Control method and device of energy storage battery system and energy storage battery system

Abstract

The invention provides a control method and device of an energy storage battery system and the energy storage battery system. The energy storage battery system comprises a heat pump and a battery exchanging heat with cooling liquid in the heat pump, and the control method comprises the steps that the current temperature of the battery is obtained in response to an instruction for starting charging or discharging of the battery; based on the current temperature, controlling the heat pump to adjust the temperature of the battery to a preset healthy temperature; starting charging or discharging of the battery according to the instruction; when the battery is charged, controlling the heat pump to operate at a first frequency; and when the battery is discharged, the heat pump is controlled to work at the corresponding operation frequency according to the residual electric quantity of the battery. The battery thermal runaway risk can be reduced, and the battery life is prolonged.

Description

Technical Field

[0001] This application relates to the field of power electronics, and more specifically, to a control method, apparatus, and energy storage battery system. Background Technology

[0002] In energy storage battery systems, chillers are typically used to cool the batteries in order to ensure they operate at relatively safe and efficient temperatures. Currently, with the vigorous development of industrial, commercial, and residential energy storage, and in order to better integrate photovoltaic power generation, energy storage, charging piles, and heat pumps, energy storage battery systems that use heat pumps to replace chillers for regulating battery temperature are gradually increasing.

[0003] In current battery temperature control methods, heat pumps typically operate at a fixed frequency, providing a constant power for cooling or heating the battery. However, in practical applications, the heat generated during different stages of charging or discharging varies. Therefore, current battery temperature control methods lead to significant temperature fluctuations during operation, increasing the risk of thermal runaway and reducing battery life. Summary of the Invention

[0004] This application provides a control method, apparatus, and energy storage battery system for an energy storage battery system. The various aspects involved in this application will be described below.

[0005] In a first aspect, a control method for an energy storage battery system is provided. The energy storage battery system includes a heat pump and a battery that exchanges heat with a coolant in the heat pump. The method includes: in response to a command to start charging or discharging the battery, acquiring the current temperature of the battery; based on the current temperature, controlling the heat pump to adjust the battery temperature to a preset healthy temperature; starting charging or discharging the battery according to the command; when the battery is charging, controlling the heat pump to operate at a first frequency; when the battery is discharging, controlling the heat pump to operate at a corresponding operating frequency according to the remaining charge of the battery.

[0006] In one possible implementation, the heat pump is controlled to operate at a corresponding operating frequency based on the remaining battery power, including: matching the remaining battery power with a plurality of preset remaining power ranges to determine the remaining power range that matches the remaining battery power; and controlling the heat pump to operate at the operating frequency corresponding to the remaining power range that matches the remaining battery power.

[0007] In one possible implementation, the operating frequency is determined based on a preset frequency coefficient and the heat pump's reference power. Different remaining power ranges correspond to different frequency coefficients, and the reference power includes heating reference power and cooling reference power.

[0008] In one possible implementation, the cooling reference power is obtained based on the external heat infiltration power of the energy storage battery system, the heat generation power of the battery, and the power required for cooling by the coolant.

[0009] In one possible implementation, the heating reference power is obtained based on the internal heat leakage power of the energy storage battery system and the power required for the cooling fluid to heat up.

[0010] In one possible implementation, the energy storage battery system further includes an energy storage cabinet for housing the battery, wherein the external heat infiltration power and the internal heat infiltration power are both obtained based on the internal and external temperature difference of the energy storage cabinet, the heat dissipation area of ​​the energy storage cabinet, and the heat transfer coefficient.

[0011] In one possible implementation, based on the current temperature, controlling the heat pump to adjust the battery temperature to a preset healthy temperature includes: when the current temperature is greater than the preset healthy temperature, controlling the heat pump to operate in a cooling mode at maximum power to adjust the battery temperature to the preset healthy temperature; and when the current temperature is less than the preset healthy temperature, controlling the heat pump to operate in a heating mode at maximum power to adjust the battery temperature to the preset healthy temperature.

[0012] Secondly, a control device for an energy storage battery system is provided. The energy storage battery system includes a heat pump and a battery that exchanges heat with a coolant in the heat pump. The device includes: an acquisition module for acquiring the current temperature of the battery in response to a command to start charging or discharging the battery; a control module for controlling the heat pump to adjust the battery temperature to a preset healthy temperature based on the current temperature; starting charging or discharging the battery according to the command; controlling the heat pump to operate at a first frequency when the battery is charging; and controlling the heat pump to operate at a corresponding operating frequency when the battery is discharging, based on the remaining charge of the battery.

