Flexible power supply device of electrified railway substation

Abstract

The invention 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. Cooperative operation and resource sharing of the traction power supply and power distribution system of the substation are achieved, the medium-voltage distribution network structure is enhanced, the regulation and control capacity is improved, and the new energy access requirement is effectively met.

Description

Technical Field

[0001] The invention relates to the technical field of electrified railway power supply, and in particular to a flexible power supply device for an electrified railway substation. Background Art

[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 the traction substation, and the railway traction power supply standard is single-phase AC 25kV; because the single-phase AC traction power supply system adopts a phase / zone power supply structure with a rotating phase sequence, an electrical phase separation area will be formed in the traction power supply system, resulting in power supply islands in the power supply system, affecting line driving, and the energy integration within the power supply system will also be restricted, thereby reducing the power supply efficiency level 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 realize flexible control of the power supply energy, and has obvious limitations in its ability to adapt to the access of new energy and emergency power supply needs.

[0003] In the railway power distribution system, there are two main power supply methods currently used for the power distribution loads in the traction substation and along the railway: one is to use an independent power through-line power supply. The power through-line power supply method cannot utilize the regenerative braking energy in the traction power supply system, and requires the configuration of an independent power supply equipment, which is not economical overall; if the power is taken from the traction network through a transformer with a special wiring form to supply the power distribution load, the power supply quality cannot be guaranteed, and there are usually serious power quality problems such as a large voltage fluctuation range and complex harmonic content; the other method is to build a new substation to supply power to the power distribution load along the railway, especially in intercity and urban / suburban railways. Usually, the newly built substation equipment for power distribution loads is built together with the traction power supply equipment to form a main substation, but in fact, the design of the traction power supply and power distribution system is relatively independent, and resource sharing cannot be achieved; the existing railway medium-voltage distribution network is a radial grid structure. In order to limit the short-circuit capacity and avoid electromagnetic ring network problems, the busbar interconnection switch is usually not closed during normal operation, so that the distribution network is in an open-loop operation state, and the flow is naturally distributed according to the circuit parameters and load demand, and the regulation ability is very limited. The weak grid structure, backward open-loop operation mode and limited control methods have hindered the improvement of the distribution network's operating flexibility and power supply reliability, easily causing problems such as unbalanced feeder load, deterioration of power quality, and prolonged power outage time. It is even more impossible to undertake the task of absorbing a large number of distributed power sources. In addition, with the global emphasis on environmental protection and the maturity of renewable energy technology, the railway traction power supply system needs to gradually introduce renewable energy such as solar and wind energy to reduce dependence on traditional energy, reduce operating costs and environmental pollution, but the passive power supply mode of the traditional traction power supply system is not suitable for the access needs of distributed new energy such as wind / solar / storage. Summary of the invention

[0004] In order to solve the problems in the above-mentioned prior art that the systems operate independently, resources cannot be shared, the medium-voltage distribution network structure is weak, the regulation capability is limited, and it is difficult to adapt to the access needs of new energy sources, the present invention proposes a flexible power supply device for an electrified railway substation to achieve coordinated operation and resource sharing of the substation traction power supply and power distribution system, enhance the medium-voltage distribution network structure, improve the regulation capability, and effectively adapt to the access needs of new energy sources.

[0005] In order to achieve the above technical effects, the technical solution of the present invention is as follows:

[0006] An electrified railway substation flexible power supply device, comprising: a three-phase high-voltage incoming line circuit, a high-voltage bus circuit, a first transformer circuit, a second transformer circuit, a third transformer circuit, a fourth transformer circuit, a medium-voltage bus distribution circuit, an electric energy router, and a medium-voltage common bus for supplying power to a train traction load contact network;

