Optical storage integrated standby power system for railway base station

Abstract

The utility model relates to the technical field of electrified railways, and discloses a light storage integrated standby power system for a railway base station, which comprises an energy storage converter, a photovoltaic unit, an energy storage unit and a power distribution unit, the energy storage converter comprises a DC / DC module and an AC / DC module; the photovoltaic unit adopts a DC / DC module to realize an MPPT module function; the energy storage unit adopts a DC / DC module to realize charging and discharging management; the power distribution unit comprises an anti-reverse power transmission device and a double-cutting device; when the through line supplies power normally, the double-switching device is switched to the main input loop, the through line supplies power to the base station main device, the reverse power transmission prevention device is closed, and the through line charges the energy storage unit. When the through line loses power or is in power failure during maintenance, the double-switching device is switched to the output loop of the standby power supply, the reverse power transmission prevention device is disconnected, and the standby power supply supplies power to the main equipment; the problem that an existing power supply system is unreliable in power supply is solved, and the stability and reliability of base station power supply are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of electrified railways, and in particular to a photovoltaic storage integrated backup power system for railway base stations. Background Art

[0002] With the rapid development of railway electrical technology, the stability and reliability of base station backup power systems are crucial to the safety of railway operations. Traditional backup power systems mainly rely on battery packs, which have problems such as limited energy storage capacity, high maintenance costs, and environmental pollution.

[0003] At present, the power supply system of most railway base stations in the northwest is only equipped with a 35KV or 10KV through-power supply line. However, base stations play a vital role in modern communication networks. Reliable power supply is one of the key factors to ensure the normal operation of communication networks. In order to ensure the reliable power supply of base station communication equipment, the solution adopted is to add lead-acid batteries on the switching power supply side inside the base station. When the external through-power is cut off, the lead-acid battery plays the role of backup power.

[0004] Although the above solutions have ensured reliable backup power for base stations to a certain extent, the lead-acid batteries used as backup power sources have shown problems such as weakened discharge performance and reduced storable electrical energy as they have been in operation for a long time in high-altitude areas. They are unable to guarantee stable power supply to base station equipment when the power grid fails. Lead-acid batteries also have problems such as manual measurement and maintenance methods and high operation and maintenance costs.

[0005] As the world pays more and more attention to green and low-carbon development, the railway transportation industry is facing an important opportunity for transformation and upgrading. Accelerating the promotion of railway electrification, upgrading the power supply system, and promoting the development of green energy power supply systems have become industry consensus. In the future, railway transportation will develop in a more green, efficient and intelligent direction.

[0006] In view of this, there is a need for an integrated photovoltaic and storage backup power system for railway base stations. Utility Model Content

[0007] The purpose of the utility model is to provide a photovoltaic and storage integrated backup power system for railway base stations, which can improve the stability and safety of the power supply of the base station power system, add a photovoltaic and storage integrated backup power supply on the basis of the through power supply line, and ensure the stable power supply of the base station load.

[0008] In order to achieve the above technical objectives, the technical solution adopted by the utility model is:

[0009] A photovoltaic and energy storage integrated backup power system for railway base stations, comprising an energy storage converter, a photovoltaic unit, an energy storage unit, and a power distribution unit;

[0010] The energy storage converter includes a DC / DC module and an AC / DC module to achieve the conversion function of voltage form from DC to AC; the photovoltaic unit uses a DC / DC module to achieve the MPPT module function; the energy storage unit uses a DC / DC module to achieve charge and discharge management; the power distribution unit includes an anti-backfeeding device and a double-switching device; the photovoltaic unit and the energy storage unit form a DC power distribution network, which is centrally inverted to the AC power distribution network through the energy storage converter; when the through line is normally powered, the double-switching device switches to the main input circuit, and the through line supplies power to the base station main equipment; the anti-backfeeding device closes, and the through line charges the energy storage unit; when the through line loses power or is under maintenance and power outage, the double-switching device switches to the standby power output circuit, the anti-backfeeding device disconnects, and the standby power supplies power to the main equipment to ensure stable power supply.