[0013] In one possible implementation, the control module is specifically used to match the remaining power of the battery with a plurality of preset remaining power ranges, determine the remaining power range that matches the remaining power of the battery, and control the heat pump to operate at the operating frequency corresponding to the remaining power range that matches the remaining power of the battery.

[0014] In one possible implementation, the operating frequency is determined based on a preset frequency coefficient and the heat pump's reference power. Different remaining power ranges correspond to different frequency coefficients, and the reference power includes heating reference power and cooling reference power.

[0015] In one possible implementation, the cooling reference power is obtained based on the external heat infiltration power of the energy storage battery system, the heat generation power of the battery, and the power required for cooling by the coolant.

[0016] In one possible implementation, the heating reference power is obtained based on the internal heat leakage power of the energy storage battery system and the power required for the cooling fluid to heat up.

[0017] In one possible implementation, the energy storage battery system further includes an energy storage cabinet for housing the battery, wherein the external heat infiltration power and the internal heat infiltration power are both obtained based on the internal and external temperature difference of the energy storage cabinet, the heat dissipation area of ​​the energy storage cabinet, and the heat transfer coefficient.

[0018] In one possible implementation, the control module is specifically configured to control the heat pump to operate in cooling mode at maximum power to adjust the battery temperature to the preset healthy temperature when the current temperature is higher than the preset healthy temperature; and to control the heat pump to operate in heating mode at maximum power to adjust the battery temperature to the preset healthy temperature when the current temperature is lower than the preset healthy temperature.

[0019] Thirdly, an energy storage battery system is provided, comprising: a heat pump and a battery that exchanges heat with a coolant in the heat pump; and a controller electrically connected to the heat pump and the battery respectively, for performing the method as described in the first aspect or any possible embodiment of the first aspect.

[0020] Fourthly, a computer-readable storage medium having program code stored thereon for controlling an energy storage battery system to perform the method as described in the first aspect or any possible implementation thereof.

[0021] In this embodiment, the battery temperature can be pre-controlled to a suitable temperature for efficient and healthy battery operation (i.e., a preset healthy temperature) before initiating battery charging or discharging. This allows the battery to start charging or discharging at a suitable temperature, improving battery safety during startup and preventing thermal runaway or reduced battery life caused by starting the battery at an unsuitable temperature. Furthermore, a corresponding heat pump operating frequency is provided for different remaining battery charge levels. This allows the battery to continue heating or cooling during discharge after startup, using a heat pump operating frequency that matches the battery's heating status. This achieves more precise battery temperature control based on the remaining charge level, reducing temperature fluctuations during battery operation and maintaining a relatively stable battery temperature near the preset healthy temperature, thus lowering the risk of thermal runaway. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a flowchart illustrating the control method for the energy storage battery system provided in an embodiment of this application;

[0024] Figure 2 This is another schematic flowchart of the control method for the energy storage battery system provided in the embodiments of this application;

[0025] Figure 3 This is a schematic diagram of the structure of the control device for the energy storage battery system provided in the embodiments of this application;

[0026] Figure 4 This is a schematic diagram of the energy storage battery system provided in the embodiments of this application. Detailed Implementation

[0027] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0028] In energy storage battery systems, chillers are typically used to cool the batteries in order to ensure they operate at relatively safe and efficient temperatures. Currently, with the vigorous development of industrial, commercial, and residential energy storage, and in order to better integrate photovoltaic power generation, energy storage, charging piles, and heat pumps, energy storage battery systems that use heat pumps to replace chillers for regulating battery temperature are gradually increasing.

[0029] In current battery temperature control methods, heat pumps typically operate at a fixed frequency, providing a constant power for cooling or heating the battery. However, in practical applications, the heat generated during different stages of charging or discharging varies. Therefore, current battery temperature control methods can lead to significant temperature fluctuations during battery operation, increasing the risk of thermal runaway and reducing battery life.

[0030] Therefore, to address the aforementioned problems, this application provides a control method for an energy storage battery system. In this embodiment, before initiating battery charging or discharging, the battery temperature is first regulated to a suitable temperature for efficient and healthy battery operation (i.e., a preset healthy temperature) through cooling or heating by a heat pump, and then charging or discharging is initiated. This allows the battery to start charging or discharging at a suitable temperature, improving the safety of battery startup and preventing thermal runaway or reduced battery life caused by starting the battery at an unsuitable temperature. Furthermore, a corresponding heat pump operating frequency is provided for different remaining battery charge levels. This allows the battery to continue heating or cooling during discharge after startup, using a heat pump operating frequency that matches the battery's heating status based on its remaining charge level. This achieves more precise battery temperature control based on the remaining charge level, reducing temperature fluctuations during battery operation and maintaining the battery temperature relatively stably near the preset healthy temperature, thus reducing the risk of battery thermal runaway.

