker QFAB, and a second high-voltage bus. The first high-voltage bus is connected to the output terminal of the first high-voltage circuit breaker QFAB, the input terminal of the first transformer circuit 3, the input terminal of the second transformer circuit 4, and one end of the third high-voltage circuit breaker QFAB. The second high-voltage bus is connected to the output terminal of the second high-voltage circuit breaker QFB, the input terminal of the third transformer circuit 5, the input terminal of the fourth transformer circuit 6, and the other end of the third high-voltage circuit breaker QFAB. The first and second high-voltage buses are 220kV or 110kV high-voltage buses.

[0042] Example 2

[0043] See Figure 2The first transformer circuit 3 includes a fifth high-voltage circuit breaker QF1, a first single-phase transformer T1, and a sixth high-voltage circuit breaker QF12. The first high-voltage busbar is connected to one end of the fifth high-voltage circuit breaker QF1, and the other end of the fifth high-voltage circuit breaker QF1 is connected to the input end of the first single-phase transformer T1. The output end of the first single-phase transformer T1 is connected to one end of the sixth high-voltage circuit breaker QF12, and the other end of the sixth high-voltage circuit breaker QF12 is connected to the medium-voltage common busbar 9. The medium-voltage common busbar 9 is a 27.5kV busbar. The output end of the first single-phase transformer T1 outputs 27.5kV power and is connected to the 27.5kV busbar through the sixth high-voltage circuit breaker QF12.

[0044] The fourth transformer circuit 6 includes a seventh high-voltage circuit breaker QF4, a second single-phase transformer T4, and an eighth high-voltage circuit breaker QF15. The second high-voltage busbar is connected to one end of the seventh high-voltage circuit breaker QF4, and the other end of the seventh high-voltage circuit breaker QF4 is connected to the input terminal of the second single-phase transformer T4. The output terminal of the second single-phase transformer T4 is connected to one end of the eighth high-voltage circuit breaker QF15, and the other end of the eighth high-voltage circuit breaker QF15 is connected to the medium-voltage common busbar 9. The output terminal of the second single-phase transformer T4 outputs 27.5kV power and is connected to the 27.5kV busbar through the eighth high-voltage circuit breaker QF15.

[0045] The second transformer circuit 4 includes a ninth high-voltage circuit breaker QF2, a first three-phase transformer T2, and a tenth high-voltage circuit breaker QF5. The first high-voltage busbar is connected to one end of the ninth high-voltage circuit breaker QF2, and the other end of the ninth high-voltage circuit breaker QF2 is connected to the input terminal of the first three-phase transformer T2. The output terminal of the first three-phase transformer T2 is connected to one end of the tenth high-voltage circuit breaker QF5, and the other end of the tenth high-voltage circuit breaker QF5 is connected to the medium-voltage busbar distribution circuit 7. The output terminal of the first three-phase transformer T2 outputs 35kV power and is connected to the medium-voltage busbar distribution circuit 7 via the tenth high-voltage circuit breaker QF5; the medium-voltage busbar distribution circuit 7 is a 35kV busbar distribution circuit.

[0046] The third transformer circuit 5 includes an eleventh high-voltage circuit breaker QF3, a second three-phase transformer T3, and a twelfth high-voltage circuit breaker QF6. The second high-voltage busbar is connected to one end of the eleventh high-voltage circuit breaker QF3, and the other end of the eleventh high-voltage circuit breaker QF3 is connected to the input terminal of the second three-phase transformer T3. The output terminal of the second three-phase transformer T3 is connected to one end of the twelfth high-voltage circuit breaker QF6, and the other end of the twelfth high-voltage circuit breaker QF6 is connected to the medium-voltage busbar distribution circuit 7. The output terminal of the second three-phase transformer T3 outputs 35kV power and is connected to the medium-voltage busbar distribution circuit 7 via the twelfth high-voltage circuit breaker QF6; the medium-voltage busbar distribution circuit 7 is a 35kV busbar distribution circuit.

[0047] Example 3

[0048] See Figure 2 The medium-voltage busbar distribution circuit 7 includes a thirteenth high-voltage circuit breaker QF10, a first medium-voltage busbar, a fourteenth high-voltage circuit breaker QF7, a second medium-voltage busbar, and a fifteenth high-voltage circuit breaker QF11. One end of the fourteenth high-voltage circuit breaker QF7 is connected to the other end of the tenth high-voltage circuit breaker QF5, the input terminal of the power router 8, and one end of the thirteenth high-voltage circuit breaker QF10. The other end of the fourteenth high-voltage circuit breaker QF7 is connected to the other end of the twelfth high-voltage circuit breaker QF6, the input terminal of the power router 8, and one end of the fifteenth high-voltage circuit breaker QF11. The other ends of the thirteenth high-voltage circuit breaker QF10 and the fifteenth high-voltage circuit breaker QF11 are respectively connected to the power distribution load. The first and second medium-voltage busbars are 35kV busbars, and the first and second medium-voltage busbars supply power to the power distribution load through the thirteenth high-voltage circuit breaker QF10 and the fifteenth high-voltage circuit breaker QF11, respectively.

