Energy storage type box transformer substation integrated transformer substation and power distribution station for railway

Abstract

The utility model relates to the technical field of electrified railways, and discloses an energy storage type box transformer substation integrated transformer distribution station for railways, which comprises a high-voltage ring main unit, a transformer, a low-voltage power distribution cabinet, an energy storage unit, a power distribution and switching unit, a remote terminal unit (RTU) and a heating and ventilation temperature control unit. Charge and discharge management of the lithium iron phosphate battery system is realized; the power distribution and switching unit comprises an isolating switch, an anti-reverse power transmission device and a dual-power switching device; a high-voltage cabinet switch is provided with a grounding interlocking device, and an energy storage unit is provided with an anti-reverse power transmission device, so that safety measures are more convenient to set, and personal safety during maintenance of the skylight is ensured; the high-voltage cabinet is provided with the ring main unit, the low-voltage cabinet is provided with the isolating switch, obvious disconnection points are achieved, power supply interval power failure is not needed when the skylight is used, the problem that a primary load is powered by a single power source when an existing railway power supply system is powered on or the planned maintenance skylight is powered off is solved, the red light band state is avoided, and the railway power supply stability and reliability are improved.

Description

Technical Field

[0001] This utility model relates to the field of electrified railway technology, specifically to an energy storage-type integrated transformer substation for railways. Background Technology

[0002] With the advancement of railway electrification upgrades, the stability and reliability of power supply to primary loads are crucial. In the existing railway power supply system, some lines are equipped with only one 10kV through-line, while secondary power sources (such as local public grids or agricultural power) have poor reliability, easily leading to power outages, triggering red light issues, and affecting railway operational safety. Traditional prefabricated substations rely on diesel generators as backup power, which suffers from long start-up times (5-30 seconds) and severe pollution (noise approximately 75dB). Existing energy storage prefabricated substations lack clearly defined backup power switching methods and energy storage media, failing to guarantee stable power supply to primary loads and incurring high operation and maintenance costs. Therefore, a highly reliable integrated energy storage prefabricated substation is urgently needed to solve the problem of primary load power supply during power outages or power failures in the existing power supply system. Utility Model Content

[0003] In view of the problems existing in the prior art, this utility model proposes an integrated energy storage box-type transformer substation for railways, which solves the problems mentioned in the background art.

[0004] To achieve the above objectives, this utility model provides the following technical solution:

[0005] An integrated energy storage transformer substation for railways includes a high-voltage ring main unit, a transformer, an energy storage unit, and a power distribution and dual-power switching unit. The high-voltage ring main unit is connected to the power distribution and switching unit via the transformer. The power distribution and switching unit includes a disconnecting switch, a grid-connected contactor, a reverse power transmission protection device, and a dual-power switching device. The power distribution and switching unit is also connected to a feeder switch equipped with an electric operating mechanism and the energy storage unit. The energy storage unit includes a lithium iron phosphate battery system and an energy storage converter. The energy storage converter is a bidirectional DC / AC module that enables the lithium iron phosphate battery to operate. The charging and discharging management of the battery system involves a dual-power switching device with a main circuit and a backup circuit. The power supply from the through line serves as the main circuit, while the output of the energy storage unit serves as the backup. When the through line is powered normally, the dual-power switching device connects to the main circuit, and the through line supplies power to the railway load. The anti-reverse power transmission device monitors the input voltage and closes normally, allowing the through line to charge the energy storage unit. When the through line loses power or is shut down during a planned maintenance window, the dual-power switching device switches to the backup circuit. The anti-reverse power transmission device monitors the voltage below the lower limit or disconnects due to a voltage phase loss, allowing the energy storage unit to supply power to the primary load.

[0006] As a further technical solution of this utility model: the high-voltage ring main unit is equipped with a high-voltage switch grounding interlocking device inside.

[0007] As a further technical solution of this utility model: the high-voltage ring main unit has a box structure with a U-shaped design, which is divided into a high-voltage room, a transformer room and a low-voltage room. The low-voltage room includes an energy storage converter cabinet, a battery cabinet, a low-voltage distribution cabinet and a communication cabinet. The low-voltage room is equipped with a heating, ventilation and temperature control unit.

[0008] As a further technical solution of this utility model: the low-voltage distribution cabinet feeds out two or more switches to the primary load, which is a redundant design.

[0009] As a further technical solution of this utility model: the sum of the switching delays of the backup power system switching from grid-connected charging mode to backup power mode and the dual power supply switching device switching from the main circuit to the backup circuit is less than 300ms.