[0011] As a further optimization of the solution, it further includes an energy management system to realize a flexible interconnection system for the efficient integration of the power grid and distributed energy.

[0012] As a further optimization of the solution, it further includes an energy monitoring platform to realize the functions of monitoring and controlling terminal equipment.

[0013] As a further optimization of the solution, the number of DC / DC modules is more than 2.

[0014] As a further optimization of the solution, the energy storage unit includes lithium batteries.

[0015] As a further optimization of the solution, the sum of the switching delays of the standby power system switching from the grid-connected charging mode to the standby power mode and the anti-backfeeding device switching from the main circuit to the standby circuit is below 300 ms.

[0016] As a further optimization of the solution, a control method for an integrated optical storage standby power system for railway base stations includes:

[0017] 1) When in the off-grid mode, when the energy storage converter, photovoltaic unit, and energy storage unit are all normal and the photovoltaic unit has sufficient power, the photovoltaic unit operates in the forced constant voltage tracking mode to maintain the DC bus voltage at 750V, the energy storage converter supplies power to the load, and the energy storage unit operates in the charging mode;

[0018] 2) When in the grid-connected mode, when the energy storage converter, photovoltaic unit, and energy storage unit are all normal and the photovoltaic unit has sufficient power, the photovoltaic unit charges the energy storage unit; the photovoltaic unit operates in the forced constant voltage tracking mode, the bus voltage is 750V, the energy storage converter feeds power to the grid and charges the load, the photovoltaic unit exits the forced constant voltage tracking mode and enters the MPPT mode, scans for the maximum power point and maintains it, and the bus voltage drops to 730V.

[0019] The beneficial effects of adopting the above technical solutions are as follows:

[0020] 1. Solve the problem that the existing power supply system lacks an independent "second power supply", resulting in unreliable power supply, and improve the stability and reliability of the base station signal power supply.

[0021] 2. Promote the distributed access of new energy in railway base stations, and promote the upgrading, green and low-carbon intelligent transformation of railway electrification. Description of the Drawings

[0022] Figure 1 It is a schematic diagram of an integrated optical storage power backup system for railway base stations;

[0023] Reference numerals: 1. Energy storage inverter, 2. Photovoltaic unit, 3. Energy storage unit, power distribution unit, 41. Anti-backfeeding device, 42. Double-switching device. Detailed Embodiments

[0024] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0025] As Figure 1 shown, an integrated optical storage power backup system for railway base stations includes an energy storage inverter 1, a photovoltaic unit 2, an energy storage unit 3, and a power distribution unit; the energy storage inverter 1 includes a DC / DC module and an AC / DC module to achieve the conversion function of DC to AC voltage form; the photovoltaic unit 2 uses a DC / DC module to achieve the MPPT module function; the energy storage unit 3 uses a DC / DC module to achieve charge and discharge management; the power distribution unit includes an anti-backfeeding device 41 and a double-switching device 42; the photovoltaic unit 2 and the energy storage unit 3 form a DC power distribution network, which is centrally inverted to an AC power distribution network through the energy storage inverter 1;

[0026] When the through line is normally powered, the double-switching device 42 switches to the main input circuit, and the through line supplies power to the base station main equipment; the anti-backfeeding device 41 is closed, and the through line charges the energy storage unit 3; when the through line loses power or is under maintenance and power outage, the double-switching device 42 switches to the standby power output circuit, and the anti-backfeeding device 41 is disconnected, and the standby power supplies power to the main equipment to ensure stable power supply.

[0027] It also includes an energy management system to realize a flexible interconnection system for the efficient integration of the power grid and distributed energy; it also includes an energy monitoring platform to realize the functions of monitoring and controlling terminal equipment; the number of DC / DC modules is more than 2. The energy storage unit 3 includes lithium batteries.

[0028] 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 anti-backfeed power device 41 switching from the main circuit to the standby circuit is less than 300 ms.

