Control method of energy storage liquid cooling system and liquid cooling system

Abstract

The invention discloses a control method of an energy storage liquid cooling system and the liquid cooling system. The method comprises the following steps: acquiring the average temperature of a battery cell and the working current of a battery; determining whether the energy storage liquid cooling system should be in a refrigeration mode or a heating mode based on the cell average temperature, and determining whether the energy storage liquid cooling system should be in a self-circulation mode or a standby mode according to the cell average temperature and the battery working current; in the refrigeration mode, a refrigeration target temperature is determined according to the cell average temperature and a first limiting condition, and the battery is controlled to be cooled according to the refrigeration target temperature; in the heating mode, the heating target temperature is determined according to the average temperature of the battery cell and a second limiting condition, and the battery is controlled to be heated according to the heating target temperature; when in the self-circulation mode, the cooling liquid is not actively cooled or heated, and the batteries are cooled or heated by utilizing the natural temperature of the cooling liquid; and when the battery is in the standby mode, cooling or heating of the battery is stopped.

Description

Technical Field

[0001] The embodiments of the present invention relate to automatic control technology, and in particular to a control method and a liquid cooling system for an energy storage liquid cooling system. Background Art

[0002] In recent years, energy storage battery systems have been widely used in power systems due to their high capacity, long life, and high transmission efficiency. However, traditional energy storage liquid cooling systems consume a lot of electricity during operation, resulting in reduced system efficiency. Especially when the thermal management system is in operation, the energy consumption of air conditioners, liquid coolers, cooling fans and other devices increases significantly.

[0003] In addition, existing liquid cooling systems usually rely on a single temperature sensor to feedback water temperature data for mode switching. This method is difficult to fully reflect the actual temperature conditions inside the battery pack, resulting in insufficient accuracy and consistency in temperature control. When the liquid cooling system is in standby or shutdown state, the reduction in temperature detection frequency may also result in temperature anomalies not being detected in time, affecting the system's response speed and accuracy.

[0004] Therefore, the control accuracy of existing technologies needs to be improved when dealing with complex working conditions and emergencies, which not only affects the working efficiency of energy storage batteries, but also may bring potential safety hazards. It is particularly important to improve the existing liquid cooling system and realize self-adjustment of cooling power consumption through refined temperature monitoring and intelligent control strategies to ensure efficient and safe operation of the system. Summary of the invention

[0005] The present invention provides a control method for an energy storage liquid cooling system and a liquid cooling system, so as to achieve the purpose of realizing refined temperature control regulation of a battery system and optimizing energy consumption of a liquid cooling system.

[0006] In a first aspect, an embodiment of the present invention provides a control method for an energy storage liquid cooling system, comprising:

[0007] Get the average cell temperature and battery operating current;

[0008] Determining whether the energy storage liquid cooling system should be placed in a cooling mode or a heating mode based on the average temperature of the battery cells, and determining whether the energy storage liquid cooling system should be placed in a self-circulation mode or a standby mode based on the average temperature of the battery cells and the battery operating current;

[0009] When in the cooling mode, determining a cooling target temperature according to the average temperature of the battery cells and the first restriction condition, and controlling the battery to cool according to the cooling target temperature;

[0010] When in the heating mode, determining a heating target temperature according to the average temperature of the battery cells and a second limiting condition, and controlling the battery to heat up according to the heating target temperature;

[0011] When in the self-circulation mode, the coolant is not actively cooled or heated, and the natural temperature of the coolant is used to cool or heat the battery;

[0012] When in the standby mode, cooling or heating the battery is stopped.

[0013] Optionally, obtain the cooling temperature point, cooling sensitivity, and maximum cell temperature;

[0014] If the average temperature of the battery cell is greater than or equal to the sum of the cooling temperature point and the first times of the cooling sensitivity, or the maximum temperature of the battery cell is greater than or equal to the sum of the cooling temperature point and the cooling sensitivity, it is determined to be placed in the cooling mode.

[0015] Optionally, obtain the heating temperature point, heating sensitivity, and minimum cell temperature;

[0016] If the average temperature of the battery cell is less than or equal to the difference between the heating temperature point and the second time of the heating sensitivity, or the lowest temperature of the battery cell is less than or equal to the difference between the heating temperature point and the heating sensitivity, it is determined to be placed in the heating mode.

[0017] Optionally, obtain the cell extreme temperature difference, cooling temperature point, and heating temperature point;

[0018] If the average temperature of the battery cell is greater than or equal to the heating temperature point and less than or equal to the cooling temperature point, and the battery cell extreme temperature difference is greater than or equal to the cooling sensitivity, it is determined to be placed in the self-circulation mode;

[0019] Alternatively, if the absolute value of the battery operating current is greater than the current threshold, it is determined to be placed in the self-circulation mode.

[0020] Optionally, if the entry conditions for being placed in the cooling mode, the heating mode and the self-circulation mode are not met, the mode is placed in the standby mode.

[0021] Optionally, the cooling target temperature is the difference between the average temperature of the battery cells and a set temperature, and the heating target temperature is the sum of the average temperature of the battery cells and the set temperature;

[0022] The first restriction condition and the second restriction condition meet the following conditions:

[0023] The cooling target temperature is not lower than a preset boundary temperature, and the heating target temperature is not higher than the preset boundary temperature.

