Control method of intelligent immersed energy storage system

Abstract

The invention relates to the field of energy storage batteries, in particular to a control method of an intelligent immersed energy storage system, which comprises the following steps of: S1, judging whether each battery pack of the energy storage system is abnormal or not, and if the battery packs are abnormal, running a step S2; s2, closing an abnormal battery pack liquid inlet valve, closing a normal battery pack liquid outlet valve, opening a branch water pump, closing a main loop water pump, pumping out normal battery pack immersion liquid, and injecting the normal battery pack immersion liquid into the abnormal battery pack; s3, closing the water pump and all valves when the pressure of the water pump reaches a preset value; abnormality treatment is carried out in a mode of reversely and circularly extracting the immersion liquid and injecting the immersion liquid into the abnormal battery pack, additional fire control measures are not needed, an additional liquid storage tank for storing the immersion liquid is also not needed, the demand quantity of the immersion liquid is greatly reduced, the cost is reduced, meanwhile, the immersion liquid does not damage a battery cell of the battery pack, and after the abnormality treatment or false alarm, the battery pack is prevented from being damaged by the immersion liquid. The battery pack can be reused, and scrapping caused by direct damage to the battery core of the battery pack is avoided.

Description

Technical Field

[0001] The present invention relates to the field of energy storage batteries, and in particular to a control method for an intelligent immersed energy storage system. Background Art

[0002] The battery pack is the basic component unit of electrochemical energy storage. Each battery pack contains multiple single cells. In order to increase the storage capacity, large-scale energy storage systems have multiple battery packs placed in parallel. On this basis, the intelligent immersion energy storage system uses liquid cooling technology to completely or partially immerse the battery cells in an insulating, non-toxic, heat-dissipating liquid. This liquid can effectively absorb the heat generated by the battery during the charging and discharging process, and bring it to the external circulation for cooling, thereby ensuring that the battery operates within the optimal temperature range. By lowering the operating temperature of the battery, the performance and life of the battery can be improved, but the battery pack will inevitably generate a lot of heat during charging and discharging. When the battery cell has thermal runaway, the violent reaction can easily cause a fire. Therefore, many intelligent energy storage systems currently have to add fire-fighting measures. The existing fire-fighting methods are mostly to add a new fire-fighting system to cool the battery cell when it is abnormal. This method not only increases the cost, but is also usually irreversible. Once triggered, it is easy to make the battery cell scrapped. Summary of the invention

[0003] In order to overcome the deficiencies of the prior art, one of the objectives of the present invention is to provide a control method for an intelligent submerged energy storage system to solve the problem that the fire-fighting method of the existing energy storage system is costly and irreversible, and easily causes the battery cells to be scrapped.

[0004] To achieve the above-mentioned purpose, the present invention provides a control method for an intelligent immersion energy storage system, which is applied to the intelligent immersion energy storage system. The intelligent immersion energy storage system adopts a dynamic semi-immersion combined with a static full immersion mode; the control method for the intelligent immersion energy storage system comprises: S1: judging whether each battery pack of the energy storage system is abnormal, if the battery pack is abnormal, running step S2; S2: closing the liquid inlet valve of the abnormal battery pack, closing the liquid outlet valve of the normal battery pack, opening the branch water pump, closing the main circuit water pump, pumping out the immersion liquid of the normal battery pack and injecting it into the abnormal battery pack; S3: when the water pump pressure reaches a predetermined value, turning off the water pump and closing all valves.

[0005] As a preferred embodiment of the present invention, after step S3, the method further includes the following steps: S4: continuously monitor the abnormal battery pack and determine whether it has returned to normal; S5: when the battery pack returns to normal, open all valves, close the branch water pump, and start the main circuit water pump to recirculate the immersion liquid and put the battery pack in a dynamic semi-immersion state.

