Uninterruptible power supply system based on energy storage management technology

Abstract

The invention discloses an uninterruptible power supply system based on an energy storage management technology, and relates to the technical field of energy storage and power supply. The system comprises an energy storage management system for supplying power to a load and an energy management system, and the energy management system monitors commercial power grid parameters and controls the energy storage system to operate in a grid-connected mode or an off-grid mode based on the commercial power grid parameters; in the grid-connected mode, the energy storage system operates according to a preset working condition to be charged, discharged or shut down; in the off-grid mode, the energy storage system supplies power to the load. According to the scheme, capability flow scheduling is carried out through energy management according to the commercial power supply state and the commercial power non-planned power failure condition, smooth switching is carried out, uninterrupted operation of high-power continuous power utilization equipment is guaranteed, and production benefits are improved.

Description

Technical Field

[0001] This invention relates to the field of energy storage power supply technology, and in particular to an uninterruptible power supply system based on energy storage management technology. Background Technology

[0002] Large-scale block power consumption is affected by factors such as grid fluctuations and insufficient power supply in summer, which leads to the obstruction of industrial production. In the field of oil and gas extraction, the block power grid operates frequently, resulting in a lack of power supply guarantee for oil and gas drilling, fracturing and gas gathering stations and booster stations during the stable production stage, and natural gas cannot be produced stably and continuously and pressurized for delivery.

[0003] Taking the Changning shale gas in Sichuan as an example, according to research statistics, in 2022, the external power grid in the Changning shale gas block experienced 92 planned maintenance shutdowns, 32 grid switching shutdowns, and 68 unplanned emergency shutdowns, totaling 192 power outages throughout the year. Of these, 72 outages impacted production, resulting in a reduction of 12.1762 million cubic meters. Power rationing in July and August 2021 affected annual production by 17 million cubic meters, with a direct impact of 8.6 million cubic meters and an indirect impact of 8.4 million cubic meters. Power rationing in July and August 2022 affected annual production by 18.06 million cubic meters, with a direct impact of 2.7 million cubic meters and an indirect impact of 15.36 million cubic meters.

[0004] Because the shale gas fields in Sichuan are primarily located in mountainous and hilly terrain, the time required for on-site maintenance personnel to arrive and for power restoration is lengthy, negatively impacting the stable production of natural gas. Statistics show that in a certain area of ​​the Changning shale gas field last year, approximately 95 power outages required the implementation of process measures, and approximately 44 power restoration and maintenance services were needed, totaling approximately 1.958 million yuan in costs, resulting in both human and economic losses.

[0005] To mitigate the impact of power outages and curtailments from external power grids, the construction of energy storage systems at oil and gas stations is essential. Currently, the main applications of energy storage systems are photovoltaic energy storage in microgrids and power systems, offering advantages such as smoothing power fluctuations and improving grid stability and reliability. However, this approach lacks practical application in ensuring uninterrupted power supply to high-power, continuously operating equipment at oil and gas stations. The solution lies in using energy storage systems to provide uninterrupted power to high-power, continuously operating equipment at platforms, gas gathering stations, and critical water transfer pumping stations, while reducing energy consumption in distribution and utilization and extending the lifespan of the energy storage system. This is crucial for ensuring stable production of such equipment. Summary of the Invention

[0006] This invention provides an uninterruptible power supply system based on energy storage management technology to solve the problem of uninterrupted power supply for high-power continuous electrical equipment such as oil and gas stations.

[0007] This invention is achieved through the following technical solution:

[0008] An uninterruptible power supply system based on energy storage management technology is provided, comprising:

[0009] Energy storage systems are used to supply power to loads;

[0010] An energy management system is used to monitor mains grid parameters and control the energy storage system to operate in grid-connected or off-grid mode based on the mains grid parameters, wherein the mains grid parameters include phase, voltage and frequency;

[0011] In grid-connected mode, the energy storage system operates according to predetermined operating conditions, which include charging, discharging, or shutdown.

[0012] In off-grid mode, the energy storage system supplies power to the load.

[0013] This invention establishes an energy storage system and an energy management system. After the energy storage system is connected to the power grid of high-power continuous electrical equipment, the energy management system monitors the grid parameters in real time and automatically switches between grid-connected and off-grid operating modes to smoothly transition between energy storage power supply and grid power supply. In grid-connected mode, the energy storage battery charges and discharges according to predetermined operating conditions to ensure the energy storage system has sufficient power in off-grid mode, thereby ensuring uninterrupted operation of the load.