[0007] The three-phase high-voltage incoming line circuit is connected to the input end of the high-voltage bus circuit, the output end of the high-voltage bus circuit is respectively connected to the input ends of the first transformer circuit, the second transformer circuit, the third transformer circuit and the fourth transformer circuit, the output ends of the first transformer circuit and the fourth transformer circuit are respectively connected to the medium-voltage common bus, the output ends of the second transformer circuit and the third transformer circuit are respectively connected to the input end of the medium-voltage bus distribution circuit, the output end of the medium-voltage bus distribution circuit is connected to the input end of the power router, the output end of the power router is connected to the medium-voltage common bus, and the output ends 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 respectively connected to the output end of the first high-voltage circuit breaker QFA, the input end of the first transformer circuit, the input end of the second transformer circuit and one end of the third high-voltage circuit breaker QFAB, and the second high-voltage bus is respectively connected to the output end of the second high-voltage circuit breaker QFB, the input end of the third transformer circuit, the input end 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 bus 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 bus.

[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 bus 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 bus.

[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 bus 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 bus 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 bus 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 bus distribution circuit.

[0014] Preferably, the medium-voltage bus distribution circuit includes a thirteenth high-voltage circuit breaker QF10, a first medium-voltage bus, a fourteenth high-voltage circuit breaker QF7, a second medium-voltage bus, and a fifteenth high-voltage circuit breaker QF11, one end of the fourteenth high-voltage circuit breaker QF7 is respectively connected to the other end of the tenth high-voltage circuit breaker QF5, the input end 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 respectively connected to the other end of the twelfth high-voltage circuit breaker QF6, the input end of the power router and one end of the fifteenth high-voltage circuit breaker QF11, and 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 bus 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, and the other end of the seventeenth high-voltage circuit breaker QF13 is connected to the medium-voltage common bus;

[0017] The second medium-voltage bus 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, and the other end of the nineteenth high-voltage circuit breaker QF14 is connected to the medium-voltage common bus;

[0018] 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, the input end of the DC / DC converter and the input end of the DC / AC converter are interconnected through a common DC bus, and the output end of the DC / DC converter and the output end of the DC / AC converter are respectively connected to the power distribution load.

[0019] Preferably, the medium voltage common bus is connected to the train traction load contact network through the twentieth high voltage circuit breaker QF16 and the twenty-first high voltage circuit breaker QF17 respectively.

[0020] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0021] The present invention proposes a flexible power supply device for an electrified railway substation. First, the three-phase high-voltage incoming line circuit and the high-voltage bus circuit are used to distribute power to each transformer circuit respectively, and the first transformer circuit and the fourth transformer circuit are connected to the medium-voltage common bus to supply power to the train traction load contact network. Then, the second transformer circuit and the third transformer circuit are connected to the power router through the medium-voltage bus distribution circuit. The medium-voltage bus distribution circuit and the DC side output end of the power router can be connected to the power distribution load, and the train traction load and the power distribution load are integrated into the same architecture, thereby constructing an integrated flexible intelligent traction power supply and power distribution system. The power supply device can supply power to the railway traction load and non-traction loads along the line at the same time, realizing the flexible interconnection and collaborative power supply resource sharing of the traction power supply system and the power distribution system; secondly, the medium-voltage bus distribution circuit realizes the flexible interconnection and power supply of different buses in the medium-voltage distribution network through the power router, avoiding the formation of electromagnetic ring network, strengthening the structure of the medium-voltage distribution network, and improving the regulation and control capability of the medium-voltage distribution network; further, the coordinated design of the medium-voltage bus distribution circuit and the 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, and effectively adapting to the demand for new energy access; BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram showing a method for a flexible power supply device for an electrified railway substation proposed in an embodiment of the present invention;

[0023] Figure 2 Another structural schematic diagram showing a method for a flexible power supply device for an electrified railway substation proposed in an embodiment of the present invention;

[0024] Figure 3 A topological diagram showing a three-phase to single-phase conversion proposed in an embodiment of the present invention;

[0025] Figure 4 It shows a power router-DC series networking diagram proposed in an embodiment of the present invention;

[0026] Figure 5 It shows a power router-DC series / parallel networking diagram proposed in an 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 DESCRIPTION

[0028] The drawings are for illustrative purposes only and should not be construed as limiting the present patent;

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

[0030] To facilitate understanding of the following embodiments, some technical terms involved are explained as follows:

[0031] Electromagnetic ring network: Electromagnetic ring network refers to two groups of lines with different voltage levels running in parallel through the connection of the magnetic circuit of the transformer at both ends. The load transfer caused by the disconnection of the high-voltage line in the high-voltage and low-voltage electromagnetic ring network is likely to cause the accident to expand and the system stability to be damaged, and the electromagnetic ring network will increase the system short-circuit current.

