Multi-port intelligent integrated emergency backup power supply system based on lithium ion battery

Abstract

The utility model discloses a multi -port intelligence integration emergency standby power supply system based on lithium ion battery, including lithium ion battery, energy storage high pressure box, energy storage converter, parallel and off -network switching device, isolation transformer, dual power supply switching device, contactor, the circuit breaker of matching electric operating mechanism, energy storage converter and parallel and off -network switching device, gather into three port electric energy conversion and switching system, and this system can realize the seamless switching of commercial power and battery power supply, and switching time is less than 10ms, and possesses multi -way commercial power standby power function, solves the important load power supply problem of weak power grid area, promotes the power supply reliability and flexibility, promotes green low -carbon energy storage technology application simultaneously, improves electric power resource utilization efficiency.

Description

Technical Field

[0001] This utility model relates to the field of backup power technology, specifically a multi-port intelligent integrated emergency backup power system based on lithium-ion batteries. Background Technology

[0002] In power supply and distribution systems, primary loads should be supplied by dual power sources to the electrical equipment or low-voltage dual power switching devices. When one power source fails, the other power source should not be damaged simultaneously.

[0003] In reality, for areas with weak power grids, especially in the western Qinghai-Tibet region where dual power supply is not possible, diesel engines are usually used as backup power. However, diesel engine backup power cannot achieve off-grid switching, and traditional diesel generators have a high failure rate of up to 38% in the low-oxygen environment of high altitude, leading to the risk of power outages and inconsistent power supply.

[0004] For some critical loads, traditional uninterruptible power supplies (UPS) are usually installed for backup power. However, UPS have a low power factor, requiring over-sizing, which leads to high costs and low economic efficiency. Secondly, non-centralized bypass UPS cannot be directly paralleled, making capacity expansion difficult. Finally, UPS have high environmental requirements, especially unsuitable for high-altitude and low-temperature environments.

[0005] While lead-acid batteries have advantages such as low cost and mature technology as backup power systems (e.g., emergency power supplies, energy storage systems), their low energy density, large size and weight, short cycle life, high long-term cost, need for regular maintenance, high maintenance requirements, high self-discharge rate, and poor long-term storage performance limit their application in emergency backup power scenarios.

[0006] Therefore, a multi-port intelligent emergency backup power system based on lithium-ion batteries is needed. Utility Model Content

[0007] To address the problems existing in the prior art, this utility model proposes a multi-port intelligent integrated emergency backup power system based on lithium-ion batteries, which solves the problems mentioned in the background art.

[0008] To achieve the above objectives, this utility model provides the following technical solution:

[0009] A multi-port intelligent integrated emergency backup power system based on lithium-ion batteries includes:

[0010] Electrically operated circuit breaker group: including energy storage input electrically operated circuit breaker, energy storage output to ATS1 electrically operated circuit breaker, and energy storage output to ATS2 electrically operated circuit breaker, all of which have dual modes of local control and remote control, and the opening and closing are realized through the electric operating mechanism;

[0011] Contactor: Installed in the mains input circuit, the coil power supply is linked to the mains power status, and it is used to control the on / off state of the energy storage system input circuit;

[0012] Grid-connected / off-grid switching device: adopts SCR components, including SCRA, SCRB, SCRC and SCRN, and realizes grid-connected and off-grid mode switching by closing / opening the corresponding SCR;

[0013] Energy storage converter: bidirectional DC / AC module, integrating PQ and BAT grid-connected control loops, VF and DROOP off-grid control loops, phase-locked loop and pre-synchronization control loop, supporting multi-unit parallel connection and black start function;

[0014] Energy storage high-voltage box: Internally integrated electrically operated circuit breaker to protect the charging and discharging circuit of lithium-ion battery system;

[0015] Lithium-ion battery system: Composed of lithium iron phosphate battery modules connected in series, equipped with a battery management system (BMS), and communicates directly with the energy storage converter via a CAN bus;

[0016] Isolation transformer: The winding method is Dyn11, used for electrical isolation between mains power and energy storage system;

[0017] Dual power supply switching device group: includes dual power supply switching devices ATS1 and ATS2, both of which are electronic non-mechanical switching devices, equipped with input port S1, input port S2 and output port S3, with a switching time of <10ms, and S1 and S2 serving as each other as primary backups.