[0010] As a further technical solution of this utility model: the energy storage unit uses lithium iron phosphate as the energy storage medium.

[0011] As a further technical solution of this utility model: the high-voltage switch incoming line of the high-voltage ring network cabinet, the outgoing line cabinet and the feeder cabinet are energized and grounded.

[0012] As a further technical solution of this utility model, it also includes a power energy management and control platform, which realizes real-time monitoring of the operating status and fault diagnosis and early warning of the equipment contained in the energy storage-type box-type substation integrated power distribution system, and has the functions of data recording and communication with the railway dispatch center.

[0013] As a further technical solution of this utility model: the energy storage unit control method includes:

[0014] 1) When the through line is powered normally, the dual power supply switching device switches to the main circuit, the through line supplies power to the railway load, the anti-reverse power transmission device closes, the energy storage converter locks the phase and controls the grid-connected contactor to close, and the energy storage unit is charged by the grid-connected constant power / constant current charging mode.

[0015] 2) When the through line loses power or is shut down during a planned maintenance window, the dual power supply switching device switches to the backup circuit, the anti-reverse power supply device is disconnected, the grid-connected contactor is disconnected, and the grid-connected constant power / constant current charging mode is switched to the off-grid VF mode / Droop mode, and the energy storage unit supplies power to the primary load.

[0016] 3) To avoid the impact caused by the mismatch in amplitude and frequency between the inverter voltage of the energy storage converter and the voltage of the through line when the anti-reverse power transmission device is closed after the power supply to the through line is restored, the grid voltage pre-synchronization control is first performed. When the inverter voltage and the voltage amplitude and frequency of the through line are consistent, the grid-connected contactor is closed to restore the charging mode. The pre-synchronization time from off-grid discharge mode to grid-connected charging mode is no more than 1 second.

[0017] The technical effects and advantages provided by this utility model in the above technical solution are as follows:

[0018] 1. Safety Assurance: The high-voltage switch grounding interlock device works in conjunction with the energy storage unit's anti-reverse power transmission device to ensure personal safety during skylight maintenance.

[0019] 2. Seamless switching: The dual power supply switching device and energy storage unit work together, with a total switching delay of less than 300ms, avoiding power outages for primary loads.

[0020] 3. High reliability: The lithium iron phosphate battery system serves as a backup power source, overcoming the shortcomings of traditional diesel generators and improving power supply stability.

[0021] 4. Green and environmentally friendly: Lithium iron phosphate energy storage medium is used to replace lead-acid batteries, reducing operation and maintenance costs and promoting the green upgrade of railway power supply system. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a primary diagram of an energy storage-type integrated transformer substation for railway use.

[0024] Figure 2 The diagram shows the I-shaped design of the energy storage-type prefabricated substation and the layout of the internal equipment.

[0025] Figure 3 This is a front view of an energy storage-type prefabricated substation.

[0026] Figure 4 This is a right view of an energy storage-type prefabricated substation.

[0027] Figure 5 This is a left view of an energy storage-type prefabricated substation.

[0028] Attached reference numerals: 1. High-voltage ring main unit; 2. High-voltage switch grounding interlock device; 3. Disconnecting switch; 4. Energy storage unit; 5. Energy storage converter; 6. Feeder switch equipped with electric operating mechanism; 7. Copper transformer; 8. Lithium iron phosphate battery system; 9. Low-voltage compartment of transformer substation; 10. High-voltage compartment of transformer substation; 11. Transformer compartment of transformer substation; 12. PCS cabinet; 13. Battery cabinet; 14. Low-voltage distribution cabinet; 15. Communication cabinet; 16. Air conditioner; 41. Grid-connected contactor; 42. Anti-reverse power transmission device; 43. Dual power supply switching device. Detailed Implementation