[0006] As a preferred embodiment of the present invention, in step S1, if the battery pack is normal, step S6 is executed: S6: Determine whether the energy storage system is in a charging and discharging state. If the energy storage system is in a charging and discharging state, execute S7; S7: Open all valves, turn on the liquid cooling unit refrigeration and the main circuit water pump to allow the immersion liquid to circulate.

[0007] As a preferred implementation of the present invention, in step S6, if the energy storage system is not in a charging or discharging state, step S8 is executed: S8: close all valves.

[0008] As a preferred embodiment of the present invention, in step S1, the determination of whether each battery pack of the energy storage system is abnormal is specifically: determining whether the battery cell temperature is greater than 55°C and whether the temperature rise rate is greater than 1°C / s.

[0009] As a preferred embodiment of the present invention, multiple abnormal modes are also included, and the abnormal modes include a high temperature warning mode, a thermal runaway suppression mode and a liquid leakage protection mode.

[0010] As a preferred embodiment of the present invention, the specific operation of the high temperature warning mode is: when it is detected that the battery cell temperature is too high, the liquid inlet valve of the abnormal battery pack is closed, the liquid outlet valves of all normal battery packs are closed, the main circuit water pump is closed, and the branch water pump is operated to extract the immersion liquid in the normal battery pack from the liquid inlet pipeline and reversely inject it into the abnormal battery pack, thereby increasing the immersion liquid in the abnormal battery pack until the temperature of the battery pack returns to normal levels.

[0011] As a preferred embodiment of the present invention, the specific operation of the thermal runaway suppression mode is: when thermal runaway of a battery cell is detected, the liquid inlet valve of the abnormal battery pack is closed, the liquid outlet valves of all normal battery packs are closed, the main circuit water pump is closed, the branch water pump is operated, and the immersion liquid of other battery packs is injected into the abnormal battery pack until the battery pack is filled with the immersion liquid, thereby suppressing thermal runaway of the battery cell.

[0012] As a preferred embodiment of the present invention, the specific operation of the leakage protection mode is: when leakage of battery cell electrolyte is detected, the liquid inlet valve of the abnormal battery pack is closed, the liquid outlet valves of all normal battery packs are closed, the main circuit water pump is closed, and the branch water pump is operated to inject the immersion liquid of other battery packs into the abnormal battery pack until the battery pack is filled with immersion liquid. Filling with immersion liquid can prevent the leaking battery cell from short circuiting and catching fire.

[0013] Principle of the technical solution: The intelligent immersion energy storage system adopts a dynamic semi-immersion combined with a static full immersion method. During normal charging and discharging, the main circuit water pump is used to circulate the immersion liquid and put multiple battery packs in a dynamic semi-immersion state.

[0014] In step S1 of the present invention, the parameters of each battery pack of the energy storage system are monitored in real time, and compared with preset parameters to determine whether they are normal. If the battery pack is abnormal, step S2 is executed.

[0015] In step S2 of the present invention, the liquid inlet valve of the abnormal battery pack is closed, the liquid outlet valve of the normal battery pack is closed, the branch water pump is opened, the main circuit water pump is closed, and the immersion liquid is reversely circulated, extracted from other normal battery packs and injected into the abnormal battery pack, and the amount of immersion liquid in the abnormal battery pack is increased to improve the cooling effect and handle abnormal situations. The present solution reversely extracts immersion liquid from other battery packs without the need for additional fire-fighting measures, thus greatly saving costs. There is no need to additionally set up a liquid storage tank to store immersion liquid or fire-fighting liquid, and a semi-immersion method is adopted to greatly reduce the demand for immersion liquid, further saving costs, and handling abnormalities of up to half of the battery packs. At the same time, handling the abnormality by filling the battery pack with immersion liquid will not damage the battery pack cells. After the abnormality is handled or in case of a false alarm, the battery pack cells can be restored for reuse, thus avoiding direct damage to the battery pack cells and causing them to be scrapped.