[0018] As a further technical solution of this utility model: the grid-connected state of the grid-connected switching device is SCRA, SCRB, and SCRC closed and SCRN open, and the off-grid state is SCRA, SCRB, and SCRC open and SCRN closed. The switching process is triggered by the pre-synchronization signal of the energy storage converter.

[0019] As a further technical solution of this utility model: it has a 1-channel AC dual power supply switching device and a 2-channel AC dual power supply switching device.

[0020] As a further technical solution of this utility model: the internal circuit breaker, input circuit breaker, 1-way output circuit breaker, and 2-way output circuit breaker of the energy storage high voltage box are electrically operated circuit breakers, which have two modes: local control and remote control.

[0021] As a further technical solution of this utility model: the energy storage converter has PQ and BAT grid-connected control loops, VF and DROOP off-grid control loops, phase-locked loops and pre-synchronization control loops, and the operating mode can be selected and switched autonomously.

[0022] As a further technical solution of this utility model: the sum of the switching delays of the backup power system from grid-connected charging mode to backup power mode and the dual power supply switching device from main circuit to standby circuit is less than 10ms.

[0023] As a further technical solution of this utility model: the contactor is installed in the 1st mains circuit, and the 2nd mains circuit has interlocking normally closed contact monitoring of the contactor coil opening and closing.

[0024] As a further technical solution of this utility model: the lithium-ion battery system is in series.

[0025] As a further technical solution of this utility model: the energy storage converter supports multiple units in parallel.

[0026] As a further technical solution of this utility model: the energy storage converter supports remote dispatch control.

[0027] The technical effects and advantages provided by this utility model in the above technical solution are as follows:

[0028] 1. The multi-port intelligent emergency backup power system can achieve seamless switching between on-grid and off-grid operation, with a switching time of less than 10ms;

[0029] 2. The multi-port intelligent emergency backup power system can realize multiple mains power backups, which is flexible. The energy storage converter supports multiple units in parallel and is easy to expand.

[0030] 3. It solves the problem of single-source power supply for important loads in areas with weak power grids, making power supply more reliable.

[0031] 4. Promote the application of energy storage systems, represented by lithium iron phosphate, in backup power technology to solve the problems of insufficient backup power capacity and environmental pollution caused by lead-acid batteries, and improve the greening and decarbonization of the power system. Attached Figure Description

[0032] 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.

[0033] Figure 1 System architecture diagram of a multi-port intelligent emergency backup power supply system;

[0034] Figure 2 Diagram showing the connection between the grid-connected / off-grid switching device and the energy storage converter in a multi-port intelligent emergency backup power system.

[0035] Figure 3 Connection diagram for lithium-ion charging and discharging logic control of multi-port intelligent emergency backup power system

[0036] Figure 4 The timing diagram for grid connection and off-grid logic control of a multi-port intelligent emergency backup power system;

[0037] Figure 5 Waveform diagram for grid-to-offline switching of a multi-port intelligent emergency backup power system;

[0038] Reference numerals: 1. Energy storage input electrically operated circuit breaker; 2. Contactor; 3. On-grid / off-grid switching device; 4. Energy storage converter; 5. Energy storage high-voltage box; 6. Lithium-ion battery system; 7. Isolation transformer; 8. Energy storage output to ATS1 electrically operated circuit breaker; 9. Energy storage output to ATS2 electrically operated circuit breaker; 10. Dual power supply switching device ATS1; 11. Dual power supply switching device ATS2; 12. Load; 13. SCRA; 14. SCRB; 15. SCRC; 16. SCRN. Detailed Implementation

[0039] 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.

[0040] 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.

[0041] 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.

[0042] This utility model provides, for example Figures 1-5 The drawings shown specifically depict a multi-port intelligent integrated emergency backup power system based on lithium-ion batteries.