[0029] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0030] It should be noted that the terms "vertical," "horizontal," "up," "down," "left," "right," and similar expressions used in this article are for illustrative purposes only and do not represent the only possible implementation.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; the terminology used herein in the description of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention; the term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0032] This utility model provides, for example Figures 1-5The drawing shown depicts a railway-type integrated transformer substation with energy storage, comprising a high-voltage ring main unit 1, a transformer 7, a low-voltage distribution cabinet 14, and an energy storage unit 4. The railway's 10kV or 35kV through-line first passes through the ring main unit, with loop-in and loop-out connections, feeding out to the transformer 7. The transformer transforms the voltage to 0.4kV or 0.23kV, which is then fed out to the low-voltage distribution cabinet 14 via a disconnecting switch 3. The low-voltage distribution cabinet outputs to the energy storage unit 4. The energy storage unit includes an energy storage converter 5 and a lithium iron phosphate battery system 8 for energy storage. The converter 5 adopts a high-efficiency three-level DCAC topology, with a three-phase four-wire connection to the power grid. Its power capacity is determined based on the power consumption of the primary load. The lithium iron phosphate battery system 8 uses square aluminum-cased cells with a voltage rating of 3.2V. The system capacity is calculated based on the backup power duration of the primary load, and considering backup power applications, it is configured at 1.2 times the calculated value. The low-voltage distribution cabinet outputs to the dual power switching device 43. The dual power switching device 43 includes a main circuit and a backup circuit, which are derived from the disconnect switch 3. The output terminal is connected to the output switch of the energy storage unit 4. The feeder circuit of the dual power supply switching device 43 includes the main power supply for the primary load, the backup power supply for the primary load, the power supply for the communication cabinet, the power supply for the transformer substation air conditioning, lighting, and dehumidification and heat dissipation. The output of the disconnecting switch is fed to the non-primary load. The dual power supply switching device 43 includes an automatic switching time of less than 300ms for the main and backup circuits. The input circuit of the energy storage unit 4 includes a grid-connected contactor 41 and a reverse power transmission prevention device 42. The grid-connected contactor 41 realizes the grid connection and off-grid of the energy storage unit 4. The reverse power transmission prevention device 42 realizes that when the through line loses power, the energy storage unit 4 is completely disconnected from the through line to prevent the voltage of the energy storage unit 4 from being fed back to the through line when it is discharged off-grid, which could cause casualties. The power energy management platform realizes real-time monitoring and fault diagnosis and early warning of the operating status of all equipment in the integrated energy storage transformer substation, protects battery safety, and has data recording and communication functions with the railway dispatch center. Through data acquisition, power flow monitoring and energy dispatching by the railway dispatch center, the internal energy control of the system is realized to ensure the normal operation of the entire system.

[0033] Example 1

[0034] The input of the energy storage unit 4 is connected to the 0.23kV or 0.4kV side of the 10kV or 35kV through line. When the through line voltage is normal, the anti-reverse power transmission device 43 detects that the input voltage is normal and closes. The energy storage converter 5 first locks the phase of the grid voltage. After the inverter voltage is synchronized with the grid voltage, the grid-connected contactor 41 is closed. The energy storage converter 5 operates in constant current / constant power charging mode to charge the lithium iron phosphate battery system 8. When the voltage is charged to the set value, the energy storage converter 5 enters standby mode.

[0035] The input of the energy storage unit 4 is connected to the 0.23kV or 0.4kV side of the 10kV or 35kV through line. When the through line voltage is abnormal, the anti-reverse power transmission device 43 detects the abnormal input voltage and disconnects. The energy storage converter 5 controls the grid-connected contactor 41 to disconnect. The energy storage converter 5 seamlessly switches from constant current / constant power charging mode to off-grid VF mode or off-grid Droop mode. The switching time is less than 10ms. The lithium iron phosphate battery system 8 is inverted and discharged by the energy storage converter 5 to provide voltage and frequency support to the load. When the voltage is discharged to the set value, the energy storage converter 5 enters the shutdown mode.

[0036] The input of the energy storage unit 4 is connected to the 0.23kV or 0.4kV side of the 10kV or 35kV through line. When the through line voltage returns to normal from abnormal, the anti-reverse power transmission device 43 detects that the input voltage is normal and closes. The energy storage converter 5 detects that the grid is normal. After pre-synchronization control, it tracks the amplitude and phase of the grid voltage. After synchronization, it controls the grid-connected contactor 41 to close. The energy storage converter 5 seamlessly switches from off-grid VF mode or off-grid Droop mode to constant current / constant power charging mode. The switching time is less than 10ms. The lithium iron phosphate battery system 8 is rectified and charged by the energy storage converter 5. When the voltage is charged to the set value, the energy storage converter 5 enters standby mode.

[0037] The dual-power switching device 43 includes a primary circuit and a backup circuit, which are drawn from the output terminal of the isolating switch 3 and the output switch of the energy storage unit 4. The feeder circuits of the dual-power switching device 43 include the primary circuit for the first-level load, the backup circuit for the first-level load, the power supply for the communication cabinet, the power supply for the transformer substation air conditioning, lighting, and dehumidification and heat dissipation. When the through-line voltage is normal, the dual-power switching device 43 switches to the primary circuit; when the through-line voltage is abnormal, the dual-power switching device 43 switches to the primary circuit.