[0024] Optionally, the priorities of the cooling mode, heating mode, self-circulation mode, and standby mode are reduced in sequence;

[0025] When the execution conditions of multiple modes among the cooling mode, heating mode, self-circulation mode and standby mode are met, the mode with the highest priority is preferentially executed.

[0026] In a second aspect, an embodiment of the present invention further provides a liquid cooling system, including a battery management unit and a liquid cooling execution unit;

[0027] The battery management unit is configured to:

[0028] Get the average cell temperature and battery operating current;

[0029] Determining whether the energy storage liquid cooling system should be placed in a cooling mode or a heating mode based on the average temperature of the battery cells, and determining whether the energy storage liquid cooling system should be placed in a self-circulation mode or a standby mode based on the average temperature of the battery cells;

[0030] When in the cooling mode, determining a cooling target temperature according to the average temperature of the battery cells and the first restriction condition, and controlling the battery to cool according to the cooling target temperature;

[0031] When in the heating mode, determining a heating target temperature according to the average temperature of the battery cells and a second limiting condition, and controlling the battery to heat up according to the heating target temperature;

[0032] When in the self-circulation mode, the coolant is not actively cooled or heated, and the natural temperature of the coolant is used to cool or heat the battery;

[0033] When in the standby mode, stopping cooling or heating the battery;

[0034] The battery management unit cools down or heats up the battery by controlling the liquid cooling execution unit.

[0035] Optionally, it also includes an energy management unit, which is used to evaluate the execution result of the control method of the energy storage liquid cooling system executed by the battery management unit.

[0036] Optionally, the energy management unit is further configured to set or change operating parameters of the battery management unit.

[0037] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention proposes a control method, in which the working mode of the liquid cooling system is set to a cooling mode, a heating mode, a self-circulation mode and a standby mode. In the cooling mode and the heating mode, the temperature of the coolant is actively controlled, and the target temperature value of the liquid cooling can be set to a suitable value in time according to the current average temperature of the battery cell to ensure the timely transfer of heat. By setting the target temperature value and the dynamic following of the average temperature of the battery cell, and setting a variety of modes. The convergence of the control method can be ensured, so that the maximum output of the liquid cooling system within the effective range can be controlled. Then the optimal power consumption control is achieved, and the perfect balance between the control effect and the power consumption control is achieved; in addition, the dynamic following of the cooling or heating target temperature and the battery cell temperature is more in line with the current safety requirements of energy storage liquid cooling control than the simple start-stop mode based on a fixed temperature value. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 is a flow chart of the control method in the embodiment;

[0039] Figure 2 is another control method flow chart in the embodiment;

[0040] Figure 3 is a structural block diagram of a liquid cooling system in an embodiment;

[0041] Figure 4 It is a structural block diagram of an electronic device in an embodiment. DETAILED DESCRIPTION

[0042] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0043] Embodiment 1

[0044] Figure 1 is a flow chart of the control method in the embodiment, refer to Figure 1 , control methods include:

[0045] S101. Obtain the average cell temperature and battery operating current.

[0046] In this solution, the battery is assumed to include a plurality of battery cells, the average temperature of the battery cells is set as a calculated value, and the average temperature of the battery cells is set to be obtained by calculating the arithmetic average of the temperatures of all the battery cells.

[0047] Exemplarily, in this solution, a temperature sensor may be configured to measure the temperature of each battery cell, and then the average temperature of the battery cells may be calculated.

[0048] In this solution, setting the battery operating current may include a discharge current and a charge current, wherein the battery operating current may adopt a current measurement value of a battery management system (BMS).

[0049] S102. Determine whether the energy storage liquid cooling system should be placed in cooling mode or heating mode based on the average temperature of the battery cells, and determine whether the energy storage liquid cooling system should be placed in self-circulation mode or standby mode based on the average temperature of the battery cells and the battery operating current.

[0050] In this solution, the energy storage liquid cooling system is set to include four functional modes, namely cooling mode, heating mode, self-circulation mode and standby mode. Among them, the cooling mode, heating mode and self-circulation mode are used to adjust the temperature of the battery cells.

[0051] Exemplarily, in this solution, the energy storage cooling system may include a coolant, a circulation pump, a radiator, and pipelines, etc., and the energy storage liquid cooling system is used to adjust the corresponding temperature of the battery;

[0052] Coolant is the core component of the liquid cooling system, and its main function is to absorb and transfer heat. Commonly used coolants include water, ethylene glycol aqueous solution, silicone oil, etc.

[0053] The circulation pump is the power source of the liquid cooling system. Its main function is to drive the coolant to circulate in the system.

[0054] The radiator is an important part of the liquid cooling system. Its main function is to dissipate the heat absorbed by the coolant into the surrounding environment.

[0055] Pipes and joints are the connecting parts of the liquid cooling system, and their main function is to transport coolant to various heat dissipation components.

[0056] Exemplarily, in this solution, the energy storage cooling system is set to heat or dissipate the coolant. For example, the following methods can be used for heating:

[0057] Install an electric heating film or heating plate in the energy storage cooling system. When the coolant needs to be heated, power is turned on to heat the heating film or plate, and the heat is transferred to the coolant by contact conduction through pipes, etc.

[0058] The coolant is heated by using a PTC thermistor. The PTC (Positive Temperature Coefficient) thermistor has a positive temperature coefficient characteristic. When the temperature rises, the resistance value increases. By passing current through the PTC thermistor, the resistance generates heat, which can heat the coolant.