[0031] It should be noted that the energy storage battery system controlled by this method can be a commercial energy storage battery system or a home energy storage battery system. For example, the energy storage battery system may include a battery for energy storage and a heat pump. The coolant in the heat pump exchanges heat with the battery, thus facilitating the temperature control of the battery by heating or cooling the coolant through the heat pump. In this embodiment, there are no specific limitations on the method of heat exchange between the coolant in the heat pump and the battery. For example, in an immersed energy storage battery system, the battery can be immersed in an insulating coolant, and the coolant is circulated by a heat pump, which heats or cools it, thereby achieving efficient heating or cooling of the battery. Alternatively, the battery can be connected to a heat exchanger, with the coolant circulating in the heat exchanger through the heat pump. The coolant exchanges heat with the battery through the heat exchanger, thereby heating or cooling the battery by heating or cooling the coolant through the heat pump.

[0032] For example, in the embodiments of this application, the energy storage battery system may further include a controller, such as an Energy Management System (EMS), connected to the battery and heat pump. The controller can then execute the control method provided in the embodiments of this application. Correspondingly, the energy storage battery system may also be equipped with a Battery Management System (BMS) to detect battery parameters such as battery temperature, remaining charge (SOC), battery charging / discharging current, and battery charging / discharging voltage. The BMS can be connected to the controller so that the controller can obtain the corresponding battery parameters. In some possible implementations, the energy storage battery system may further include an energy storage cabinet to house components such as the battery, providing physical protection for the energy storage battery system. For submersible energy storage battery systems, the energy storage cabinet may also be used to hold (or contain) coolant, so that the battery is submerged in the coolant.

[0033] Of course, the above is only an exemplary description of the components included in the energy storage battery system. In the embodiments of this application, the energy storage battery system may also include other necessary components involved in the related technologies, which will not be elaborated here.

[0034] The control method of the energy storage battery system provided in this application will be described below with reference to the accompanying drawings.

[0035] like Figure 1 As shown in the embodiments of this application, a control method for an energy storage battery system may include the following S101-S105.

[0036] S101. In response to a command to start charging or discharging the battery, obtain the current temperature of the battery.

[0037] The battery charging or discharging command can be issued by the controller of the energy storage battery system, such as an EMS. This command can be used to control the corresponding circuit to discharge the battery to external sources (such as loads or the power grid), or to charge the battery. When this command is detected, it can be determined that the energy storage battery system needs to initiate battery charging or discharging.

[0038] As a possible example, the battery temperature can be detected using a temperature sensor designed to detect battery temperature. Therefore, the current battery temperature can be obtained by acquiring the sensor signal from this temperature sensor.

[0039] The current temperature of the battery can be either the overall temperature of the battery or the temperature of the battery cells; there is no restriction here.

[0040] S102. Based on the current temperature, control the heat pump to adjust the battery temperature to a preset healthy temperature;

[0041] Once the current battery temperature is obtained, the heat pump can be controlled to adjust the battery temperature to a preset healthy temperature, thus facilitating subsequent battery charging or discharging. It can be activated when the battery is at the preset healthy temperature. This avoids thermal runaway or internal short circuits caused by starting charging or discharging the battery at excessively low or high temperatures, thereby improving safety when initiating battery charging or discharging.

[0042] For example, the preset health temperature can be set in advance according to the relevant parameters of the battery configured in the energy storage battery system (such as battery type, battery structure, etc.). For instance, depending on the battery type, the preset health temperature can be set to 25°C when the battery is a lithium-ion battery, 23°C when the battery is a nickel-metal hydride battery, and 20°C when the battery is a lead-acid battery, and so on.

[0043] Of course, the preset healthy temperature can also be set as a temperature range. For example, depending on the battery type, when the battery is a lithium-ion battery, the preset healthy temperature can be set to 25±5℃ (i.e., 20℃-30℃); when the battery is a nickel-metal hydride battery, the preset healthy temperature can be set to 15℃-30℃; when the battery is a lead-acid battery, the preset healthy temperature can be set to 15℃-25℃, and so on. Accordingly, when adjusting the battery temperature to the preset healthy temperature, the battery temperature can be considered to have been adjusted to the preset healthy temperature when the battery temperature reaches the midpoint of the preset healthy temperature range. Of course, the battery temperature can also be considered to have been adjusted to the preset healthy temperature when it enters the preset healthy temperature range; there is no limitation here.

