A control method of an intelligent submerged energy storage system

Abstract

The present application relates to the field of energy storage battery, and particularly relates to a control method of intelligent immersed energy storage system, comprising the following steps: S1: judging whether each battery pack of the energy storage system is abnormal, if the battery pack is abnormal, then 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 loop water pump, pumping out the immersion liquid of the normal battery pack and injecting into the abnormal battery pack; S3: the water pump pressure reaches a predetermined value, closing the water pump and closing all valves; the present application carries out abnormal treatment through the mode of pumping out the immersion liquid and injecting into the abnormal battery pack in reverse circulation, does not need to additionally set up fire-fighting measures, also does not need to additionally set up the immersion liquid storage tank to store the immersion liquid, greatly reduces the demand of the immersion liquid, reduces the cost, meanwhile, the immersion liquid does not damage the battery pack cell, can be recovered and used again after the abnormal treatment or false alarm, avoids directly damaging the battery pack cell to cause scrapping.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of energy storage batteries, in particular to a control method of an intelligent immersed energy storage system. BACKGROUND

[0002] The battery pack is the basic unit of electrochemical energy storage, and each battery pack contains multiple single cells inside. In order to improve the energy storage capacity, multiple battery packs are placed side by side in a large energy storage system. The intelligent immersed energy storage system uses liquid cooling technology to completely or partially immerse the battery cells in an insulating, non-toxic and heat-dissipating liquid. This liquid can effectively absorb the heat generated by the battery during charging and discharging and take it to the outside for cooling, thereby ensuring that the battery operates within the optimal temperature range. By reducing the operating temperature of the battery, the performance and life of the battery can be improved. However, the battery pack will inevitably generate a large amount of heat during charging and discharging, and when the battery cell experiences thermal runaway, the intense reaction can easily cause a fire. Therefore, many intelligent energy storage systems have added fire protection measures. The existing fire protection methods mainly add a fire protection system to cool the battery cell when it is abnormal. This method not only increases the cost but is also usually irreversible, and once triggered, it can easily cause the battery cell to be scrapped. SUMMARY

[0003] In order to overcome the shortcomings of the prior art, one of the purposes of the present application is to provide a control method of an intelligent immersed energy storage system to solve the problem of high cost and irreversibility of the existing energy storage system fire protection method, which easily causes the battery cell to be scrapped.

[0004] To achieve the above-mentioned purpose, the present application provides a control method of an intelligent immersed energy storage system, which is applied to an intelligent immersed energy storage system. The intelligent immersed energy storage system adopts a dynamic semi-immersed combined with static fully-immersed mode. The control method of the intelligent immersed energy storage system comprises the following steps: S1: judging whether each battery pack of the energy storage system is abnormal, if the battery pack is abnormal, then 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 loop water pump, and 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, closing the water pump and all valves.

[0005] As a preferred embodiment of the present application, after step S3, the method further comprises the following steps: S4: continuously monitoring the abnormal battery pack and judging whether it returns to normal; S5: when the battery pack returns to normal, opening all valves, closing the branch water pump, opening the main loop water pump, and allowing the immersion liquid to recirculate and the battery pack to be in a dynamic semi-immersed state.

[0006] As a preferred embodiment of the present application, in step S1, if the battery pack is normal, step S6 is performed: S6: determine whether the energy storage system is in charging and discharging state, if the energy storage system is in charging and discharging state, S7 is performed; S7: open all valves, start the refrigeration of the liquid cooling unit and the main loop water pump, and circulate the immersion liquid.

[0007] As a preferred embodiment of the present application, in step S6, if the energy storage system is not in charging and discharging state, step S8 is performed: S8: close all valves.

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

[0009] As a preferred embodiment of the present application, it further includes multiple abnormal modes, and the abnormal modes include a high temperature early warning mode, a thermal runaway suppression mode and a liquid leakage protection mode.

[0010] As a preferred embodiment of the present application, the high temperature early warning mode is specifically operated as follows: when it is detected that the temperature of the battery cell is too high, the liquid inlet valve of the abnormal battery pack is closed, the liquid outlet valve of all normal battery packs is closed, the main loop water pump is closed, the branch water pump is operated, the immersion liquid in the normal battery pack is extracted from the liquid inlet pipeline, and the immersion liquid is reversely injected into the abnormal battery pack to increase the immersion liquid in the abnormal battery pack until the temperature of the battery pack returns to the normal level.