[0043] The system includes an energy storage input electrically operated circuit breaker 1, a contactor 2, a grid-connected / off-grid switching device 3, an energy storage converter 4, an energy storage high-voltage box 5, a lithium-ion battery system 6, an isolation transformer 7, an energy storage output electrically operated circuit breaker 8 to ATS1, an energy storage output electrically operated circuit breaker 9 to ATS2, a dual-power switching device ATS1 10, a dual-power switching device ATS2 11, and a load 12. The energy storage input electrically operated circuit breaker 1 is connected to the contactor 2 and is used to control the input circuit of the energy storage system. The energy storage high-voltage box 5 contains an electrically operated circuit breaker with local control and remote dispatch control modes, enabling unattended operation and remote opening and closing. The lithium-ion battery system 6 consists of lithium iron phosphate battery modules and a battery management system (BMS). It maintains battery consistency through series connection and communicates directly with the energy storage converter 4 through the BMS, controlling charging and discharging based on the BMS's status information, eliminating the need for an additional energy management system (EMS).

[0044] Example:

[0045] The grid-connected / off-grid switching device 3 uses a silicon controlled rectifier (SCR) as its core component, including SCRA 13, SCRB 14, SCRC 15, and SCRN 16. When the system is in grid-connected mode, SCRA 13, SCRB 14, and SCRC 15 are closed, and SCRN 16 is opened; when the system switches to off-grid mode, SCRA 13, SCRB 14, and SCRC 15 are opened, and SCRN 16 is closed. The energy storage converter 4 includes PQ and BAT grid-connected control loops, VF and DROOP off-grid control loops, phase-locked loop and pre-synchronization control loops, and a black-start control module. The phase-locked loop and pre-synchronization control loop ensures that the inverter voltage and the grid voltage have the same amplitude and frequency, thereby achieving seamless switching.

[0046] The charging and discharging logic control of the lithium-ion battery system 6 is managed by the energy storage converter 4 based on the status information of the battery management system (BMS18). When the mains power supply is normal, the energy storage converter 4 charges the lithium-ion battery system 6 through rectification; when the mains power fails, the energy storage converter 4 switches to the off-grid control loop, and the lithium-ion battery system 6 supplies power to the load 12. Peak shaving and valley filling control adjusts the charging and discharging strategy according to electricity price information to improve the efficiency of power resource utilization and generate revenue.

[0047] The on-grid / off-grid logic control timing diagram illustrates the system's switching process from on-grid to off-grid. When the mains power supply 301 is normal, the dual power supply switching device ATS1 10 switches to the main input circuit S1, and the mains power supply 301 supplies power to the load 12. The contactor 2 coil is powered normally and automatically engages. At this time, the energy storage converter 4 performs an off-grid black start and is pre-synchronized through the phase-locked loop and pre-synchronization control loop 20. When the inverter voltage matches the grid voltage, the on-grid / off-grid switching device 3 monitors the synchronization success signal of the energy storage converter 4, closes SCRA 13, SCRB 14, and SCRC 15, and opens SCRN 16. The energy storage converter 4 switches to the on-grid control loop to charge the lithium-ion battery system 6. When the mains power supply fails, the contactor 2 coil experiences abnormal power supply and automatically disconnects. The on-grid / off-grid switching device 3 monitors the abnormal voltage, sends a cut-off SCR command, opens SCRA 13, SCRB 14, and SCRC 15, and closes SCRN 16. The energy storage converter 4 monitors the off-grid signal of the off-grid switching device 3 and switches to the off-grid VF control loop. The voltage setpoint is the amplitude of the previous cycle before the grid abnormality, and the frequency setpoint is the frequency of the previous cycle before the grid abnormality. The transition operation from grid connection to off-grid is 10ms. After the transition operation ends, the voltage and frequency setpoints are soft-started to the set values, Vref=220V, Fref=50Hz. The off-grid operation is stable. The dual power supply switching device ATS1 10 switches to the backup power output circuit S2, and the lithium-ion battery system 6 supplies power to the load 12.

[0048] The waveform diagram illustrating the grid-connected / off-grid switching process demonstrates the dynamic process of grid-connected / off-grid switching. In grid-connected mode, the inverter voltage is completely consistent with the grid voltage; in off-grid mode, the energy storage converter 4 maintains a stable output voltage through the VF and DROOP off-grid control loops, ensuring continuous power supply to load 12, further verifying that the grid-connected / off-grid switching time is within 10ms.