[0029] A control method for a photovoltaic-storage integrated backup power system for a railway base station, the control method comprising:

[0030] 1. When in the off-grid mode, when the energy storage converter 1, the photovoltaic unit 2, and the energy storage unit 3 are all normal and the power of the photovoltaic unit 2 is sufficient, the photovoltaic unit 2 operates in the forced constant voltage tracking mode to maintain the DC bus voltage at 750 V, the energy storage converter supplies power to the load, and the energy storage unit 3 operates in the charging mode;

[0031] 2. When in the grid-connected mode, when the energy storage converter 1, the photovoltaic unit 2, and the energy storage unit 3 are all normal and the power of the photovoltaic unit 2 is sufficient, the photovoltaic unit 2 charges the energy storage unit 3; the photovoltaic unit 2 operates in the forced constant voltage tracking mode, the bus voltage is 750 V, the energy storage converter 1 feeds power to the grid and charges the load, the photovoltaic unit 2 exits the forced constant voltage tracking mode and enters the MPPT mode, scans and maintains the maximum power point, and the bus voltage drops to 730 V.

[0032] Embodiment 1

[0033] In view of the current situation of railway power supply, adapt measures to local conditions, make full use of the renewable resources of the resource endowment along the railway base stations, obtain materials locally and nearby, build a self-consistent energy system of "renewable resources + lithium battery energy storage", connect a technical green transformation plan to the power supply side of the railway power supply system, improve the stability and safety of the power supply of the base station power system, and add a photovoltaic-storage integrated backup power supply on the basis of the original through-power supply line to ensure the stable power supply of the communication base station load.

[0034] A self-consistent energy system of "photovoltaic + energy storage", which is a flexible interconnection system with a power electronic device as the core, obtaining materials locally, consisting of a DC distribution network formed by connecting the photovoltaic power generation through a DC / DC module and the energy storage lithium battery system through a DC / DC module, centrally inverted to an AC distribution network through an energy storage converter PCS, and equipped with an intelligent energy management system EMS, realizing the intelligent routing of electric energy in the local power grid and the efficient utilization of distributed energy through the integration of primary and secondary.

[0035] By analyzing the current situation of railway base station power supply in some areas, a self-consistent power supply and backup system of a photovoltaic-storage integrated backup power supply is proposed; the green energy is converted into a power supply through the DC conversion of the photovoltaic system; from the perspective of real-time power control of the multi-state energy system, the stable operation method of the multi-state energy system of the railway base station is studied to realize the coordinated operation of the multi-state energy under the multi-scenario energy demand of the railway base station;

[0036] Mainly by adding a self-consistent energy power supply system of "photovoltaic + energy storage" on the railway power supply side, a second backup power supply is added nearby for the signal load of railway base stations, solving the problem of unreliable power supply caused by the lack of an independent "second power supply" in the existing power supply system, and improving the stability and reliability of the signal power supply for base stations.

[0037] Adopt a new model of autonomous photovoltaic and energy storage green energy power supply and optimize the use of traditional electrification systems, promote the distributed access of new energy in railway base stations, and promote the upgrading and green, low-carbon and intelligent transformation of railway electrification.

[0038] Embodiment 2

[0039] When the communication base station through-circuit is normally powered, the dual-switching device switches to the main input circuit, and the 35kV through-line supplies power to the main equipment of the base station through the box transformer. The anti-backfeed power supply contactor of the integrated photovoltaic and energy storage backup power supply closes, and the through-line charges the lithium battery through the emergency power input circuit until it is full.

[0040] When the 35kV through-circuit of the communication base station loses power or is under maintenance power outage, the power dual-switching device switches to the emergency power output circuit, the anti-backfeed power supply contactor disconnects, and the integrated photovoltaic and energy storage backup power supply supplies power to the main equipment of the communication base station to ensure the stable power supply of the main equipment of the base station. The switching delay between the integrated photovoltaic and energy storage backup power supply switching from the grid-connected charging mode to the backup power mode + the power dual-switching device switching from the main circuit to the standby circuit is about 300ms.