[0011] As a preferred embodiment of the present application, the thermal runaway suppression mode is specifically operated as follows: when it is detected that the battery cell has thermal runaway, the liquid inlet valve of the abnormal battery pack is closed, the liquid outlet valve of all normal battery packs is closed, the main loop 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.

[0012] As a preferred embodiment of the present application, the liquid leakage protection mode is specifically operated as follows: when it is detected that the electrolyte of the battery cell leaks, the liquid inlet valve of the abnormal battery pack is closed, the liquid outlet valve of all normal battery packs is closed, the main loop 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, so that the immersion liquid filled can avoid the short circuit and fire of the leaking battery cell.

[0013] The principle of the technical solution is that the intelligent immersion energy storage system adopts a dynamic semi-immersion combined with a static full-immersion mode, the main loop water pump is used to circulate the immersion liquid when normally charging and discharging, and multiple battery packs are in a dynamic semi-immersed state.

[0014] The step S1 of the application monitors the parameters of each battery pack of the energy storage system in real time, and compares them with the preset parameters to determine whether they are normal. If the battery pack is abnormal, the step S2 is run.

[0015] The step S2 of the application closes the liquid inlet valve of the abnormal battery pack, closes the liquid outlet valve of the normal battery pack, starts the branch water pump, and closes the main circuit water pump, so that the immersion liquid is circulated in the reverse direction, is extracted from other normal battery packs, and is injected into the abnormal battery pack. By increasing the amount of immersion liquid in the abnormal battery pack, the cooling effect is improved, and the abnormal condition is handled. The present application reversely extracts the immersion liquid from other battery packs without the need for additional fire-fighting measures, which greatly saves costs. It also does not need to additionally set up a liquid storage tank to store the immersion liquid or fire-fighting liquid, and uses a semi-immersion method to greatly reduce the demand for immersion liquid, further saving costs, and can handle up to half of the battery pack abnormalities. At the same time, the abnormality is handled by filling the immersion liquid, which does not damage the battery pack cell, and can be restored for reuse after abnormal handling or false reporting, avoiding direct damage to the battery pack cell and resulting in scrap.

[0016] The step S3 of the application monitors the outlet pressure value of the water pump in real time. When the abnormal battery pack is filled, the outlet pressure of the water pump rises. When it reaches a predetermined value, the water pump is closed, and then all the valves are closed. At this time, the abnormal battery pack is filled with immersion liquid, which achieves the effects of cooling, fire extinguishing, and heat runaway suppression on the abnormal battery pack. Closing all the valves can avoid liquid leakage and pollution of other battery packs, and prevent heat runaway from spreading to other battery packs.

[0017] The step S4 of the application continuously monitors the parameters of the abnormal battery pack and compares them with the preset values to determine whether the immersion liquid injection has restored normalcy.

[0018] The step S5 of the application opens all the valves, closes the branch water pump, and starts the main circuit water pump when the parameters of the battery pack return to normal, so that the immersion liquid is circulated again and the battery pack is in a dynamic semi-immersed state.

[0019] In the step S1 of the application, if the battery pack is normal, the step S6 is run.

[0020] The step S6 of the application determines whether the energy storage system is in a charging and discharging state, i.e., whether it is in a normal use state. If the energy storage system is in a charging and discharging state, the step S7 is run.

[0021] The step S7 of the application opens all the valves, starts the liquid cooling unit refrigeration and the main circuit water pump, and circulates the immersion liquid. At this time, the battery pack is in a dynamic semi-immersed state, and the immersion liquid circulation removes the heat generated during charging and discharging to achieve the effect of temperature control.

[0022] In the step S6 of the application, if the energy storage system is not in a charging and discharging state, the step S8 is run.

[0023] Step S8 of the present application, when the energy storage system is not in the charging and discharging state, that is, in the unused state, all the valves are closed, and the whole system is in the shutdown state.

[0024] Compared with the prior art, the present application has the beneficial effects that: 1. The abnormality is handled by the way of reverse circulation extraction of immersion liquid injection into the abnormal battery pack, without the need for additional fire-fighting measures, reducing the cost.

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

[0026] 3. Under normal circumstances, the energy storage system is in a dynamic semi-immersion state, and the present application extracts the immersion liquid in the normal battery pack and injects it into the abnormal battery pack, which can fill half of the battery pack and handle multiple battery pack abnormalities. Compared with the semi-immersed state and the additional storage of excess immersion liquid in the liquid tank, the immersion liquid demand is less when the battery pack is abnormal, especially when the number of battery packs in the energy storage system is large, such as when used in energy storage containers. The present application saves more immersion liquid, and the cost advantage is more obvious.