[0059] For heat dissipation, the following methods can be used:

[0060] Use natural convection or forced convection of air to remove the heat of the coolant;

[0061] The coolant is cooled using a compressor refrigeration system, which transfers heat from the coolant to the external environment through processes such as compression, condensation, expansion and evaporation.

[0062] Exemplarily, in this solution, the mode switching threshold (the mode switching threshold is expressed as a temperature value) can be determined by simulation test, test, etc., and the cooling mode or heating mode can be determined based on the comparison result between the average temperature of the battery cell and the mode switching threshold;

[0063] For example, it can be set that when the average temperature of the battery cells is greater than a first mode switching threshold, it is determined to be placed in the cooling mode, and when the average temperature of the battery cells is less than a second mode switching threshold, it is determined to be placed in the heating mode.

[0064] In this scheme, the average cell temperature and the battery operating current are used to jointly determine whether the energy storage liquid cooling system is placed in the self-circulation mode;

[0065] For example, the temperature threshold interval and the current threshold may be determined by simulation tests, experiments, etc., and when the average temperature of the battery cell is within the temperature threshold interval, it is determined whether the battery operating current is greater than the current threshold;

[0066] When the average temperature of the battery cell is not within the temperature threshold range, it is determined not to be placed in the self-circulation mode;

[0067] When the average temperature of the battery cell is within the temperature threshold range and the battery operating current is greater than the current threshold, it is determined to be placed in the self-circulation mode;

[0068] When the average temperature of the battery cell is within the temperature threshold range and the battery operating current is less than or equal to the current threshold, it is determined not to be placed in the self-circulation mode.

[0069] Exemplarily, in this solution, when in the self-circulation mode, the temperature of the coolant is not controlled or actively adjusted, and the natural temperature of the coolant is used to cool down or heat up the battery.

[0070] In this solution, it is set to determine whether to be placed in the cooling mode, heating mode, and self-circulation mode. When the energy storage liquid cooling system should not be placed in the cooling mode, heating mode, and self-circulation mode, it is determined to be placed in the standby mode.

[0071] Exemplarily, in this solution, when it is set in cooling mode, the liquid cooling system dissipates heat to the battery cells; when it is in heating mode, the liquid cooling system heats the battery cells; when it is in self-circulation mode, it dissipates heat or heats the battery cells; when it is in standby mode, the liquid cooling system is shut down.

[0072] S103. When in cooling mode, determine a cooling target temperature according to the average temperature of the battery cells and the first restriction condition, and control cooling of the battery according to the cooling target temperature.

[0073] In this solution, when in cooling mode, the target temperature of the coolant is dynamically set according to the current average temperature of the battery cell, that is, the cooling target temperature is determined;

[0074] Among them, based on the average temperature of the battery cells, the average temperature of the battery cells can be used as an input quantity, and the corresponding cooling target temperature can be determined by using fuzzy control or other methods;

[0075] After determining the cooling target temperature, closed-loop control and other methods can be used to control the coolant temperature at the coolant outlet of the liquid cooling system to reach the cooling target temperature, thereby cooling the battery cells through the coolant.

[0076] S104. When in the heating mode, determine a heating target temperature according to the average temperature of the battery cells and the second limiting condition, and control the battery temperature to rise according to the heating target temperature.

[0077] In this solution, when in heating mode, the target temperature of the coolant is dynamically set according to the current average temperature of the battery cell, that is, the heating target temperature is determined;

[0078] Among them, based on the average temperature of the battery cells, the average temperature of the battery cells can be used as an input quantity, and the corresponding heating target temperature can be determined by using fuzzy control or other methods;

[0079] After determining the heating target temperature, closed-loop control and other methods can be used to control the coolant temperature at the coolant outlet of the liquid cooling system to reach the heating target temperature, thereby heating the battery cells through the coolant.

[0080] Exemplarily, in step S103 and step S104, the implementation method of fuzzy control is the same as that in the prior art, and the specific content is not described in detail.

[0081] In combination with step S103 and step S104, in this solution, the first limit condition is set to satisfy that the cooling target temperature should be between the first temperature boundary value and the second temperature boundary value, and the second limit condition is set to satisfy that the heating target temperature is less than the first temperature boundary value;

[0082] If the cooling target temperature or the heating target temperature obtained by calculation exceeds the above numerical range, the cooling target temperature may take the first temperature boundary value or the second temperature boundary value, and the heating target temperature may take the first temperature boundary value.

[0083] Exemplarily, in this embodiment, the first temperature boundary value and the second temperature boundary value can be determined through experience, experiments, etc. The first temperature boundary value and the second temperature boundary value are used to control the temperature of the coolant within a suitable range to ensure the charging and discharging process of the battery.

[0084] S105. When in the self-circulation mode, the coolant is not actively cooled or heated, and the natural temperature of the coolant is used to cool or heat the battery.

[0085] In this solution, when in the self-circulation mode, the temperature of the coolant is not controlled or actively adjusted. The coolant is only controlled to circulate in the pipeline, and heat is exchanged with the battery cells through the temperature of the coolant itself, thereby achieving the purpose of cooling or heating the battery cells.

[0086] S106. When in standby mode, stop cooling or heating the battery.

[0087] In this solution, when in standby mode, the energy storage liquid cooling system is shut down and the coolant stops circulating.