[0041] Photovoltaic and energy storage self-consistent operation control method:

[0042] 1. Energy storage unit

[0043] 1) When the battery is in the discharge mode, the given value of the bus voltage is 750V;

[0044] 2) When the battery is in the charging mode, the bus voltage suddenly drops, and the given value of the bus voltage is 720V;

[0045] 3) When the battery is in the forced discharge mode, the given value of the bus voltage is 720V;

[0046] 2. Photovoltaic unit

[0047] 1) When the photovoltaic unit is in the CVT mode, the given value of the bus voltage is 750V;

[0048] 2) When the photovoltaic unit is in the MPPT mode, only when the photovoltaic unit is insufficient, the given value of the bus voltage is 720V

[0049] 3) When the photovoltaic unit is in the forced CVT mode, the given value of the bus voltage is 750V;

[0050] 3. Energy storage inverter

[0051] The given value of the bus voltage of the energy storage converter is 730V.

[0052] Embodiment 3

[0053] A control method for an integrated optical storage power backup system for a railway base station, the control method comprising:

[0054] 1. Startup process (abnormal power grid)

[0055] 1) Monitor and issue a startup command, and the system board determines whether it is possible to start up (such as whether there are shutdown faults, etc.)

[0056] 2) If the startup conditions are met, the system board needs to determine which modules are normal. If both the photovoltaic unit and the energy storage unit are normal, the system board will first issue a charging startup instruction to the energy storage unit to let it establish the bus. At this time, the energy storage unit actively enters the forced discharge mode; after the system board determines that the bus establishment is complete, it will issue a startup instruction to the energy storage converter, and the energy storage converter starts up with off-grid soft start and operates in the off-grid mode; at the same time, after a 5s delay, the photovoltaic unit will receive the MPPT startup instruction. At this time, due to the power scanning of the photovoltaic unit, the energy storage unit will exit the forced discharge mode and enter the charging mode

[0057] 3) If the startup conditions are met, the photovoltaic unit is normal, but the energy storage unit is not normal, the system board will issue a CVT (constant voltage tracking mode) startup instruction to the photovoltaic unit to let it establish the bus; after the system board determines that the bus establishment is complete, it will issue a startup instruction to the energy storage converter, and the energy storage converter starts up with off-grid soft start.

[0058] 4) If the startup conditions are met, the photovoltaic unit is not normal, and the energy storage unit is normal, the system board will first issue a discharge startup instruction to the energy storage unit to let it establish the bus; after the system board determines that the bus establishment is complete, it will issue a startup instruction to the energy storage converter, and the energy storage converter starts up with off-grid soft start.

[0059] 5) If the startup conditions are met, and both the photovoltaic unit and the energy storage unit are abnormal, the startup is abnormal.

[0060] 2. Startup process (normal power grid)

[0061] 1) Monitor and issue a startup command, and the system board determines whether it is possible to start up (such as whether there are shutdown faults, etc.)

[0062] 2) If the startup conditions are met, the system board needs to determine which modules are normal. If both the photovoltaic unit and the energy storage unit are normal, the system board will first send a charging startup command to the energy storage unit to establish the bus. At this time, the energy storage unit will actively enter the forced discharge mode. After the system board determines that the bus establishment is completed, the system board will perform a 12s soft start on the transformer, and then send a startup command to the energy storage converter. The energy storage converter will be connected to the grid and start up. 5s after the bus establishment is completed, the system board will send an MPPT startup command to the photovoltaic unit, and the energy storage unit will exit the forced discharge mode and enter the charging mode.

[0063] 3) If the startup conditions are met, the photovoltaic unit is normal, but the energy storage unit is not normal, the system board will send a CVT startup command to the photovoltaic unit to establish the bus. After the system board determines that the bus establishment is completed, the system board will send an MPPT command to the photovoltaic unit and start to soft start the transformer at the same time. At this time, since the transformer soft start is not completed and the energy storage converter has not been started up, the power of the photovoltaic unit is sufficient, and the photovoltaic unit will be forced to enter the CVT mode. After the soft start is completed, the system board will send a startup command to the energy storage converter, and the energy storage converter will start to feed power. During the DCAC power feeding process, the DC bus voltage will be pulled down, and the photovoltaic unit will exit the forced CVT mode and enter the MPPT mode to scan and maintain the maximum power point.