[0014] Furthermore, the energy storage system includes a battery pack, an energy storage battery management system, a combiner cabinet, an energy storage converter, a transformer, and a ring main unit;

[0015] The battery pack includes multiple battery clusters. The output current of each battery cluster is collected by the combiner cabinet and then sequentially input to the ring main unit via the energy storage converter and the transformer.

[0016] The ring main unit is connected to the box-type transformer, and the output of the energy storage system is connected to the busbar through the box-type transformer to achieve grid connection with the mains power grid;

[0017] The energy storage battery management system is connected to each of the battery clusters and is used to monitor the operating parameters of the battery clusters, manage the charging and discharging of the battery clusters, actively equalize voltage, and isolate faulty battery clusters.

[0018] Furthermore, the energy management system is connected to the energy storage battery management system and the energy storage converter, and is used to monitor the operating data of the energy storage battery management system and the energy storage converter, as well as to set the operating parameters of the energy storage battery management system and the energy storage converter.

[0019] Furthermore, the energy management system is also used to: in grid-connected mode, when a mains power failure is detected, control the energy storage system to disconnect from the mains power grid, and control the energy storage converter to switch to VF mode to achieve off-grid operation.

[0020] Furthermore, the energy management system is also used to: in off-grid mode, when the mains power is detected to be restored, adjust the output phase, voltage and frequency of the energy storage system to synchronize with the mains power, connect the energy storage system to the mains power grid, and control the energy storage converter to switch to PQ mode to achieve grid connection.

[0021] Furthermore, the battery pack, energy storage battery management system, and combiner cabinet are installed in the battery skid-mounted box, and the energy management system, energy storage converter, transformer, and ring main unit are installed in the converter skid-mounted box. The battery skid-mounted box and the converter skid-mounted box are separated by a preset safe distance.

[0022] Furthermore, the energy management system is also used to: in grid-connected mode, send power commands to the energy storage inverter in real time according to the energy storage operation curve, so that the energy storage inverter outputs charging power or discharging power corresponding to the power command.

[0023] Furthermore, the energy management system is also used to monitor the remaining power of the battery pack, and when the remaining power reaches the lower limit, it controls the energy storage system to shut down.

[0024] Furthermore, the battery pack uses lithium iron phosphate batteries.

[0025] Furthermore, the energy management system is also used to receive mode switching commands and control the energy storage system to switch from grid-connected mode to off-grid mode according to the mode switching commands.

[0026] Compared with existing technologies, this invention has the following advantages and beneficial effects: By monitoring the real-time operation data of the mains power grid through an energy management system, and scheduling capacity flow according to the mains power supply status and unplanned power outages, it ensures uninterrupted operation of high-power, continuously operating equipment, thereby improving production efficiency. By monitoring the operating parameters of each part of the energy storage system through the energy management system, and setting these parameters, it manages the charging and discharging of the energy storage system under different operating modes, achieving peak shaving and valley filling, improving battery efficiency and lifespan. By controlling the energy storage converter, it achieves synchronization between the energy storage output and the mains power, completing a smooth switch and ensuring safe and uninterrupted operation of the load. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0028] Figure 1This is a schematic diagram of an uninterruptible power supply system based on energy storage management technology according to an embodiment of the present invention;

[0029] Figure 2 This is a wiring diagram of an energy storage system according to an embodiment of the present invention;

[0030] Figure 3 This is a schematic diagram of the charge and discharge test of the energy storage system of the present invention in grid-connected mode;

[0031] Figure 4 This is a diagram showing the test results of the energy storage system of the present invention switching from grid connection to off-grid operation under unplanned power outage conditions;

[0032] Figure 5 This is a diagram showing the test results of the energy storage system of the present invention switching from grid connection to off-grid connection under planned power outage conditions. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0034] It should be noted that the terms "comprising" and "having" and any variations thereof in the specification, claims, and accompanying drawings of this invention are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to other steps or units inherent in the device.

[0035] The terminology used in the various embodiments of this application is for the purpose of describing particular embodiments only and is not intended to limit the various embodiments of this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which the various embodiments of this application pertain. The terms (such as those defined in a generally used dictionary) are to be interpreted as having the same meaning as in the context of the relevant technical field and are not to be interpreted as having an idealized or overly formal meaning, unless clearly defined in the various embodiments of this application.

[0036] The embodiments of the present invention provide an uninterruptible power supply system based on energy storage management technology, which is suitable for uninterrupted power supply to large-scale continuous power-consuming production equipment such as oil and gas stations, and helps to ensure the uninterrupted and stable operation of production equipment.