[0044] In this embodiment, controlling the heat pump to adjust the battery temperature to a preset healthy temperature can be based on the battery's current temperature. When the current temperature is higher than the preset healthy temperature, the heat pump is controlled to operate in cooling mode at maximum power to lower the battery temperature, thereby adjusting it to the preset healthy temperature. Conversely, when the current temperature is lower than the preset healthy temperature, the heat pump is controlled to operate in heating mode at maximum power to raise the battery temperature, thereby adjusting it to the preset healthy temperature. When the battery temperature is equal to or within the preset healthy temperature range, no temperature adjustment is needed. By controlling the heat pump to cool or heat the battery at maximum power, the battery temperature can be adjusted to the preset healthy temperature as quickly as possible, allowing for faster initiation of battery charging or discharging, thus reducing the delay in initiating battery charging or discharging. Of course, in some other possible embodiments of this application, the power of the heat pump for heating and / or cooling can be set to other power levels to comprehensively consider the rate of battery temperature adjustment and heat pump energy consumption. Alternatively, based on the difference between the battery's current temperature and the preset healthy temperature, when the difference is large, the heat pump can be controlled to heat or cool at maximum power to increase the rate of battery temperature adjustment, while when the difference is small, the heat pump can be controlled to heat or cool at a lower power to reduce heat pump energy consumption while ensuring that the battery temperature adjustment time is relatively short.

[0045] When the battery temperature is adjusted to a preset healthy temperature, the corresponding circuit can be controlled to start the battery charging or discharging according to the command to start the battery charging or discharging in S101, that is, S103 is executed to start the battery charging or discharging according to the command. For details on how to start the battery charging or discharging according to the corresponding command, please refer to the implementation methods involved in related technologies, which will not be repeated here.

[0046] When a battery begins charging or discharging, it generates heat as it continues to charge or discharge. Even though the battery temperature has been adjusted to a preset healthy temperature upon startup, the battery temperature will still fluctuate due to the heat it generates. Therefore, a heat pump is needed to regulate the battery temperature during charging or discharging. For the two different operating states of battery charging and discharging, the following steps S104 and S105 can be executed.

[0047] S104. When the battery is charging, control the heat pump to operate at the first frequency.

[0048] When the battery is charging, the heat generated by the battery is relatively stable. Therefore, the heat pump can be controlled to operate at a relatively constant frequency (or power) to balance the heat generated by the battery, thereby keeping the battery temperature relatively stable near the preset healthy temperature during charging. Whether the heat pump uses the first frequency for heating or cooling remains consistent with whether it was heating or cooling before the battery started charging or discharging to adjust the battery temperature to the preset healthy temperature. That is, after the heat pump adjusts the battery temperature to the preset healthy temperature using cooling or heating before the battery starts charging or discharging, the cooling or heating mode of the heat pump remains unchanged during battery charging; only its operating frequency changes to the first frequency.

[0049] For example, the first operating frequency of the heat pump can be determined based on the heat generation power of the battery, thereby avoiding situations where the battery temperature rises due to insufficient cooling power or excessive heating power of the heat pump, increasing the risk of battery thermal runaway. Of course, the first frequency can also be calculated and determined based on other factors, such as the heat exchange between the coolant and the environment, and the power required for cooling or heating by the coolant itself, in addition to considering the heat generation power of the battery.

[0050] S105. When the battery is discharging, the heat pump is controlled to operate at the corresponding frequency according to the remaining charge (State of Charge, SOC) of the battery.

[0051] Specifically, whether the heat pump uses a corresponding operating frequency for heating or cooling remains consistent with whether it operates in heating or cooling mode before the battery is started charging or discharging, once the battery temperature has been adjusted to the preset healthy temperature by the heat pump. That is, after the heat pump adjusts the battery temperature to the preset healthy temperature using either cooling or heating before the battery starts charging or discharging, the heat pump's cooling or heating mode remains unchanged during battery discharge, only its operating frequency changes to the corresponding frequency.

[0052] For example, in the embodiments of this application, after starting the charging or discharging of the battery, the remaining power of the battery can be obtained in real time or according to a preset period (such as 1 minute, 10 seconds, etc.), so as to facilitate the subsequent control of the heat pump to work based on the remaining power of the battery.

