Energy storage liquid cooling control method and system based on static pressure dynamic compensation

Abstract

The application relates to a kind of energy storage liquid cooling control method and system based on static pressure dynamic compensation, relate to battery liquid cooling technical field, for improving the heat exchange efficiency of energy storage liquid cooling system.In the method, replace rigid liquid cooling plate with thin-walled elastic liquid cooling plate and adhere to energy storage battery, the change of equivalent heat transfer thermal resistance is monitored in real time to perceive interface adhesion state, and the rotation speed of water pump at inlet and the opening of back pressure valve at outlet are coordinated and controlled, while maintaining the target cooling liquid flow, the target hydrostatic pressure is established in the liquid cooling plate, the controlled elastic deformation of the outer wall of the liquid cooling plate is driven to follow the deformation of the energy storage battery during charging and discharging to dynamically adhere to the surface of the battery, which helps to maintain the interface contact state between the battery and the liquid cooling plate, reduce the contact thermal resistance, thereby improve the heat dissipation effect of energy storage battery during charging and discharging, and improve the heat exchange efficiency.

Description

Technical Field

[0001] This application relates to the field of battery liquid cooling technology, and in particular to an energy storage liquid cooling control method and system based on static pressure dynamic compensation. Background Technology

[0002] With the rapid development of new energy technologies, electrochemical energy storage systems have been widely used in grid peak shaving and frequency regulation, renewable energy grid connection, and new energy vehicles. Lithium-ion batteries, as the core component of energy storage systems and new energy vehicles, generate a large amount of heat during charging and discharging. To improve battery pack safety and extend service life, a thermal management system is needed to control battery temperature within a reasonable range. Liquid cooling technology, due to its advantages such as high specific heat capacity, high heat exchange efficiency, and good temperature uniformity, has become the mainstream heat dissipation solution for high-energy-density energy storage systems.

[0003] In relevant energy storage liquid cooling systems, rigid liquid cooling plates are typically bonded to the surface of individual battery cells. The control method is primarily based on a temperature feedback mechanism. This involves the battery management system collecting real-time temperature data of the battery surface. When an increase in battery temperature is detected, the speed of the liquid cooling circulating water pump is increased accordingly, thereby increasing the circulation flow rate of the coolant within the liquid cooling plate. By accelerating the coolant flow rate, the heat absorbed by the liquid cooling plate is carried away, thus achieving cooling and heat dissipation for the battery pack.

[0004] However, as energy storage systems develop towards high-rate charging and discharging, the battery cells undergo periodic micro-expansion and contraction deformation under intense electrochemical reactions. This causes partial separation of the interface between the outer wall of the battery cell and the rigid liquid cooling plate and the intermediate thermally conductive silicone pad, resulting in an increase in the micro-gap at the interface. Related technologies rely on adjusting the pump speed to change the circulation flow of the coolant. The rigid liquid cooling plate is unable to adaptively compensate for the interface gap with the deformation of the battery cell, leading to a decrease in heat exchange efficiency. Summary of the Invention

[0005] This application provides a method and system for controlling liquid cooling in energy storage based on static pressure dynamic compensation, which is used to improve the heat exchange efficiency of the liquid cooling system in energy storage.

[0006] Firstly, a hydrostatic dynamic compensation-based energy storage liquid cooling control method is provided, applied to an energy storage liquid cooling system. The method includes: acquiring the charging / discharging current, surface temperature, and inlet / outlet water temperatures of a thin-walled elastic liquid cooling plate attached to the surface of the energy storage battery; determining the real-time heating power of the energy storage battery based on the charging / discharging current, and calculating the real-time equivalent heat transfer resistance between the energy storage battery and the thin-walled elastic liquid cooling plate by combining the surface temperature and the inlet / outlet water temperatures; calculating the target coolant flow rate required to maintain the thermal balance of the energy storage battery based on the real-time heating power and a preset target coolant temperature difference; and selecting a preset thermal resistance shape based on the charging / discharging state indicated by the charging / discharging current. By changing the mapping relationship and combining the difference between the real-time equivalent heat transfer thermal resistance and the preset thermal resistance benchmark value, the target hydrostatic pressure inside the plate required to drive the thin-walled elastic liquid cooling plate to undergo elastic deformation to compensate for the interface deformation is determined. The target hydrostatic pressure inside the plate and the target coolant flow rate are substituted into the preset hydraulic pipeline flow resistance model for joint solution to obtain the target speed of the inlet pump and the target opening of the outlet back pressure valve. The inlet pump is controlled according to the target speed, and the outlet back pressure valve is adjusted simultaneously according to the target opening to establish the target hydrostatic pressure inside the thin-walled elastic liquid cooling plate while maintaining the target coolant flow rate, so that the thin-walled elastic liquid cooling plate dynamically adapts to the charging and discharging deformation of the energy storage battery.

[0007] By adopting the above technical solution, a thin-walled elastic liquid cooling plate is used to replace the rigid liquid cooling plate in bonding with the energy storage battery. The interface bonding state is sensed by real-time monitoring of changes in equivalent heat transfer resistance, and the speed of the water pump at the inlet end and the opening of the back pressure valve at the outlet end are coordinated and controlled. While maintaining the target coolant flow rate, a target hydrostatic pressure is established inside the liquid cooling plate, driving the outer wall surface of the liquid cooling plate to produce controlled elastic deformation to dynamically bond with the battery surface in accordance with the charging and discharging deformation of the energy storage battery. This helps to maintain the interface contact state between the battery and the liquid cooling plate, reduce the contact thermal resistance, and thus improve the heat dissipation effect of the energy storage battery during charging and discharging, and improve the heat exchange efficiency.

[0008] In some embodiments of the first aspect, the step of calculating the real-time equivalent heat transfer resistance between the energy storage battery and the thin-walled elastic liquid cooling plate by combining the surface temperature and the inlet and outlet water temperatures specifically includes: performing first-order thermal inertia compensation on the currently collected inlet and outlet water temperatures according to the pre-calibrated thermal time constants of the inlet and outlet water temperature sensors to obtain the corrected inlet and outlet water temperatures; determining the average of the corrected inlet and outlet water temperatures as the coolant-side reference temperature; and dividing the difference between the surface temperature and the coolant-side reference temperature by the real-time heating power to obtain the real-time equivalent heat transfer resistance.

[0009] By adopting the above technical solution, first-order thermal inertia compensation is performed on the temperature sensors at the inlet and outlet ends, reducing the temperature measurement error introduced by the sensor response hysteresis under dynamic conditions. This makes the calculated reference temperature on the coolant side closer to the actual temperature state of the coolant, thereby improving the estimation accuracy of the real-time equivalent heat transfer resistance and providing a more accurate input for the subsequent calculation of the target hydrostatic pressure within the plate.

[0010] In conjunction with some embodiments of the first aspect, in some embodiments, after obtaining the real-time equivalent heat transfer resistance, the method further includes: continuously monitoring the rate of change of the real-time equivalent heat transfer resistance when the absolute value of the charging and discharging current is continuously lower than a preset resting current threshold and the duration of such monitoring exceeds a preset resting time; and when the rate of change of the real-time equivalent heat transfer resistance is lower than a preset thermal resistance stabilization threshold, using the current real-time equivalent heat transfer resistance as the measured updated value of the thermal resistance, and performing rolling correction on the preset thermal resistance reference value.

[0011] By adopting the above technical solution, taking advantage of the characteristic that the thermal system of the energy storage battery gradually approaches equilibrium during the resting period, and when the resting time is met and the rate of change of thermal resistance tends to stabilize, the preset thermal resistance reference value is rolled over by the current measured thermal resistance. This helps to compensate for the thermal resistance reference drift caused by long-term battery cycle aging, changes in the contact interface state, etc., so that the thermal resistance reference value can continuously reflect the current actual heat exchange state of the system, thereby maintaining the effectiveness of pressure compensation control during long-term operation.