[0032] Power router: A multi-port intelligent power management device based on high-power conversion and control technology, used to efficiently distribute and control the flow of power between multiple nodes.

[0033] Train traction load contact network: an overhead wire system that supplies electric energy to the locomotive through a pantograph, mainly composed of pillars, foundations, supporting structures and contact suspensions.

[0034] Power through-line: The power through-line is connected to the public power grid or power plants, substations and transmission and distribution lines outside the public power grid. It is a 10kV or 35kV power line that connects two adjacent substations / distribution stations along the railway and mainly supplies power to the railway power loads along the line.

[0035] The technical solution of the present invention is further described below in conjunction with 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, comprising: a three-phase high-voltage incoming line circuit 1, a high-voltage bus 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 bus distribution circuit 7, an electric energy router 8, and a medium-voltage common bus 9 for supplying power to a train traction load contact network;

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

[0039] First, through the three-phase high-voltage incoming line circuit and the high-voltage bus circuit, each transformer circuit is distributed separately, and the first transformer circuit and the fourth transformer circuit are connected to the medium-voltage common bus to supply power to the train traction load contact network. Then, the second transformer circuit and the third transformer circuit are connected to the power router through the medium-voltage bus distribution circuit, and the power distribution load can be connected to the medium-voltage bus distribution circuit and the DC side output end of the power router, integrating the train traction load and the power distribution load into the same architecture, thereby constructing an integrated flexible intelligent power supply device that integrates traction power supply and power distribution, which can be used at the same time. Power is supplied to the railway traction load and non-traction loads along the line, realizing the flexible interconnection and collaborative power supply resource sharing of the traction power supply system and the power distribution system; secondly, the medium-voltage bus distribution circuit realizes the flexible interconnection and power supply of different buses in the medium-voltage distribution network through the power router, avoiding the formation of electromagnetic ring network, strengthening the structure of the medium-voltage distribution network, and improving the regulation and control capability of the medium-voltage distribution network; further, the coordinated design of the medium-voltage bus distribution circuit and the 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, and effectively adapting to the demand for new energy access;

[0040] See also Figure 2 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. 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 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 respectively 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. The second high-voltage bus is respectively 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. The first high-voltage bus and the second high-voltage bus are 220kV or 110kV high-voltage buses;

[0042] Example 2

[0043] See also Figure 2, 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, the first high-voltage bus 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 bus 9; the medium-voltage common bus 9 is a 27.5kV bus; the output end of the first single-phase transformer T1 outputs a 27.5kV power supply and is connected to the 27.5kV bus 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 bus 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 bus 9. The output end of the second single-phase transformer T4 outputs a 27.5 kV power supply and is connected to the 27.5 kV bus 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 bus 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 bus distribution circuit 7. The output end of the first three-phase transformer T2 outputs a 35kV power supply and is connected to the medium-voltage bus distribution circuit 7 through the tenth high-voltage circuit breaker QF5; the medium-voltage bus distribution circuit 7 is a 35kV bus 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 bus 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 bus distribution circuit 7. The output end of the second three-phase transformer T3 outputs a 35kV power supply and is connected to the medium-voltage bus distribution circuit 7 through the twelfth high-voltage circuit breaker QF6; the medium-voltage bus distribution circuit 7 is a 35kV bus distribution circuit;

