Energy storage system liquid cooling control method, device and computer readable storage medium

Abstract

The application discloses a liquid cooling control method and device of an energy storage system and a computer readable storage medium, belongs to the field of liquid cooling systems, and determines the cluster estimated power and the target liquid temperature of the battery cluster at the next electricity price updating moment in advance in combination with the planned working power, the load side estimated power and the anti-backflow value, and determines the liquid cooling starting moment in combination with the preset time step, the temperature difference step value, the temperature difference between the liquid inlet temperature and the target liquid temperature and the preset maximum starting time, so that the liquid cooling is started in advance before the electricity price is updated, heat dissipation is in place before power switching, and the heat dissipation effect is improved; meanwhile, the liquid temperature reference value is gradually adjusted to the target liquid temperature according to the step and the step value, so that the liquid cooling equipment operates in a gradually reduced temperature increasing interval, the energy efficiency ratio can be improved compared with one-time adjustment, and the heat dissipation timeliness and the energy efficiency level are considered.

Description

Technical Field

[0001] This invention relates to the field of liquid cooling systems, and in particular to a liquid cooling control method, device, and computer-readable storage medium for an energy storage system. Background Technology

[0002] Energy storage systems are connected to substations and can assist in powering the load side or performing other functions. Energy storage systems can also dissipate heat through liquid cooling systems. However, there is a lack of mature liquid cooling control methods for energy storage systems in related technologies. Under the current liquid cooling control methods, the heat dissipation effect of energy storage systems is slow and the energy efficiency of liquid cooling systems is relatively low.

[0003] Therefore, how to provide a solution to the above-mentioned technical problems is a problem that needs to be solved by those skilled in the art. Summary of the Invention

[0004] The purpose of this invention is to provide a liquid cooling control method, device, and computer-readable storage medium for an energy storage system. The liquid cooling is activated in advance before the electricity price is updated, so that heat dissipation is in place before the power switch, thus improving the heat dissipation effect. At the same time, the liquid temperature reference value is gradually adjusted to the target liquid temperature according to the step size and step value, so that the liquid cooling equipment operates within a gradually decreasing temperature rise range. Compared with a one-time adjustment, this can improve the energy efficiency ratio and take into account both the timeliness of heat dissipation and the energy efficiency level.

[0005] To address the aforementioned technical problems, this invention provides a liquid cooling control method for an energy storage system, comprising: Based on the planned operating power of the energy storage system at the next electricity price update time, the estimated power of the load side at the next electricity price update time, and the anti-reverse current value of the load side, the estimated power of each battery cluster of the energy storage system at the next electricity price update time is determined. The target liquid temperature of the battery cluster at the next electricity price update time is determined based on the cluster's estimated power. The liquid cooling start-up time of the battery cluster is determined based on the preset time step, preset temperature difference step value, temperature difference between the current liquid inlet temperature and the target liquid temperature of the battery cluster, and preset maximum start-up time. Starting from the liquid cooling start time before the next electricity price update time, the liquid temperature reference value of the battery cluster is gradually adjusted from the current liquid inlet temperature to the target liquid temperature according to the preset time step and preset temperature difference step value, so as to gradually adjust the liquid inlet temperature of the battery cluster to the target liquid temperature.

[0006] On the other hand, determining the estimated cluster power of each battery cluster of the energy storage system at the next electricity price update time based on the planned operating power of the energy storage system at the next electricity price update time, the estimated power of the load side at the next electricity price update time, and the anti-reverse current value of the load side includes: According to the preset allocation rules, the planned operating power of the energy storage system at the next electricity price update time is divided into each battery cluster to obtain the cluster planned power of each battery cluster; According to the preset allocation rule, the estimated power of the load side at the next electricity price update time and the anti-reverse current value of the load side are respectively divided into each battery cluster to obtain the cluster load estimate and cluster anti-reverse current value of each battery cluster. The smaller of the cluster planned power, the cluster load estimate, and the cluster anti-reverse current value is determined as the cluster estimated power at the next electricity price update time.

[0007] On the other hand, the estimated power on the load side at the next electricity price update time is determined in the following way: Obtain the average power on the load side within a preset time period prior to the current moment; The average power is determined as the estimated power of the load side at the next electricity price update time.

[0008] On the other hand, before determining the estimated power of each battery cluster of the energy storage system at the next electricity price update time based on the planned operating power of the energy storage system at the next electricity price update time, the estimated power of the load side at the next electricity price update time, and the anti-reverse current value of the load side, the liquid cooling control method of the energy storage system further includes: Determine whether the estimated power on the load side at the next electricity price update time is not less than the product of the preset multiple and the anti-reverse current value on the load side; If it is not less than, then proceed with the step of determining the estimated cluster power of each battery cluster in the energy storage system at the next electricity price update time; If the value is less than the specified value, the determination of the liquid cooling start-up time for the battery cluster will not be performed.

[0009] On the other hand, before determining the estimated power of each battery cluster of the energy storage system at the next electricity price update time based on the planned operating power of the energy storage system at the next electricity price update time, the estimated power of the load side at the next electricity price update time, and the anti-reverse current value of the load side, the liquid cooling control method of the energy storage system further includes: Determine whether the energy storage system is in a discharge state at the time of the next electricity price update. If it is in a discharge state, then perform the step of determining the estimated cluster power of each battery cluster of the energy storage system at the next electricity price update time; If the battery cluster is in a charging state, the determination of the liquid cooling start-up time will not be performed.

[0010] On the other hand, the liquid cooling control method of the energy storage system also includes: According to the preset detection cycle, check whether there is charging and discharging current in the energy storage system; If there is no charging or discharging current in the energy storage system, then the step of determining the estimated power of each battery cluster of the energy storage system at the next electricity price update time is performed based on the planned operating power of the energy storage system at the next electricity price update time, the estimated power of the load side at the next electricity price update time, and the anti-reverse current value of the load side. If the energy storage system currently has a charging / discharging current, then the process ends; During the process of gradually adjusting the liquid temperature reference value of the battery cluster to the target liquid temperature according to the preset time step and preset temperature difference step value, if the energy storage system generates a charging and discharging current, the adjustment of the liquid temperature reference value of the battery cluster is stopped, so that the battery management system of the energy storage system can control the liquid inlet temperature of the battery cluster.