[0016] Step S3 of the present invention monitors the pressure value at the outlet of the water pump in real time. When the abnormal battery pack is filled, the pressure at the outlet of the water pump rises. When it reaches a predetermined value, the water pump is turned off, and then all valves are closed. At this time, the abnormal battery pack is filled with immersion liquid, and the immersion liquid is used to cool the abnormal battery pack, extinguish fire, and inhibit thermal runaway. Closing all valves can prevent leakage from contaminating other battery packs and prevent thermal runaway from spreading to other battery packs.

[0017] In step S4 of the present invention, various parameters of the abnormal battery pack are continuously monitored and compared with preset values ​​to determine whether the battery pack returns to normal after the immersion liquid is injected.

[0018] In step S5 of the present invention, when the parameters of the battery pack return to normal, all valves are opened, the branch water pump is closed, and the main circuit water pump is turned on to allow the immersion liquid to recirculate and put the battery pack in a dynamic semi-immersion state.

[0019] In step S1 of the present invention, if the battery pack is normal, step S6 is executed.

[0020] In step S6 of the present invention, it is determined whether the energy storage system is in a charging and discharging state, that is, whether it is in a normal use state. If the energy storage system is in a charging and discharging state, S7 is executed.

[0021] In step S7 of the present invention, all valves are opened, the liquid cooling unit and the main circuit water pump are turned on, and the immersion liquid is circulated. At this time, the battery pack is in a dynamic semi-immersion state, and the heat during charging and discharging is taken away by the circulation of the immersion liquid to achieve the effect of controlling the temperature.

[0022] In step S6 of the present invention, if the energy storage system is not in a charging or discharging state, step S8 is executed.

[0023] In step S8 of the present invention, when the energy storage system is not in a charging or discharging state, that is, in an unused state, all valves are closed to put the entire system in a shutdown state.

[0024] Compared with the prior art, the beneficial effects of the present invention are: 1. Abnormality handling is performed by extracting immersion liquid through reverse circulation and injecting it into abnormal battery packs, without the need for additional fire-fighting measures, thereby reducing costs.

[0025] 2. By extracting the immersion liquid from the normal battery pack and injecting it into the abnormal battery pack, there is no need to reserve additional immersion liquid, nor is there a tank for storing the reserved immersion liquid, so the demand for immersion liquid is greatly reduced. At the same time, since the immersion liquid has the effects of cooling, fire extinguishing, and insulation, reducing the demand for immersion liquid will also further reduce costs.

[0026] 3. Under normal circumstances, the energy storage system is in dynamic semi-immersion. This solution extracts the immersion fluid of the normal battery pack and injects it into the abnormal battery pack. It can fill half of the battery pack and handle the abnormalities of multiple battery packs. Compared with semi-immersion and additionally setting up a liquid storage tank to store excess immersion fluid, when the battery pack is abnormal, the immersion fluid in the liquid storage tank is injected into the abnormal battery pack. The immersion fluid demand is less, especially when there are a large number of battery packs in the energy storage system, such as when used in energy storage containers. This solution saves more immersion fluid and has a more obvious cost advantage.

[0027] 4. Compared with the traditional way of setting fire-fighting measures, this solution handles the abnormality by filling the battery with immersion liquid, which will not damage the battery pack cells. After the abnormality is handled or in case of false alarm, it can be restored and used again, avoiding direct damage to the battery pack cells and causing them to be scrapped. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below.

[0029] Figure 1 It is a structural schematic diagram of an embodiment of an intelligent submerged energy storage system of the present invention.

[0030] Figure 2 This is a schematic diagram of the operation of the main circuit water pump and the branch circuit water pump of an intelligent submerged energy storage system embodiment of the present invention.

[0031] Figure 3 A logic schematic diagram of an embodiment of a control method for an intelligent submerged energy storage system of the present invention.

[0032] Figure 4 A schematic diagram of an abnormal mode of an embodiment of a control method for an intelligent submerged energy storage system of the present invention.