[0064] 4) If the startup conditions are met, the photovoltaic unit is not normal, and the energy storage unit is normal, the system board will first send a discharge startup command to the energy storage unit to establish the bus. After the system board determines that the bus establishment is completed, the system board will start to soft start the transformer and send a charging command to the energy storage unit at the same time. At this time, since the transformer soft start is not completed and the energy storage converter has not been started up, it cannot be charged, and the energy storage unit will enter the forced discharge mode. After the soft start is completed, the system board will send a startup command to the energy storage converter, and the energy storage converter will start to work. Since the bus voltage of the energy storage converter is higher than that of the energy storage unit, the battery will exit the forced discharge state and enter the charging mode.

[0065] 5) If the startup conditions are met and both the photovoltaic unit and the energy storage unit are abnormal, the startup will be abnormal.

[0066] III. Operation Process

[0067] 1. Operation Process in Islanding Mode

[0068] a. When the photovoltaic unit and the energy storage unit are normal, determine whether the energy storage converter is normal

[0069] 1) During the operation process, if the energy storage converter is normal and the power of the photovoltaic unit is sufficient, the photovoltaic unit will operate in the forced CVT mode to maintain the DC bus voltage at 750V. The energy storage converter will supply power to the load, and the energy storage unit will operate in the charging mode. During the constant current charging stage, it can charge with the given current value.

[0070] 2) If the power of the photovoltaic unit is insufficient, the photovoltaic unit operates in the MPPT mode, maintaining the DC bus voltage at 720V. The energy storage converter supplies power to the load. If the maximum power of the photovoltaic unit cannot support the load power, the energy storage unit enters the forced discharge mode and supplies power to the load together with the photovoltaic unit; if the maximum power of the photovoltaic unit can not only support the load power but also charge the battery, the energy storage unit continues to operate in the charging mode, and the charging current in the constant current stage is less than or equal to the given value of the charging current.

[0071] 3) During operation, if the energy storage converter malfunctions, when the power of the photovoltaic unit is sufficient, the photovoltaic unit operates in the forced CVT mode, maintaining the DC bus voltage at 750V. The energy storage converter supplies power to the load, and the energy storage unit operates in the charging mode, and can charge at the given current value in the constant current charging stage; if the power of the photovoltaic unit is insufficient, the photovoltaic unit operates in the MPPT mode, maintaining the DC bus voltage at 720V, and the energy storage unit continues to operate in the charging mode, and the charging current in the constant current stage is less than or equal to the given value of the charging current.

[0072] b. The energy storage unit and the energy storage converter are normal, and it is judged that the photovoltaic unit is normal

[0073] 1) During operation, when the photovoltaic unit is normal, if the power of the photovoltaic unit is sufficient, the photovoltaic unit operates in the forced CVT mode, maintaining the DC bus voltage at 750V. The energy storage converter supplies power to the load. If the energy storage unit operates in the discharge mode, the energy storage unit switches to the charging mode, and can charge at the given current value in the constant current charging stage;

[0074] 2) If the power of the photovoltaic unit is insufficient, the photovoltaic unit operates in the MPPT mode, maintaining the DC bus voltage at 720V. The energy storage converter supplies power to the load. If the maximum power of the photovoltaic unit cannot support the load power, the energy storage unit enters the forced discharge mode and supplies power to the load together with the photovoltaic unit; if the maximum power of the photovoltaic unit can not only support the load power but also charge the battery, the energy storage unit continues to operate in the charging mode, and the charging current in the constant current stage is less than or equal to the given value of the charging current.

[0075] 3) During operation, if the photovoltaic unit malfunctions, if the energy storage unit operates in the charging mode, the energy storage unit switches to the forced discharge mode, maintaining the DC bus voltage at 720V; if the energy storage unit operates in the discharge mode, the DC bus voltage is maintained at 750V.