[0011] On the other hand, determining the target liquid temperature of the battery cluster at the next electricity price update time based on the cluster's estimated power includes: The estimated power of the battery cluster at the next electricity price update time is converted into the charge / discharge rate of the battery cluster; Based on the preset mapping relationship between charge / discharge rate and target liquid temperature, the target liquid temperature corresponding to the charge / discharge rate is determined, and this is set as the target liquid temperature of the battery cluster at the next electricity price update time.

[0012] On the other hand, determining the liquid cooling start-up time of the battery cluster based on a preset time step, a preset temperature difference step value, the temperature difference between the current inlet temperature and the target liquid temperature of the battery cluster, and a preset maximum start-up time includes: If the temperature difference between the current inlet temperature and the target liquid temperature of the battery cluster is less than the preset temperature difference threshold, then it is determined that liquid cooling pre-start is not required for the battery cluster. If the temperature difference between the current inlet temperature and the target temperature of the battery cluster is not less than the preset temperature difference threshold, then the number of step adjustments is determined according to the ratio of the temperature difference to the preset temperature difference step value. The smaller of the product of the number of step adjustments and the preset time step, and the preset maximum start time, is determined as the advance start time of the battery cluster before the next electricity price update. The liquid-cooled start-up time of the battery cluster is determined based on the next electricity price update time and the aforementioned advance start-up duration.

[0013] To address the aforementioned technical problems, the present invention also provides a liquid-cooled control device for an energy storage system, comprising: Memory, used to store computer programs; A processor is used to execute the computer program to implement the steps of the liquid cooling control method for the energy storage system as described above.

[0014] To address the aforementioned technical problems, the present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the liquid cooling control method for the energy storage system as described above.

[0015] Beneficial Effects: This invention provides a liquid cooling control method for energy storage systems. Considering that liquid cooling control methods in related technologies typically only passively adjust after power or temperature changes, and the liquid temperature is adjusted to the target temperature all at once, resulting in slow heat dissipation and low energy efficiency, this invention combines planned operating power, estimated load-side power, and anti-reverse current values ​​to pre-determine the estimated power and target liquid temperature of the battery cluster at the next electricity price update time. It also combines a preset time step, temperature difference step value, the temperature difference between the inlet liquid temperature and the target liquid temperature, and a preset maximum start time to determine the liquid cooling start time. This allows liquid cooling to be started before the electricity price update, ensuring heat dissipation is in place before power switching, thus improving heat dissipation performance. Simultaneously, the liquid temperature reference value is gradually adjusted to the target liquid temperature according to the step size and step value, allowing the liquid cooling equipment to operate within a gradually decreasing temperature rise range. This improves the energy efficiency ratio compared to a one-time adjustment, balancing heat dissipation timeliness and energy efficiency.

[0016] The present invention also provides a liquid cooling control device and a computer-readable storage medium for an energy storage system, which have the same beneficial effects as the liquid cooling control method for the energy storage system described above. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the relevant technologies and the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A first flowchart illustrating the liquid cooling control method for the energy storage system provided by the present invention; Figure 2 A schematic diagram of the second process for gradually adjusting the liquid temperature reference value of the battery cluster in the liquid cooling control method of the energy storage system provided by the present invention; Figure 3 A schematic diagram of the structure of the liquid cooling control device for the energy storage system provided by the present invention. Detailed Implementation

[0019] The core of this invention is to provide a liquid cooling control method, device, and computer-readable storage medium for an energy storage system. The liquid cooling is activated in advance before the electricity price is updated, so that heat dissipation is in place before the power switch, thus improving the heat dissipation effect. At the same time, the liquid temperature reference value is gradually adjusted to the target liquid temperature according to the step size and step value, so that the liquid cooling equipment operates within a gradually decreasing temperature rise range. Compared with a one-time adjustment, this can improve the energy efficiency ratio and take into account both the timeliness of heat dissipation and the energy efficiency level.

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] The energy storage system consists of multiple battery clusters, which are the basic units for liquid cooling control in the system. The system regulates the liquid inlet temperature of each battery cluster through the liquid cooling system to ensure that the battery clusters are always within a suitable temperature range during charging and discharging.

[0022] Please refer to Figure 1 , Figure 1 This is a first flowchart illustrating the liquid cooling control method for an energy storage system provided by the present invention. The liquid cooling control method for the energy storage system includes: S101: Based on the planned operating power of the energy storage system at the next electricity price update time, the estimated power of the load side at the next electricity price update time, and the anti-reverse current value of the load side, determine the estimated power of each battery cluster of the energy storage system at the next electricity price update time. Specifically, considering that the actual power that the battery clusters need to withstand at the next electricity price update time is related to the overall planned operating power of the energy storage system, the actual load demand on the load side, and the anti-reverse current value required to avoid backflow to the grid side, if the power that the battery clusters need to withstand is determined solely based on the planned operating power, it is difficult to reflect the impact of the actual load on the battery clusters' operating power. If the power that the battery clusters need to withstand is determined solely based on the load level on the load side, it may exceed the original planned operating power of the energy storage system. Therefore, in this embodiment of the invention, the estimated cluster power of each battery cluster in the energy storage system at the next electricity price update time is determined by comprehensively considering the planned operating power of the energy storage system at the next electricity price update time, the estimated power of the load side at the next electricity price update time, and the anti-reverse current value of the load side. This makes the determined estimated cluster power more consistent with the actual operating conditions that the battery clusters will withstand at the next electricity price update time, providing an accurate data basis for determining the target liquid temperature and liquid cooling start-up time.