[0033] The figure marks in the drawings of the specification include: 1 energy storage device, 2 battery pack, 3 liquid cooling unit, 4 liquid inlet pipeline, 5 liquid inlet branch pipe, 6 liquid outlet pipeline, 7 liquid outlet branch pipe, 8 liquid inlet valve, 9 liquid outlet valve, 10 main circuit water pump, 11 branch water pump. DETAILED DESCRIPTION

[0034] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the embodiments of the present invention, and should not be construed as limiting the present invention.

[0035] In the description of the embodiments of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0036] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0037] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0038] As attached Figure 1 As shown, the present invention provides a control method for an intelligent immersion energy storage system: applied to an intelligent immersion energy storage system, the intelligent immersion energy storage system includes an energy storage device 1, and the energy storage device 1 can be in the form of an energy storage cabinet, an energy storage container, etc., and the energy storage cabinet is used in the drawings of this embodiment; a plurality of battery packs 2 are arranged in the energy storage device 1, and a plurality of battery cells are arranged in the battery pack 2 for charging, discharging and storing energy; the battery pack 2 adopts a dynamic semi-immersion combined with static full immersion method of an immersion liquid, and a fluorinated liquid can be selected.

[0039] As attached Figure 1 and attached Figure 2As shown, in this embodiment, an immersion liquid circulation subsystem is provided at the lower part of the energy storage device 1, which is used to control the circulation of the immersion liquid, and when the battery pack 2 is abnormal, the immersion liquid in other battery packs 2 can be reversely circulated and injected into the abnormal battery pack 2; wherein the immersion liquid circulation subsystem includes a liquid cooling unit 3, and the liquid cooling unit 3 is connected with a liquid inlet pipeline 4 and a liquid outlet pipeline 6, the liquid inlet pipeline 4 is connected with the lower part of the front of the plurality of battery packs 2 through a plurality of liquid inlet branches 5, and the liquid outlet pipeline 6 is connected with the upper part of the front of the plurality of battery packs 2 through a plurality of liquid outlet branches 7, the liquid inlet branch 5 is provided with a liquid inlet valve 8, and the liquid outlet branch 7 is provided with a liquid outlet valve 9, the liquid inlet pipeline 4 and the liquid outlet pipeline 6 are connected with a main circuit water pump 10 and a branch water pump 11; the The main circuit water pump 10, the branch water pump 11, the liquid inlet pipeline 4 and the liquid outlet pipeline 6 are all connected; when the battery pack 2 is charging and discharging and operating normally, the liquid inlet valve 8 and the liquid outlet valve 9 are both opened, and the main circuit water pump 10 is running to allow the immersion liquid to circulate forward in the liquid inlet pipeline 4, multiple battery packs 2 and the liquid outlet pipeline 6, and the battery cells are always in a semi-immersed state; the branch water pump 11 is used to allow the immersion liquid to circulate reversely in the liquid inlet pipeline 4, multiple battery packs 2 and the liquid outlet pipeline 6; two opposite circulation loops are formed by the main circuit water pump 10 and the branch water pump 11, and by adjusting the liquid inlet valve 8 and the liquid outlet valve 9, the immersion liquid in other normal battery packs 2 is reversely circulated and injected into the abnormal battery pack 2.

[0040] In addition, in the present embodiment, when a single battery pack 2 has a high temperature or thermal runaway, only the immersion liquid with the lowest temperature in the normal battery pack 2 can be extracted and reversely circulated and injected into the abnormal battery pack 2. The specific operation is: when a single battery pack 2 has a high temperature or thermal runaway, the liquid inlet valves 8 of all battery packs 2 and the liquid outlet valves 9 of the normal battery pack 2 are closed, and then the temperature of each battery pack 2 is detected by the temperature sensor. The battery management subsystem determines the serial number of the battery pack 2 with the lowest immersion liquid temperature, opens the liquid inlet valve 8 corresponding to the battery pack 2, and allows the low-temperature immersion liquid in the battery pack 2 to flow out through the liquid inlet valve 8, and then switches the liquid cooling unit 3 to the branch water pump 11 to pump the low-temperature immersion liquid into the abnormal battery pack 2; the immersion liquid with the lowest temperature and the immersion liquid with the highest temperature are mixed to improve the cooling efficiency in the abnormal battery pack 2; when multiple battery packs 2 have a high temperature or thermal runaway, the immersion liquid of a corresponding number of normal battery packs 2 can be extracted, and the normal battery packs 2 with lower immersion liquid temperature are preferentially extracted.