[0047] Example 3

[0048] See also Figure 2 , the medium-voltage bus distribution circuit 7 includes a thirteenth high-voltage circuit breaker QF10, a first medium-voltage bus, a fourteenth high-voltage circuit breaker QF7, a second medium-voltage bus, and a fifteenth high-voltage circuit breaker QF11. One end of the fourteenth high-voltage circuit breaker QF7 is respectively connected to the other end of the tenth high-voltage circuit breaker QF5, the input end 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 respectively connected to the other end of the twelfth high-voltage circuit breaker QF6, the input end 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 medium-voltage bus and the second medium-voltage bus are 35kV buses. The first medium-voltage bus and the second medium-voltage bus 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 the flexible power supply device, and 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 bus 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, and the other end of the seventeenth high-voltage circuit breaker QF13 is connected to the medium-voltage common bus 9;

[0051] The second medium-voltage bus 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, and the other end of the nineteenth high-voltage circuit breaker QF14 is connected to the medium-voltage common bus 9;

[0052] 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, the input end of the DC / DC converter and the input end of the DC / AC converter are interconnected through a common DC bus, and the output end of the DC / DC converter and the output end of the DC / AC converter are respectively connected to the power distribution load.

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

[0054] In this embodiment, first, an integrated flexible intelligent power supply device integrating traction power supply and power distribution is constructed, which can supply power to railway traction loads and non-traction loads along the line at the same time, realize flexible interconnection and coordinated power supply of traction power supply system and power distribution system, realize flexible interconnection of substation traction power supply system and power distribution system, share external power supply and internal power supply bus, realize resource sharing; at the same time, the regenerative braking energy of traction network can be transferred to power distribution system for use, which can further improve the utilization rate of regenerative braking energy of traction power supply system and save electricity cost. Secondly, the flexible interconnection power supply of different buses of medium voltage distribution network is realized through power router, so as to avoid the formation of electromagnetic ring network, enable the distribution network to operate in closed loop, flexibly control the power between different power supply buses, realize balanced distribution of power supply load, improve the capacity utilization rate and power supply capacity of power supply equipment, and improve power supply safety and economy. Furthermore, by constructing a flexible multi-port power supply architecture, flexible access to distributed energy can be supported: the DC side bus of the flexible multi-port converter can be connected to the 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 energy or wind energy, making the traction energy more diverse and clean; the independent three-phase AC bus can also be flexibly connected to various distributed energy sources that are adapted to AC grid connection, which can promote the railway traction power supply system and power distribution system to absorb distributed energy, improve energy utilization efficiency and green energy penetration, and reduce the operating cost of the railway power supply system.

[0055] Example 4

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

[0057] The flexible power supply device for an electrified railway substation proposed in the above embodiment is responsible for supplying power to the traction load and the power load through a transformer and an electric energy router. Regardless of normal operation or abnormal operation, the flexible power supply device for an electrified railway substation proposed in the above embodiment uses the same medium-voltage common busbar of a 27.5kV power supply to supply power to the train traction load contact network.

[0058] During normal operation, the two sections of 35kV busbars composed of the first medium-voltage busbar and the second medium-voltage busbar are flexibly interconnected and powered 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 is used as a backup) to avoid forming a fixed electromagnetic ring network; the power router 8 detects the power 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, and uniformly adjusts the power of the four AC ports of the power router 8 (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 ports) through real-time and adaptive control, balancing the power supply between different power branches of the flexible power supply device to meet the safe, reliable and efficient power supply requirements of the train traction load and the power distribution load. The public DC bus side of the power router 8 is flexibly connected to the power distribution load and distributed energy through the DC / DC converter and the DC / AC converter to meet the needs of green and efficient energy supply and emergency power supply.

[0059] There are multiple operating conditions for abnormal operation: 1) When a 220 / 110kV three-phase incoming line in the three-phase high-voltage incoming line circuit fails; the third high-voltage circuit breaker QFAB is closed, and power is supplied by another 220 / 110kV three-phase incoming line; 2) When one of the first three-phase transformer T2 and the second three-phase transformer T3 fails, the fourteenth high-voltage circuit breaker QF7 is closed, and power is supplied by another normal three-phase transformer; 3) When one of the first single-phase transformer T1 and the second single-phase transformer T4 fails, power is supplied to the train traction load by another 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 need to be configured in linkage.