[0023] S102: Determine the target liquid temperature of the battery cluster at the next electricity price update time based on the cluster's estimated power; Specifically, considering that the heat generated by the battery cluster during operation is closely related to its operating power, the higher the estimated power of the cluster, the more heat the battery cluster will generate at the next electricity price update time, and the lower the target liquid temperature should be to ensure that the battery cluster has sufficient heat dissipation capacity and avoid the battery cluster overheating due to insufficient heat dissipation; on the other hand, the lower the estimated power of the cluster, the less heat the battery cluster will generate, and the target liquid temperature can be set relatively high to avoid unnecessary energy consumption due to setting the target liquid temperature too low. Therefore, in this embodiment of the invention, the target liquid temperature of the battery cluster at the next electricity price update time is determined according to the estimated power of the cluster, so that the target liquid temperature matches the operating power that the battery cluster will soon bear.

[0024] S103: Determine the liquid cooling start time of the battery cluster based on the preset time step, preset temperature difference step value, temperature difference between the current liquid inlet temperature and the target liquid temperature of the battery cluster, and preset maximum start time. Specifically, considering that it takes a certain amount of time for the liquid cooling system to adjust the inlet temperature of the battery cluster from the current inlet temperature to the target liquid temperature, if the adjustment of the inlet temperature of the battery cluster only begins after the next electricity price update, the adjustment speed of the liquid cooling system will be difficult to keep up with the change rate of the energy storage system's operating power. This may easily lead to insufficient heat dissipation of the battery cluster for a period of time after the next electricity price update. Therefore, in this embodiment of the invention, the liquid cooling start time of the battery cluster is determined in advance by combining a preset time step, a preset temperature difference step value, the temperature difference between the current inlet temperature and the target liquid temperature of the battery cluster, and a preset maximum start time. This allows the liquid cooling system to start adjusting the inlet temperature of the battery cluster at the liquid cooling start time before the next electricity price update, thereby ensuring that the inlet temperature of the battery cluster has been adjusted to or is close to the target liquid temperature when the next electricity price update arrives.

[0025] The preset time step and preset temperature difference step value can be set flexibly and independently. For example, the preset time step can be set to 5 minutes and the preset temperature difference step value can be set to 5°C. This embodiment of the invention does not limit these settings.

[0026] S104: Starting from the liquid cooling start time before the next electricity price update time, according to the preset time step and preset temperature difference step value, the liquid temperature reference value of the battery cluster is gradually adjusted from the current liquid inlet temperature to the target liquid temperature, so as to gradually adjust the liquid inlet temperature of the battery cluster to the target liquid temperature.

[0027] Specifically, considering that if the reference value of the battery cluster liquid temperature is directly adjusted from the current inlet temperature to the target liquid temperature at the moment of liquid cooling start-up, it is easy for the liquid cooling equipment to complete the cooling task of a large temperature difference in a short period of time, causing a sudden increase in the operating load of the liquid cooling equipment, the embodiment of the present invention does not adjust it all at once. Instead, starting from the moment of liquid cooling start-up before the next electricity price update, the reference value of the battery cluster liquid temperature is gradually adjusted from the current inlet temperature to the target liquid temperature according to the preset time step and the preset temperature difference step value. This allows the liquid cooling equipment to continuously and steadily adjust the inlet temperature of the battery cluster according to the gradually issued liquid temperature reference value, and finally gradually adjust the inlet temperature of the battery cluster to the target liquid temperature.

[0028] This invention provides a liquid cooling control method for an energy storage system. Considering that liquid cooling control methods in related technologies for energy storage systems typically only passively adjust after power or temperature changes, and the liquid temperature is adjusted to the target temperature all at once, resulting in slow heat dissipation and low energy efficiency, this invention combines the planned operating power, the estimated power on the load side, and the anti-reverse current value to determine the estimated power of the battery cluster and the target liquid temperature at the next electricity price update time in advance. Furthermore, it combines a preset time step, a temperature difference step value, the temperature difference between the inlet liquid temperature and the target liquid temperature, and a preset maximum start time to determine the liquid cooling start time. This allows liquid cooling to be started in advance before the electricity price update, ensuring heat dissipation is in place before the power switch, thus improving the heat dissipation effect. Simultaneously, the liquid temperature reference value is gradually adjusted to the target liquid temperature according to the step size and step value, allowing the liquid cooling equipment to operate within a gradually decreasing temperature rise range. This improves the energy efficiency ratio compared to a one-time adjustment, balancing heat dissipation timeliness and energy efficiency.

[0029] Based on the above embodiments: As an optional embodiment, based on the planned operating power of the energy storage system at the next electricity price update time, the estimated power of the load side at the next electricity price update time, and the anti-reverse current value of the load side, the estimated cluster power of each battery cluster of the energy storage system at the next electricity price update time is determined as follows: According to the preset allocation rules, the planned operating power of the energy storage system at the next electricity price update time is divided into each battery cluster to obtain the cluster planned power of each battery cluster; According to the preset allocation rules, the estimated power of the load side at the next electricity price update time and the anti-reverse current value of the load side are respectively divided into each battery cluster to obtain the cluster load estimate and cluster anti-reverse current value of each battery cluster. The smaller of the cluster planned power, the cluster load estimate, and the cluster anti-reverse current value is determined as the cluster estimated power at the next electricity price update time.

[0030] Specifically, considering that liquid cooling control uses battery clusters as the basic execution unit, and that the planned operating power of the energy storage system at the next electricity price update time, the estimated power of the load side at the next electricity price update time, and the anti-reverse current value of the load side are all data oriented towards the entire energy storage system, this embodiment of the invention first divides the planned operating power of the energy storage system at the next electricity price update time into each battery cluster according to a preset allocation rule, to obtain the cluster planned power of each battery cluster. Then, according to the preset allocation rule, the estimated power of the load side at the next electricity price update time and the anti-reverse current value of the load side are respectively divided into each battery cluster, to obtain the cluster load estimate and cluster anti-reverse current value of each battery cluster. Finally, the smaller of the cluster planned power of the battery cluster and the difference between the cluster load estimate and the cluster anti-reverse current value is determined as the cluster estimated power of the battery cluster at the next electricity price update time. The estimated power of the cluster determined in this way will not exceed the original planned power of the battery cluster, and will also take into account the actual load level of the corresponding part of the battery cluster on the load side and the power margin required to avoid reverse current, so that the determined estimated power of the cluster is more in line with the actual working conditions that the battery cluster will be subjected to.