[0053] When a battery discharges, the amount of heat it generates is related to its remaining charge. When the remaining charge is high, the active materials inside the battery are in a high-energy state, exhibiting high chemical activity and relatively vigorous chemical reactions, and the battery voltage is also high, resulting in higher heat generation. When the remaining charge is moderate, the internal chemical reactions tend to stabilize, leading to a more moderate amount of heat generated compared to when the remaining charge is high. Conversely, when the remaining charge is low, the number of active materials inside the battery is less, the chemical reaction rate is slower, and therefore, the battery generates very little heat.

[0054] Therefore, based on the difference in heat generated by the battery at different remaining charge levels, the correspondence between the remaining charge and the operating frequency of the heat pump can be preset. This allows the heat pump to operate at different frequencies corresponding to different remaining charge levels during battery discharge, thereby achieving precise control of the battery temperature during discharge and maintaining relative temperature stability. This ensures that the battery temperature remains relatively stable near the preset healthy temperature.

[0055] For example, multiple remaining power ranges can be preset, and different operating frequencies can be set for different remaining power ranges. This allows the remaining power of the battery to be matched with multiple remaining power ranges, determining the remaining power range that matches the remaining power, and then controlling the heat pump to operate at the operating frequency corresponding to the remaining power range that matches the battery's remaining power.

[0056] For example, a lower remaining battery capacity range can be set, such as a first range (e.g., 0%-30%), corresponding to a second operating frequency for the heat pump. Thus, when the battery's remaining capacity falls within the first range, the heat pump can be controlled to operate at the second frequency to heat or cool the battery.

[0057] A moderate remaining battery charge range can also be set, such as a second range (e.g., 30%-70%), corresponding to a third operating frequency for the heat pump. Thus, when the battery's remaining charge falls within the second range, the heat pump can be controlled to operate at the third frequency to cool or heat the battery.

[0058] A higher remaining battery capacity range can also be set, such as the third range (e.g., 70%-100%), corresponding to a fourth operating frequency for the heat pump. Thus, when the battery's remaining capacity is within the third range, the heat pump can be controlled to operate at the fourth frequency to cool or heat the battery.

[0059] Additionally, it should be noted that, based on the aforementioned example, the first interval represents a lower remaining battery level, the second interval represents a medium remaining battery level, and the third interval represents a higher remaining battery level. Therefore, the values ​​in the first interval are less than the values ​​in the second interval, and the values ​​in the second interval are less than the values ​​in the third interval.

[0060] It should also be noted that the range of each interval in the above examples can be set according to the actual situation, thereby dividing the remaining battery power into three intervals: high, medium, and low. In this embodiment of the application, there is no limitation on the specific range value of each interval. For example, the first interval range can also be 0%-20%, the second interval range can also be 20%-80%, the third interval range can also be 80%-100%, and so on.

[0061] Of course, in some other possible implementations, the remaining battery power can be divided into more intervals, thereby presetting corresponding heat pump operating frequencies for different intervals. This allows for more precise control of the heat pump to regulate the battery temperature based on the remaining battery power, maintaining a relatively stable temperature during battery discharge. In this embodiment, the number of remaining battery power intervals is not limited.

[0062] The corresponding operating frequency for controlling the heat pump during battery charging or discharging, such as the first frequency and the second, third, and fourth frequencies in the aforementioned examples, can be determined based on the heat generation power of the battery discharge, or based on other conditions. There are no restrictions here, as long as the needs for heating or cooling the battery under the corresponding remaining power are met.

[0063] For example, in this embodiment, the operating frequency can be determined based on a preset frequency coefficient and the heat pump's reference power, which may include both heating and cooling reference power. For instance, when the heat pump is cooling, the operating frequency can be the product of the frequency coefficient and the cooling reference power; when the heat pump is heating, the operating frequency can be the product of the frequency coefficient and the heating reference power. Therefore, different frequency coefficients can be set for different remaining power ranges to determine the operating frequency corresponding to different remaining power ranges.

[0064] For example, based on the aforementioned example, the first frequency can be obtained based on the reference power and a preset first frequency coefficient, the second frequency can be obtained based on the reference power and a preset second frequency coefficient, the third frequency can be obtained based on the reference power and a preset third frequency coefficient, and the fourth frequency can be obtained based on the reference power and a preset fourth frequency coefficient.

[0065] For example, both the cooling reference power and the heating reference power can be calculated and determined solely based on the battery's heat generation power. Of course, the effects of externally infiltrated or internally infiltrated heat, as well as the power required for cooling or heating by the coolant itself, can also be taken into account.