[0012] In conjunction with some embodiments of the first aspect, in some embodiments, after controlling the inlet water pump according to the target rotational speed and simultaneously adjusting the outlet back pressure valve according to the target opening degree, the method further includes: recording the measured value of the hydrostatic pressure inside the thin-walled elastic liquid cooling plate during the current control cycle, and the real-time equivalent heat transfer thermal resistance deviation calculated with reference to the preset thermal resistance benchmark value after rolling correction, forming a pressure-thermal resistance deviation sample pair; after completing one complete charge-discharge cycle, based on all pressure-thermal resistance deviation sample pairs accumulated during the charge-discharge cycle, updating the characteristic parameters of the preset thermal resistance deformation mapping relationship through recursive identification.

[0013] By adopting the above technical solution, using the pressure-thermal resistance deviation sample pairs accumulated in the charge-discharge cycle as the data basis, the characteristic parameters of the thermal resistance deformation mapping relationship are periodically updated after each complete charge-discharge cycle through the recursive identification method. This enables the mapping model to be adaptively corrected as the system operating state evolves, which helps to reduce the pressure compensation error caused by the deviation between the mapping relationship parameters and the actual system characteristics, and improves the control accuracy of the system during long-term operation.

[0014] In conjunction with some embodiments of the first aspect, in some embodiments, the target hydrostatic pressure and target coolant flow rate within the plate are substituted into a preset hydraulic network flow resistance model for joint solution to obtain the target rotational speed of the inlet pump and the target opening degree of the outlet back pressure valve. Specifically, this includes: based on a pre-established deformation flow resistance relationship between the cross-sectional area of ​​the internal flow channel of the thin-walled elastic liquid-cooled plate and the hydrostatic pressure within the plate, calculating the equivalent flow resistance of the thin-walled elastic liquid-cooled plate after elastic deformation according to the target hydrostatic pressure within the plate, and updating the equivalent flow resistance in the hydraulic network flow resistance model; and setting the target coolant flow rate... The target hydrostatic pressure inside the plate is substituted into the updated hydraulic network flow resistance model for joint solution to obtain candidate target rotational speed and candidate target opening. Based on the candidate target rotational speed and candidate target opening, the predicted pressure inside the thin-walled elastic liquid-cooled plate is calculated. If the difference between the predicted pressure inside the plate and the target hydrostatic pressure inside the plate exceeds the preset convergence threshold, the equivalent flow resistance is recalculated based on the predicted pressure inside the plate and the hydraulic network flow resistance model is updated. This process is iterated until convergence or the preset maximum number of iterations is reached. The final candidate target rotational speed and candidate target opening are then used as the target rotational speed and target opening, respectively.

[0015] By adopting the above technical solution, the deformation flow resistance relationship of the thin-walled elastic liquid cooling plate is introduced into the joint solution process. By iteratively updating the equivalent flow resistance, the nonlinear influence of the elastic deformation of the liquid cooling plate on the hydraulic resistance of the pipeline network is considered. This allows the target speed of the water pump and the target opening of the back pressure valve obtained from the solution to more accurately reflect the actual hydraulic conditions of the liquid cooling plate under elastic deformation, thereby improving the accuracy of the joint solution results and helping to reduce steady-state pressure control errors.

[0016] In conjunction with some embodiments of the first aspect, in some embodiments, when the energy storage liquid cooling system includes multiple energy storage batteries arranged in parallel, each energy storage battery is respectively attached to a thin-walled elastic liquid cooling plate, and the outlet back pressure valve includes multiple independent back pressure valves corresponding one-to-one with each thin-walled elastic liquid cooling plate, the step of substituting the target hydrostatic pressure and target coolant flow rate inside the plate into a preset hydraulic pipeline flow resistance model for joint solution specifically includes: calculating the corresponding target coolant flow rate and target hydrostatic pressure inside the plate for each energy storage battery, and summing the target coolant flow rates of each energy storage battery to obtain the total system flow rate. Target flow rate; For each thin-walled elastic liquid cooling plate, the equivalent flow resistance is calculated based on its own deformation flow resistance relationship and the target hydrostatic pressure within the plate. The equivalent flow resistance is then updated in the hydraulic pipeline flow resistance model. The total target flow rate of the system and the target hydrostatic pressure within each thin-walled elastic liquid cooling plate are substituted into the updated hydraulic pipeline flow resistance model. The model is then solved jointly through multivariate iterative loops until the difference between the predicted pressure within each thin-walled elastic liquid cooling plate and the corresponding target hydrostatic pressure within the plate meets the preset convergence threshold. This yields the target speed of the inlet pump and the target opening of each independent back pressure valve.

[0017] By adopting the above technical solution, for scenarios where multiple energy storage battery cells are connected in parallel to the same liquid cooling circuit, the target coolant flow rate and target hydrostatic pressure inside the plate are calculated independently for each cell. The target speed of the water pump at the inlet end and the target opening degree of each independent back pressure valve are solved jointly through multivariate cyclic iteration. This allows for independent management of the pressure inside each parallel liquid cooling plate branch, which helps each battery cell establish an appropriate hydrostatic pressure inside the plate according to its own heat exchange requirements, thereby improving the heat dissipation uniformity of each battery in the multi-cell parallel system.

[0018] In conjunction with some embodiments of the first aspect, in some embodiments, after determining the target hydrostatic pressure within the plate required to drive the thin-walled elastic liquid cooling plate to undergo elastic deformation to compensate for interface deformation, the method further includes: calculating the rate of change of the charging and discharging current within the current control cycle; when the absolute value of the rate of change exceeds a preset switching judgment threshold, determining that the charging and discharging state is in a switching transition period; querying a preset current rate of change-feedforward compensation pressure mapping relationship based on the direction and magnitude of the rate of change to obtain the feedforward compensation pressure; superimposing the feedforward compensation pressure onto the target hydrostatic pressure within the plate to obtain the feedforward corrected target hydrostatic pressure within the plate; replacing the target hydrostatic pressure within the plate with the feedforward corrected target hydrostatic pressure within the plate, and performing a joint solution step to pre-adjust the deformation of the thin-walled elastic liquid cooling plate before the charging and discharging state switching is completed, thereby suppressing interface detachment at the moment of switching.

[0019] By adopting the above technical solution, the transition period of charge and discharge state switching is identified by detecting the change rate of charge and discharge current. Before the switching is completed, the feedforward compensation pressure is superimposed on the target hydrostatic pressure inside the plate, so that the thin-walled elastic liquid cooling plate can establish additional elastic deformation margin in advance before the switch of charge and discharge state is completed. This helps to suppress the phenomenon of temporary deterioration of interface bonding state caused by high cell deformation rate at the moment of switching, and improves the continuity of heat exchange during the transition of charge and discharge state switching.

[0020] In a second aspect, embodiments of this application provide an energy storage liquid cooling system, which includes: one or more processors and a memory; the memory is coupled to the one or more processors, and the memory is used to store computer program code, which includes computer instructions, and the one or more processors call the computer instructions to cause the energy storage liquid cooling system to perform the method described in the first aspect and any possible implementation thereof.

[0021] Thirdly, embodiments of this application provide a computer program product containing instructions that, when the computer program product is run on an energy storage liquid cooling system, cause the energy storage liquid cooling system to perform the method described in the first aspect and any possible implementation thereof.

[0022] Fourthly, embodiments of this application provide a computer-readable storage medium including instructions that, when executed on an energy storage liquid cooling system, cause the energy storage liquid cooling system to perform the method described in the first aspect and any possible implementation thereof.

[0023] Understandably, the energy storage liquid cooling system provided in the second aspect, the computer program product provided in the third aspect, and the computer storage medium provided in the fourth aspect are all used to execute the methods provided in the embodiments of this application. Therefore, the beneficial effects they can achieve can be referred to the beneficial effects in the corresponding methods, and will not be repeated here.

[0024] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages:

[0025] 1. A thin-walled elastic liquid cooling plate is used to replace the rigid liquid cooling plate in contact with the energy storage battery. The interface contact state is sensed by real-time monitoring of changes in equivalent heat transfer resistance. The speed of the water pump at the inlet end and the opening of the back pressure valve at the outlet end are coordinated and controlled. While maintaining the target coolant flow rate, a target hydrostatic pressure is established inside the liquid cooling plate. This drives the outer wall of the liquid cooling plate to produce controlled elastic deformation, so as to dynamically contact the battery surface in accordance with the deformation of the energy storage battery during charging and discharging. This helps to maintain the interface contact state between the battery and the liquid cooling plate, reduce the contact thermal resistance, and thus improve the heat dissipation effect of the energy storage battery during charging and discharging, and improve the heat exchange efficiency.