[0049] The working principle is as follows:

[0050] In a practical application scenario, assuming an important load 12 is located in a weak power grid area, its stable power supply needs to be guaranteed. When the mains power supply 301 is supplying power normally, the dual power supply switching device ATS1 10 switches to the main input circuit S1, and the mains power supply 301 supplies power to the load 12 through the Dyn11 winding of the isolation transformer 7. The contactor 2 coil is powered normally and automatically engages. The energy storage converter 4 performs off-grid black start and performs pre-synchronization control through the phase-locked loop and pre-synchronization control loop. When the inverter voltage is consistent with the grid voltage, the on-grid switching device 3 closes SCRA 13, SCRB 14 and SCRC 15 and opens SCRN 16. The energy storage converter 4 switches to the grid-connected control loop 21 to charge the lithium-ion battery system 6.

[0051] When the mains power supply 301 fails, the contactor 2 coil experiences an abnormal power supply and automatically disconnects. The off-grid switching device 3 monitors the voltage anomaly, disconnecting SCRA 13, SCRB 14, and SCRC 15, and closing SCRN 16. The energy storage converter 4 monitors the off-grid signal from the off-grid switching device 3 and switches to the off-grid control loop. The dual power supply switching device ATS1 10 switches to the backup power output circuit, and the lithium-ion battery system 6 supplies power to load 12 via energy storage output to the ATS1 electrically operated circuit breaker 8. The total delay of the entire switching process is less than 10ms, ensuring seamless power supply to load 12.

[0052] In addition, the system also has peak shaving and valley filling functions. Based on electricity price information, the peak shaving and valley filling control charges the lithium-ion battery system 6 during off-peak hours and supplies power to the load 12 through the energy storage converter 4 during peak hours, thereby improving the efficiency of power resource utilization and generating revenue.

[0053] The specific structural innovations of the innovation points are as follows:

[0054] 1. Three-port coordinated control of grid-connected and off-grid switching device 3 and energy storage converter 4: The grid-connected and off-grid switching device 3 adopts a silicon controlled rectifier (SCR) design, combined with the phase-locked loop and pre-synchronization control loop of the energy storage converter 4, to achieve seamless grid-connected and off-grid switching with a switching time of less than 10ms.

[0055] 2. Three-port design of dual power supply switching devices ATS1 10 and ATS2 11: Dual power supply switching devices ATS1 10 and ATS2 11 adopt an electronic non-mechanical design with a switching time of less than 10ms, and have the flexible switching capability of AC power input port S1, AC power input port S2 and AC power output port S3.

[0056] 3. Series design of lithium-ion battery system 6: The lithium-ion battery system 6 adopts a series configuration, which avoids the battery consistency problem in parallel design and improves the reliability and safety of the system.

[0057] 4. Multi-unit parallel connection function of energy storage converter 4: Energy storage converter 4 supports multi-unit parallel connection function, which can be flexibly expanded according to needs to adapt to different scales of backup power needs.

[0058] 5. The multi-port intelligent emergency backup power system supports local and remote control, enabling unattended operation and improving the system's intelligence level.

[0059] This utility model patent proposes a multi-port intelligent emergency backup power system based on lithium-ion batteries, which can achieve the following:

[0060] 1. The multi-port intelligent emergency backup power system can achieve seamless switching between on-grid and off-grid operation with a switching time of less than 10ms.

[0061] 2. The multi-port intelligent emergency backup power system can realize multiple mains power backups, which is flexible. The energy storage converter supports multiple units in parallel and can be flexibly expanded according to needs to adapt to different scales of backup power requirements.

[0062] 3. It solves the problem of single-source power supply for important loads in areas with weak power grids, making power supply more reliable.

[0063] 4. Promote the application of energy storage systems, represented by lithium iron phosphate, in backup power technology to solve the problems of insufficient backup power capacity and environmental pollution caused by lead-acid batteries, and improve the greening and decarbonization of the power system.

[0064] 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.