[0049] The power router is a power flow control component of a flexible power supply device. The power router 8 includes a sixteenth high-voltage circuit breaker QF8, a third three-phase transformer T5, a first three-phase to single-phase converter Q1, a third single-phase transformer T7, a seventeenth high-voltage circuit breaker QF13, an eighteenth high-voltage circuit breaker QF9, a fourth three-phase transformer T6, a second three-phase to single-phase converter Q2, a fourth single-phase transformer T8, a nineteenth high-voltage circuit breaker QF14, a DC / DC converter, and a DC / AC converter.

[0050] The first medium-voltage busbar is connected to one end of the sixteenth high-voltage circuit breaker QF8. The other end of the sixteenth high-voltage circuit breaker QF8 is connected to the input end of the third three-phase transformer T5. The output end of the third three-phase transformer T5 is connected to the input end of the first three-phase to single-phase converter Q1. The output end of the first three-phase to single-phase converter Q1 is connected to the input end of the third single-phase transformer T7. The output end of the third single-phase transformer T7 is connected to one end of the seventeenth high-voltage circuit breaker QF13. The other end of the seventeenth high-voltage circuit breaker QF13 is connected to the medium-voltage common busbar 9.

[0051] The second medium-voltage busbar is connected to one end of the eighteenth high-voltage circuit breaker QF9. The other end of the eighteenth high-voltage circuit breaker QF9 is connected to the input end of the fourth three-phase transformer T6. The output end of the fourth three-phase transformer T6 is connected to the input end of the second three-phase to single-phase converter Q2. The output end of the second three-phase to single-phase converter Q2 is connected to the input end of the fourth single-phase transformer T8. The output end of the fourth single-phase transformer T8 is connected to one end of the nineteenth high-voltage circuit breaker QF14. The other end of the nineteenth high-voltage circuit breaker QF14 is connected to the medium-voltage common busbar 9.

[0052] The output terminals of the first three-phase to single-phase converter Q1, the output terminals of the second three-phase to single-phase converter Q2, the input terminals of the DC / DC converter and the DC / AC converter are interconnected through a common DC bus. The output terminals of the DC / DC converter and the DC / AC converter are respectively connected to the power distribution load.

[0053] The medium-voltage common busbar 9 is connected to the train traction load contact network through the twentieth high-voltage circuit breaker QF16 and the twentieth high-voltage circuit breaker QF17, respectively, to supply power to the train traction load.

[0054] In this embodiment, an integrated flexible intelligent power supply device that combines traction power supply and power distribution is first constructed. This device can simultaneously supply power to railway traction loads and non-traction loads along the line, achieving flexible interconnection and coordinated power supply between the traction power supply system and the power distribution system. It also enables flexible interconnection between the substation traction power supply system and the power distribution system, sharing external power sources and internal power supply buses, thus achieving resource sharing. Simultaneously, it allows the transfer of regenerative braking energy from the traction network to the power distribution system, further improving the utilization rate of regenerative braking energy in the traction power supply system and saving electricity costs. Secondly, a power router enables flexible interconnection of power supply between different buses in the medium-voltage distribution network, avoiding the formation of electromagnetic loops and allowing the distribution network to operate in a closed loop. This allows for flexible control of the power output between different power supply buses, achieving balanced load distribution, improving the capacity utilization and power supply capacity of power supply equipment, and enhancing power supply safety and economy. Furthermore, a flexible multi-port power supply architecture is constructed to support the flexible access of distributed energy: the DC-side bus of the flexible multi-port converter can be connected to an energy storage unit, which can absorb the regenerative braking energy of the traction network. At the same time, the intermediate DC port can also be connected to other renewable energy sources such as solar or wind power, making traction energy more diversified and cleaner. The independent three-phase AC bus can also flexibly connect to various distributed energy sources that are adapted to AC grid connection, which can promote the absorption of distributed energy by the railway traction power supply system and power distribution system, improve energy utilization efficiency and green energy penetration rate, and reduce the operating cost of the railway power supply system.

[0055] Example 4

[0056] This embodiment further explains the working principle of the flexible power supply device for electrified railway substations proposed in the above embodiments.