[0037] Example 1

[0038] like Figure 1 As shown, Figure 1 This is a schematic diagram of an uninterruptible power supply system based on energy storage management technology according to an embodiment of the present invention, including an energy storage system and an energy management system (EMS);

[0039] Energy storage systems are used to power loads;

[0040] The energy management system is used to monitor the mains power grid parameters and control the energy storage system to operate in grid-connected or off-grid mode based on the mains power grid parameters. The mains power grid parameters include phase, voltage and frequency.

[0041] In grid-connected mode, the energy storage system operates according to predetermined operating conditions, which include, but are not limited to, one or more of charging, discharging, and shutdown.

[0042] In off-grid mode, the energy storage system supplies power to the load.

[0043] After the energy storage system is connected to the prefabricated substation incoming line cabinet that is matched with high-power continuous electrical equipment, the energy management system collects voltage, current and switch status, controls the energy storage system to switch between grid-connected and off-grid working modes, so that the energy storage battery can charge and discharge according to the actual situation, ensuring the uninterrupted operation of high-power electrical equipment, and thus ensuring the production efficiency of oil and gas fields.

[0044] In this embodiment, the energy storage system includes a battery bank, a battery management system (BMS), a combiner cabinet, a power supply converter (PCS), a transformer, and a ring main unit. The battery bank includes multiple battery clusters, such as... Figure 1 The battery clusters 1 to 8 shown are electrochemical energy storage batteries with power supply and energy storage functions. Based on the application scenario of a 10KV continuous power booster in an oil and gas field, lithium iron phosphate batteries are preferred.

[0045] like Figure 2 The diagram shows the wiring schematic of the energy storage system. The output current of each battery cluster is collected by the combiner cabinet and then sequentially input to the ring main unit via the energy storage converter (PCS) and transformer. The transformer steps up the output voltage of the PCS before outputting it. For example, if the output voltage of the PCS is 690V, it is converted to 10kV by the step-up transformer. The ring main unit is connected to the box-type transformer, which connects the output of the energy storage system to the combiner busbar, enabling it to be connected to the same power grid as high-power continuous electrical equipment.

[0046] The Battery Management System (BMS) connects to each battery cluster to monitor its operating parameters, manage charge and discharge, actively equalize voltage, and isolate faulty battery clusters. Operating parameters include voltage, current, remaining capacity, and number of charge / discharge cycles. Each battery cluster can be equipped with its own BMS for one-to-one monitoring and management, and the BMS can set the charging and discharging parameters for each cluster.

[0047] The Energy Management System (EMS) is connected to the Battery Management System (BMS) and the Converter System (PCS) to monitor the operating data of the Battery Management System and the Converter System, and to set the operating parameters of the Battery Management System and the Converter System.

[0048] Furthermore, energy storage systems also include fire suppression systems, intelligent air-cooled air conditioners, etc. The energy management system monitors the operational data of each component of the energy storage system; receives control commands from higher levels; and schedules energy flow. In addition, the energy management system should also perform online forecasting of battery characteristics, stored energy, and load trends.

[0049] The energy storage converter (PCS) switches between grid-connected and off-grid operating modes to control the charging and discharging process of the energy storage system, performing AC-DC conversion and directly supplying power to AC loads in the absence of a power grid. Specifically, the energy storage system has multiple operating modes, including:

[0050] (1) When there is mains power, the energy storage system operates according to the established strategy.

[0051] When there is mains power, the energy storage system operates in grid-connected mode according to a predetermined strategy, including but not limited to: peak shaving and valley filling, regular battery maintenance, and other operating modes.

[0052] (2) When the mains power is interrupted unplanned, the energy storage system switches from grid-connected to off-grid operation.

[0053] In grid-connected mode, if the mains power suddenly fails, the energy management system detects the power failure and controls the energy storage system to disconnect from the mains power grid (disconnect the mains power switch). The energy storage converter PCS is switched to VF mode via 485 / goose control to drive the load to run without power until full power output is achieved, thus realizing off-grid operation.

[0054] (3) When the mains power is restored, the energy storage system switches from off-grid to grid-connected operation mode.

[0055] In off-grid mode, when the energy management system detects the restoration of mains power (the voltage signal of the grid is detected again), it obtains the grid phase, voltage, and frequency parameters at this time through mains power monitoring. By adjusting the energy storage converter PCS to synchronize with the grid through 485 / goose, the output phase, voltage, and frequency of the energy storage system are synchronized with the mains power. After synchronization, the energy storage system is connected to the mains grid (the grid mains switch is closed), and the energy storage converter PCS is controlled to switch to PQ mode to achieve grid connection.