[0031] Specifically, the formula for determining the cluster estimated power in this embodiment of the invention can be flexibly set, for example, it can be expressed as: ; in, Pgu The estimated power of the battery cluster at the next electricity price update time. Pjh For the planned power of the battery cluster, Pfh Estimate the cluster load of the battery cluster. Pfn This is the cluster anti-reverse current value for the battery cluster.

[0032] The preset allocation rules can be set flexibly and independently. For example, they can be allocated according to the proportion of the rated capacity of each battery cluster in the total rated capacity of the energy storage system. This embodiment of the invention does not limit the specific allocation rules.

[0033] As an optional implementation, the estimated power on the load side at the next electricity price update time is determined as follows: Obtain the average power on the load side within a preset time period prior to the current moment; The average power is defined as the estimated power on the load side at the next electricity price update time.

[0034] Specifically, considering that the actual power of the load side at the next electricity price update time has not yet been generated at the current time and cannot be directly obtained, this embodiment of the invention obtains the average power of the load side within a preset time period before the current time and determines this average power as the estimated power of the load side at the next electricity price update time. This allows for the acquisition of an estimated power reflecting the recent load level of the load side in advance, without waiting for the actual power at the next electricity price update time, providing a data basis for determining the subsequent cluster estimated power. Since the load level of the load side usually has a certain degree of continuity within a short time range, using the average power within a preset time period before the current time as the estimated power at the next electricity price update time can achieve both computational simplicity and a certain degree of estimation accuracy.

[0035] The preset duration can be set flexibly, for example, it can be set to 5 minutes, etc., and this embodiment of the invention does not limit it.

[0036] As an optional embodiment, before determining the estimated power of each battery cluster of the energy storage system at the next electricity price update time based on the planned operating power of the energy storage system at the next electricity price update time, the estimated power of the load side at the next electricity price update time, and the anti-reverse current value of the load side, the liquid cooling control method of the energy storage system further includes: Determine whether the estimated power on the load side at the next electricity price update time is not less than the product of the preset multiple and the anti-reverse current value on the load side; If it is not less than, then proceed to the step of determining the estimated cluster power of each battery cluster in the energy storage system at the next electricity price update time; If the value is less than the specified value, the determination of the liquid cooling start-up time for the battery cluster will not be performed.

[0037] Specifically, considering that when the estimated power of the load side at the next electricity price update time is small and insufficient to trigger the energy storage system to discharge, if the estimated power of the battery cluster and the subsequent liquid cooling start time are still determined, it will lead to unnecessary liquid cooling adjustment operations and increase operating energy consumption. Therefore, this embodiment of the invention sets a judgment condition to determine whether the estimated power of the load side at the next electricity price update time is not less than the product of a preset multiple and the anti-reverse current value of the load side, so as to determine whether the energy storage system needs to discharge at the next electricity price update time: if the estimated power of the load side at the next electricity price update time is not less than the product of a preset multiple and the anti-reverse current value of the load side, the energy storage system needs to discharge at the next electricity price update time. If the estimated power is not less than the product of the preset multiple and the anti-reverse current value on the load side, it indicates that the load level on the load side has exceeded the range allowed by the anti-reverse current value. The energy storage system is likely to need to output power to discharge at the next electricity price update time. Therefore, the subsequent step of determining the estimated power of the cluster is performed. If the estimated power on the load side at the next electricity price update time is less than the product of the preset multiple and the anti-reverse current value on the load side, it indicates that the energy storage system is unlikely to need to discharge at the next electricity price update time. Therefore, the determination of the liquid cooling start time of the battery cluster is not performed, avoiding unnecessary liquid cooling adjustment operations and taking into account the operating economy.

[0038] The judgment condition in the embodiments of the present invention can be expressed as follows: ; in, Pf This represents the estimated power output on the load side at the time of the next electricity price update. Pfz This is the backflow prevention value on the load side. k This is a preset multiple.

[0039] The preset multiplier can be set flexibly and independently, for example, it can be set to 1.1. This embodiment of the invention does not limit it.

[0040] As an optional embodiment, before determining the estimated power of each battery cluster of the energy storage system at the next electricity price update time based on the planned operating power of the energy storage system at the next electricity price update time, the estimated power of the load side at the next electricity price update time, and the anti-reverse current value of the load side, the liquid cooling control method of the energy storage system further includes: Determine whether the energy storage system is in a discharge state at the time of the next electricity price update. If it is in a discharge state, then the step of determining the estimated cluster power of each battery cluster in the energy storage system at the next electricity price update time is performed; If the battery cluster is in a charging state, the determination of the liquid cooling start-up time will not be performed.

[0041] Specifically, considering that the charging and discharging plans of energy storage systems are usually associated with time-of-use electricity prices, the operating power of the battery cluster during the charging phase usually has different characteristics than that during the discharging phase. The charging phase usually corresponds to a low electricity price, which means that the current electricity price is higher than the electricity price at the next electricity price update time. If the battery cluster is liquid-cooled in advance at the current time, it will increase the operating cost of the energy storage system during the charging phase. Therefore, in this embodiment of the invention, a judgment condition is set to determine whether the planned operating state of the energy storage system at the next electricity price update time is a discharging state: if it is a discharging state, it means that the battery cluster will be subjected to a high discharge power at the next electricity price update time, and liquid cooling adjustment needs to be performed in advance to ensure heat dissipation effect. Therefore, the subsequent step of determining the estimated power of the cluster is executed; if it is a charging state, the determination of the liquid cooling start time of the battery cluster is not performed, thereby limiting the liquid cooling control method of the present invention to be executed in the scenario before discharging, taking into account the operating economy of the energy storage system.

[0042] Therefore, the judgment of the planned operating state of the energy storage system at the next electricity price update time in the embodiments of the present invention can be used in conjunction with the aforementioned judgment condition of whether the estimated power of the load side at the next electricity price update time is not less than the product of a preset multiple and the anti-reverse current value of the load side, or can be used alone: ​​under the premise that the planned operating state is the discharge state, the judgment can be made by combining the relationship between the estimated power of the load side and the anti-reverse current value, which can further improve the accuracy of the judgment on whether the energy storage system needs to perform liquid cooling pre-start and reduce unnecessary liquid cooling adjustment operations.