[0041] The control method of the intelligent immersion energy storage system includes: S1: real-time monitoring of the parameters of each battery pack of the energy storage system, and comparing with the preset parameters to determine whether each battery pack of the energy storage system is abnormal. If the battery pack is abnormal, run step S2; the specific abnormality judgment standard is: determine whether the battery cell temperature is greater than 55°C and whether the temperature rise rate is greater than 1°C / s.

[0042] S2: Close the liquid inlet valve of the abnormal battery pack, close the liquid outlet valve of the normal battery pack, start the branch water pump, close the main circuit water pump, let the immersion liquid circulate in reverse, extract it from other normal battery packs and inject it into the abnormal battery pack, and increase the amount of immersion liquid in the abnormal battery pack to improve the cooling effect and handle the abnormal situation.

[0043] In addition, when only one battery pack is abnormal, step S2 is preferably: close the liquid inlet valve of the abnormal battery pack, compare the immersion liquid temperature of normal battery packs, close the liquid outlet valve of the normal battery pack with the lowest immersion liquid temperature, close the liquid inlet valves and liquid outlet valves of other normal battery packs, run the liquid cooling unit branch water pump, suck the immersion liquid in the normal battery pack with the lowest immersion liquid temperature out of the liquid inlet pipeline, and reversely inject it into the abnormal battery pack; by extracting the immersion liquid of the battery pack with the lowest temperature and injecting it into the abnormal battery pack, the cooling efficiency of the abnormal battery pack can be improved compared to extracting the immersion liquid of multiple normal battery packs and then mixing them and injecting them into the abnormal battery pack.

[0044] S3: Real-time monitoring of the pressure value at the outlet of the water pump. When the abnormal battery pack is filled, the pressure at the outlet of the water pump rises. When it reaches the preset value, the water pump is turned off, and then all valves are closed. At this time, the abnormal battery pack is filled with immersion liquid, and the immersion liquid can be used to cool the abnormal battery pack, extinguish fire, and inhibit thermal runaway. Closing all valves can prevent leakage from contaminating other battery packs and prevent thermal runaway from spreading to other battery packs.

[0045] S4: Continuously monitor various parameters of the abnormal battery pack and compare them with preset values ​​to determine whether they return to normal after injecting immersion liquid.

[0046] S5: When the parameters of the battery pack return to normal, open all valves, close the branch water pump, and start the main circuit water pump to allow the immersion liquid to recirculate and put the battery pack in a dynamic semi-immersion state; when the parameters of the battery pack do not return to normal, an alarm can be issued and the abnormal battery pack serial number can be uploaded for staff to handle.

[0047] In step S1 of the present invention, if the battery pack is normal, step S6 is executed. S6: determine whether the energy storage system is in a charging and discharging state, that is, whether it is in a normal use state. If the energy storage system is in a charging and discharging state, step S7 is executed.

[0048] S7: Open all valves, turn on the liquid cooling unit refrigeration and main circuit water pump to circulate the immersion liquid. At this time, the battery pack is in a dynamic semi-immersion state. The heat during charging and discharging is removed through the circulation of the immersion liquid to achieve the effect of controlling the temperature.

[0049] In step S6 of the present invention, if the energy storage system is not in a charging or discharging state, step S8 is executed. S8: When the energy storage system is not in a charging or discharging state, that is, it is in an unused state, all valves are closed to put the entire system in a shutdown state.

[0050] As attached Figure 3 As shown, in this embodiment, the control method of the intelligent submerged energy storage system also includes multiple abnormal modes, and the abnormal modes include a high temperature warning mode, a thermal runaway suppression mode and a liquid leakage protection mode.