[0056] In grid-connected mode, the energy management system is also used to send power commands to the energy storage inverter in real time according to the energy storage operation curve, so that the energy storage inverter outputs charging power or discharging power corresponding to the power command.

[0057] Furthermore, the energy management system is also used to monitor the remaining power of the battery pack. When the remaining power reaches the lower limit, it controls the energy storage system to shut down to prevent the battery from being discharged and to extend the service life of the battery pack.

[0058] Furthermore, the energy management system is also used to receive mode switching commands and control the energy storage system to switch from grid-connected mode to off-grid mode according to the mode switching commands. It is also used to complete the off-grid mode switch of the energy storage system via manual commands in the event of a planned power outage.

[0059] Example 2

[0060] This invention simulates the on-site working conditions of an oil and gas station and verifies the grid-connected / off-grid switching mode of the energy storage system. The mains power is switched to the energy storage system, and the energy storage system is boosted and connected to the electrical system at the AC 690V terminal. In mode (2), taking a 10kV switch as an example, since the opening and closing time of the 10kV switch is relatively long, the 10kV transformer is re-excited, so the energy storage converter PCS needs to be controlled to achieve 0V soft start. The entire grid-connected / off-grid switching time takes about 1 to 2 minutes, including: SPA grid status detection and switch action time (1S) + energy storage converter PCS grid-connected / off-grid switching time (100ms) + energy storage PCS soft start time (60s). In mode (3), the entire grid-connected / off-grid switching time takes about 1 to 2 minutes, including: SPA grid status detection time (200ms) + energy storage synchronization time (60s) + switch action and detection time (1S) + energy storage converter PCS grid-connected / off-grid switching time (100ms).

[0061] The simulation results are summarized as follows: Under the conditions of the original power grid and electrical system, soft starting, combined with the 10kV circuit breaker, soft starting, and communication delay time, the booster compressor motor startup time includes the SPA power grid status detection time (200ms) + switch action and detection time (1s) + energy storage PCS grid-connection / off-grid switching time (100ms). With optimized electrical system, the energy-saving switch action and detection time (1s) can be reduced, and the booster compressor motor startup time still includes the SPA power grid status detection time (200ms) + energy storage PCS grid-connection / off-grid switching time (100ms). Due to the influence of communication protocols and line distances on the station control layer, equipment layer, and bay layer, there will be certain delays. In conclusion, in the simulation experiment, when the mains power fails, the power supply can be switched from mains power to energy storage system within 200ms, ensuring the booster compressor can operate without stopping.

[0062] Example 3

[0063] This embodiment verifies the grid-connected charging and discharging functions and performance of the energy storage system by applying it to an oil and gas station.

[0064] Based on Example 1, this example of the energy storage system adopts a separate design for the energy storage battery skid-mounted box and the energy storage booster skid-mounted box. The battery pack, energy storage battery management system, and combiner cabinet are installed in the battery skid-mounted box, while the energy management system, energy storage converter, transformer, and ring main unit are installed in the converter skid-mounted box. The battery skid-mounted box and the converter skid-mounted box are separated by a preset safe distance.

[0065] (1) Selection of test equipment

[0066] One 500kW booster compressor is selected. For this 500kW booster compressor, the energy storage system consists of two skid-mounted units, primarily one battery skid-mounted unit and one converter skid-mounted unit. The energy storage system is required to meet the operating needs of the 500kW booster compressor and achieve an output capacity of 2MWh, meaning it must be able to operate continuously at full power for 4 hours. The minimum configuration requirement for the energy storage system is 500kW / 2.65MWh, with an actual output capacity of 2MWh.

[0067] For the energy storage booster skid-mounted enclosure of the energy storage system, its output power should take into account the booster capacity, the capacity of the booster auxiliary equipment, and the booster hot-start overcurrent problem during grid switching. Based on the survey, the energy storage booster skid is designed with the grid switching hot-start current at twice the rated current and a 200ms power supply interval considered during grid switching; the battery capacity of the energy storage system is considered to provide power for 4 hours at the booster's rated power, with a battery charge / discharge depth of 90% and a charge / discharge efficiency of 90%. One energy storage system is selected for on-site configuration, mainly including a 2637kWh energy storage battery compartment and a 1600kVA booster transformer compartment. The energy storage battery compartment houses the battery bank and the energy storage battery management system, while the booster transformer compartment houses the energy storage inverter PCS, the energy management system EMS, and the transformer system.