[0043] As an optional embodiment, the liquid cooling control method for the energy storage system further includes: According to the preset detection cycle, check whether there is charging and discharging current in the energy storage system; If there is no charging or discharging current in the energy storage system, then the step of determining the estimated power of each battery cluster of the energy storage system at the next electricity price update time is performed based on the planned operating power of the energy storage system at the next electricity price update time, the estimated power of the load side at the next electricity price update time, and the anti-reverse current value of the load side. If the energy storage system is currently experiencing charging and discharging current, the determination of the liquid-cooled start-up time for the battery cluster will not be performed. During the process of gradually adjusting the liquid temperature reference value of the battery cluster to the target liquid temperature according to the preset time step and preset temperature difference step value, if the energy storage system generates a charging and discharging current, the adjustment of the liquid temperature reference value of the battery cluster will be stopped, so that the battery management system (BMS) of the energy storage system can control the liquid temperature of the battery cluster.

[0044] Specifically, considering that when the energy storage system already has a charging / discharging current, it indicates that the energy storage system is already in the formal charging / discharging operation phase. At this time, the liquid inlet temperature of the battery cluster is usually adjusted by the battery management system of the energy storage system according to its own control logic. If the determination of the liquid cooling start time of the battery cluster is still performed, it is easy to conflict with the liquid inlet temperature adjustment process already being performed by the battery management system. Therefore, in this embodiment of the invention, the presence of a charging / discharging current in the energy storage system is detected according to a preset detection cycle. Only when it is detected that the energy storage system does not currently have a charging / discharging current (i.e., the energy storage system is in a static state) is the step of determining the cluster estimated power of each battery cluster of the energy storage system at the next electricity price update time based on the planned operating power of the energy storage system at the next electricity price update time, the estimated power of the load side at the next electricity price update time, and the anti-reverse current value of the load side executed. If the presence of a charging / discharging current in the energy storage system is detected, the determination of the liquid cooling start time of the battery cluster is not performed. Furthermore, during the process of gradually adjusting the liquid temperature reference value of the battery cluster to the target liquid temperature according to the preset time step and preset temperature difference step value, if the energy storage system generates a charging and discharging current, it indicates that the energy storage system has entered the formal charging and discharging operation stage from the static state. At this time, the adjustment of the liquid temperature reference value of the battery cluster should be stopped in time, and the battery management system of the energy storage system should control the liquid inlet temperature of the battery cluster according to its own control logic, so as to avoid mutual interference between the liquid cooling control method of the present invention and the control logic of the battery management system.

[0045] The preset detection cycle can be set flexibly and independently. For example, it can be set to perform a detection at the 30th minute of each hour (such as 0:30, 1:30, 2:30, etc.). This embodiment of the invention does not limit this.

[0046] As an optional embodiment, determining the target liquid temperature of the battery cluster at the next electricity price update time based on the cluster's estimated power includes: The estimated power of the battery cluster at the next electricity price update time is converted into the charge / discharge rate of the battery cluster; Based on the preset mapping relationship between charge / discharge rate and target liquid temperature, the target liquid temperature corresponding to the charge / discharge rate is determined and set as the target liquid temperature of the battery cluster at the next electricity price update time.

[0047] Specifically, considering that the charge / discharge rate of a battery cluster can more intuitively reflect the working intensity of the battery cluster relative to its own capacity, and that the heat generated by the battery cluster during operation is closely related to the charge / discharge rate, this embodiment of the invention first converts the estimated power of the battery cluster at the next electricity price update time into the charge / discharge rate of the battery cluster. Then, based on the preset mapping relationship between the charge / discharge rate and the target liquid temperature, the target liquid temperature corresponding to the charge / discharge rate is determined. The mapping relationship between the charge / discharge rate and the target liquid temperature generally shows a negative correlation trend, that is, the higher the charge / discharge rate, the more heat the battery cluster generates during operation, and the lower the corresponding target liquid temperature should be set to ensure that the battery cluster has a heat dissipation capacity that matches its working intensity; the lower the charge / discharge rate, the less heat the battery cluster generates, and the corresponding target liquid temperature can be set relatively higher to avoid unnecessary energy consumption.

[0048] Specifically, there are various ways to convert the estimated power of the battery cluster at the next electricity price update time into the charge / discharge rate of the battery cluster. For example, it can be converted by the following relationship. This embodiment of the invention does not limit the specific method.

[0049] ; Among them, C rate I represents the charge / discharge rate. BC To estimate cluster power, The rated capacity of the battery cluster can be, for example, 314 Ah.

[0050] In a specific example, Table 1 shows the mapping relationship between charge / discharge rate and target liquid temperature: Table 1

[0051] Where nC represents the charging / discharging current being equal to n times the rated capacity C. N .

[0052] It should be noted that the specific correspondence between charge / discharge rate and target liquid temperature in the table above is only an example. The actual mapping relationship can be set independently according to the heat dissipation characteristics of the battery cluster and specific engineering requirements. This embodiment of the invention does not limit this.

[0053] As an optional embodiment, the liquid cooling start-up time of the battery cluster is determined based on a preset time step, a preset temperature difference step value, the temperature difference between the current inlet temperature and the target liquid temperature of the battery cluster, and a preset maximum start-up time, including: If the temperature difference between the current inlet temperature and the target liquid temperature of the battery cluster is less than the preset temperature difference threshold, then it is determined that liquid cooling pre-start is not required for the battery cluster. If the temperature difference between the current inlet temperature and the target temperature of the battery cluster is not less than the preset temperature difference threshold, the number of step adjustments is determined according to the ratio of the temperature difference to the preset temperature difference step value. The smaller of the product of the number of tiered adjustments and the preset time step, and the preset maximum start time, is determined as the advance start time of the battery cluster before the next electricity price update. The liquid-cooled start-up time of the battery cluster is determined based on the next electricity price update time and the advance start-up time.