[0066] As an example, considering the heat infiltrating from the outside in summer, the cooling reference power in this application embodiment can be obtained based on the heat infiltrating power of the energy storage battery system, the heating power of the battery, and the cooling power required by the coolant.

[0067] For example, the cooling reference power P ac The following formula can be satisfied:

[0068] P ac =P R(电池发热功率) +P S(热量外部渗入功率) +P y1(冷却液制冷所需功率)

[0069] Of course, in some possible implementations, considering the different insulation levels and materials of different energy storage battery systems, a correction factor γ can be introduced for the external heat infiltration power (which can be configured according to actual conditions or experience). Therefore, the cooling reference power P ac It can also satisfy the following formula:

[0070] P ac =P R(电池发热功率) +γP S(热量外部渗入功率) +P y1(冷却液制冷所需功率)

[0071] Among them, the external heat infiltration power P S(热量外部渗入功率) It can be based on the temperature difference between the energy storage battery system and the environment, such as the temperature difference ΔT between the inside and outside of the energy storage cabinet, the heat dissipation area of ​​the energy storage battery system, such as the heat dissipation area S of the energy storage cabinet, and the heat transfer coefficient of the energy storage battery system, such as the heat transfer coefficient K of the energy storage cabinet. For example:

[0072] P s(热量外部渗入功率) =ΔTKS

[0073] Battery heating power P R(电池发热功率) This can be based on the total number of battery cells X, the battery charging / discharging current I, and the internal resistance R of the battery cells. For example:

[0074] P R(电池发热功率) =XI 2 R

[0075] Power P required for coolant cooling y(冷却液制冷所需功率) It can be based on the coolant temperature T before cooling. y1 Target cooling temperature T iThe coolant density ρ, specific heat capacity C, mass M, and cooling time t are used to obtain the coolant (e.g., preset healthy temperature). For example:

[0076]

[0077] As another example, taking into account the heat leakage inside during winter, the heating reference power in the embodiments of this application can be obtained based on the heat leakage power inside the energy storage battery system and the power required for cooling liquid heating.

[0078] For example, the heating reference power P ah The following formula can be satisfied:

[0079] P ah =P S(热量内部渗出功率) +P y2(冷却液制热所需功率)

[0080] Of course, in some possible implementations, considering the different insulation levels and materials of different energy storage battery systems, a correction factor γ can be introduced for the internal heat leakage power (which can be configured according to actual conditions or experience). Therefore, the heating reference power P ah It can also satisfy the following formula:

[0081] P ah =γP S(热量内部渗出功率) +P y2(冷却液制热所需功率)

[0082] Among them, the external heat infiltration power P S(热量内部渗出功率) It can be based on the temperature difference between the energy storage battery system and the environment, such as the temperature difference ΔT between the inside and outside of the energy storage cabinet, the heat dissipation area of ​​the energy storage battery system, such as the heat dissipation area S of the energy storage cabinet, and the heat transfer coefficient of the energy storage battery system, such as the heat transfer coefficient K of the energy storage cabinet. For example:

[0083] P s(热量内部渗出功率) =ΔTKS

[0084] Power P required for coolant heating y2(冷却液制热所需功率) It can be based on the coolant temperature T before heating. y2 Target heating temperature T i (Assuming a preset healthy temperature), the coolant density ρ, the coolant specific heat capacity C, the coolant mass M, and the heating time t are used to obtain the values. For example:

[0085]

[0086] It should be noted that when calculating and determining the corresponding cooling or heating reference power based on the above examples, relevant parameters such as the temperature difference ΔT between the inside and outside of the energy storage cabinet and the battery charging and discharging current I can be detected and obtained through the corresponding sensors. Additionally, parameters such as the heat dissipation area S, the heat transfer coefficient K of the energy storage cabinet, the total number of battery cells X, the internal resistance R of the battery cells, and the coolant temperature T before cooling are also important. y1 Target cooling temperature T i Coolant density ρ, coolant specific heat capacity C, coolant mass M, cooling time t, coolant temperature T before heating y2 Target heating temperature T i Parameters such as heating time t can be configured in advance according to actual conditions.

[0087] Based on the above example, taking the first frequency coefficient as K1, the second frequency coefficient as K2, the third frequency coefficient as K3, and the fourth frequency coefficient as K4 as an example, the first frequency P1 during heat pump cooling is P1 = K1 × P ac The second frequency P2 = K2 × P ac The third frequency P3 = K3 × P ac The fourth frequency P4 = K4 × P ac The first frequency during heat pump heating is P1 = K1 × P. ah The second frequency P2 = K2 × P ah The third frequency P3 = K3 × P ah The fourth frequency p4 = K4 × P ah .