[0027] 4. Compared with the traditional way of setting fire-fighting measures, the present application handles the abnormality by filling the immersion liquid, which does not damage the battery pack cell, and can be recovered for reuse after abnormality handling or false alarm, avoiding direct damage to the battery pack cell leading to scrap. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description.

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

[0030] Figure 2 It is a main loop pump and branch pump operation schematic diagram of an embodiment of the intelligent immersion type energy storage system of the present application.

[0031] Figure 3 It is a logic schematic diagram of an embodiment of the control method of the intelligent immersion type energy storage system of the present application.

[0032] Figure 4 It is an abnormal mode schematic diagram of an embodiment of the control method of the intelligent immersion type energy storage system of the present application.

[0033] The reference signs 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 application will be described in detail below with reference to drawings, examples of which are shown in the drawings, wherein the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the drawings are exemplary and are intended to explain the embodiments of the present application, and cannot be understood as a limitation of the present application.

[0035] In the description of the embodiments of the present application, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the embodiments of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0036] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, the meaning of "multiple" is two or more, unless otherwise explicitly specified.

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

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

[0039] As shown in the drawings Figure 1 and the drawings Figure 2As shown, in the embodiment, the lower part of the energy storage device 1 is provided with a sub-system for circulating the immersion liquid, which is used to control the circulation of the immersion liquid and can reverse the circulation of the immersion liquid in other battery packs 2 into the abnormal battery pack 2 when the battery pack 2 is abnormal; wherein the sub-system for circulating the immersion liquid comprises a liquid cooling unit 3, the liquid cooling unit 3 is communicated with a liquid inlet pipeline 4 and a liquid outlet pipeline 6, the liquid inlet pipeline 4 is communicated with a plurality of liquid inlet branch pipes 5 and the lower part of the front of a plurality of battery packs 2, the liquid outlet pipeline 6 is communicated with a plurality of liquid outlet branch pipes 7 and the upper part of the front of a plurality of battery packs 2, the liquid inlet branch pipe 5 is provided with a liquid inlet valve 8, the liquid outlet branch pipe 7 is provided with a liquid outlet valve 9, the liquid inlet pipeline 4 and the liquid outlet pipeline 6 are communicated with a main loop water pump 10 and a branch water pump 11; the main loop water pump 10, the branch water pump 11 and the liquid inlet pipeline 4, the liquid outlet pipeline 6 are all communicated; when the battery pack 2 is charging and discharging and normally operating, the liquid inlet valve 8 and the liquid outlet valve 9 are both opened, the main loop water pump 10 is operated to make the immersion liquid in the liquid inlet pipeline 4, a plurality of battery packs 2 and the liquid outlet pipeline 6 circulate forward, and the battery cell is always in a semi-immersed state; the branch water pump 11 is used to make the immersion liquid in the liquid inlet pipeline 4, a plurality of battery packs 2 and the liquid outlet pipeline 6 circulate reversely; through the main loop water pump 10 and the branch water pump 11, two opposite circulation loops are formed, and through the adjustment of the liquid inlet valve 8 and the liquid outlet valve 9, the immersion liquid in other normal battery packs 2 is injected into the abnormal battery pack 2 reversely.

[0040] In addition, in the embodiment, when a single battery pack 2 appears high temperature or thermal runaway, only the immersion liquid with the lowest temperature in the normal battery pack 2 can be extracted and injected into the abnormal battery pack 2 reversely, and the specific operation is as follows: when a single battery pack 2 appears high temperature or thermal runaway, the liquid inlet valve 8 of all battery packs 2 and the liquid outlet valve 9 of the normal battery pack 2 are closed, then the temperature of each battery pack 2 at this time is detected by a temperature sensor, the battery management subsystem judges 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, makes the low-temperature immersion liquid in the battery pack 2 flow out through the liquid inlet valve 8, then the liquid cooling unit 3 is switched to the branch water pump 11, and the low-temperature immersion liquid is pumped 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 appear high temperature or thermal runaway, the corresponding number of normal battery packs 2 immersion liquid can be extracted, and the normal battery pack 2 with lower immersion liquid temperature is extracted preferentially.

[0041] The control method of the intelligent immersed energy storage system comprises the following steps: S1, real-time monitoring of each battery pack parameter of the energy storage system, comparison with a preset parameter to determine whether each battery pack of the energy storage system is abnormal, if the battery pack is abnormal, step S2 is performed; the specific abnormality determination standard is: whether the temperature of the battery cell is greater than 55 DEG C, and whether the temperature rise rate is greater than 1 DEG C / s.