[0054] Specifically, considering that when the temperature difference between the current inlet temperature and the target liquid temperature of the battery cluster is small, the liquid cooling system can complete the temperature adjustment in a short time without the need for pre-starting the liquid cooling, a preset temperature difference threshold is set in this embodiment of the invention as the basis for determining whether pre-starting the liquid cooling of the battery cluster is required: if the temperature difference between the current inlet temperature and the target liquid temperature of the battery cluster is less than the preset temperature difference threshold, it is determined that pre-starting the liquid cooling of the battery cluster is not required; if the temperature difference is not less than the preset temperature difference threshold, it indicates that the inlet temperature of the battery cluster is significantly different from the target liquid temperature, and the liquid cooling system needs to be started in advance for stepwise adjustment. At this point, in this embodiment of the invention, the number of step adjustments required to complete the entire step adjustment process is determined based on the ratio of the temperature difference to the preset temperature difference step value. The smaller of the product of the number of step adjustments and the preset time step (i.e., the time required to complete all step adjustments) and the preset maximum start time is determined as the advance start time of the battery cluster before the next electricity price update. This ensures that the liquid temperature of the battery cluster is adjusted to the correct position before the next electricity price update, while avoiding unnecessary energy consumption due to an excessively long advance start time. Finally, based on the next electricity price update time and the advance start time, the liquid cooling start time of the battery cluster can be determined, i.e., the liquid cooling start time is the next electricity price update time minus the time corresponding to the advance start time.

[0055] In this embodiment of the invention, the formulas for determining the number of step adjustments, the advance start-up duration, and the liquid cooling start-up time can be expressed as follows: ; ; ; in, N For the number of steps to adjust, dT This represents the temperature difference between the current inlet temperature and the target liquid temperature of the battery cluster. dTs To preset the temperature difference step value, Ta To advance the start time, dt To preset the time step, Tmax To preset the maximum startup time, ts This is the liquid-cooled start-up time for the battery cluster. tpThis is the time for the next electricity price update.

[0056] The preset temperature difference threshold, preset temperature difference step value, preset time step, and preset maximum start-up time can all be set flexibly and independently. For example, the preset temperature difference threshold can be set to 5 degrees Celsius, and the preset maximum start-up time can be set to 30 minutes, etc. The embodiments of the present invention do not limit these settings.

[0057] Additionally, please refer to Figure 2 , Figure 2 The third flowchart of the liquid cooling control method for the energy storage system provided by the present invention, which gradually adjusts the liquid temperature reference value of the battery cluster, is shown as an optional embodiment. Starting from the liquid cooling start time before the next electricity price update time, the liquid temperature reference value of the battery cluster is gradually adjusted from the current inlet liquid temperature to the target liquid temperature according to a preset time step and a preset temperature difference step value. S201: At the moment of liquid cooling start-up, the difference between the current liquid inlet temperature of the battery cluster and the preset temperature difference step value is determined as the liquid temperature reference value of the battery cluster, and the liquid inlet temperature of the battery cluster is adjusted according to the liquid temperature reference value. S202: After each preset time step, the difference between the latest liquid inlet temperature of the battery cluster and the preset temperature difference step value is determined as the liquid temperature reference value corresponding to the current control step, and the liquid inlet temperature of the battery cluster is adjusted according to the liquid temperature reference value corresponding to the current control step. S203: When the temperature difference between the current inlet temperature and the target liquid temperature of the battery cluster is less than the preset temperature difference threshold, adjust the liquid temperature reference value of the battery cluster to the target liquid temperature and keep the target liquid temperature unchanged.

[0058] Specifically, in this embodiment of the invention, the reference value of the battery cluster's liquid temperature is not directly adjusted to the target liquid temperature at the moment of liquid cooling startup. Instead, a step-wise adjustment method is adopted: at the moment of liquid cooling startup, the current inlet temperature of the battery cluster is first subtracted by a preset temperature difference step value, and the resulting difference is determined as the reference value of the battery cluster's liquid temperature. The liquid cooling system adjusts the inlet temperature of the battery cluster according to this reference value. After that, every preset time step, the latest inlet temperature of the battery cluster (i.e., the inlet temperature actually reached in the previous control step) is used as the basis, and a preset temperature difference step value is subtracted to obtain the liquid temperature reference value corresponding to the current control step. The inlet temperature of the battery cluster is continuously adjusted accordingly. This cycle is repeated until the temperature difference between the current inlet temperature of the battery cluster and the target liquid temperature is less than a preset temperature difference threshold. At this point, the reference value of the battery cluster's liquid temperature is adjusted to the target liquid temperature and the target liquid temperature is maintained unchanged.

[0059] Because liquid cooling equipment (such as compressors) typically needs to operate continuously at high loads when performing cooling tasks with large temperature differences, its operating efficiency is relatively low. However, in the embodiments of the present invention, the liquid cooling equipment only needs to complete the temperature adjustment task corresponding to a small preset temperature difference step value in each control step. This allows the liquid cooling equipment to operate continuously under conditions where the temperature rise range is small and the operating efficiency is high. Compared with the method of directly adjusting the liquid temperature reference value to the target liquid temperature at the time of liquid cooling start-up, the embodiments of the present invention can avoid the impact caused by excessive adjustment of the liquid cooling equipment, improve the operating energy efficiency ratio of the liquid cooling equipment, and reduce the operating energy consumption of the liquid cooling system.

[0060] The formula for determining the liquid temperature reference value in this embodiment of the invention can be expressed as: ; in, Tref This is a reference value for the liquid temperature of the battery cluster. Tin This refers to the current or latest inlet temperature of the battery cluster. dTs This is the preset temperature difference step value.