[0026] 2. In the joint solution process, the deformation flow resistance relationship of the thin-walled elastic liquid cooling plate is introduced. By iteratively updating the equivalent flow resistance, the nonlinear influence of the elastic deformation of the liquid cooling plate on the hydraulic resistance of the pipeline network is considered. This allows the target speed of the water pump and the target opening of the back pressure valve obtained from the solution to more accurately reflect the actual hydraulic conditions of the liquid cooling plate under elastic deformation, thereby improving the accuracy of the joint solution results and helping to reduce steady-state pressure control errors.

[0027] 3. For scenarios where multiple energy storage battery cells are connected in parallel to the same liquid cooling circuit, the target coolant flow rate and target hydrostatic pressure within the plate are calculated independently for each cell. The target speed of the water pump at the inlet end and the target opening degree of each independent back pressure valve are solved jointly through multivariate iterative calculation. This allows for independent management of the pressure within each parallel liquid cooling plate branch, which helps each battery cell establish an appropriate hydrostatic pressure within the plate according to its own heat exchange requirements, thereby improving the heat dissipation uniformity of each battery in a multi-cell parallel system. Attached Figure Description

[0028] Figure 1 This is a schematic flowchart of an energy storage liquid cooling control method based on static pressure dynamic compensation in an embodiment of this application.

[0029] Figure 2This is another schematic diagram of a liquid cooling control method for energy storage based on static pressure dynamic compensation in an embodiment of this application.

[0030] Figure 3 This is a schematic diagram of the physical device structure of an energy storage liquid cooling system in the embodiments of this application. Detailed Implementation

[0031] The terminology used in the following embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. As used in the specification and appended claims of this application, the singular expressions “a,” “an,” “the,” “the,” “the,” and “this” are intended to include the plural expressions as well, unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in this application refers to and includes any or all possible combinations of one or more of the listed items.

[0032] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature, and in the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more.

[0033] This application provides a method and system for controlling liquid cooling in energy storage based on static pressure dynamic compensation, which is used to improve the heat exchange efficiency of the liquid cooling system in energy storage.

[0034] Please see Figure 1 This is a schematic flowchart of an energy storage liquid cooling control method based on static pressure dynamic compensation in an embodiment of this application.

[0035] S101. Obtain the charging and discharging current, surface temperature, and inlet and outlet water temperatures of the thin-walled elastic liquid cooling plate attached to the surface of the energy storage battery.

[0036] Energy storage batteries refer to electrochemical battery units used to store and release electrical energy. They are typically integrated in the form of multiple individual cells or modules, with typical forms including square aluminum-cased batteries and pouch batteries. Charge / discharge current refers to the current flowing through the energy storage battery; its positive and negative directions correspond to the charging and discharging states, respectively. The magnitude of the charge / discharge current directly determines the electrochemical reaction rate and heat generation intensity of the battery at the current moment. Surface temperature refers to the local temperature collected by temperature sensors attached to the surface of the battery casing or electrodes, used to characterize the thermal state of the battery's outer surface at the current moment. Thin-walled elastic liquid cooling plates are plate-shaped heat exchange elements encapsulated from thin-walled materials (such as aluminum alloy sheets) with a certain elastic deformation capability and internal cooling channels. They are directly or indirectly bonded to the surface of the energy storage battery through a thin layer of phase change thermally conductive material to achieve contact heat dissipation. Unlike rigid liquid cooling plates, thin-walled elastic liquid cooling plates can generate controllable elastic deformation under the action of internal fluid static pressure, thereby actively adapting to the microscopic deformation of the battery surface. The inlet and outlet water temperatures refer to the temperatures at which the coolant flows into and out of the thin-walled elastic liquid cooling plate, respectively. These temperatures are collected by temperature sensors installed on the inlet and outlet water pipes, respectively, and are used to characterize the heat absorption state of the coolant as it flows through the liquid cooling plate.

[0037] Specifically, the charging and discharging current can be acquired in real time by the battery management system (BMS) of the energy storage system through Hall current sensors or shunts. The surface temperature of the energy storage battery is acquired by temperature sensors (such as NTC thermistors) pre-positioned at key locations on the surface of the battery cells. To comprehensively reflect the thermal state of the battery, sensors are usually arranged at the top, middle, and bottom of the battery cells, and the statistical values ​​of the multi-point temperatures (such as the average or maximum value) are used as the representative surface temperature. The inlet and outlet water temperatures of the thin-walled elastic liquid cooling plate are acquired by temperature sensors installed on the inlet and outlet pipes of the liquid cooling circuit, respectively.

[0038] S102. Determine the real-time heating power of the energy storage battery based on the charging and discharging current, and calculate the real-time equivalent heat transfer resistance between the energy storage battery and the thin-walled elastic liquid cooling plate by combining the surface temperature and the inlet and outlet water temperatures.

[0039] Real-time heat generation power refers to the heat generated by the energy storage battery per unit time under the current charge / discharge state. Its magnitude is determined by the current charge / discharge current and electrochemical characteristic parameters such as the battery's internal resistance. Real-time equivalent heat transfer resistance refers to the equivalent thermal resistance that comprehensively characterizes the overall heat transfer resistance between the energy storage battery and the thin-walled elastic liquid cooling plate. Its value comprehensively reflects the thermal conductivity of the battery's outer wall, the contact thermal resistance at the interface between the battery and the liquid cooling plate, and the thermal conductivity of the liquid cooling plate's wall itself. The larger the value of the real-time equivalent heat transfer resistance, the higher the total resistance of each heat transfer link and the lower the interface heat transfer efficiency. When the energy storage battery deforms due to charge / discharge, causing the interface gap to increase, the real-time equivalent heat transfer resistance will increase accordingly. Therefore, its change can serve as an effective monitoring indicator of whether the interface bonding state has deteriorated.

[0040] Specifically, the real-time heat generation power of an energy storage battery is calculated based on the charge and discharge current using a battery heat generation model. A commonly used heat generation model is based on a simplified form of the Bernardi equation, i.e., the real-time heat generation power. (Unit: W) consists of two parts: heat generated by ohmic internal resistance and heat generated by reversible entropy change. The calculation formula is: ,in, This is the charging and discharging current (unit: A, negative value for charging, positive value for discharging). This is the DC internal resistance (in Ω) at the current operating point. This represents the current battery surface temperature (in K). This is the open-circuit voltage temperature coefficient (unit: V / K). The first term on the right-hand side of the equation... This is the ohmic resistance heat generation term, reflecting the heat generated by irreversible ohmic losses, and its value is always positive. The second term... This is the reversible entropy change heat generation term, reflecting the heat exchange caused by the reversible entropy change effect in the electrochemical reaction. Its sign is determined by the direction of charging and discharging and the sign of the open-circuit voltage temperature coefficient at the current state of charge (SOC), and can be positive (heat generation) or negative (heat absorption). The battery management system obtains the internal resistance-SOC-temperature three-dimensional lookup table by querying the current SOC and battery temperature in advance through pulse discharge test in a laboratory environment. Based on the OCV-temperature data calibrated through pre-tested open-circuit voltage under different temperature conditions, interpolation is performed using the current SOC as an index. After obtaining the real-time heating power, the average of the inlet and outlet water temperatures is used as the coolant-side reference temperature. The real-time equivalent heat transfer resistance is obtained by dividing the difference between the battery surface temperature and the coolant-side reference temperature by the real-time heating power. Sensor thermal inertia compensation can be performed on the inlet and outlet water temperatures before calculation to eliminate dynamic errors introduced by sensor response hysteresis and improve the accuracy of thermal resistance estimation.