[0088] Based on the above illustrative examples of the control method for the energy storage battery system provided in this application embodiment, taking the remaining power in the first interval as the second frequency, the remaining power in the second interval as the third frequency, and the remaining power in the third interval as the fourth frequency, then... Figure 2As shown, the control method for the energy storage battery system based on this application allows for the acquisition of the battery's current temperature upon detecting a command to initiate battery charging or discharging. Then, based on the relationship between the current temperature and a preset healthy temperature, the heat pump is controlled. The battery temperature is adjusted by using the heat pump to cool or heat at maximum power to ensure it equals the preset healthy temperature. This allows for initiating battery charging or discharging and acquiring the remaining battery charge. When the battery is charging, the heat pump is controlled to operate at a first frequency to maintain a relatively stable battery temperature until shutdown. When the battery is discharging, the heat pump is controlled to operate at the corresponding operating frequency according to the range of remaining charge until shutdown. For example, when the remaining charge is in the first range, the heat pump is controlled to operate at a second frequency; when the remaining charge is in the second range, it is controlled to operate at a third frequency; and when the remaining charge is in the third range, it is controlled to operate at a fourth frequency. This precise control of the heat pump at corresponding operating frequencies for different ranges of remaining charge maintains a stable battery temperature during discharge, improving the safety of the battery discharge process.

[0089] The control method for the energy storage battery system provided in this application embodiment can adjust the battery temperature to a suitable temperature for efficient and healthy battery operation, i.e., a preset healthy temperature, before initiating battery charging or discharging. This allows the battery to start charging or discharging at a suitable temperature, improving the safety of battery startup and operation, and preventing battery thermal runaway or reduced battery life caused by starting the battery at an unsuitable temperature. Furthermore, the method employs corresponding heat pump operating frequencies for different remaining battery charge levels. This allows the battery to continue heating or cooling during discharge after startup, using heat pump operating frequencies matched to the battery's heating status based on its remaining charge level. This achieves more precise battery temperature control based on the remaining charge level, reducing temperature fluctuations during battery operation and maintaining the battery temperature relatively stably near the preset healthy temperature, thus lowering the risk of battery thermal runaway.

[0090] The method embodiments of this application have been described in detail above with reference to the accompanying drawings. The apparatus embodiments of this application will now be described in detail. It should be understood that the descriptions of the apparatus embodiments correspond to the descriptions of the method embodiments; therefore, any parts not described in detail can be referred to the foregoing method embodiments.

[0091] This application also provides a control device for an energy storage battery system. The energy storage battery system controlled by this control device includes a heat pump and a battery that exchanges heat with the coolant in the heat pump. (See also...) Figure 3The control device includes: an acquisition module 301, used to acquire the current temperature of the battery in response to a command to start charging or discharging the battery; and a control module 302, used to control the heat pump to adjust the battery temperature to a preset healthy temperature based on the current temperature; to start charging or discharging the battery according to the command; to control the heat pump to operate at a first frequency when the battery is charging; and to control the heat pump to operate at a corresponding operating frequency according to the remaining charge of the battery when the battery is discharging.

[0092] In one possible implementation, the control module 302 is specifically used to match the remaining power of the battery with a plurality of preset remaining power ranges, determine the remaining power range that matches the remaining power of the battery, and control the heat pump to operate at the operating frequency corresponding to the remaining power range that matches the remaining power of the battery.

[0093] In one possible implementation, the operating frequency is determined based on a preset frequency coefficient and the heat pump's reference power. Different remaining power ranges correspond to different frequency coefficients, and the reference power includes heating reference power and cooling reference power.

[0094] In one possible implementation, the cooling reference power is obtained based on the external heat infiltration power of the energy storage battery system, the heat generation power of the battery, and the power required for cooling by the coolant.

[0095] In one possible implementation, the heating reference power is obtained based on the internal heat leakage power of the energy storage battery system and the power required for the cooling fluid to heat up.

[0096] In one possible implementation, the energy storage battery system further includes an energy storage cabinet for housing the battery, wherein the external heat infiltration power and the internal heat infiltration power are both obtained based on the internal and external temperature difference of the energy storage cabinet, the heat dissipation area of ​​the energy storage cabinet, and the heat transfer coefficient.

[0097] In one possible implementation, the control module 302 is specifically configured to control the heat pump to operate in cooling mode at maximum power to adjust the battery temperature to the preset healthy temperature when the current temperature is higher than the preset healthy temperature; and to control the heat pump to operate in heating mode at maximum power to adjust the battery temperature to the preset healthy temperature when the current temperature is lower than the preset healthy temperature.