[0068] Regarding the test site requirements, a 500kW booster compressor was used for the technical verification experiment, with the corresponding settings as follows:

[0069] (A) The battery skid-mounted box for the energy storage system is 8800mm long, 3200mm wide, and 2900mm high. Door opening positions and personnel access passages need to be reserved at both ends. Quantity: 1 unit.

[0070] (B) The energy storage system converter skid is 5500mm long × 3200mm wide × 3000mm high. Door opening positions and personnel access passages need to be reserved at both ends. Quantity: 1 unit.

[0071] (C) Safety distance between battery skid-mounted boxes and converter skid-mounted boxes: 12m;

[0072] (D) The total weight of the battery skid-mounted box is approximately 26 tons, and the total weight of the converter skid-mounted box is approximately 5 tons. It is necessary to ensure that the placement location has sufficient load-bearing capacity.

[0073] Regarding the mains power requirements, for the 500kW booster energy storage system, one AC 10kV / 100A mains power supply is provided for energy storage charging and discharging.

[0074] Requirements for the distribution cabinet: The energy storage system should be equipped with a 10kV distribution cabinet and a step-up transformer; the test site should be equipped with a 10kV outgoing switch cabinet, and the energy storage system should be connected to the outgoing switch cabinet.

[0075] (2) Test plan and test

[0076] Energy storage tests can verify the technical feasibility and reliability of energy storage systems, including the performance of energy storage devices, the stability of control systems, and energy conversion efficiency. Through testing, technical bottlenecks and improvement directions of energy storage systems can be identified, providing technical support and assurance for practical applications. The main points demonstrated in this experiment are as follows:

[0077] A. Verification of the charging and discharging functions and performance of the energy storage system during grid-connected operation;

[0078] B. Verification test of planned power outage and off-grid operation of energy storage system;

[0079] C. Verification test of off-grid operation technology for unplanned power outages of energy storage systems;

[0080] D. Verification test of off-grid to grid-connected energy storage system technology.

[0081] (3) On-site implementation plan

[0082] During the test, the energy storage system output 690V AC and was connected to a box-type transformer. The box-type transformer output 10kV AC and was connected to a 10kV busbar. The system was connected to the same power grid as the booster. The wiring of the energy storage system was as follows: Figure 2 When the power grid is normal, the energy storage system operates in parallel with the grid. The energy storage system can operate under charging, discharging, and shutdown conditions. During charging, it can automatically adjust the charging power in real time according to the total capacity of the line transformer to achieve dynamic charging and prevent charging overload. During discharging, it can automatically adjust the discharging power in real time according to the current signal at the line input end to prevent line reverse current.

[0083] (4) Verification results

[0084] Under grid-connected conditions, the energy storage operation curve is arranged according to the peak, flat, and valley electricity price periods within a 24-hour period, and real-time power commands are sent to the energy storage inverter through the energy management system (EMS). During the test, the energy storage system was able to output matching charging or discharging power in real time according to the command curve, charging during valley electricity price periods and discharging during peak electricity price periods, realizing the "valley charging and peak discharging" function. See the verification results below. Figure 4 As shown, Figure 4 The diagram shows the charge and discharge capacity of the energy storage system in grid-connected mode. The conclusions are as follows:

[0085] Charging power and duration: From 11 PM to 7 AM, the charging power is set to 350kW;

[0086] Discharge power and duration: From 10:00 to 12:00, the discharge power is 200kW; from 15:00 to 17:00, the discharge power is 300kW; from 17:00 to 19:00, the discharge power is 200kW; and from 19:00 to 21:00, the discharge power is 300kW.

[0087] Energy storage system charge / discharge conversion efficiency: greater than 92% (energy storage unit charge / discharge energy conversion efficiency = ratio of total discharge amount of energy storage unit to total charge amount during the evaluation period).

[0088] Example 4

[0089] Based on Example 3, this embodiment conducts on-site verification of the off-grid operation technology of the energy storage system under both unplanned and planned power outages.

[0090] (1) Unplanned power outages and disconnection from the grid

[0091] When the power grid experiences unplanned outages due to factors such as lightning strikes or line faults, the energy storage system can detect abnormal grid voltage and frequency, quickly disconnect from the grid, and switch to off-grid operation mode. Within 200ms, the energy storage system will re-establish stable off-grid voltage and frequency, restoring power to the booster compressor and ensuring its normal operation. While operating in off-grid mode, when the energy storage battery reaches the set minimum remaining charge level, the energy management system can shut down the system to prevent the battery from being completely discharged.