[0088] This embodiment proposes a control method, in which the working mode of the liquid cooling system is set to a cooling mode, a heating mode, a self-circulation mode, and a standby mode. In the cooling mode and the heating mode, the temperature of the coolant is actively controlled, and the target temperature value of the liquid cooling can be set to a suitable value in time according to the current average temperature of the battery cell to ensure the timely transfer of heat. By setting the target temperature value and the dynamic following of the average temperature of the battery cell, and setting a variety of modes. The convergence of the control method can be ensured, so that the maximum output of the liquid cooling system within the effective range can be controlled. Then the optimal power consumption control is achieved, and the perfect balance between the control effect and the power consumption control is achieved; in addition, this method dynamically follows the cooling or heating target temperature with the battery cell temperature, which is more in line with the current safety requirements of energy storage liquid cooling control than the simple start-stop mode based on a fixed temperature value.

[0089] exist Figure 1 On the basis of the scheme shown, in one possible implementation scheme, the cooling temperature point, cooling sensitivity, and maximum temperature of the battery cell are obtained;

[0090] If the average temperature of the battery cell is greater than or equal to the sum of the cooling temperature point and the first cooling sensitivity, or the maximum temperature of the battery cell is greater than or equal to the sum of the cooling temperature point and the cooling sensitivity, it is determined to be placed in cooling mode.

[0091] Illustratively, in this solution, the specific value of the first times refrigeration sensitivity can be determined based on experience or simulation tests. For example, the first times refrigeration sensitivity can be 0.5 times refrigeration sensitivity.

[0092] In this scheme, the cooling temperature point is recorded as T cool, the cooling sensitivity is recorded as T cool-sensitivity , the highest temperature of the battery cell is recorded as T cell-max , the average cell temperature is recorded as T average ;

[0093] Among them, the cooling temperature point and cooling sensitivity are preset values, the maximum temperature of the battery cell is the measured value, and the average temperature of the battery cell is the calculated value.

[0094] In this solution, the cooling temperature point represents a temperature threshold, the cooling sensitivity represents the allowable fluctuation value of the cooling temperature point, and the maximum temperature of the battery cell represents the maximum value of all temperature measurement values ​​of the battery cell.

[0095] In this solution, the entry conditions of the cooling mode are set as follows:

[0096] T average ≥T cool +T cool-sensitivity / 2

[0097] or,

[0098] T cell-max ≥T cool +T cool-sensitivity

[0099] Set the exit condition of cooling mode as follows:

[0100] T average <T cool +T cool-sensitivity / 2

[0101] or,

[0102] T cell-max <T cool

[0103] On the basis of any of the foregoing solutions, in one possible implementation, a heating temperature point, a heating sensitivity, and a minimum temperature of a battery cell are obtained;

[0104] If the average cell temperature is less than or equal to the difference between the heating temperature point and the second heating sensitivity, or the lowest cell temperature is less than or equal to the difference between the heating temperature point and the heating sensitivity, it is determined to be placed in the heating mode.

[0105] Illustratively, in this solution, the specific value of the second times cooling sensitivity can be determined based on experience or simulation tests. For example, the second times cooling sensitivity can be 0.5 times heating sensitivity.

[0106] In this scheme, the heating temperature point is recorded as T heat , heating sensitivity is recorded as T heat-sensitivity , the lowest temperature of the battery cell is recorded as T cell-min , the average cell temperature is recorded as T average ;

[0107] Among them, the heating temperature point and heating sensitivity are preset values, the lowest temperature of the battery cell is the measured value, and the average temperature of the battery cell is the calculated value.

[0108] In this solution, the heating temperature point represents a temperature threshold, the heating sensitivity represents the allowable fluctuation value of the heating temperature point, and the minimum temperature of the battery cell represents the minimum value of all temperature measurement values ​​of the battery cell.

[0109] In this solution, the entry conditions for the heating mode are set as follows:

[0110] T average ≤T heat +T heat-sensitivity / 2

[0111] or,

[0112] T cell-min ≤T heat +T heat-sensitivity

[0113] Set the exit condition of heating mode as follows:

[0114] T average >T heat +T heat-sensitivity / 2

[0115] or,

[0116] T cell-min >T heat +T heat-sensitivity

[0117] On the basis of any of the foregoing solutions, in one possible implementation, the extreme temperature difference of the battery cell, the cooling temperature point, and the heating temperature point are obtained;

[0118] If the average cell temperature is greater than or equal to the heating temperature point, less than or equal to the cooling temperature point, and the cell extreme temperature difference is greater than or equal to the cooling sensitivity, it is determined to be placed in the self-circulation mode;

[0119] Alternatively, if the absolute value of the battery operating current is greater than the current threshold, it is determined to be placed in the self-circulation mode.

[0120] In this scheme, the cell extreme temperature difference is recorded as T cell-difference , the cooling temperature point is recorded as T cool , the heating temperature point is recorded as T heat , the cooling sensitivity is recorded as T cool-sensitivity , the average cell temperature is recorded as T average , the battery operating current is recorded as I;

[0121] Among them, the heating temperature point and the cooling temperature point are preset values, the battery cell extreme temperature difference and the battery cell average temperature are calculated values, among which the battery cell extreme temperature difference is the difference between the highest temperature of the battery cell and the lowest temperature of the battery cell.

[0122] In this solution, the heating temperature point and the cooling temperature point represent two temperature thresholds.