[0041] In some embodiments, before calculating the coolant-side reference temperature, first-order thermal inertia compensation can be performed on the sampled values ​​of the inlet and outlet temperature sensors, respectively. The thermal time constants of each sensor required for compensation are obtained by pre-calibrating each sensor under controlled conditions by applying a temperature step excitation and fitting the response curve. The average of the compensated corrected inlet and outlet temperatures is used as the coolant-side reference temperature. The difference between the battery surface temperature and this reference temperature is then divided by the real-time heating power to obtain the real-time equivalent heat transfer resistance corrected for inertia error. Furthermore, an adaptive reference update mechanism can be set to address parameter drift caused by long-term operation. Specifically, when the absolute value of the charging and discharging current is continuously lower than the preset resting current threshold and the duration exceeds the preset resting time, the rate of change of the real-time equivalent heat transfer resistance is continuously monitored. When the rate of change is lower than the preset thermal resistance stability threshold, the current real-time equivalent heat transfer resistance is used as the measured updated value of the thermal resistance, and the thermal resistance reference value used in subsequent steps is rolled over to compensate for the reference offset caused by long-term battery cycle aging or changes in system installation status. The above preset thresholds are determined in advance during the commissioning phase according to the system characteristics.

[0042] S103. Based on the real-time heating power and the preset target temperature difference of the coolant, calculate the target coolant flow rate required to maintain the thermal balance of the energy storage battery.

[0043] The preset target coolant temperature difference refers to the maximum allowable temperature difference between the inlet and outlet of the coolant after it flows through the thin-walled elastic liquid cooling plate, pre-set to meet the cooling performance design requirements. This parameter comprehensively considers the battery's maximum allowable operating temperature, the coolant inlet temperature range, and system energy efficiency requirements, and is optimized and determined during the system design phase through a combination of thermal simulation and bench testing. The target coolant flow rate refers to the minimum coolant flow rate required to maintain the thermal balance of the energy storage battery and continuously remove heat generated by the battery without exceeding the preset target coolant temperature difference. This is calculated with the constraint of meeting the battery's heat dissipation needs and not exceeding the system's rated flow rate range. Thermal balance refers to the steady-state heat transfer state where the heat generated by the battery per unit time is equal to the heat absorbed and removed by the coolant per unit time, and is the theoretical basis for determining the target coolant flow rate.

[0044] Specifically, based on the thermodynamic principle of energy conservation, the heat absorbed by the coolant during its flow through the liquid cooling plate is equal to the product of the mass flow rate, the specific heat capacity of the coolant, and the temperature difference between the inlet and outlet water. Let the inlet and outlet water temperature difference equal the preset target temperature difference of the coolant. Using real-time heat generation power as the heat dissipation target, a heat balance equation is established and the target coolant flow rate is obtained. The calculated target coolant flow rate needs to be truncated to upper and lower limits. The lower limit is not lower than the minimum flow rate required to maintain normal system circulation, and the upper limit does not exceed the maximum flow rate allowed by the pump's rated parameters and pipeline design specifications. These upper and lower limits are predetermined during the system commissioning phase. The specific heat capacity of the coolant is predetermined during system initialization based on the coolant type and ratio. For water-based coolants, a known constant can be directly used; for ethylene glycol-water mixtures, the specific heat capacity is obtained by consulting standard property data tables based on the ratio and current temperature.

[0045] In some embodiments, the target coolant flow rate can be calculated in multiple ways. Optionally, within each control cycle, the original target flow rate is obtained by directly dividing the current real-time heat generation power by the product of the coolant specific heat capacity and the preset target coolant temperature difference. After being truncated by upper and lower limits, this is output as the target coolant flow rate. This method is simple and efficient, and suitable for operating conditions where the heat generation power changes relatively smoothly with the charging and discharging current. Optionally, considering that the heat generation power will fluctuate drastically when the charging and discharging current changes rapidly, in order to avoid frequent and large fluctuations in the target flow rate causing mechanical shock to the water pump and back pressure valve, the real-time heat generation power is smoothed by low-pass filtering before being substituted into the flow formula. When the heat generation power increases, the low-pass filter cutoff frequency is appropriately increased to ensure the timeliness of the cooling response. When the heat generation power decreases, the cutoff frequency is decreased to smooth the flow rate reduction process. At the same time, the ratio of the current real-time equivalent heat transfer resistance to the thermal resistance reference value is used as a correction coefficient to adaptively correct the calculated original target flow rate. When the heat transfer resistance is too high, the target flow rate is appropriately increased to compensate for the decrease in heat transfer efficiency, so that the liquid cooling circuit can still maintain the necessary heat dissipation capacity when the thermal resistance is high.

[0046] S104. Select the preset thermal resistance deformation mapping relationship according to the charging and discharging state indicated by the charging and discharging current, and combine the difference between the real-time equivalent heat transfer thermal resistance and the preset thermal resistance reference value to determine the target hydrostatic pressure inside the plate required to drive the thin-walled elastic liquid cooling plate to undergo elastic deformation in order to compensate for the interface deformation.

[0047] The charge / discharge state refers to the current operating state of the energy storage battery, determined by the direction and magnitude of the charge / discharge current. This includes charging, discharging, and resting states. The lithium insertion and delithiation directions of the active materials inside the battery are opposite in the charging and discharging states, resulting in different directions and magnitudes of microscopic dimensional changes on the battery casing surface. Therefore, differentiated mapping models need to be established for different charge / discharge states. The preset thermal resistance deformation mapping relationship is a pre-established mapping model, calibrated experimentally, describing the correspondence between the hydrostatic pressure within the thin-walled elastic liquid cooling plate and the real-time equivalent heat transfer resistance between the energy storage battery and the liquid cooling plate. This mapping relationship reflects the heat transfer resistance level achievable under a given charge / discharge state by applying a specific hydrostatic pressure to cause the liquid cooling plate to elastically deform and adhere tightly to the battery surface. Since the surface deformation characteristics of the battery differ between the charging and discharging states, corresponding mapping relationships are established for each state. These mapping relationships are obtained through laboratory bench testing and calibration after system assembly and debugging. The calibration method is as follows: Under controlled conditions, different levels of hydrostatic pressure are applied to the thin-walled elastic liquid cooling plate, and the measured thermal resistance under each pressure condition is measured. The above tests are performed in both charging and discharging states. The functional relationship between pressure and thermal resistance under each state is fitted and pre-stored in the energy storage liquid cooling system in the form of a lookup table or parameterized function. The preset thermal resistance reference value refers to the reference value of the equivalent thermal resistance between the energy storage battery and the thin-walled elastic liquid cooling plate obtained through laboratory calibration under the initial calibration state, i.e., under good interface bonding conditions. It is used to compare with the real-time equivalent thermal resistance to determine whether the current interface bonding state has deteriorated. Interface deformation refers to the phenomenon where the periodic volume change of the active material during the charging and discharging process of the energy storage battery causes microscopic dimensional changes on the surface of the battery casing, resulting in local gaps at the bonding interface between the battery surface and the liquid cooling plate. The target hydrostatic pressure inside the plate refers to the target hydrostatic pressure that needs to be established inside the liquid cooling plate to drive the outer wall of the thin-walled elastic liquid cooling plate to generate sufficient elastic deformation in order to actively compensate for the interface gap and restore the tight fit between the battery surface and the liquid cooling plate.

[0048] Specifically, the energy storage liquid cooling system first determines the current charge / discharge state based on the direction of the charge / discharge current, and selects a preset thermal resistance deformation mapping relationship corresponding to the current state from a pre-stored mapping relationship library. Then, it calculates the difference between the real-time equivalent heat transfer thermal resistance and the preset thermal resistance benchmark value. Using this difference as input, it solves inversely through the selected mapping relationship to obtain the intra-plate hydrostatic pressure compensation amount required to restore the thermal resistance to the benchmark level, i.e., the intra-plate target hydrostatic pressure. When the thermal resistance difference is zero or negative, it indicates good interface adhesion. The intra-plate target hydrostatic pressure is taken as a preset maintenance pressure lower limit to maintain basic contact between the outer wall of the liquid cooling plate and the battery surface. This maintenance pressure lower limit is predetermined during the commissioning phase based on the elastic properties of the liquid cooling plate material and the assembly pre-pressure level.