[0057] The above-described embodiment of the flexible power supply device for electrified railway substations utilizes a transformer and a power router to collaboratively supply power to both traction and dynamic loads. Regardless of normal or abnormal operating conditions, the flexible power supply device for electrified railway substations in the above-described embodiment uses the same 27.5kV medium-voltage common busbar to supply power to the contact network of the train traction load.

[0058] During normal operation, the two 35kV busbars, consisting of the first and second medium-voltage busbars, are flexibly interconnected and supplied power through the power router 8. Only one of the first single-phase transformer T1 and the second single-phase transformer T4 is in operation (the other transformer serves as a backup), avoiding the formation of a fixed electromagnetic loop. The power router 8 monitors the power levels of the first single-phase transformer T1, the first three-phase transformer T2, the second three-phase transformer T3, and the second single-phase transformer T4 in real time. Through real-time and adaptive control, it uniformly adjusts the power levels of the four AC ports of the power router 8 (the ports of the third three-phase transformer T5, the fourth three-phase transformer T6, the third single-phase transformer T7, and the fourth single-phase transformer T8), balancing the power supply power among different power branches of the flexible power supply device to meet the safe, reliable, and efficient power supply requirements of train traction loads and power distribution loads. The common DC busbar side of the power router 8 flexibly connects to power distribution loads and distributed energy sources through DC / DC converters and DC / AC converters, meeting the needs of green and efficient energy supply and emergency power supply.

[0059] There are several abnormal operating conditions: 1) When a fault occurs in one of the 220 / 110kV three-phase incoming lines in the three-phase high-voltage incoming line circuit, the third high-voltage circuit breaker QFAB closes, and power is supplied by the other 220 / 110kV three-phase incoming line; 2) When a fault occurs in either the first three-phase transformer T2 or the second three-phase transformer T3, the fourteenth high-voltage circuit breaker QF7 closes, and power is supplied by the other normal three-phase transformer; 3) When a fault occurs in either the first single-phase transformer T1 or the second single-phase transformer T4, power is supplied to the train traction load by the other normal single-phase transformer, and the opening and closing logic of the sixth high-voltage circuit breaker QF12 and the eighth high-voltage circuit breaker QF15 needs to be linked.

[0060] It should be specifically stated that the three-phase transformer in the Power Router 8 has multiple wiring configurations, and can use either a split transformer or a non-split transformer. The single-phase transformer in the Power Router 8 can also use either a split transformer or a non-split transformer. The three-phase to single-phase converter in the Power Router 8 has various topologies, such as two-level and three-level AC-DC-AC converter topologies, high-voltage cascaded topologies, and high-voltage modular multi-level back-to-back topologies. Any topology that can achieve multi-port AC / DC (including DC-DC) power conversion can meet the power conversion requirements of this three-phase to single-phase power supply. When the three-phase to single-phase power supply adopts a modular multi-level back-to-back topology, the matching transformers for the three phases and single phases can be omitted. In this case, the three-phase to single-phase converter topology is as follows: Figure 3 As shown; Figure 2 The DC-side networking mode of the power router 8 in the configuration is parallel networking. Other typical DC-side networking structures of optional power routers are as follows: Figure 4 and Figure 5 As shown;

[0061] The working principle of the flexible power supply device for electrified railway substations proposed in this embodiment has the following advantages:

[0062] 1) The main substation adopts a hybrid power supply network for traction power supply and power distribution, realizing flexible interconnection between the substation traction power supply system and power distribution system, sharing external power sources, achieving resource sharing, and reducing substation construction investment; at the same time, it can transfer the regenerative braking energy of the traction network to the power supply system for use, which can improve the utilization rate of regenerative braking energy of the traction power supply system and save electricity costs.

[0063] 2) The medium-voltage AC ring network of the main substation can be flexibly connected to distributed new energy power generation units and energy storage units; the DC side of the power router can also be equipped with energy storage units, which can absorb the regenerative braking energy of the traction network. At the same time, the intermediate DC port can also be connected to other renewable energy sources such as solar or wind power, making traction energy more diversified and cleaner.

[0064] 3) The 35kV AC ring network buses in the main substation are flexibly interconnected through power routers, which can flexibly control the power of different buses, realize balanced distribution of power supply load, improve the capacity utilization and power supply capacity of power supply equipment, and improve power supply safety and economy.