[0123] In this scheme, the entry conditions of the self-circulation mode are set as follows:

[0124] T cool ≥T average ≥T heat

[0125] T cell-difference ≥T cool-sensitivity

[0126] or,

[0127] |I|>I ref

[0128] In the formula, I ref Indicates the current threshold;

[0129] Set the exit condition of the self-loop mode to:

[0130] T average >T cool

[0131] |I|≤I ref

[0132] or,

[0133] T average <T cool

[0134] |I|≤I ref

[0135] or,

[0136] T cell-difference <T cool-sensitivity

[0137] |I|≤I ref

[0138] Based on any of the above solutions, in one possible implementation, if the entry conditions for being placed in cooling mode, heating mode and self-circulation mode are not met, the mode is placed in standby mode.

[0139] Based on any of the foregoing solutions, in one possible implementation scheme, the cooling target temperature is the difference between the average temperature of the battery cells and the set temperature, and the heating target temperature is the sum of the average temperature of the battery cells and the set temperature;

[0140] The first and second constraints are met:

[0141] The cooling target temperature is not lower than the preset boundary temperature, and the heating target temperature is not higher than the preset boundary temperature. Exemplarily, in this solution, the cooling target temperature is calculated by the following formula:

[0142] T cr =T average -T m

[0143] The heating target temperature is calculated by the following formula:

[0144] T hr =T average +T m

[0145] Where, T cr Indicates the cooling target temperature, T hr Indicates the heating target temperature, T average Indicates the average cell temperature, T m Indicates the set temperature.

[0146] In this scheme, T cr Should meet:

[0147] T2≥T cr ≥T1

[0148] Set T hr Should meet:

[0149] T1≥T hr

[0150] Wherein, T1 represents a preset boundary temperature, and T2 represents a temperature threshold.

[0151] On the basis of any of the foregoing solutions, in one possible implementation scheme, the priorities of cooling mode, heating mode, self-circulation mode, and standby mode are reduced in sequence;

[0152] When the execution conditions of multiple modes among the cooling mode, the heating mode, the self-circulation mode and the standby mode are met, the mode with the highest priority is executed first.

[0153] In this solution, the cooling mode is set as the first priority, the heating mode is set as the second priority, the self-circulation mode is set as the third priority, and the standby mode is set as the fourth priority. When multiple modes can be executed, the mode with the highest priority is executed first;

[0154] For example, if it is determined according to the preset conditions that the heating mode or the self-circulation mode can be executed, the heating mode is executed and the self-circulation mode is not executed.

[0155] Figure 2 is another control method flow chart in the embodiment, refer to Figure 2 Based on any of the above solutions, in one possible implementation method, the control method may include:

[0156] S201. Obtain the average cell temperature, battery operating current, cooling temperature point, cooling sensitivity, heating temperature point, heating sensitivity, cell maximum temperature and cell minimum temperature.

[0157] S202: If the average cell temperature is greater than or equal to the sum of the cooling temperature point and 0.5 times the cooling sensitivity, or the maximum cell temperature is greater than or equal to the sum of the cooling temperature point and the cooling sensitivity, determine to place in cooling mode.

[0158] S203: If the average cell temperature is less than or equal to the difference between the heating temperature point and 0.5 times the heating sensitivity, or the lowest cell temperature is less than or equal to the difference between the heating temperature point and the heating sensitivity, determine to place in heating mode.

[0159] S204. If the average temperature of the battery cell is greater than or equal to the heating temperature point, less than or equal to the cooling temperature point, and the extreme temperature difference of the battery cell is greater than or equal to the cooling sensitivity, it is determined to be placed in the self-circulation mode;

[0160] Alternatively, if the absolute value of the battery operating current is greater than the current threshold, it is determined to be placed in the self-circulation mode.

[0161] S205. If the entry conditions for the cooling mode, heating mode and self-circulation mode are not met, the mode is placed in the standby mode.

[0162] Based on the above corresponding scheme, in this scheme, the entry conditions of the cooling mode are set as follows:

[0163] T average ≥T cool +T cool-sensitivity / 2

[0164] or,

[0165] T cell-max ≥T cool +T cool-sensitivity

[0166] Set the exit condition of cooling mode as follows:

[0167] T average <T cool +T cool-sensitivity / 2

[0168] or,

[0169] T cell-max <T cool

[0170] Set the entry conditions for heating mode as follows:

[0171] T average ≤T heat +T heat-sensitivity / 2

[0172] or,

[0173] T cell-min ≤T heat +T heat-sensitivity

[0174] Set the exit condition of heating mode as follows:

[0175] T average >T heat +T heat-sensitivity / 2

[0176] or,

[0177] T cell-min >T heat +T heat-sensitivity

[0178] Set the entry conditions of the self-circulation mode as follows:

[0179] T cool ≥T average ≥T heat

[0180] T cell-difference ≥T cool-sensitivity

[0181] or,

[0182] |I|>I ref

[0183] In the formula, I ref Indicates the current threshold, the current threshold is 20A;

[0184] Set the exit condition of the self-loop mode to:

[0185] T average >T cool

[0186] |I|≤I ref

[0187] or,

[0188] T average <T cool

[0189] |I|≤I ref

[0190] or,

[0191] T cell-difference <T cool-sensitivity

[0192] |I|≤I ref

[0193] In this solution, set the set temperature T m The cooling target temperature for 10°C is calculated by the following formula:

[0194] T cr =T average -10

[0195] The heating target temperature is calculated by the following formula:

[0196] T hr =T average +10

[0197] In this solution, the preset boundary temperature T1 is set to 18°C, the temperature threshold T2 is set to 28°C, and T cr Should meet:

[0198] 28≥T cr ≥18

[0199] Set T hr Should meet:

[0200] 18≥T hr

[0201] In this scheme, the cooling mode, heating mode, self-circulation mode, and standby mode are set as the first priority, the second priority, the third priority, and the fourth priority, respectively;

[0202] When the execution conditions of multiple modes among the cooling mode, the heating mode, the self-circulation mode and the standby mode are met, the mode with the highest priority is executed.