[0092] During the test, by manually disconnecting the grid connection to simulate an unplanned power outage, the energy storage system automatically detected voltage fluctuations and switched to off-grid operation. It re-established the off-grid voltage and frequency within 150ms, ensuring continuous operation of the booster compressor under both no-load and load conditions. Figure 5 The figure shown is a test result of the grid-connected to off-grid system under unplanned power outage conditions.

[0093] (2) Planned power outages and disconnection from the grid

[0094] When the power grid experiences a planned outage due to equipment maintenance, line renovation, or summer power rationing, the connection to the grid can be manually disconnected. The energy storage system automatically detects the grid outage and switches to off-grid mode. The energy storage system can re-establish a stable off-grid voltage and frequency within 200ms, restoring power to the booster compressor. In field tests, the grid-to-off-grid switching time during a planned outage was 64ms. Figure 5 The figure shown is a test result of the grid-connected to off-grid operation of the energy storage system under planned power outage conditions.

[0095] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An uninterruptible power supply system based on energy storage management technology, characterized in that, include: Energy storage systems are used to supply power to loads; An energy management system is used to monitor mains grid parameters and control the energy storage system to operate in grid-connected or off-grid mode based on the mains grid parameters, wherein the mains grid parameters include phase, voltage and frequency; In grid-connected mode, the energy storage system operates according to predetermined operating conditions, which include charging, discharging, or shutdown. In off-grid mode, the energy storage system supplies power to the load.

2. The uninterruptible power supply system based on energy storage management technology according to claim 1, characterized in that, The energy storage system includes a battery pack, an energy storage battery management system, a combiner cabinet, an energy storage converter, a transformer, and a ring main unit; The battery pack includes multiple battery clusters. The output current of each battery cluster is collected by the combiner cabinet and then sequentially input to the ring main unit via the energy storage converter and the transformer. The ring main unit is connected to the box-type transformer, and the output of the energy storage system is connected to the busbar through the box-type transformer to achieve grid connection with the mains power grid; The energy storage battery management system is connected to each of the battery clusters and is used to monitor the operating parameters of the battery clusters, manage the charging and discharging of the battery clusters, actively equalize voltage, and isolate faulty battery clusters.

3. The uninterruptible power supply system based on energy storage management technology according to claim 2, characterized in that, The energy management system is connected to the energy storage battery management system and the energy storage converter, and is used to monitor the operating data of the energy storage battery management system and the energy storage converter, as well as to set the operating parameters of the energy storage battery management system and the energy storage converter.

4. The uninterruptible power supply system based on energy storage management technology according to claim 2, characterized in that, The energy management system is also used to: in grid-connected mode, when a mains power failure is detected, control the energy storage system to disconnect from the mains power grid, and control the energy storage converter to switch to VF mode to achieve off-grid operation.

5. The uninterruptible power supply system based on energy storage management technology according to claim 2, characterized in that, The energy management system is also used to: in off-grid mode, when the mains power is detected to be restored, adjust the output phase, voltage and frequency of the energy storage system to synchronize with the mains power, connect the energy storage system to the mains power grid, and control the energy storage converter to switch to PQ mode to achieve grid connection.

6. The uninterruptible power supply system based on energy storage management technology according to claim 2, characterized in that, The battery pack, energy storage battery management system, and combiner cabinet are installed in the battery skid-mounted box, and the energy management system, energy storage converter, transformer, and ring main unit are installed in the converter skid-mounted box. The battery skid-mounted box and the converter skid-mounted box are separated by a preset safe distance.

7. The uninterruptible power supply system based on energy storage management technology according to claim 2, characterized in that, The energy management system is also used to: in grid-connected mode, send power commands to the energy storage inverter in real time according to the energy storage operation curve, so that the energy storage inverter outputs charging power or discharging power corresponding to the power command.

8. The uninterruptible power supply system based on energy storage management technology according to claim 2, characterized in that, The energy management system is also used to monitor the remaining power of the battery pack, and when the remaining power reaches the lower limit, it controls the energy storage system to shut down.

9. The uninterruptible power supply system based on energy storage management technology according to claim 2, characterized in that, The battery pack uses lithium iron phosphate batteries.

10. The uninterruptible power supply system based on energy storage management technology according to claim 1, characterized in that, The energy management system is also used to receive mode switching instructions and control the energy storage system to switch from grid-connected mode to off-grid mode according to the mode switching instructions.

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