[0065] Currently, there is a lack of safe, reliable, and economically feasible system solutions to address issues in electrified railway power supply systems, such as power quality, phase separation, energy utilization efficiency, new energy access, and emergency / auxiliary power supply in special scenarios, as well as the coordinated configuration and resource sharing of traction power supply and power distribution. Therefore, this embodiment focuses on constructing a flexible power supply device that integrates traction power supply and power distribution. This device can simultaneously supply power to railway traction loads and non-traction loads along the line, achieving flexible interconnection and unified power flow control between the traction power supply system and the power distribution system. This improves power supply efficiency and resource utilization efficiency, and further supports the realization of full-line through-power supply for traction power supply and power distribution, as well as the flexible aggregation of distributed energy sources, providing key technical support for building a higher-level green and ecological railway. Overall, the flexible power supply device for electrified railways can significantly improve the safety, economy, and green, low-carbon operation level of the entire railway power supply system. It is a power supply system solution for building a higher-level green and ecological railway, and this system solution has significant technical and economic advantages.

[0066] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating this utility model, and are not intended to limit the implementation of this utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A flexible power supply for an electrified railway substation, characterized in that, The utility model relates to a kind of high-voltage power supply system for train traction, including: Three-phase high-voltage incoming line circuit (1), high-voltage bus circuit (2), first transformer circuit (3), second transformer circuit (4), third transformer circuit (5), fourth transformer circuit (6), medium-voltage bus distribution circuit (7), power router (8) and medium-voltage common bus (9) for catenary power supply for train traction load; The three-phase high-voltage incoming line circuit (1) is connected to the input end of the high-voltage bus circuit (2), the output end of the high-voltage bus circuit (2) is connected to the input end of the first transformer circuit (3), the second transformer circuit (4), the third transformer circuit (5) and the fourth transformer circuit (6) respectively, the output end of the first transformer circuit (3) and the fourth transformer circuit (6) is connected to the medium-voltage common bus (9) respectively, the output end of the second transformer circuit (4) and the third transformer circuit (5) is connected to the input end of the medium-voltage bus distribution circuit (7) respectively, the output end of the medium-voltage bus distribution circuit (7) is connected to the input end of the power router (8), the output end of the power router (8) is connected to the medium-voltage common bus (9), and the output end of the medium-voltage bus distribution circuit (7) and the power router (8) is also connected to the power distribution load.

2. The flexible power supply for an electrified railway substation of claim 1, characterized in that, The three-phase high-voltage incoming line circuit (1) includes a first three-phase high-voltage incoming line, a second three-phase high-voltage incoming line, a first high-voltage circuit breaker QFA and a second high-voltage circuit breaker QFB, one end of the first three-phase high-voltage incoming line is connected to the first high-voltage circuit breaker QFA, one end of the second three-phase high-voltage incoming line is connected to the second high-voltage circuit breaker QFB, and the other end of the first high-voltage circuit breaker QFA and the second high-voltage circuit breaker QFB is connected to the high-voltage bus circuit (2) respectively.

3. The flexible power supply for an electrified railway substation of claim 2, wherein, The high-voltage bus circuit (2) includes a first high-voltage bus, a third high-voltage circuit breaker QFAB and a second high-voltage bus, the first high-voltage bus is connected to the output end of the first high-voltage circuit breaker QFA, the input end of the first transformer circuit (3), the input end of the second transformer circuit (4) and one end of the third high-voltage circuit breaker QFAB respectively, and the second high-voltage bus is connected to the output end of the second high-voltage circuit breaker QFB, the input end of the third transformer circuit (5), the input end of the fourth transformer circuit (6) and the other end of the third high-voltage circuit breaker QFAB respectively.

4. The flexible power supply for an electrified railway substation of claim 3, characterized in that, The first transformer circuit (3) includes a fifth high-voltage circuit breaker QF1, a first single-phase transformer T1 and a sixth high-voltage circuit breaker QF12, one end of the first high-voltage bus is connected to the fifth high-voltage circuit breaker QF1, the other end of the fifth high-voltage circuit breaker QF1 is connected to the input end of the first single-phase transformer T1, the output end of the first single-phase transformer T1 is connected to one end of the sixth high-voltage circuit breaker QF12, and the other end of the sixth high-voltage circuit breaker QF12 is connected to the medium-voltage common bus (9).

5. The flexible power supply for an electrified railway substation of claim 3, wherein, The fourth transformer circuit (6) comprises a seventh high-voltage circuit breaker QF4, a second single-phase transformer T4 and an eighth high-voltage circuit breaker QF15, one end of the second high-voltage bus is connected to the seventh high-voltage circuit breaker QF4, the other end of the seventh high-voltage circuit breaker QF4 is connected to the input end of the second single-phase transformer T4, the output end of the second single-phase transformer T4 is connected to one end of the eighth high-voltage circuit breaker QF15, and the other end of the eighth high-voltage circuit breaker QF15 is connected to the medium-voltage common bus (9).