[0042] S2, closing the liquid inlet valve of the abnormal battery pack, closing the liquid outlet valve of the normal battery pack, starting the branch pump, closing the main loop pump, allowing the immersion liquid to be reversely circulated, and pumping out the immersion liquid from other normal battery packs and injecting it into the abnormal battery pack, so as to increase the amount of immersion liquid in the abnormal battery pack and improve the cooling effect, and handle the abnormal situation.

[0043] In addition, when only one battery pack is abnormal, step S2 is preferably: closing the liquid inlet valve of the abnormal battery pack, comparing the immersion liquid temperature of the normal battery pack, closing the liquid outlet valve of the normal battery pack with the lowest immersion liquid temperature, closing the liquid inlet valve and the liquid outlet valve of other normal battery packs, and starting the liquid cooling unit branch pump to suck out the immersion liquid in the normal battery pack with the lowest immersion liquid temperature from the liquid inlet pipeline and reversely inject it into the abnormal battery pack; compared with pumping out the immersion liquid from multiple normal battery packs and injecting it into the abnormal battery pack, pumping out the immersion liquid from the battery pack with the lowest temperature and injecting it into the abnormal battery pack can improve the cooling efficiency of the abnormal battery pack.

[0044] S3, real-time monitoring of the outlet end pressure value of the water pump, when the abnormal battery pack is full, the outlet end pressure of the water pump rises, when reaching a predetermined value, the water pump is closed, and then all the valves are closed, at this time, the abnormal battery pack is full of immersion liquid, and the immersion liquid can achieve the effects of cooling, fire extinguishing, heat runaway suppression, etc. on the abnormal battery pack, and closing all the valves can avoid liquid leakage to pollute other battery packs and avoid heat runaway from spreading to other battery packs.

[0045] S4, continuous monitoring of each parameter of the abnormal battery pack and comparison with a preset value to determine whether the immersion liquid after injection restores to normal.

[0046] S5, when each parameter of the battery pack restores to normal, all the valves are opened, the branch pump is closed, and the main loop pump is started to allow the immersion liquid to be circulated again and make the battery pack in a dynamic semi-immersed state; when each parameter of the battery pack does not restore to normal, an alarm can be issued, and the serial number of the abnormal battery pack is uploaded to allow the staff to handle it.

[0047] In step S1 of the present application, if the battery pack is normal, step S6 is performed, S6, determining whether the energy storage system is in a charging and discharging state, i.e. whether it is in a normal use state, if the energy storage system is in a charging and discharging state, step S7 is performed.

[0048] S7: open all valves, start the refrigeration of the liquid cooling unit and the main loop water pump, and circulate the immersion liquid, at this time the battery pack is in a dynamic semi-immersed state, and the heat generated during charging and discharging is taken away by the circulation of the immersion liquid, so as to achieve the effect of temperature control.

[0049] In step S6 of the present application, if the energy storage system is not in the charging and discharging state, step S8 is run, S8: when the energy storage system is not in the charging and discharging state, i.e. in the unused state, all valves are closed, and the entire system is in a shutdown state.

[0050] As shown in the accompanying Figure 3 In the present embodiment, the control method of the intelligent immersion energy storage system further includes a plurality of abnormal modes, including a high temperature early warning mode, a thermal runaway suppression mode and a liquid leakage protection mode.

[0051] The high temperature early warning mode: when the temperature of the battery cell is detected to be too high, the liquid inlet valve of the abnormal battery pack is closed, the liquid outlet valve of all normal battery packs is closed, the main loop water pump is closed, and the branch water pump is run, at this time the normal battery pack discharges the immersion liquid through the liquid inlet, 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, 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 as to realize the pumping of the immersion liquid in the normal battery pack from the liquid inlet pipeline and the reverse injection into the abnormal battery pack, increase the immersion degree of the abnormal battery pack, improve the heat dissipation capacity, and restore the temperature of the battery pack to the normal level.

[0052] The thermal runaway suppression mode: when it is detected that the battery cell has thermal runaway, the liquid inlet valve of the abnormal battery pack is closed, the liquid outlet valve of all normal battery packs is closed, the main loop water pump is closed, and the branch water pump is run, at this time the normal battery pack discharges the immersion liquid through the liquid inlet, 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, 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 as to realize the pumping of the immersion liquid in the normal battery pack from the liquid inlet pipeline and the reverse injection into the abnormal battery pack, and completely fill the abnormal battery pack, so as to suppress the thermal runaway of the battery cell, and wait for further detection.