[0061] To more clearly illustrate the overall execution process of the liquid cooling control method for the energy storage system provided in this embodiment of the invention, an example based on a specific application scenario is given below. Assuming a battery cluster has a planned power of 100 kW, and the estimated power of the load side at the next electricity price update time is converted to a cluster load estimate of 90 kW, and the cluster anti-reverse current value of the battery cluster is 10 kW, with a preset multiplier of 1.1; if the estimated power of the load side is not less than the product of the preset multiplier and the anti-reverse current value of the load side, and the planned operating state of the energy storage system at the next electricity price update time is the discharge state, then the estimated power of the battery cluster at the next electricity price update time can be determined as 80 kW based on the smaller of the cluster planned power, the difference between the cluster load estimate and the cluster anti-reverse current value (i.e., 90 kW minus 10 kW equals 80 kW); then the estimated power of 80 kW is converted into the corresponding charge / discharge rate, and the target liquid temperature of the battery cluster at the next electricity price update time is determined based on the preset mapping relationship between the charge / discharge rate and the target liquid temperature, for example, 15 degrees Celsius.

[0062] After obtaining the target liquid temperature, assuming the current inlet liquid temperature of the battery cluster is 25 degrees Celsius, the temperature difference between it and the target liquid temperature is 10 degrees Celsius, which is greater than the preset temperature difference threshold (e.g., 5 degrees Celsius). At this time, the number of step adjustments can be determined to be 5 based on the ratio of this temperature difference to the preset temperature difference step value (e.g., 2 degrees Celsius). The smaller value between the product of the number of step adjustments and the preset time step (e.g., 5 minutes) (i.e., 25 minutes) and the preset maximum start time (e.g., 30 minutes) is determined as the advance start time, i.e., 25 minutes. Then, based on the next electricity price update time and the 25-minute advance start time, the liquid cooling start time of the battery cluster is determined, i.e., the liquid cooling start time is the time corresponding to 25 minutes before the next electricity price update time.

[0063] Starting from the moment of liquid cooling startup, the current inlet liquid temperature of the battery cluster (25 degrees Celsius) is first subtracted from a preset temperature difference step value (2 degrees Celsius) to obtain 23 degrees Celsius, which is determined as the reference value for the battery cluster's liquid temperature, and the inlet liquid temperature of the battery cluster is adjusted accordingly. Subsequently, after each preset time step (5 minutes), the latest inlet liquid temperature of the battery cluster is subtracted by 2 degrees Celsius to obtain the liquid temperature reference value corresponding to the current control step, and the inlet liquid temperature of the battery cluster is continuously adjusted accordingly. This adjustment is repeated until the temperature difference between the current inlet liquid temperature of the battery cluster and the target liquid temperature (15 degrees Celsius) is less than a preset temperature difference threshold. At this point, the reference value for the battery cluster's liquid temperature is adjusted to 15 degrees Celsius, and the target liquid temperature is maintained unchanged. Thus, before the next electricity price update, the inlet liquid temperature of the battery cluster is adjusted in advance and smoothly to the target liquid temperature that matches the discharge power it will soon withstand. The specific values ​​mentioned above are merely examples to illustrate the technical solution of the embodiments of the present invention and are not intended to limit the scope of protection of the present invention.

[0064] Furthermore, it is worth mentioning that the planned operating power of the energy storage system in the embodiments of the present invention at the next electricity price update time can be obtained in the following way: the energy management system (EMS) of the energy storage system acquires the charging and discharging plan data for a preset period of time in the future at each electricity price update time. The charging and discharging plan data includes time period information corresponding to multiple time periods, the charging or discharging status corresponding to each time period, and the planned operating power of the energy storage system corresponding to each time period. The planned operating power of the energy storage system in the embodiments of the present invention at the next electricity price update time is the planned operating power of the energy storage system corresponding to the time period corresponding to the next electricity price update time in the above-mentioned charging and discharging plan data, thereby providing a data basis for determining the cluster estimated power in the embodiments of the present invention.

[0065] The preset duration can be set flexibly and independently, for example, it can be set to several hours in the future. This embodiment of the invention does not limit this setting.

[0066] Alternatively, as an alternative implementation, a fixed-advance-time start-up of the liquid cooling system for pre-cooling can be adopted. This involves not determining the cluster's estimated power and target liquid temperature based on the energy storage system's planned operating power at the next electricity price update, the load's estimated power at the next electricity price update, and the load's backflow prevention value. Instead, the liquid cooling system is directly started at a fixed time before the next electricity price update to adjust the inlet liquid temperature of the battery cluster. While this alternative implementation can achieve the goal of adjusting the battery cluster's inlet liquid temperature to some extent, it lacks precise judgment based on the actual load level on the load side and the battery cluster's estimated power. Therefore, its heat dissipation effect and the improvement in the liquid cooling system's operating efficiency ratio are relatively limited when the actual operating power of the energy storage system changes.

[0067] Furthermore, the preset time step, preset temperature difference step value, preset temperature difference threshold, preset multiple, preset maximum start-up time, preset detection cycle, preset allocation rule, and preset mapping relationship between charge / discharge rate and target liquid temperature in the embodiments of the present invention are only examples of the specific values ​​described above. They can all be set flexibly and independently according to the actual structure of the energy storage system, the heat dissipation characteristics of the battery cluster, and specific engineering requirements. The embodiments of the present invention do not limit these parameters.

[0068] In addition, the liquid cooling control method for the energy storage system provided in this embodiment of the invention can be implemented by optimizing the control logic of the energy management system and the battery management system of the energy storage system. It does not require additional hardware equipment to be added to the energy storage system, and therefore has a relatively low modification cost in practical engineering applications.

[0069] Please refer to Figure 3 , Figure 3 This is a schematic diagram of the structure of the liquid cooling control device for the energy storage system provided by the present invention. The liquid cooling control device for the energy storage system includes: Memory 31 is used to store computer programs; The processor 32 is used to execute a computer program to implement the steps of the liquid cooling control method for the energy storage system as described in the foregoing embodiments.

[0070] For a description of the liquid cooling control device for the energy storage system provided in the embodiments of the present invention, please refer to the embodiments of the liquid cooling control method for the aforementioned energy storage system. The embodiments of the present invention will not be repeated here.

[0071] The present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the liquid cooling control method for the energy storage system as described in the foregoing embodiments.

[0072] For a description of the computer-readable storage medium provided in the embodiments of the present invention, please refer to the embodiments of the liquid cooling control method for the aforementioned energy storage system. The embodiments of the present invention will not be repeated here.