[0060] It should be specially stated that the three-phase transformer in the power router 8 has a variety of wiring forms, and can adopt a split transformer or a non-split transformer. The single-phase transformer in the power router 8 can adopt a split transformer or a non-split transformer. The three-phase to single-phase converter in the power router 8 has a variety of topology schemes, such as two-level and three-level AC-DC-AC conversion topologies, high-voltage cascade topologies, and high-voltage modular multi-level back-to-back topologies. As long as the topology can realize multi-port AC-DC (including DC to DC) power conversion, it can meet the power conversion requirements of the 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 structure, the three-phase and single-phase matching transformers can be omitted. At this time, the three-phase to single-phase conversion topology is as follows: Figure 3 As shown; Figure 2 The DC side networking mode of the power router 8 in the embodiment is parallel networking. Other optional typical structures of the DC side networking of the power router are as follows: Figure 4 and Figure 5 As shown;

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

[0062] 1) The main substation traction power supply and electric power supply adopt a hybrid power supply network, which realizes the flexible interconnection of the substation traction power supply system and the electric power distribution system, shares the external power supply, realizes resource sharing, and reduces the investment in substation construction; at the same time, it can realize the transfer of the regenerative braking energy of the traction network to the electric power supply system, which can improve the utilization rate of the 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 renewable energy power generation units and energy storage units; the DC side of the power router can also be configured 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 energy or wind energy, making the traction energy more diverse and clean.

[0064] 3) The medium voltage 35kV AC ring network busbars of the main substation are flexibly interconnected through the power router, which can flexibly control the power size between different busbars, realize balanced distribution of power supply load, improve the capacity utilization rate and power supply capacity of power supply equipment, and improve power supply safety and economy.

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

[0066] Obviously, the above embodiments of the present invention are only examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A flexible power supply device for an electrified railway substation, characterized in that: include: A three-phase high-voltage incoming line circuit (1), a high-voltage bus 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 bus distribution circuit (7), an electric energy router (8), and a medium-voltage common bus (9) for supplying power to a train traction load overhead contact network; 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 respectively connected to the input ends of the first transformer circuit (3), the second transformer circuit (4), the third transformer circuit (5) and the fourth transformer circuit (6); the output ends of the first transformer circuit (3) and the fourth transformer circuit (4) are respectively connected to the medium-voltage common bus (9); the output ends of the second transformer circuit (5) and the third transformer circuit (6) are respectively connected to the input end of the medium-voltage bus distribution circuit (7); 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 ends of the medium-voltage bus distribution circuit (7) and the power router (8) are also connected to power distribution loads.

2. The flexible power supply device for an electrified railway substation according to claim 1, characterized in that: The three-phase high-voltage incoming line circuit (1) comprises 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, wherein 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 (2).

3. The flexible power supply device for an electrified railway substation according to claim 2, characterized in that: The high-voltage bus circuit (2) comprises a first high-voltage bus, a third high-voltage circuit breaker QFAB and a second high-voltage bus, wherein the first high-voltage bus is respectively 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, and the second high-voltage bus is respectively 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.

4. The flexible power supply device for an electrified railway substation according to claim 3, characterized in that: The first transformer circuit (3) comprises 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 bus 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 bus (9).

5. The flexible power supply device for an electrified railway substation according to claim 3, characterized in that: 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, the second high-voltage bus 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 bus (9).

6. The flexible power supply device for an electrified railway substation according to claim 3, characterized in that: 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, the first high-voltage bus 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 bus distribution circuit (7).

7. The flexible power supply device for an electrified railway substation according to 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, the second high-voltage bus 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 bus distribution circuit (7).

8. The flexible power supply device for an electrified railway substation according to 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, and a fifteenth high-voltage circuit breaker QF11; one end of the fourteenth high-voltage circuit breaker QF7 is respectively 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; the other end of the fourteenth high-voltage circuit breaker QF7 is respectively 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; and 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.

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

10. The flexible power supply device for an electrified railway substation according to any one of claims 1 to 9, characterized in that: The medium voltage common busbar (9) is connected to the train traction load contact network via a twentieth high voltage circuit breaker QF16 and a twenty-first high voltage circuit breaker QF17 respectively.

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