[0053] The liquid leakage protection mode: when detecting that the electrolyte of the battery cell leaks, the liquid inlet valve of the abnormal battery pack is closed, the liquid outlet valve of all normal battery packs is closed, the main loop water pump is closed, and the branch water pump is started. 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. 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. The immersion liquid in the normal battery pack is pumped out from the liquid inlet and injected into the abnormal battery pack in reverse, until the abnormal battery pack is completely filled. After filling, the immersion liquid can avoid short circuiting and fire of the leaking battery cell, and the liquid inlet valve of the abnormal battery pack is closed, which can avoid the immersion liquid containing electrolyte being injected into the normal battery pack in reverse.

[0054] In addition, the control method of the intelligent immersion energy storage system further includes an analysis and early warning module. The analysis and early warning module monitors the temperature and temperature rise rate of each battery cell in real time, judges 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 injects the immersion liquid into the battery pack in reverse circulation in advance to achieve the effect of pretreatment, reduce the risk of thermal runaway, and improve the safety of the battery pack.

[0055] The preferred embodiments of the present application are described in detail above in combination with the drawings, and typical known structures and known common knowledge technologies are not described in detail here. The skilled person in the art can improve and implement the technical solutions of the present application based on their own ability and the inspiration given by the present embodiment, and some typical known structures, known methods or known common knowledge technologies should not be an obstacle for the skilled person to implement the present application.

[0056] The scope of protection claimed by the present application should be based on the content of its claims, and the content recorded in the summary, detailed description and drawings of the specification is used to explain the claims.

[0057] Within the scope of the technical concept of the present application, several modifications can be made to the specific embodiments of the present application, and these modified specific embodiments should also be considered within the scope of protection of the present application.

Claims

1. A control method for an intelligent submerged energy storage system, applied to an intelligent submerged energy storage system, wherein the intelligent submerged energy storage system adopts a dynamic semi-submersion combined with a static full submersion mode; characterized in that, The control method for the intelligent submerged energy storage system includes: S1: Determine if each battery pack in the energy storage system is abnormal. If the battery pack is abnormal, proceed to step S2. S2: Close the inlet valve of the abnormal battery pack, close the outlet valve of the normal battery pack, turn on the branch water pump, turn off 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, turn off the water pump and close all valves; S4: Continuously monitor abnormal battery packs and determine whether they have returned to normal; S5: When the battery pack returns to normal, open all valves, close 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. If the battery pack is normal in step S1, then proceed to step S6: S6: Determine whether the energy storage system is in a charging / discharging state. If the energy storage system is in a charging / discharging state, then run S7. S7: Open all valves, start the liquid chiller unit's cooling and main circuit water pumps, and allow the submerged liquid to circulate; If the energy storage system is not in a charging / discharging state during step S6, then step S8 is executed: S8: Close all valves; In step S1, determining whether each battery pack in the energy storage system is abnormal specifically involves determining whether the cell temperature is greater than 55°C and whether the temperature rise rate is greater than 1°C / s.

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

3. The control method for the intelligent submerged energy storage system according to claim 2, characterized in that: The specific operation of the high temperature warning mode is as follows: when the cell temperature is detected to be too high, the liquid inlet valve of the abnormal battery pack is closed, the liquid outlet valve of all normal battery packs is closed, the main circuit water pump is turned off, the branch water pump is run, the immersion liquid in the normal battery pack is drawn out from the liquid inlet pipeline and injected back into the abnormal battery pack to increase the immersion liquid in the abnormal battery pack until the temperature of the battery pack returns to the normal level.

4. The control method for the intelligent submerged energy storage system according to claim 2, characterized in that: The specific operation of the thermal runaway suppression mode is as follows: when thermal runaway of a battery cell 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 turned off, the branch water pump is run, and the immersion liquid of other battery packs is injected into the abnormal battery pack until the battery pack is filled with immersion liquid, thereby suppressing the thermal runaway of the battery cell.

5. The control method for the intelligent submerged energy storage system according to claim 2, characterized in that: The specific operation of the leakage protection mode is as follows: when leakage of electrolyte in the battery cell 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 turned off, the branch water pump is run, 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 the battery pack with immersion liquid can prevent the leaking battery cell from short-circuiting and catching fire.

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