[0073] The various embodiments described in this specification are presented in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. It should also be noted that in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0074] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A liquid cooling control method for an energy storage system, characterized in that, include: Based on the planned operating power of the energy storage system at the next electricity price update time, the estimated power of the load side at the next electricity price update time, and the anti-reverse current value of the load side, the estimated power of each battery cluster of the energy storage system at the next electricity price update time is determined. The target liquid temperature of the battery cluster at the next electricity price update time is determined based on the cluster's estimated power. The liquid cooling start-up time of the battery cluster is determined based on the preset time step, preset temperature difference step value, temperature difference between the current liquid inlet temperature and the target liquid temperature of the battery cluster, and preset maximum start-up time. Starting from the liquid cooling start time before the next electricity price update time, the liquid temperature reference value of the battery cluster is gradually adjusted from the current liquid inlet temperature to the target liquid temperature according to the preset time step and preset temperature difference step value, so as to gradually adjust the liquid inlet temperature of the battery cluster to the target liquid temperature.

2. The liquid cooling control method for the energy storage system according to claim 1, characterized in that, The determination of the estimated cluster power of each battery cluster of the energy storage system at the next electricity price update time, based on the planned operating power of the energy storage system at the next electricity price update time, the estimated power of the load side at the next electricity price update time, and the anti-reverse current value of the load side, includes: According to the preset allocation rules, the planned operating power of the energy storage system at the next electricity price update time is divided into each battery cluster to obtain the cluster planned power of each battery cluster; According to the preset allocation rule, the estimated power of the load side at the next electricity price update time and the anti-reverse current value of the load side are respectively divided into each battery cluster to obtain the cluster load estimate and cluster anti-reverse current value of each battery cluster. The smaller of the cluster planned power, the cluster load estimate, and the cluster anti-reverse current value is determined as the cluster estimated power at the next electricity price update time.

3. The liquid cooling control method for the energy storage system according to claim 1, characterized in that, The estimated power on the load side at the next electricity price update time is determined in the following way: Obtain the average power on the load side within a preset time period prior to the current moment; The average power is determined as the estimated power of the load side at the next electricity price update time.

4. The liquid cooling control method for the energy storage system according to claim 1, characterized in that, Before determining the estimated power of each battery cluster of the energy storage system at the next electricity price update time based on the planned operating power of the energy storage system at the next electricity price update time, the estimated power of the load side at the next electricity price update time, and the anti-reverse current value of the load side, the liquid cooling control method of the energy storage system further includes: Determine whether the estimated power on the load side at the next electricity price update time is not less than the product of the preset multiple and the anti-reverse current value on the load side; If it is not less than, then proceed with the step of determining the estimated cluster power of each battery cluster in the energy storage system at the next electricity price update time; If the value is less than the specified value, the determination of the liquid cooling start-up time for the battery cluster will not be performed.

5. The liquid cooling control method for an energy storage system according to claim 1, characterized in that, Before determining the estimated power of each battery cluster of the energy storage system at the next electricity price update time based on the planned operating power of the energy storage system at the next electricity price update time, the estimated power of the load side at the next electricity price update time, and the anti-reverse current value of the load side, the liquid cooling control method of the energy storage system further includes: Determine whether the energy storage system is in a discharge state at the time of the next electricity price update. If it is in a discharge state, then the step of determining the estimated cluster power of each battery cluster of the energy storage system at the next electricity price update time is performed; If the battery cluster is in a charging state, the determination of the liquid cooling start-up time will not be performed.

6. The liquid cooling control method for an energy storage system according to claim 1, characterized in that, The liquid cooling control method for the energy storage system further includes: According to the preset detection cycle, check whether the energy storage system currently has charging and discharging current; If there is no charging or discharging current in the energy storage system, then the step of determining the estimated power of each battery cluster of the energy storage system at the next electricity price update time is performed based on the planned operating power of the energy storage system at the next electricity price update time, the estimated power of the load side at the next electricity price update time, and the anti-reverse current value of the load side. If the energy storage system currently has a charging / discharging current, then the process ends; During the process of gradually adjusting the liquid temperature reference value of the battery cluster to the target liquid temperature according to the preset time step and preset temperature difference step value, if the energy storage system generates a charging and discharging current, the adjustment of the liquid temperature reference value of the battery cluster is stopped, so that the battery management system of the energy storage system can control the liquid inlet temperature of the battery cluster.

7. The liquid cooling control method for an energy storage system according to claim 1, characterized in that, The step of determining the target liquid temperature of the battery cluster at the next electricity price update time based on the cluster's estimated power includes: The estimated power of the battery cluster at the next electricity price update time is converted into the charge / discharge rate of the battery cluster; Based on the preset mapping relationship between charge / discharge rate and target liquid temperature, the target liquid temperature corresponding to the charge / discharge rate is determined, and this is set as the target liquid temperature of the battery cluster at the next electricity price update time.

8. The liquid cooling control method for an energy storage system according to any one of claims 1 to 7, characterized in that, The determination of the liquid cooling start-up time of the battery cluster based on a preset time step, a preset temperature difference step value, the temperature difference between the current inlet temperature and the target liquid temperature of the battery cluster, and a preset maximum start-up time includes: If the temperature difference between the current inlet temperature and the target liquid temperature of the battery cluster is less than the preset temperature difference threshold, then it is determined that liquid cooling pre-start is not required for the battery cluster. If the temperature difference between the current inlet temperature and the target temperature of the battery cluster is not less than the preset temperature difference threshold, then the number of step adjustments is determined according to the ratio of the temperature difference to the preset temperature difference step value. The smaller of the product of the number of step adjustments and the preset time step, and the preset maximum start time, is determined as the advance start time of the battery cluster before the next electricity price update. The liquid-cooled start-up time of the battery cluster is determined based on the next electricity price update time and the aforementioned advance start-up duration.

9. A liquid-cooled control device for an energy storage system, characterized in that, include: Memory, used to store computer programs; A processor, configured to execute the computer program to implement the steps of the liquid cooling control method for the energy storage system as claimed in any one of claims 1 to 8.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the liquid cooling control method for the energy storage system as described in any one of claims 1 to 8.

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