[0065] 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 multi-port intelligent integrated emergency backup power system based on lithium-ion batteries. Its characteristics include: Electrically operated circuit breaker group: including energy storage input electrically operated circuit breaker (1), ATS1 electrically operated circuit breaker (8), ATS2 electrically operated circuit breaker (9), all of which have dual modes of local control and remote control, and realize opening and closing through the electric operating mechanism; Contactor (2): Installed in the mains input circuit, the coil power supply is linked with the mains status, and it is used to control the on and off of the energy storage system input circuit; The grid-connected and off-grid switching device (3) adopts a silicon controlled rectifier (SCR) component, including SCRA (13), SCRB (14), SCRC (15) and SCRN (16), and realizes grid-connected and off-grid mode switching by closing / opening the corresponding SCR; Energy storage converter (4): bidirectional DC / AC module, integrating PQ and BAT grid-connected control loop, VF and DROOP off-grid control loop, phase-locked loop and pre-synchronization control loop, supporting multi-machine parallel connection and black start function; Energy storage high voltage box (5): Internally integrated electric circuit breaker for protecting the charging and discharging circuit of lithium-ion battery system (6); The lithium-ion battery system (6) consists of lithium iron phosphate battery modules connected in series, equipped with a battery management system (BMS), and communicates directly with the energy storage converter (4) via a CAN bus. Isolation transformer (7): The winding method is Dyn11, used for electrical isolation between the mains power and the energy storage system; Dual power switching device group: including dual power switching devices ATS1 (10) and ATS2 (11), both of which are electronic non-mechanical switching devices, with input port S1, input port S2 and output port S3, switching time <10ms, and S1 and S2 are each other's main backups.

2. The multi-port intelligent integrated emergency backup power system based on lithium-ion batteries according to claim 1, characterized in that: The grid-connected switching device (3) is in the grid-connected state with SCRA (13), SCRB (14), and SCRC (15) closed and SCRN (16) open, and in the off-grid state with SCRA (13), SCRB (14), and SCRC (15) open and SCRN (16) closed. The switching process is triggered by the pre-synchronization signal of the energy storage converter (4).

3. The multi-port intelligent integrated emergency backup power system based on lithium-ion batteries according to claim 1, characterized in that: It is equipped with a dual power supply switching device ATS1 (10) with one mains power (301) and a dual power supply switching device ATS2 (11) with two mains power (302).

4. The multi-port intelligent integrated emergency backup power system based on lithium-ion batteries according to claim 1, characterized in that: The internal circuit breaker of the energy storage high voltage box (5), the energy storage input electrically operated circuit breaker (1), the 1-way output circuit breaker (8), and the 2-way output circuit breaker (9) are electrically operated circuit breakers, which have two modes: local control and remote control.

5. The multi-port intelligent integrated emergency backup power system based on lithium-ion batteries according to claim 1, characterized in that: The energy storage converter (4) has PQ and BAT grid-connected control loops, VF and DROOP off-grid control loops, phase-locked loops and pre-synchronization control loops, and the operating mode can be selected and switched independently.

6. The multi-port intelligent integrated emergency backup power system based on lithium-ion batteries according to claim 1, characterized in that: The sum of the switching delays of the system from grid-connected charging mode to standby mode and the dual power supply switching device ATS1 (10) from the main circuit to the standby circuit is less than 10ms.

7. The multi-port intelligent integrated emergency backup power system based on lithium-ion batteries according to claim 1, characterized in that: The contactor (2) is installed in the 1-way mains power (301) circuit, and the 2-way mains power (302) has interlocking normally closed contact monitoring for contactor coil engagement and disengagement.

8. The multi-port intelligent integrated emergency backup power system based on lithium-ion batteries according to claim 1, characterized in that: The lithium-ion battery system (6) is connected in series.

9. The multi-port intelligent integrated emergency backup power system based on lithium-ion batteries according to claim 1, characterized in that: The energy storage converter (4) supports multiple units in parallel.

10. The multi-port intelligent integrated emergency backup power system based on lithium-ion batteries according to claim 1, characterized in that: The energy storage converter (4) supports remote dispatch control.

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