[0049] In some embodiments, the calibrated thermal resistance-pressure mapping relationships for the charging and discharging states can be stored in non-volatile memory as two-dimensional lookup tables (indexed by the charging / discharging state and the thermal resistance difference). Within each control cycle, the corresponding lookup table is selected based on the current charging / discharging state, with the current thermal resistance difference as the query input. The target hydrostatic pressure within the plate is calculated through linear interpolation. When the thermal resistance difference exceeds the calibration range of the lookup table, boundary values ​​are used for extrapolation or saturation limiting to ensure that the target hydrostatic pressure remains within the achievable range of the system.

[0050] S105. Substitute the target static water pressure and target coolant flow rate into the preset hydraulic pipeline flow resistance model for joint solution to obtain the target speed of the water pump at the inlet end and the target opening degree of the back pressure valve at the outlet end.

[0051] The preset hydraulic pipeline flow resistance model refers to a pre-established mathematical model describing the pressure and flow relationship between various components in the hydraulic pipeline of the energy storage liquid cooling system. This model is based on the flow resistance characteristics of each component in the pipeline and is constructed through node pressure balance equations and branch flow continuity equations. The flow resistance parameters of each fixed pipeline component (such as the friction resistance of each pipeline section and the local resistance of pipe joints) are determined through actual measurement and calibration after system assembly and are pre-stored in the energy storage liquid cooling system. The inlet pump refers to the hydraulic pump installed at the inlet of the liquid cooling circuit to provide the driving head for coolant circulation. Its head-flow characteristic curves at different speeds are pre-stored in the energy storage liquid cooling system after pre-test calibration at the factory. The target speed is the pump speed setting value required to meet the target coolant flow rate and the target static water pressure requirements within the plate. The outlet back pressure valve is an adjustable flow element installed at the outlet of the liquid cooling circuit. By adjusting the valve opening, the throttling resistance on the outlet side is changed, thereby establishing back pressure on the outlet side of the liquid cooling plate to control the internal static water pressure. The relationship between its opening and flow resistance is pre-stored in the energy storage liquid cooling system through factory calibration. The target opening is the back pressure valve opening setting value required to establish the target static water pressure inside the thin-walled elastic liquid cooling plate. The deformation flow resistance relationship refers to the relationship established in advance through experimental calibration, describing the change of the equivalent flow resistance of the internal flow channel of the thin-walled elastic liquid cooling plate with the static water pressure inside the plate. Since the cross-sectional area of ​​the flow channel of the thin-walled elastic liquid cooling plate changes with elastic deformation under internal pressure, its equivalent flow resistance changes nonlinearly with the static water pressure inside the plate. This relationship is obtained during the system assembly and commissioning stage by performing differential pressure-flow tests on the liquid cooling plate under different internal pressure conditions.

[0052] Specifically, firstly, based on the pre-calibrated deformation flow resistance relationship, the equivalent flow resistance of the thin-walled elastic liquid-cooled plate after elastic deformation under the target pressure is calculated using the current target hydrostatic pressure within the plate as input. This equivalent flow resistance is then updated in the branch parameters corresponding to the hydraulic network flow resistance model. Subsequently, using the target coolant flow rate and the target hydrostatic pressure within the plate as constraints, the updated hydraulic network flow resistance model is substituted into the solution to obtain candidate target rotational speed and candidate target opening. The candidate control variables are then substituted into the hydraulic network flow resistance model to back-calculate the predicted pressure within the liquid-cooled plate. If the difference between the predicted pressure within the plate and the target hydrostatic pressure exceeds a preset convergence threshold, the deformation flow resistance relationship is re-queried using the predicted pressure within the plate as input, and the equivalent flow resistance is updated. The hydraulic network flow resistance model is then updated and the solution is performed again. This process is iterated until convergence or the preset maximum number of iterations is reached. The finally converged candidate target rotational speed and candidate target opening are output as the target rotational speed and target opening, respectively. The preset convergence threshold and the preset maximum number of iterations are both predetermined during the debugging phase based on the system's comprehensive requirements for control accuracy and real-time performance.

[0053] In some embodiments, the target pump speed and the target back pressure valve opening can be solved jointly in multiple ways. Optionally, the hydraulic pipeline equations can be numerically solved based on the Newton-Raphson iterative method. In each iteration, the Jacobian matrix at the current solution is used to linearize the pipeline equations to accelerate convergence. At the same time, after each iteration, the equivalent flow resistance of the thin-walled elastic liquid-cooled plate is updated based on the pressure inside the current candidate plate. When the difference between two adjacent iteration results is less than a preset convergence threshold, convergence is determined and the result is output. This method can usually achieve convergence in a relatively small number of iterations when the initial value is selected reasonably, and is suitable for control scenarios with high real-time requirements. Optionally, a fast approximate solution can also be achieved based on a pre-generated offline multidimensional lookup table. The lookup table uses the target coolant flow rate and the target hydrostatic pressure inside the plate as two-dimensional indexes, and stores the target pump speed and the target back pressure valve opening obtained through offline iterative optimization. When the energy storage liquid cooling system is running, the approximate control quantity is directly obtained by looking up the table and linear interpolation. Only when the deviation between the current operating point and the calibration point of the lookup table is large, a small amount of online iterative correction is performed to achieve a balance between calculation speed and control accuracy.

[0054] S106. Control the water pump at the inlet end according to the target speed, and simultaneously adjust the back pressure valve at the outlet end according to the target opening degree, so as to maintain the target coolant flow rate and establish the target hydrostatic pressure inside the thin-walled elastic liquid cooling plate, so that the thin-walled elastic liquid cooling plate dynamically adapts to the charging and discharging deformation of the energy storage battery.

[0055] Among them, charge-discharge deformation refers to the phenomenon that during the charging and discharging process of an energy storage battery, the volume of the positive and negative electrode active materials undergoes periodic changes during lithium insertion and extraction, causing periodic microscopic changes in the normal dimensions of the battery casing surface. Typically, the battery expands during charging and contracts during discharging, with the amplitude and rate of charge-discharge deformation increasing with the charge-discharge rate. Dynamic adaptation refers to the ability of a thin-walled elastic liquid-cooled plate, driven by controlled intraplate hydrostatic pressure, to continuously adjust the deformation of its outer wall surface in response to the dynamic changes in charge-discharge deformation of the energy storage battery, thereby maintaining a continuous and tight fit with the battery surface. This process is updated in real time with each control cycle.

[0056] Specifically, the energy storage liquid cooling system sends the target speed command to the water pump frequency converter, driving the inlet water pump to operate at the target speed to provide the hydraulic driving force required to maintain the target coolant flow rate. Simultaneously, the target opening command is sent to the electric actuator of the outlet back pressure valve, adjusting the back pressure valve to the target opening. Through the throttling effect of the back pressure valve, back pressure is established on the outlet side of the liquid cooling plate, raising the internal hydrostatic pressure of the liquid cooling plate to the target hydrostatic pressure. This drives the outer wall of the thin-walled elastic liquid cooling plate to undergo corresponding elastic deformation to conform to the battery surface. The synchronous and coordinated adjustment of the water pump speed and the back pressure valve opening hydraulically decouples the coolant circulation flow control from the internal pressure control of the liquid cooling plate, allowing independent control of the internal pressure while maintaining a constant coolant circulation flow rate. These execution commands are continuously updated in each control cycle, achieving continuous tracking of the target hydrostatic pressure and target coolant flow rate within the plate, enabling the thin-walled elastic liquid cooling plate to continuously and dynamically adapt to the charging and discharging deformation of the energy storage battery.