6. The flexible power supply for an electrified railway substation of claim 3, wherein, The second transformer circuit (4) comprises a ninth high-voltage circuit breaker QF2, a first three-phase transformer T2 and a tenth high-voltage circuit breaker QF5, one end of the first high-voltage bus is connected to the ninth high-voltage circuit breaker QF2, the other end of the ninth high-voltage circuit breaker QF2 is connected to the input end of the first three-phase transformer T2, the output end of the first three-phase transformer T2 is connected to one end of the tenth high-voltage circuit breaker QF5, and the other end of the tenth high-voltage circuit breaker QF5 is connected to the medium-voltage bus distribution circuit (7).

7. The flexible power supply for an electrified railway substation of claim 6, characterized in that, The third transformer circuit (5) comprises an eleventh high-voltage circuit breaker QF3, a second three-phase transformer T3 and a twelfth high-voltage circuit breaker QF6, one end of the second high-voltage bus is connected to the eleventh high-voltage circuit breaker QF3, the other end of the eleventh high-voltage circuit breaker QF3 is connected to the input end of the second three-phase transformer T3, the output end of the second three-phase transformer T3 is connected to one end of the twelfth high-voltage circuit breaker QF6, and the other end of the twelfth high-voltage circuit breaker QF6 is connected to the medium-voltage bus distribution circuit (7).

8. The flexible power supply for an electrified railway substation of claim 7, characterized in that, The medium-voltage bus distribution circuit (7) comprises a thirteenth high-voltage circuit breaker QF10, a first medium-voltage bus, a fourteenth high-voltage circuit breaker QF7, a second medium-voltage bus, a fifteenth high-voltage circuit breaker QF11, one end of the fourteenth high-voltage circuit breaker QF7 is connected to the other end of the tenth high-voltage circuit breaker QF5, the input end of the electric energy router (8) and one end of the thirteenth high-voltage circuit breaker QF10 respectively, the other end of the fourteenth high-voltage circuit breaker QF7 is connected to the other end of the twelfth high-voltage circuit breaker QF6, the input end of the electric energy router (8) and one end of the fifteenth high-voltage circuit breaker QF11 respectively, and the other ends of the thirteenth high-voltage circuit breaker QF10 and the fifteenth high-voltage circuit breaker QF11 are connected to the power distribution load respectively.

9. The flexible power supply for an electrified railway substation of claim 8, wherein, The electric energy router (8) comprises a sixteenth high-voltage circuit breaker QF8, a third three-phase transformer T5, a first three-phase single-phase converter Q1, a third single-phase transformer T7, a seventeenth high-voltage circuit breaker QF13, an eighteenth high-voltage circuit breaker QF9, a fourth three-phase transformer T6, a second three-phase single-phase converter Q2, a fourth single-phase transformer T8, a nineteenth high-voltage circuit breaker QF14, a DC / DC converter and a DC / AC converter. The first medium voltage bus connects one end of a sixteenth high voltage circuit breaker QF8, the other end of the sixteenth high voltage circuit breaker QF8 connects an input end of a third three-phase transformer T5, an output end of the third three-phase transformer T5 connects an input end of a first three-phase to single-phase converter Q1, an output end of the first three-phase to single-phase converter Q1 connects an input end of a third single-phase transformer T7, an output end of the third single-phase transformer T7 connects one end of a seventeenth high voltage circuit breaker QF13, the other end of the seventeenth high voltage circuit breaker QF13 connects a medium voltage common bus (9); The second medium voltage bus connects one end of an eighteenth high voltage circuit breaker QF9, the other end of the eighteenth high voltage circuit breaker QF9 connects an input end of a fourth three-phase transformer T6, an output end of the fourth three-phase transformer T6 connects an input end of a second three-phase to single-phase converter Q2, an output end of the second three-phase to single-phase converter Q2 connects an input end of a fourth single-phase transformer T8, an output end of the fourth single-phase transformer T8 connects one end of a nineteenth high voltage circuit breaker QF14, the other end of the nineteenth high voltage circuit breaker QF14 connects the medium voltage common bus (9); The output end of the first three-phase to single-phase converter Q1, the output end of the second three-phase to single-phase converter Q2, an input end of a DC / DC converter and an input end of a DC / AC converter are interconnected through a common DC bus, an output end of the DC / DC converter and an output end of the DC / AC converter respectively connect the power distribution load.

10. The flexible power supply arrangement for an electrified railway substation of any of claims 1-9, characterized in that, The medium voltage common bus (9) connects the train traction load catenary through a twentieth high voltage circuit breaker QF16 and a twenty-first high voltage circuit breaker QF17.

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