[0098] This application also provides an energy storage battery system. (Refer to...) Figure 4 The energy storage battery system includes: a heat pump 401 and a battery 403 that exchanges heat with a coolant 402 of the heat pump 401; and a controller 404, electrically connected to the heat pump 401 and the battery 403 respectively, for performing the method as described in any embodiment.

[0099] This application also provides a computer-readable storage medium having program code stored thereon, the program code being used to control an energy storage battery system to perform the methods described in any of the preceding embodiments.

[0100] It should be understood that, in the embodiments of this application, determining B based on A does not mean determining B solely based on A; B can also be determined based on A and / or other information.

[0101] It should be understood that in the embodiments of this application, "B corresponding to A" means that B is associated with A, and B can be determined based on A. However, it should also be understood that determining B based on A does not mean that B is determined solely based on A; B can also be determined based on A and / or other information.

[0102] It should be understood that the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0103] It should be understood that in the various embodiments of this application, the order of the above-mentioned processes does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0104] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0105] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0106] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0107] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. A 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 flow or function according to the embodiments of this application is 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, 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 (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can read or a data storage device such as a server or data center that integrates one or more available media. The available media can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., digital video discs, DVDs) or semiconductor media (e.g., solid-state disks, SSDs) etc.

[0108] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A control method for an energy storage battery system, characterized in that, The energy storage battery system includes a heat pump and a battery that exchanges heat with coolant in the heat pump, and the method includes: In response to a command to initiate charging or discharging of the battery, the current temperature of the battery is obtained; based on the current temperature, the heat pump is controlled to adjust the temperature of the battery to a preset healthy temperature; According to the instruction, start charging or discharging the battery; When the battery is charging, the heat pump is controlled to operate at a first frequency; When the battery is discharging, the heat pump is controlled to operate at a corresponding frequency based on the remaining charge of the battery.

2. The method according to claim 1, characterized in that, The step of controlling the heat pump to operate at a corresponding operating frequency based on the remaining charge of the battery includes: The remaining power of the battery is matched with multiple preset remaining power ranges to determine the remaining power range that matches the remaining power of the battery. The heat pump is controlled to operate at a frequency corresponding to the remaining power range that matches the remaining power of the battery.

3. The method according to claim 2, characterized in that, The operating frequency is determined based on a preset frequency coefficient and the reference power of the heat pump. Different remaining power ranges correspond to different frequency coefficients. The reference power includes heating reference power and cooling reference power.

4. The method according to claim 3, characterized in that, The cooling reference power is obtained based on the external heat infiltration power of the energy storage battery system, the heat generation power of the battery, and the cooling power required by the coolant.

5. The method according to claim 4, characterized in that, The heating reference power is obtained based on the internal heat leakage power of the energy storage battery system and the heating power required by the coolant.

6. The method according to claim 5, characterized in that, The energy storage battery system also includes an energy storage cabinet for housing the battery. The external heat infiltration power and the internal heat outfiltration power are both obtained based on the internal and external temperature difference of the energy storage cabinet, the heat dissipation area of ​​the energy storage cabinet, and the heat transfer coefficient.

7. The method according to any one of claims 1-6, characterized in that, The step of controlling the heat pump to adjust the battery temperature to a preset healthy temperature based on the current temperature includes: When the current temperature is greater than the preset healthy temperature, the heat pump is controlled to operate in cooling mode at maximum power to adjust the battery temperature to the preset healthy temperature. When the current temperature is lower than the preset healthy temperature, the heat pump is controlled to operate in heating mode at maximum power to adjust the battery temperature to the preset healthy temperature.

8. A control device for an energy storage battery system, characterized in that, The energy storage battery system includes a heat pump and a battery that exchanges heat with the coolant in the heat pump. The device includes: The acquisition module is used to acquire the current temperature of the battery in response to a command to start charging or discharging the battery; The control module is used to control the heat pump to adjust the battery temperature to a preset healthy temperature based on the current temperature; to start charging or discharging the battery according to the instruction; to control the heat pump to run at a first frequency when the battery is charging; and to control the heat pump to operate at a corresponding operating frequency according to the remaining charge of the battery when the battery is discharging.

9. An energy storage battery system, characterized in that, include: A heat pump and a battery that exchanges heat with the coolant in the heat pump; A controller, electrically connected to the heat pump and the battery respectively, is used to perform the method as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, It stores program code that controls the energy storage battery system to perform the method as described in any one of claims 1 to 7.

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