[0057] In some embodiments, coordinated control of the inlet pump and the outlet back pressure valve can be achieved in various ways. Optionally, before performing joint solution in each control cycle, the rate of change of the charging / discharging current relative to the previous control cycle can be calculated first. When the absolute value of the rate of change exceeds a preset switching judgment threshold, the charging / discharging state is determined to be in a switching transition period. Based on the direction and magnitude of the rate of change, the preset current rate of change-feedforward compensation pressure mapping relationship is queried to obtain the feedforward compensation pressure. The preset switching judgment threshold refers to the absolute value threshold of the current rate of change used to determine whether the charging / discharging state is in a switching transition period. This threshold is predetermined during the commissioning phase based on the system's requirements for switching transition response sensitivity. The preset current rate of change-feedforward compensation pressure mapping relationship is a mapping model describing the correspondence between the charging / discharging current rate of change and the feedforward compensation pressure that needs to be additionally superimposed during the switching transition period of the charging / discharging state. This relationship reflects the influence of the instantaneous overshoot of cell deformation on the interface bonding state under different switching rates. It is obtained through systematic testing and calibration of the dynamic response of interface deformation under different switching rates on a laboratory bench. The feedforward compensation pressure is superimposed on the target hydrostatic pressure within the plate determined in step S104. The feedforward-corrected target hydrostatic pressure within the plate is then used to replace the original target hydrostatic pressure within the plate, and the joint solution in step S105 is performed again. The control quantity obtained from the solution drives the water pump and back pressure valve to operate, so that the thin-walled elastic liquid cooling plate has an additional deformation margin before the switch between charging and discharging states is completed, suppressing the interface from detaching due to cell deformation overshoot at the moment of switching. After the switch between charging and discharging states is completed, the feedforward compensation pressure automatically exits the superposition, and the target hydrostatic pressure within the plate is restored to the value determined by thermal resistance feedback calculation. Optionally, closed-loop feedback correction can be superimposed on the open-loop feedforward control. The energy storage liquid cooling system simultaneously collects the measured pressure value from the differential pressure sensor of the liquid cooling plate pipeline and the measured flow value from the pipeline flow sensor, and compares them with the target static water pressure and target coolant flow rate in the plate, respectively. The pressure deviation and flow deviation are input into their respective PI controllers to calculate the incremental correction amount for the target pump speed and the target opening degree of the back pressure valve. This correction amount is then superimposed on the feedforward control amount obtained by joint solution and sent out synchronously to suppress steady-state errors caused by pipeline flow resistance parameter drift or external disturbances. In this mode, the measured value of the static water pressure in the liquid cooling plate and the thermal resistance deviation calculated based on the current thermal resistance reference value can also be recorded in each control cycle to form a pressure-thermal resistance deviation sample pair and store it in the cache. After completing a full charge-discharge cycle, all sample pairs accumulated in the cycle are used as training data, and the characteristic parameters of the thermal resistance deformation mapping relationship used in step S104 are updated through recursive identification methods such as recursive least squares.

[0058] In the above embodiments, a thin-walled elastic liquid cooling plate is used instead of a rigid liquid cooling plate to bond with the energy storage battery. The interface bonding state is sensed by real-time monitoring of changes in equivalent heat transfer resistance, and the speed of the water pump at the inlet end and the opening of the back pressure valve at the outlet end are coordinated and controlled. While maintaining the target coolant flow rate, a target hydrostatic pressure is established inside the liquid cooling plate, driving the outer wall surface of the liquid cooling plate to produce controlled elastic deformation to dynamically bond with the battery surface in accordance with the charging and discharging deformation of the energy storage battery. This helps to maintain the interface contact state between the battery and the liquid cooling plate, reduce the contact thermal resistance, thereby improving the heat dissipation effect of the energy storage battery during charging and discharging and increasing the heat exchange efficiency.

[0059] However, in multi-cell parallel scenarios, the real-time heating power and interface bonding state of each cell may differ due to variations in their thermal environment, historical usage, and current state of charge. Consequently, the required target hydrostatic pressure within the plate often varies. If only a single back pressure valve is used to uniformly adjust the outlet back pressure for all parallel branches, it is difficult to provide independent pressure compensation for the actual heat exchange needs of each cell, potentially leading to insufficient or over-compensation of interface deformation for some cells.

[0060] Please see Figure 2 This is another schematic diagram of a liquid cooling control method for energy storage based on static pressure dynamic compensation in an embodiment of this application.

[0061] S201. Obtain the charging and discharging current, surface temperature, and inlet and outlet water temperatures of the thin-walled elastic liquid cooling plate attached to the surface of the energy storage battery.

[0062] S202. Determine the real-time heating power of the energy storage battery based on the charging and discharging current, and calculate the real-time equivalent heat transfer resistance between the energy storage battery and the thin-walled elastic liquid cooling plate by combining the surface temperature and the inlet and outlet water temperatures.

[0063] S203. Based on the real-time heating power and the preset target temperature difference of the coolant, calculate the target coolant flow rate required to maintain the thermal balance of the energy storage battery.

[0064] S204. Select the preset thermal resistance deformation mapping relationship according to the charging and discharging state indicated by the charging and discharging current, and combine the difference between the real-time equivalent heat transfer thermal resistance and the preset thermal resistance reference value to determine the target hydrostatic pressure inside the plate required to drive the thin-walled elastic liquid cooling plate to undergo elastic deformation in order to compensate for the interface deformation.

[0065] Step S201 is similar to step S101, step S202 is similar to step S102, step S203 is similar to step S103, and step S204 is similar to step S104, so they will not be repeated here.

[0066] S205. In an energy storage liquid cooling system comprising multiple energy storage batteries arranged in parallel, each energy storage battery being attached to a thin-walled elastic liquid cooling plate, and the outlet back pressure valve comprising multiple independent back pressure valves corresponding to each thin-walled elastic liquid cooling plate, the target coolant flow rate and the target hydrostatic pressure within the plate are calculated for each energy storage battery, and the target coolant flow rates of each energy storage battery are summed to obtain the total target flow rate of the system.

[0067] In this system, multiple parallel-connected energy storage batteries refer to multiple battery cells or modules connected in parallel to the same main liquid cooling circuit in the energy storage liquid cooling system. Each energy storage battery cell is connected to the main liquid cooling circuit through its own independent branch pipeline. These branches are interconnected in parallel on the hydraulic topology and share the same inlet water pump to provide circulation driving force. Each energy storage battery is individually fitted with a thin-walled elastic liquid cooling plate, meaning that each battery cell has its own thin-walled elastic liquid cooling plate attached to its surface. Each liquid cooling plate is connected to the main circuit through an independent branch, allowing for independent control of the flow rate and internal pressure of each liquid cooling plate. Multiple independent back pressure valves refer to multiple independently adjustable back pressure valves configured one-to-one with each thin-walled elastic liquid cooling plate. Each independent back pressure valve is installed at the outlet end of the corresponding liquid cooling plate branch. By differentially adjusting the opening of each independent back pressure valve, independent and precise control of the internal pressure of each liquid cooling plate is achieved. The total target flow rate of the system refers to the sum of the target coolant flow rates required by all parallel energy storage battery cells, that is, the total circulating flow rate target value that the water pump at the inlet end of the liquid cooling main pipeline needs to provide. It is a flow-side constraint for uniformly solving the target speed of the water pump at the inlet end.

[0068] Step S205 applies to applications where the energy storage liquid cooling system includes multiple parallel-connected energy storage batteries, and each battery cell is independently attached to a thin-walled elastic liquid cooling plate. In this scenario, the real-time heating power and the required target hydrostatic pressure within the plate are usually not exactly the same due to differences in the location, historical usage status, and current state of charge of each battery cell. Therefore, it is necessary to calculate the flow requirements of each cell independently and then summarize the flow requirements of each cell to determine the total flow target at the system level. Specifically, for each parallel energy storage battery, the energy storage liquid cooling system independently calculates the real-time heating power and the corresponding target coolant flow rate within the current control cycle according to the methods described in steps S202 and S203. The target coolant flow rate of each cell is determined independently based on its real-time heating power and the corresponding preset target coolant temperature difference. At the same time, the target hydrostatic pressure within the plate corresponding to each cell is calculated according to the method described in step S204. After the calculation of each cell is completed, the target coolant flow rates of all cells are added together to obtain the total target flow rate of the system, which serves as the flow-side constraint for the subsequent solution of the target speed of the water pump.