[0051] Among them, the high temperature warning mode: when it is detected that the battery cell temperature is too high, the liquid inlet valve of the abnormal battery pack is closed, the liquid outlet valves of all normal battery packs are closed, the main circuit water pump is closed, and the branch water pump is operated. At this time, the normal battery pack discharges the immersion liquid through the liquid inlet, and the immersion liquid in the abnormal battery pack cannot be discharged through the liquid inlet. After the branch water pump is started, the immersion liquid enters the battery pack from the liquid outlet, and at this time, the liquid outlet valve of the normal battery pack is closed, and the pumped immersion liquid only enters the abnormal battery pack, so that the immersion liquid in the normal battery pack is extracted from the liquid inlet pipeline and reversely injected into the abnormal battery pack, thereby increasing the immersion liquid in the abnormal battery pack, increasing the immersion degree, and improving the heat dissipation capacity until the temperature of the battery pack returns to normal levels.

[0052] Among them, the thermal runaway suppression mode: when thermal runaway of the battery cell is detected, the liquid inlet valve of the abnormal battery pack is closed, the liquid outlet valves of all normal battery packs are closed, the main circuit water pump is closed, and the branch water pump is operated. At this time, the normal battery pack discharges the immersion liquid through the liquid inlet, and the immersion liquid in the abnormal battery pack cannot be discharged through the liquid inlet. After the branch water pump is started, the immersion liquid enters the battery pack from the liquid outlet, and at this time the liquid outlet valve of the normal battery pack is closed, and the pumped immersion liquid only enters the abnormal battery pack, so that the immersion liquid in the normal battery pack is extracted from the liquid inlet pipeline and reversely injected into the abnormal battery pack until the abnormal battery pack is completely filled, thereby suppressing the thermal runaway of the battery cell and waiting for further detection.

[0053] Among them, the leakage protection mode: when a leakage of battery cell electrolyte is detected, the inlet valve of the abnormal battery pack is closed, the outlet valves of all normal battery packs are closed, the main circuit water pump is closed, and the branch water pump is operated. At this time, the normal battery pack discharges the immersion liquid through the inlet port, and the immersion liquid in the abnormal battery pack cannot be discharged through the inlet port. After the branch water pump is started, the immersion liquid enters the battery pack from the outlet port, and at this time, the outlet valve of the normal battery pack is closed, and the pumped immersion liquid only enters the abnormal battery pack, so that the immersion liquid in the normal battery pack is extracted from the inlet pipeline and reversely injected into the abnormal battery pack until the abnormal battery pack is completely filled. After filling, the immersion liquid can prevent the leaking battery cell from short-circuiting and catching fire, and the inlet valve of the abnormal battery pack is in a closed state, which can prevent the immersion liquid containing electrolyte from being reversely injected into the normal battery pack.

[0054] In addition, the control method of the intelligent immersion energy storage system also includes an analysis and warning module, which monitors the temperature and heating rate of each battery pack cell in real time, determines whether there is a risk of thermal runaway in the future, calculates the time required for the current temperature to rise to the thermal runaway temperature, and reversely cycles the immersion liquid into the battery pack in advance to achieve a pretreatment effect, reduce the risk of thermal runaway, and improve the safety of the battery pack.

[0055] The preferred implementation modes of the present application are described in detail above in conjunction with the accompanying drawings. Typical known structures and common knowledge technologies in the preferred implementation modes are not described in detail here. Ordinary technicians in the relevant field can improve and implement the technical solutions of the present invention based on their own abilities under the inspiration given by the present implementation modes. Some typical known structures, known methods or common knowledge technologies should not become obstacles for ordinary technicians in the relevant field to implement the present application.

[0056] The scope of protection required by this application shall be based on the contents of its claims, and the contents recorded in the invention content, specific implementation methods and drawings of the specification shall be used to interpret the claims.