[0076] c. The photovoltaic unit and the energy storage converter are normal, and it is judged that the energy storage unit is normal

[0077] 1) During operation, when the energy storage unit is normal, if the power of the photovoltaic unit is sufficient, the photovoltaic unit operates in the forced CVT mode, maintaining the DC bus voltage at 750V. The energy storage converter supplies power to the load. If the energy storage unit operates in the charging mode, the energy storage unit can charge at the given current value in the constant current charging stage;

[0078] 2) If the power of the photovoltaic unit is insufficient, the photovoltaic unit operates in the MPPT mode, maintaining the DC bus voltage at 720V. The energy storage converter supplies power to the load. If the maximum power of the photovoltaic unit cannot support the load power, the energy storage unit enters the forced discharge mode and supplies power to the load together with the photovoltaic unit. If the maximum power of the photovoltaic unit can not only support the load power but also charge the battery, the energy storage unit continues to operate in the charging mode, and the charging current in the constant current stage is less than or equal to the given value of the charging current.

[0079] 3) During operation, if an abnormality occurs in the energy storage unit, when the power of the photovoltaic unit is sufficient, the photovoltaic unit operates in the forced CVT mode, maintaining the bus voltage at 750V, and the energy storage converter supplies power to the load. When the power of the photovoltaic unit is insufficient, the photovoltaic unit operates in the MPPT mode, maintaining the bus voltage at 720V.

[0080] 2. Operation process in grid-connected mode

[0081] a. The photovoltaic unit and the energy storage unit are normal. Determine whether the energy storage converter is normal

[0082] 1) During operation, when the photovoltaic unit is normal and the energy storage unit is normal, the photovoltaic unit charges the battery, and the charging current in the constant current stage is less than or equal to the given current value. When the energy storage converter is normal and the power of the photovoltaic unit is sufficient, the photovoltaic unit operates in the forced CVT (constant voltage tracking mode) mode, with the bus voltage at 750V. The energy storage converter feeds power to the grid and charges the load, and the photovoltaic unit exits the forced CVT mode and enters the MPPT mode to scan and maintain the maximum power point, and the bus voltage drops to 730V.

[0083] 2) If the power of the photovoltaic unit is insufficient and the photovoltaic unit has operated in the MPPT mode and scanned the maximum power point, if the battery charging current is not equal to the given value of the charging current, the energy storage converter operates in the rectification mode and charges the battery together with the photovoltaic unit, and the grid supplies power to the load. If the battery charging current is exactly equal to the given current value, the energy storage converter stands by and the grid supplies power to the load.

[0084] 3) During operation, if the energy storage converter is abnormal, the grid supplies power to the load. When the power of the photovoltaic unit is sufficient, the photovoltaic unit operates in the forced CVT mode, with the bus voltage at 750V, and the battery operates in the charging mode, and the charging current in the constant current stage can charge at the given current value. When the power of the photovoltaic unit is insufficient, the photovoltaic unit operates in the MPPT mode, scans and maintains the maximum power point, and at this time the bus voltage is 720V, which is maintained by the energy storage unit.

[0085] b. The energy storage unit and the energy storage converter are normal. Determine whether the photovoltaic unit is normal

[0086] 1) During operation, when the energy storage converter is normal, the energy storage unit is normal, and if the photovoltaic unit is normal, the energy storage unit operates in the charging mode. During the constant current stage, the charging current is less than or equal to the given current value. When the photovoltaic unit has sufficient power, the photovoltaic unit operates in the forced CVT mode, the bus voltage is 750V, the energy storage converter feeds power to the grid and charges the load. The photovoltaic unit exits the forced CVT mode and enters the MPPT mode to scan and maintain the maximum power point, and the bus voltage drops to 730V;

[0087] 2) If the photovoltaic unit is insufficient and the photovoltaic unit has already operated in the MPPT mode and scanned the maximum power point, if the battery charging current is not equal to the given charging current value, the energy storage converter operates in the rectification mode to charge the battery together with the photovoltaic unit, and the grid supplies power to the load. If the battery charging current is exactly equal to the given current value, the energy storage converter stands by and the grid supplies power to the load.