[0069] S206. For each thin-walled elastic liquid cooling plate, calculate the corresponding equivalent flow resistance based on its own deformation flow resistance relationship and the target hydrostatic pressure inside the plate, and update each equivalent flow resistance to the hydraulic pipeline flow resistance model.

[0070] The deformation flow resistance relationship of each liquid cooling plate refers to the mapping relationship between the hydrostatic pressure inside the plate and the equivalent flow resistance, which is independently calibrated for each thin-walled elastic liquid cooling plate. Due to potential individual differences in manufacturing tolerances and assembly conditions, the deformation flow resistance relationship of each liquid cooling plate needs to be obtained separately during the system assembly and debugging phase by applying different internal pressures to each plate and measuring the corresponding differential pressure-flow rate data. This relationship is then pre-stored in the energy storage liquid cooling system in the form of lookup tables or parametric functions. The equivalent flow resistance refers to the fluid resistance parameter corresponding to the fluid flow channel morphology of the thin-walled elastic liquid cooling plate after elastic deformation under a specific hydrostatic pressure, which is equivalent to a uniform cross-section flow channel. As the hydrostatic pressure inside the plate increases, the cross-sectional area of ​​the flow channel expands, and the equivalent flow resistance decreases; as the hydrostatic pressure inside the plate decreases, the cross-sectional area of ​​the flow channel shrinks, and the equivalent flow resistance increases. In a multi-battery parallel system, since the target hydrostatic pressure inside each liquid cooling plate is usually different, the equivalent flow resistance corresponding to each liquid cooling plate is also different, forming a non-uniform parallel branch flow resistance distribution. It is necessary to calculate and update the corresponding branch parameters of the hydraulic pipeline flow resistance model independently.

[0071] Specifically, for each thin-walled elastic liquid-cooled plate in the energy storage liquid cooling system, based on its pre-calibrated deformation flow resistance relationship, the target hydrostatic pressure within each liquid-cooled plate is substituted into the corresponding deformation flow resistance relationship to calculate the equivalent flow resistance of each liquid-cooled plate after elastic deformation under the target pressure. After the equivalent flow resistance of each liquid-cooled plate is calculated, it is updated to the corresponding flow resistance parameter positions of each parallel branch in the hydraulic pipeline flow resistance model, completing the update of the non-uniform parallel branch flow resistance distribution in the hydraulic pipeline flow resistance model, and providing a corrected pipeline model for subsequent joint solution steps.

[0072] S207. Substitute the total target flow rate of the system and the target hydrostatic pressure inside each thin-walled elastic liquid cooling plate into the updated hydraulic pipeline flow resistance model, and solve them together through multivariate iterative loops until the difference between the predicted pressure inside each thin-walled elastic liquid cooling plate and the corresponding target hydrostatic pressure inside the plate meets the preset convergence threshold, thereby obtaining the target speed of the water pump at the inlet end and the target opening degree of each independent back pressure valve.

[0073] The multivariate iterative solution process involves using the total system target flow rate and the target hydrostatic pressure within each thin-walled elastic liquid-cooled plate as constraints, and the target speed of the inlet pump and the target opening of each independent back pressure valve as variables to be solved. In each iteration, the equivalent flow resistance of each liquid-cooled plate is updated based on the deviation between the predicted pressure within the plate and the target hydrostatic pressure, and the pipeline equations are resolved. This process is repeated until the global convergence condition is met. The predicted pressure within the plate refers to the pressure difference between the inlet and outlet of each liquid-cooled plate branch, calculated from the hydraulic pipeline flow resistance model under the current candidate pump target speed and the target opening of each candidate back pressure valve. This pressure is compared with the corresponding target hydrostatic pressure within the plate to evaluate the iterative convergence status. The target opening of each independent back pressure valve is the valve opening setting value calculated by the energy storage liquid cooling system for each liquid cooling plate branch, which is required to establish the target hydrostatic pressure inside each liquid cooling plate. Since the target hydrostatic pressure inside each liquid cooling plate is usually different, the target opening of each independent back pressure valve is also usually different, reflecting the need for differentiated pressure management of each branch in a multi-battery parallel system.

[0074] Specifically, constrained by the total system target flow rate and the target hydrostatic pressure within each liquid-cooled plate, the current equivalent flow resistance of each liquid-cooled plate is substituted into the hydraulic network flow resistance model. A set of network equations is constructed with the target speed of the inlet pump and the target opening of each independent back pressure valve as unknowns for initial solution, yielding candidate target speeds and openings. Candidate control variables are then substituted into the hydraulic network flow resistance model to back-calculate the predicted pressure within each liquid-cooled plate branch. The difference between the predicted pressure within each liquid-cooled plate and the corresponding target hydrostatic pressure is checked to ensure it meets the preset convergence threshold. If the pressure deviation of any liquid-cooled plate does not meet the convergence threshold, the equivalent flow resistance is updated by re-querying its deformation flow resistance relationship using the current predicted pressure within that liquid-cooled plate as input. The updated equivalent flow resistances of all liquid-cooled plates are then written into the hydraulic network flow resistance model and solved jointly again. This iterative process continues until the predicted pressure deviations within all liquid-cooled plates meet the preset convergence threshold or the preset maximum number of iterations is reached. The target speed of the candidate water pump and the target opening degree of each independent back pressure valve, which are finally converged in the final iteration, are used as the output control quantities for this control cycle.

[0075] S208. Control the water pump at the inlet end according to the target speed, and simultaneously adjust the back pressure valve at the outlet end according to the target opening degree, so as to maintain the target coolant flow rate and establish the target hydrostatic pressure inside the thin-walled elastic liquid cooling plate, so that the thin-walled elastic liquid cooling plate dynamically adapts to the charging and discharging deformation of the energy storage battery.

[0076] Step S208 is similar to step S106, and will not be described again here.

[0077] In the above embodiments, for scenarios where multiple energy storage battery cells are connected in parallel to the same liquid cooling circuit, the target coolant flow rate and target hydrostatic pressure within the plate are calculated independently for each cell. The target speed of the water pump at the inlet end and the target opening degree of each independent back pressure valve are jointly solved through multivariate iterative calculation. This allows for independent management of the pressure within each parallel liquid cooling plate branch, which helps each battery cell establish an appropriate hydrostatic pressure within the plate according to its own heat exchange requirements, thereby improving the heat dissipation uniformity of each battery in the multi-cell parallel system.

[0078] The above describes an energy storage liquid cooling control method based on static pressure dynamic compensation in the embodiments of this application. The following describes an exemplary energy storage liquid cooling system 300 provided in the embodiments of this application.

[0079] Figure 3 This is an exemplary hardware structure diagram of the energy storage liquid cooling system 300 provided in an embodiment of this application. In some embodiments, the energy storage liquid cooling system 300 is a computer device. The computer device includes a processor, a memory, and a network interface connected via a system bus. The processor of the computer device provides computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system, computer programs, and a database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The database of the computer device is used to store data. The network interface of the computer device is used to communicate with other external terminals or servers via a network connection. In some embodiments, the network interface can be a wired network interface; in some embodiments, the network interface can also be a wireless network interface. When the computer program is executed by the processor, it implements an energy storage liquid cooling control method based on static pressure dynamic compensation according to an embodiment of this application.

[0080] Those skilled in the art will understand that Figure 3 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0081] In some embodiments of this application, a computer-readable storage medium is also provided, including instructions that, when executed on the energy storage liquid cooling system 300, cause the energy storage liquid cooling system 300 to perform an energy storage liquid cooling control method based on static pressure dynamic compensation according to an embodiment of this application.

[0082] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit it. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

[0083] As used in the above embodiments, depending on the context, the term "when..." can be interpreted as meaning "if...", "after...", "in response to determining...", or "in response to detecting...". Similarly, depending on the context, the phrase "when determining..." or "if (the stated condition or event) is interpreted as meaning "if determining...", "in response to determining...", "when (the stated condition or event) is detected", or "in response to detecting (the stated condition or event)".

[0084] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid-state drive), etc.

[0085] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. This program can be stored in a computer-readable storage medium, and when executed, it can include the processes described in the above method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as ROM or random access memory (RAM), magnetic disks, or optical disks.