[0203] In this solution, the temperature of each battery cell is collected in real time, and the average temperature of the battery cell is calculated based on the temperature, as well as the maximum and minimum temperatures of the battery cell.

[0204] In this solution, the cooling temperature point, cooling sensitivity, heating temperature point, heating sensitivity, set temperature, preset boundary temperature, temperature threshold, and current threshold are default or set policy parameter values;

[0205] When in cooling mode or heating mode, after entering the corresponding mode, the target temperature of the coolant is set by combining the difference between the average temperature of the battery cell and the default temperature (set temperature) representing the physical thermal conductivity property, so that the temperature control effect is effective;

[0206] The target temperature value of the coolant is not a fixed value, but a value that changes with the temperature of the battery cell. Its changing pattern is not only affected by the temperature difference, but also by the boundary value, that is, it is affected by the preset boundary temperature and temperature threshold.

[0207] Exemplarily, in one solution, all the temperatures T and currents I of the battery cells are collected in real time, and the average temperature T0 of the battery cells, the maximum temperature T1 of the battery cells, the minimum temperature T2 of the battery cells, and the extreme temperature difference T3 of the battery cells (T3=T1-T2) are calculated;

[0208] Set the cooling temperature point to 28°C, the cooling sensitivity to 2°C, the heating temperature point to 10°C, and the heating sensitivity to 3°C;

[0209] In order to ensure the convergence of the control method execution process, the cooling target temperature is set to T0–10 in the cooling mode, and the minimum cooling target temperature is not lower than 18°C ​​and the maximum is not higher than 28°C;

[0210] In heating mode, heating target temperature = T0 + 10, and the maximum heating target temperature is not higher than 18°C;

[0211] Set cooling mode (priority 1), heating mode (priority 2), self-circulation mode (priority 3) and standby mode (priority 4), among which cooling mode has the highest priority;

[0212] based on Figure 2 In the method shown, when the initial temperature of the battery cells is 25°C, the battery cell extreme temperature difference T3 = 0, and the liquid cooling system is in standby mode;

[0213] When the energy storage system is charging or discharging, if the charging and discharging current of the energy storage system exceeds 20A, the mode will automatically be selected as the self-circulation mode, and the liquid cooling system will start circulating coolant to ensure uniform temperature between the battery cells;

[0214] When the average cell temperature T0 reaches 29°C, that is, T0 ≥ cooling temperature point + cooling sensitivity / 2, the mode is automatically selected as cooling mode;

[0215] At this time, the calculated cooling target temperature is T0-10, that is, 19°C. At this time, the liquid cooling system will adjust the output capacity and gradually reduce the temperature of the coolant outlet temperature until the maximum output capacity is reached;

[0216] If the average cell temperature T0 continues to rise to 35°C, the calculated cooling target temperature is 25°C. At this time, the liquid cooling unit continues to adjust the output capacity, and the control target is to make the coolant outlet temperature approach the target temperature of 25°C;

[0217] If the average cell temperature T0 continues to rise to 40°C, the calculated cooling target temperature is 30°C, which exceeds the upper limit of the boundary of 28°C. 28°C is taken, and the cooling target temperature is 28°C. At this time, the average cell temperature and the coolant outlet target temperature will ensure the full power output of the liquid cooling system as much as possible to suppress the terminal temperature rise.

[0218] The temperature of the battery cell accumulates and rises continuously during the charging or discharging process. In this solution, when charging and discharging starts, if the battery cell temperature does not meet the cooling conditions, the system will self-circulate to ensure the uniformity of the battery temperature. When the battery cell temperature rises to meet the cooling conditions, the liquid cooling system intervenes, and the control method will promptly set the target temperature value of the liquid cooling to an appropriate value to ensure the timely transfer of heat, and a dynamic follow-up of the target temperature value is designed to ensure the convergence of the control method, that is, to control the maximum output of the liquid cooling system within the effective range. The method proposed in this solution can not only meet the temperature rise control requirements in the application scenarios of the energy storage system, but also achieve optimal power consumption control through intelligent working mode selection, achieving a perfect balance between control effect and power consumption control;

[0219] The strategy included in this method effectively solves the contradiction between control effect and power consumption, and dynamically follows the cooling or heating target temperature with the battery cell temperature. Compared with the simple start-stop mode based on a fixed temperature value, this method is more in line with the current safety requirements of energy storage liquid cooling control.