[0057] Within the technical concept of the present application, several modifications may be made to the specific implementation methods of the present application, and these modified specific implementation methods should also be regarded as within the protection scope of the present application.

Claims

1. A control method for an intelligent immersion energy storage system, applied to the intelligent immersion energy storage system, wherein the intelligent immersion energy storage system adopts a dynamic semi-immersion combined with a static full immersion mode; characterized in that: The control method of the intelligent submerged energy storage system includes: S1: Determine whether each battery pack of the energy storage system is abnormal. If the battery pack is abnormal, execute step S2; S2: Close the liquid inlet valve of the abnormal battery pack, close the liquid outlet valve of the normal battery pack, start the branch water pump, close the main circuit water pump, extract the immersion liquid of the normal battery pack and inject it into the abnormal battery pack; S3: When the water pump pressure reaches the preset value, the water pump is turned off and all valves are closed.

2. The control method of the intelligent submerged energy storage system according to claim 1, characterized in that: After step S3, the method further comprises the following steps: S4: Continuously monitor the abnormal battery pack and determine whether it has returned to normal; S5: When the battery pack returns to normal, open all valves, turn off the branch water pump, and turn on the main circuit water pump to allow the immersion liquid to recirculate and put the battery pack in a dynamic semi-immersion state.

3. The control method of the intelligent submerged energy storage system according to claim 1, characterized in that: In step S1, if the battery pack is normal, then execute step S6: S6: Determine whether the energy storage system is in a charging and discharging state. If the energy storage system is in a charging and discharging state, execute S7; S7: Open all valves, start the refrigeration of the liquid cooling unit and the main circuit water pump to allow the immersion liquid to circulate.

4. The control method of the intelligent submerged energy storage system according to claim 3, characterized in that: In step S6, if the energy storage system is not in the charging or discharging state, step S8 is executed: S8: Close all valves.

5. The control method of the intelligent submerged energy storage system according to claim 1, characterized in that: In step S1, the determination of whether each battery pack of the energy storage system is abnormal is specifically: determining whether the battery cell temperature is greater than 55°C and whether the temperature rise rate is greater than 1°C / s.

6. The control method of the intelligent submerged energy storage system according to claim 1, characterized in that: It also includes multiple abnormal modes, including a high temperature warning mode, a thermal runaway suppression mode and a liquid leakage protection mode.

7. The control method of the intelligent submerged energy storage system according to claim 6, characterized in that: The specific operation of the high temperature warning mode is: when it is detected that the battery cell temperature is too high, the liquid inlet valve of the abnormal battery pack is closed, the liquid outlet valves of all normal battery packs are closed, the main circuit water pump is closed, and the branch water pump is operated to extract the immersion liquid in the normal battery pack from the liquid inlet pipeline and reversely inject it into the abnormal battery pack to increase the immersion liquid in the abnormal battery pack until the temperature of the battery pack returns to normal levels.

8. The control method of the intelligent submerged energy storage system according to claim 6, characterized in that: The specific operation of the thermal runaway suppression mode is: when thermal runaway of a battery cell is detected, the liquid inlet valve of the abnormal battery pack is closed, the liquid outlet valves of all normal battery packs are closed, the main circuit water pump is closed, the branch water pump is operated, and the immersion liquid of other battery packs is injected into the abnormal battery pack until the battery pack is filled with the immersion liquid, thereby suppressing the thermal runaway of the battery cell.

9. The control method of the intelligent submerged energy storage system according to claim 6, characterized in that: The specific operation of the leakage protection mode is: when a leakage of battery cell electrolyte is detected, the liquid inlet valve of the abnormal battery pack is closed, the liquid outlet valves of all normal battery packs are closed, the main circuit water pump is closed, the branch water pump is operated, and the immersion liquid of other battery packs is injected into the abnormal battery pack until the battery pack is filled with immersion liquid. Filling with immersion liquid can prevent the leaking battery cell from short circuiting and catching fire.

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