[0088] 3) During operation, if the photovoltaic unit is abnormal, the grid supplies power to the load; at the same time, the energy storage converter rectifies to charge the battery, and during the constant current stage, the charging current can charge at the given value, the bus voltage is 730V, and the energy storage converter maintains.

[0089] c. The photovoltaic unit and the energy storage converter are normal, but the energy storage unit is not normal

[0090] 1) During operation, when the energy storage converter is normal, the photovoltaic unit is normal, and if the energy storage unit is normal, the energy storage unit operates in the charging mode. During the constant current stage, the charging current is less than or equal to the given current value. When the photovoltaic unit has sufficient power, the photovoltaic unit operates in the forced CVT mode, the bus voltage is 750V, the energy storage converter feeds power to the grid and charges the load. The photovoltaic unit exits the forced CVT mode and enters the MPPT mode to scan and maintain the maximum power point, and the bus voltage drops to 730V;

[0091] 2) If the photovoltaic unit is insufficient and the photovoltaic unit has already operated in the MPPT mode and scanned the maximum power point, if the battery charging current is not equal to the given charging current value, the energy storage converter operates in the rectification mode to charge the battery together with the photovoltaic unit, and the grid supplies power to the load. If the battery charging current is exactly equal to the given current value, the energy storage converter stands by and the grid supplies power to the load.

[0092] 3) During operation, if the energy storage unit is abnormal, the photovoltaic unit supplies power to the load and feeds power to the grid; the bus voltage is 730V, and the energy storage converter maintains.

[0093] For those skilled in the art, it is obvious that the present utility model is not limited to the details of the above-described exemplary embodiments, and the present utility model can be implemented in other specific forms without departing from the spirit or basic characteristics of the present utility model. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present utility model is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present utility model. Any reference signs in the claims should not be construed as limiting the claims involved.

[0094] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative manner of the specification is only for clarity. Those skilled in the art should regard 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 photovoltaic and energy storage integrated power backup system for railway base stations, characterized in that It includes an energy storage converter (1), a photovoltaic unit (2), an energy storage unit (3), and a power distribution unit; The energy storage converter (1) includes a DC / DC module and an AC / DC module to achieve the conversion function of voltage form from DC to AC; the photovoltaic unit (2) uses a DC / DC module to achieve the MPPT module function; the energy storage unit (3) uses a DC / DC module to achieve charge and discharge management; the power distribution unit includes an anti-backfeeding power device (41) and a double-switching device (42); The photovoltaic unit (2) and the energy storage unit (3) form a DC power distribution network, which is centrally inverted to an AC power distribution network through the energy storage converter (1); When the through line is normally powered, the double-switching device (42) switches to the main input circuit, and the through line supplies power to the base station main equipment; the anti-backfeeding power device (41) closes, and the through line charges the energy storage unit (3); When the through line loses power or is under maintenance and power outage, the double-switching device (42) switches to the standby power output circuit, and the anti-backfeeding power device (41) disconnects, and the standby power supplies power to the main equipment to ensure stable power supply.

2. The integrated optical storage power backup system for railway base stations according to claim 1, characterized in that, It further includes an energy management system to achieve a flexible interconnection system for the efficient integration of the power grid and distributed energy.

3. The integrated optical storage power backup system for railway base stations according to claim 1, characterized in that, It further includes an energy monitoring platform to achieve the functions of monitoring and controlling terminal equipment.

4. The integrated optical storage power backup system for railway base stations according to claim 1, characterized in that The number of the DC / DC modules is more than 2.

5. A photovoltaic and energy storage integrated power backup system for a railway base station according to claim 1, wherein, The energy storage unit (3) includes lithium batteries.

6. The integrated optical storage power backup system for railway base stations according to claim 1, characterized in that, The sum of the switching delays of the standby power system switching from the grid-connected charging mode to the standby mode and the anti-backfeeding power device (41) switching from the main circuit to the standby circuit is below 300 ms.

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