[0220] Embodiment 2

[0221] This embodiment provides a liquid cooling system, including a battery management unit and a liquid cooling execution unit;

[0222] The battery management unit is configured to:

[0223] Get the average cell temperature and battery operating current;

[0224] Determine whether the energy storage liquid cooling system should be placed in cooling mode or heating mode based on the average temperature of the battery cells, and determine whether the energy storage liquid cooling system should be placed in self-circulation mode or standby mode based on the average temperature of the battery cells and the battery operating current;

[0225] When in cooling mode, a cooling target temperature is determined according to the average temperature of the battery cells and the first limiting condition, and the battery is cooled according to the cooling target temperature control;

[0226] When in heating mode, a heating target temperature is determined according to the average temperature of the battery cells and the second limiting condition, and the battery temperature is raised according to the heating target temperature control;

[0227] When in self-circulation mode, the coolant is not actively cooled or heated, and the natural temperature of the coolant is used to cool or heat the battery.

[0228] When in standby mode, stop cooling or heating the battery;

[0229] The battery management unit cools down or heats up the battery by controlling the liquid cooling execution unit.

[0230] Exemplarily, in this solution, the battery management unit can be configured to implement any one of the control methods in Example 1. The execution process and beneficial effects of the method are the same as the corresponding contents recorded in Example 1, and the specific contents will not be repeated here.

[0231] Exemplarily, in this solution, the battery management unit (BMS) serves as the control core to collect and process data and control the working mode and set temperature of the liquid cooler. However, the control logic can be implemented not only in the BMS, but also in other media with data acquisition and control capabilities. Specifically, systems such as liquid cooling hosts, PCS or EMS can also serve as execution entities to implement the same strategy application and achieve the same technical purpose. This flexibility allows the implementation of this strategy on different hardware platforms, improving the adaptability and scalability of the system.

[0232] Figure 3 is a structural block diagram of the liquid cooling system in the embodiment, refer to Figure 3 In one possible implementation, the liquid cooling system includes: a battery management unit 100, a liquid cooling execution unit 200, and an energy management unit (Energy Management System, EMS) 300;

[0233] The battery management unit 100 is respectively connected to the energy management unit 300 , the liquid cooling execution unit 200 and the battery 400 for communication, and the liquid cooling execution unit 200 is used for heating or cooling the battery 400 .

[0234] Exemplarily, in this scheme, the battery management unit 100 is configured to execute any one of the control methods described in Example 1, including real-time monitoring of the temperature and current status of the battery cells, and real-time calculation of the parameter values ​​required for the control method, and participation in the mode and target temperature control of the liquid cooling execution unit based on the default strategy parameter values ​​or the values ​​changed by the energy management unit 300.

[0235] In this solution, the energy management unit 300 is configured to monitor the operating status of the liquid-cooled execution unit 200 in real time, and then evaluate the execution status of the control method.

[0236] Exemplarily, in this solution, the energy management unit 300 may be configured to obtain the coolant temperature at the coolant outlet of the liquid-cooled execution unit 200 and the working mode of the liquid-cooled execution unit 200, and determine whether the liquid-cooled execution unit 200 is operating normally based on the obtained coolant temperature and whether the working mode is a cooling target temperature or a heating target temperature;

[0237] The energy management unit 300 is configured to obtain the temperature of the battery cell, and whether the control method is effectively executed is determined by whether the battery cell temperature matches the cooling target temperature or the heating target temperature.

[0238] In one possible implementation, the energy management unit is further configured to set or modify operating parameters of the battery management unit.

[0239] Exemplarily, in this solution, the energy management unit can be configured to set or change parameters such as cooling temperature point, cooling sensitivity, heating temperature point, heating sensitivity, set temperature, preset boundary temperature, temperature threshold, current threshold, etc.

[0240] The liquid cooling system proposed in this solution has intelligent temperature control strategy and mode selection function, which can improve the response capability of cooling or heating, and achieve control convergence in the control method. The system monitors the temperature and current of the battery cell in real time, combines the mode priority, and dynamically adjusts the cooling and heating power consumption, solving the energy consumption and temperature control problems of the existing energy storage liquid cooling system. , improves efficiency and safety, extends battery life, and is suitable for complex working conditions. This solution improves the performance and reliability of the energy storage system and has the potential for wide application.

[0241] Embodiment 3

[0242] Figure 4 A schematic diagram of the structure of an electronic device 10 that can be used to implement an embodiment of the present invention is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or required herein.

[0243] like Figure 4As shown, the electronic device 10 includes at least one processor 11, and a memory connected to the at least one processor 11, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc., wherein the memory stores a computer program that can be executed by at least one processor, and the processor 11 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 12 or the computer program loaded from the storage unit 18 to the random access memory (RAM) 13. In the RAM 13, various programs and data required for the operation of the electronic device 10 can also be stored. The processor 11, the ROM 12, and the RAM 13 are connected to each other through a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0244] A number of components in the electronic device 10 are connected to the I / O interface 15, including: an input unit 16, such as a keyboard, a mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a disk, an optical disk, etc.; and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the electronic device 10 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0245] The processor 11 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The processor 11 executes the various methods and processes described above, such as a control method for an energy storage liquid cooling system.

[0246] In some embodiments, the control method of the energy storage liquid cooling system may be implemented as a computer program, which is tangibly contained in a computer-readable storage medium, such as a storage unit 18. In some embodiments, part or all of the computer program may be loaded and / or installed on the electronic device 10 via the ROM 12 and / or the communication unit 19. When the computer program is loaded into the RAM 13 and executed by the processor 11, one or more steps of the control method of the energy storage liquid cooling system described above may be performed. Alternatively, in other embodiments, the processor 11 may be configured to execute the control method of the energy storage liquid cooling system in any other appropriate manner (e.g., by means of firmware).