[0038] The power energy management platform enables real-time monitoring and fault diagnosis and early warning of the operating status of all equipment in the integrated energy storage transformer substation, protects battery safety, and has data recording and communication functions with the railway dispatch center. Through data acquisition, power flow monitoring and energy dispatching by the railway dispatch center, it realizes internal energy control of the system to ensure the normal operation of the entire system.

[0039] This utility model patent proposes an integrated energy storage prefabricated substation for railways, which can achieve the following:

[0040] 1) The high-voltage switchgear is equipped with a grounding interlock device and the energy storage unit is equipped with a reverse power transmission prevention device, which makes it easier to set up safety measures and ensure personal safety during skylight maintenance.

[0041] 2) The high-voltage switchgear is equipped with a ring main unit, and the low-voltage switchgear is equipped with a disconnecting switch, with a clear disconnection point, so there is no need to shut down the power supply section during the power outage.

[0042] 3) The energy storage-type integrated transformer substation is equipped with an energy storage emergency power supply system. During planned power outages, the existing power supply system does not have a single power supply for the primary load, thus avoiding the occurrence of red light bands.

[0043] 4) The energy storage-type integrated transformer substation adopts an energy storage system represented by lithium iron phosphate. The lithium iron phosphate battery system is more environmentally friendly, promoting the green and low-carbon upgrading of railway power supply and distribution.

[0044] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0045] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A power distribution substation with energy storage and integrated prefabricated substation for railways, comprising a high-voltage ring main unit (1), a transformer (7), an energy storage unit (4), and a power distribution and dual-power switching unit, characterized in that; The high-voltage ring main unit (1) is connected to the power distribution and switching unit through a transformer (7). The power distribution and switching unit includes a disconnector (3), a grid-connected contactor (41), an anti-backfeeding device (42) and a dual-power switching device (43). The power distribution and switching unit is also respectively connected to a feeder switch (6) equipped with an electric operating mechanism and an energy storage unit (4). The energy storage unit (4) includes a lithium iron phosphate battery system (8) and an energy storage inverter (5). The energy storage inverter (5) is a bidirectional DC / AC module, which realizes the charge and discharge management of the lithium iron phosphate battery system (8). The dual-power switching device (43) is divided into a main circuit and a standby circuit. The through-line power supply is used as the main circuit, and the output of the energy storage unit (4) is used as the standby. When the through-line is normally powered, the dual-power switching device (43) connects the main circuit, and the through-line supplies power to the railway load. The anti-backfeeding device (42) monitors the normal input voltage and closes, and the through-line charges the energy storage unit (4). When the through-line loses power or the planned maintenance skylight is powered off, the dual-power switching device (43) switches to the standby circuit, and the anti-backfeeding device (42) monitors the voltage lower than the lower limit or the voltage phase loss and disconnects, and the energy storage unit (4) supplies power to the primary load.

2. The integrated energy storage prefabricated substation for railways according to claim 1, characterized in that: A high-voltage switch grounding interlock device (2) is provided inside the high-voltage ring main unit (1).

3. The integrated energy storage prefabricated substation for railways according to claim 1, characterized in that: The box structure of the high-voltage ring main unit (1) is designed in an eye shape, and is divided into a high-voltage chamber (10), a transformer chamber (11) and a low-voltage chamber (9). The low-voltage chamber includes an energy storage inverter cabinet (12), a battery cabinet (13), a low-voltage power distribution cabinet (14), and a communication cabinet (15). A heating, ventilation and temperature control unit (16) is equipped inside the low-voltage chamber.

4. A railway energy storage integrated transformer substation according to claim 3, characterized in that: The number of switches for the low-voltage power distribution cabinet (14) to feed the primary load is more than 2, with redundant design.

5. A railway energy storage integrated transformer substation according to claim 1, characterized in that: The sum of the switching delays of the backup power system switching from the grid-connected charging mode to the backup power mode and the dual-power switching device (43) switching from the main circuit to the standby circuit is less than 300 ms.

6. The integrated energy storage prefabricated substation for railways according to claim 1, characterized in that: The energy storage unit (4) uses lithium iron phosphate as the energy storage medium.

7. A power substation with integrated energy storage and distribution capabilities for railways according to claim 1, characterized in that: The high-voltage switches of the incoming line cabinet, outgoing line cabinet and feeder cabinet of the high-voltage ring main unit (1) are locked with the incoming line charged to ground.

8. A railway energy storage integrated transformer substation according to claim 1, characterized in that: It also includes a power energy control platform, which realizes real-time monitoring, fault diagnosis and early warning of the operating states of the equipment included in the integrated energy storage box-type substation for power distribution and transformation, and has the functions of data recording and communication with the railway dispatching center.

Images