Claims

1. A method for controlling liquid cooling of energy storage based on static pressure dynamic compensation, characterized in that, The method, applied to energy storage liquid cooling systems, includes: The charging and discharging current, surface temperature, and inlet and outlet water temperatures of the thin-walled elastic liquid cooling plate attached to the surface of the energy storage battery are obtained. The real-time heating power of the energy storage battery is determined based on the charging and discharging current, and the real-time equivalent heat transfer resistance between the energy storage battery and the thin-walled elastic liquid cooling plate is calculated by combining the surface temperature and the inlet and outlet water temperatures. Based on the real-time heat generation power and the preset target temperature difference of the coolant, calculate the target coolant flow rate required to maintain the thermal balance of the energy storage battery; Based on the charging and discharging state indicated by the charging and discharging current, a preset thermal resistance deformation mapping relationship is selected, and combined with the difference between the real-time equivalent heat transfer thermal resistance and the preset thermal resistance reference value, the target hydrostatic pressure inside the plate required to drive the thin-walled elastic liquid cooling plate to undergo elastic deformation to compensate for the interface deformation is determined. Substitute the target static water pressure inside the plate and the target coolant flow rate into the preset hydraulic pipeline flow resistance model for joint solution to obtain the target speed of the water pump at the inlet end and the target opening of the back pressure valve at the outlet end. The water pump at the inlet end is controlled according to the target rotation speed, and the back pressure valve at the outlet end is adjusted synchronously according to the target opening degree, so as to maintain the target coolant flow rate and establish the target hydrostatic pressure inside the thin-walled elastic liquid cooling plate, so that the thin-walled elastic liquid cooling plate dynamically adapts to the charging and discharging deformation of the energy storage battery.

2. The method according to claim 1, characterized in that, The step of calculating the real-time equivalent heat transfer resistance between the energy storage battery and the thin-walled elastic liquid cooling plate by combining the surface temperature and the inlet and outlet water temperatures specifically includes: Based on the pre-calibrated thermal time constants of the inlet and outlet temperature sensors, first-order thermal inertia compensation is performed on the currently collected inlet and outlet temperatures to obtain the corrected inlet and outlet temperatures. The average of the corrected inlet water temperature and the corrected outlet water temperature is determined as the coolant side reference temperature; The real-time equivalent heat transfer resistance is obtained by dividing the difference between the surface temperature and the coolant side reference temperature by the real-time heating power.

3. The method according to claim 2, characterized in that, After obtaining the real-time equivalent heat transfer resistance, the method further includes: When the absolute value of the charging and discharging current is continuously lower than the preset static current threshold and the duration exceeds the preset static duration, the rate of change of the real-time equivalent heat transfer resistance is continuously monitored. When the rate of change of the real-time equivalent heat transfer resistance is lower than the preset thermal resistance stability threshold, the current real-time equivalent heat transfer resistance is used as the measured update value of the thermal resistance, and the preset thermal resistance reference value is rolled over for correction.

4. The method according to claim 3, characterized in that, After the steps of controlling the inlet water pump according to the target rotation speed and simultaneously adjusting the outlet back pressure valve according to the target opening degree, the method further includes: Record the measured value of the hydrostatic pressure inside the thin-walled elastic liquid cooling plate during the current control cycle, and the real-time equivalent heat transfer thermal resistance deviation calculated with reference to the preset thermal resistance benchmark value after rolling correction, to form a pressure-thermal resistance deviation sample pair. After completing one full charge-discharge cycle, the feature parameters of the preset thermal resistance deformation mapping relationship are updated by recursive identification based on all pressure-thermal resistance deviation sample pairs accumulated during the charge-discharge cycle.

5. The method according to claim 1, characterized in that, The step of substituting the target hydrostatic pressure within the plate and the target coolant flow rate into a preset hydraulic pipeline flow resistance model for joint solution to obtain the target rotational speed of the inlet pump and the target opening degree of the outlet back pressure valve specifically includes: Based on the pre-established deformation flow resistance relationship of the cross-sectional area of ​​the internal flow channel of the thin-walled elastic liquid cooling plate as a function of the hydrostatic pressure inside the plate, the equivalent flow resistance of the thin-walled elastic liquid cooling plate after elastic deformation is calculated according to the target hydrostatic pressure inside the plate, and the equivalent flow resistance is updated in the hydraulic pipeline flow resistance model. Substitute the target coolant flow rate and the target hydrostatic pressure inside the plate into the updated hydraulic network flow resistance model for joint solution to obtain the candidate target rotational speed and candidate target opening. Based on the candidate target rotational speed and the candidate target opening, the predicted pressure inside the thin-walled elastic liquid cooling plate is calculated. If the difference between the predicted pressure inside the plate and the target hydrostatic pressure inside the plate exceeds a preset convergence threshold, the equivalent flow resistance is recalculated based on the predicted pressure inside the plate, and the hydraulic network flow resistance model is updated. This process is repeated until convergence or the preset maximum number of iterations is reached. The final candidate target rotational speed and candidate target opening are then used as the target rotational speed and target opening, respectively.

6. The method according to claim 5, characterized in that, In the case where the energy storage liquid cooling system includes multiple energy storage batteries arranged in parallel, each energy storage battery is respectively attached to a thin-walled elastic liquid cooling plate, and the outlet back pressure valve includes multiple independent back pressure valves corresponding one-to-one with each of the thin-walled elastic liquid cooling plates, the step of substituting the target hydrostatic pressure inside the plate and the target coolant flow rate into a preset hydraulic pipeline flow resistance model for joint solution specifically includes: Calculate the target coolant flow rate and target hydrostatic pressure within the plate for each of the energy storage batteries, and sum the target coolant flow rates of each energy storage battery to obtain the total target flow rate of the system. Based on their respective deformation flow resistance relationships, the equivalent flow resistance of each thin-walled elastic liquid cooling plate is calculated using the target hydrostatic pressure within the plate, and the equivalent flow resistance is updated in the hydraulic pipeline flow resistance model. The total target flow rate of the system and the target hydrostatic pressure within each of the thin-walled elastic liquid cooling plates are substituted into the updated hydraulic pipeline flow resistance model. The model is then solved jointly through multivariate iterative cycles until the difference between the predicted pressure within each thin-walled elastic liquid cooling plate and the corresponding target hydrostatic pressure within the plate satisfies the preset convergence threshold. This yields the target rotational speed of the inlet pump and the target opening degree of each independent back pressure valve.

7. The method according to claim 1, characterized in that, After determining the target hydrostatic pressure within the plate required to drive the thin-walled elastic liquid-cooled plate to undergo elastic deformation to compensate for the interface deformation, the method further includes: Calculate the rate of change of the charging and discharging current during the current control cycle; When the absolute value of the rate of change exceeds the preset switching judgment threshold, it is determined that the charging and discharging state is in the switching transition period. Based on the direction and magnitude of the rate of change, the preset current change rate-feedforward compensation pressure mapping relationship is queried to obtain the feedforward compensation pressure. The feedforward compensation pressure is superimposed on the target hydrostatic pressure inside the plate to obtain the feedforward corrected target hydrostatic pressure inside the plate. The target hydrostatic pressure inside the plate is replaced by the feedforward corrected target hydrostatic pressure inside the plate, and the joint solution step is performed to pre-adjust the deformation of the thin-walled elastic liquid cooling plate before the charging and discharging state switching is completed, so as to suppress the interface from detaching at the moment of switching.

8. An energy storage liquid cooling system, characterized in that, The energy storage liquid cooling system includes: one or more processors and a memory; the memory is coupled to the one or more processors, the memory is used to store computer program code, the computer program code including computer instructions, and the one or more processors call the computer instructions to cause the energy storage liquid cooling system to perform the method as described in any one of claims 1-7.

9. A computer program product containing instructions, characterized in that, When the computer program product is run on the energy storage liquid cooling system, it causes the energy storage liquid cooling system to perform the method as described in any one of claims 1-7.

10. A computer-readable storage medium comprising instructions, characterized in that, When the instruction is executed on the energy storage liquid cooling system, the energy storage liquid cooling system performs the method as described in any one of claims 1-7.

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