[0247] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0248] Computer programs for implementing the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that when the computer program is executed by the processor, the functions / operations specified in the flow chart and / or block diagram are implemented. The computer program may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0249] In the context of the present invention, a computer-readable storage medium may be a tangible medium that may contain or store a computer program for use by or in combination with an instruction execution system, device or equipment. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices or equipment, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0250] To provide interaction with a user, the systems and techniques described herein may be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or trackball) through which the user can provide input to the electronic device. Other types of devices may also be used to provide interaction with the user; for example, the feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user may be received in any form (including acoustic input, voice input, or tactile input).

[0251] The systems and techniques described herein may be implemented in a computing system that includes backend components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes frontend components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such backend components, middleware components, or frontend components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0252] A computing system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The client and server relationship is generated by computer programs running on the corresponding computers and having a client-server relationship with each other. The server may be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system to solve the defects of difficult management and weak business scalability in traditional physical hosts and VPS services.

[0253] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A control method for an energy storage liquid cooling system, characterized in that: include: Get the average cell temperature and battery operating current; Determining whether the energy storage liquid cooling system should be placed in a cooling mode or a heating mode based on the average temperature of the battery cells, and determining whether the energy storage liquid cooling system should be placed in a self-circulation mode or a standby mode based on the average temperature of the battery cells and the battery operating current; When in the cooling mode, determining a cooling target temperature according to the average temperature of the battery cells and the first restriction condition, and controlling the battery to cool according to the cooling target temperature; When in the heating mode, determining a heating target temperature according to the average temperature of the battery cells and a second limiting condition, and controlling the battery to heat up according to the heating target temperature; When in the self-circulation mode, the coolant is not actively cooled or heated, and the natural temperature of the coolant is used to cool or heat the battery; When in the standby mode, cooling or heating the battery is stopped.

2. The control method according to claim 1, characterized in that: Get the cooling temperature point, cooling sensitivity, and maximum cell temperature; If the average temperature of the battery cell is greater than or equal to the sum of the cooling temperature point and the first times of the cooling sensitivity, or the maximum temperature of the battery cell is greater than or equal to the sum of the cooling temperature point and the cooling sensitivity, it is determined to be placed in the cooling mode.

3. The control method according to claim 1, characterized in that: Get the heating temperature point, heating sensitivity, and the lowest temperature of the battery cell; If the average temperature of the battery cell is less than or equal to the difference between the heating temperature point and the second time of the heating sensitivity, or the lowest temperature of the battery cell is less than or equal to the difference between the heating temperature point and the heating sensitivity, it is determined to be placed in the heating mode.

4. The control method according to claim 1, characterized in that: Obtain the extreme temperature difference of the battery cell, the cooling temperature point, and the heating temperature point; If the average temperature of the battery cell is greater than or equal to the heating temperature point and less than or equal to the cooling temperature point, and the battery cell extreme temperature difference is greater than or equal to the cooling sensitivity, it is determined to be placed in the self-circulation mode; Alternatively, if the absolute value of the battery operating current is greater than the current threshold, it is determined to be placed in the self-circulation mode.

5. The control method according to claim 1, characterized in that: If the entry conditions for being placed in the cooling mode, the heating mode and the self-circulation mode are not met, the mode is placed in the standby mode.

6. The control method according to claim 1, characterized in that: The cooling target temperature is the difference between the average temperature of the battery core and the set temperature, and the heating target temperature is the sum of the average temperature of the battery core and the set temperature; The first restriction condition and the second restriction condition meet the following conditions: The cooling target temperature is not lower than a preset boundary temperature, and the heating target temperature is not higher than the preset boundary temperature.

7. The control method according to claim 1, characterized in that: The priorities of the cooling mode, heating mode, self-circulation mode and standby mode are reduced in sequence; When the execution conditions of multiple modes among the cooling mode, heating mode, self-circulation mode and standby mode are met, the mode with the highest priority is preferentially executed.

8. A liquid cooling system, characterized in that: Including battery management unit, liquid-cooled execution unit; The battery management unit is configured to: Get the average cell temperature and battery operating current; Determining whether the energy storage liquid cooling system should be placed in a cooling mode or a heating mode based on the average temperature of the battery cells, and determining whether the energy storage liquid cooling system should be placed in a self-circulation mode or a standby mode based on the average temperature of the battery cells and the battery operating current; When in the cooling mode, determining a cooling target temperature according to the average temperature of the battery cells and the first restriction condition, and controlling the battery to cool according to the cooling target temperature; When in the heating mode, determining a heating target temperature according to the average temperature of the battery cells and a second limiting condition, and controlling the battery to heat up according to the heating target temperature; When in the self-circulation mode, the coolant is not actively cooled or heated, and the natural temperature of the coolant is used to cool or heat the battery; When in the standby mode, stopping cooling or heating the battery; The battery management unit cools down or heats up the battery by controlling the liquid cooling execution unit.

9. The liquid cooling system according to claim 8, characterized in that: It also includes an energy management unit, which is used to evaluate the execution result of the control method of the energy storage liquid cooling system executed by the battery management unit.

10. The liquid cooling system according to claim 8, characterized in that: The energy management unit is also configured to set or change operating parameters of the battery management unit.

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