Energy storage system and temperature control method for energy storage system

Abstract

Embodiments of the present disclosure disclose an energy storage system and a temperature control method for an energy storage system. The energy storage system comprises at least one battery cluster and a control apparatus. Each battery cluster comprises: a plurality of battery apparatuses; a thermal management pipe for providing a heat exchange medium to each battery apparatus, the thermal management pipe comprising a plurality of valve apparatuses and a main pipe and branch pipes in communication with one another, the branch pipes being connected in parallel, each battery apparatus being in communication with the main pipe via a branch pipe, and the valve apparatuses being respectively configured for the branch pipes and being used to control respective flow rates of the branch pipes; and a temperature measurement apparatus for measuring the temperature of each battery apparatus. The control apparatus is configured to determine, on the basis of the measured temperature of each battery apparatus, a temperature difference between the temperature of each battery apparatus and a specified temperature, and to control the degree of opening of a valve apparatus on the basis of the temperature difference, such that the temperature difference does not exceed a specified range.

Description

Energy storage systems and temperature control methods for energy storage systems

[0001] Cross-reference to related applications

[0002] This disclosure is based on and claims priority to Chinese Patent Application No. 202411711741.0, filed on November 27, 2024, entitled “Energy Storage System and Temperature Control Method for Energy Storage System”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to the field of energy storage technology, and in particular to energy storage systems and methods for temperature control of energy storage systems. Background Technology

[0004] New energy technologies are being applied more and more widely in daily life and industry. For example, new energy technologies are widely used in the automotive industry, and they are also being increasingly applied to the field of energy storage.

[0005] Energy storage systems typically deploy multiple battery devices. To ensure that these devices operate at suitable temperatures, energy storage systems are also equipped with thermal management systems for thermal management of the battery devices. How to utilize thermal management systems to improve temperature consistency among multiple battery devices is one of the research topics in the industry. Summary of the Invention

[0006] To address the aforementioned technical problems, this disclosure provides an energy storage system and a temperature control method for the energy storage system that can improve temperature consistency among battery devices.

[0007] A first aspect of this disclosure provides an energy storage system comprising at least one battery cluster and a control device. Each battery cluster includes: a plurality of battery devices; a thermal management pipeline for providing a heat exchange medium to each battery device, the thermal management pipeline including a plurality of valve devices and a main pipeline and branch pipelines interconnected with each other, the branch pipelines being connected in parallel, each battery device being connected to the main pipeline via a branch pipeline, and a valve device configured for each branch pipeline for controlling the flow rate of each branch pipeline; a temperature detection device for detecting the temperature of each battery device; and a control device configured to determine the temperature difference between the temperature of each battery device and a predetermined temperature based on the detected temperature of the battery device, and to control the opening degree of the valve devices based on the temperature difference so that the temperature difference does not exceed the predetermined range.

[0008] Because each branch pipe in the parallel configuration is equipped with a valve device, and these valve devices can control the flow rate of each branch pipe, and control the opening degree of these valve devices according to the temperature difference between the battery device temperature and the specified temperature, it is possible to accurately adjust the temperature of the battery device that significantly affects temperature uniformity. This helps to quickly bring the temperature of the battery devices to uniformity, and improved temperature uniformity among the battery devices helps to extend the service life of the battery devices.

[0009] In some embodiments, the control device is configured to determine the temperature difference between the temperature of each battery device and a predetermined temperature based on the temperature of each battery device in the same battery cluster, and to control the opening degree of the valve device based on the temperature difference, wherein the valve device corresponding to the branch pipe where the battery device with the higher temperature is located is preferentially controlled.

[0010] Because the temperature is adjusted first for the battery devices with higher temperatures within the same battery cluster, the adverse effects of excessively high battery temperatures can be suppressed as quickly as possible, while simultaneously bringing the temperatures of the battery devices together rapidly.

[0011] In some embodiments, the specified temperature includes an upper or lower limit of a specified temperature range. If the temperature difference between the battery device temperature and the upper limit of the temperature range is greater than 0, or if the temperature difference between the battery device temperature and the lower limit of the temperature range is less than 0, the control device determines that the temperature difference exceeds the specified range.

[0012] This ensures that the temperature of each battery device is within the specified temperature range, which not only improves the temperature consistency between battery devices but also allows each battery device to operate in a suitable temperature environment; moreover, a suitable temperature range can be set according to the operating conditions of the energy storage system.

[0013] In some embodiments, the specified temperature range is a temperature range of 20 degrees Celsius to 23 degrees Celsius; or, the specified temperature range is a range defined by part or all of the temperatures of the battery devices in the same battery cluster, excluding the highest and lowest temperatures.

[0014] This allows for improved temperature uniformity among battery devices while enabling each device to operate in a suitable temperature environment.

[0015] In some embodiments, when the temperature difference is greater than 0, the control device controls the valve device corresponding to the branch pipe where the battery device with that temperature is located to increase the opening degree, wherein the heat exchange medium is used to cool the battery device.

[0016] Therefore, by increasing the opening of the valve device and increasing the flow rate of the heat exchange medium in the branch pipe that needs to be cooled, it is possible to specifically cool all battery devices whose temperature is higher than the specified temperature range, so that the temperature of each battery device in the same battery cluster can quickly become uniform.

[0017] In some embodiments, for valve devices corresponding to branch pipes where multiple battery devices with a temperature difference greater than 0 are located, the valve devices are controlled to increase their opening degree simultaneously; or, for valve devices corresponding to branch pipes where multiple battery devices with a temperature difference greater than 0 are located, the valve devices are controlled to increase their opening degree sequentially according to the order of battery device temperature from high to low.

[0018] Therefore, the opening degree of multiple valve devices can be controlled at one time to quickly cool down multiple battery devices with high temperatures; or, the battery devices with relatively high temperatures can be cooled down first, which can suppress the adverse effects of excessive temperature as early as possible, and also help reduce the impact of flow regulation on the flow in other pipelines.

[0019] In some embodiments, when the temperature difference is less than 0, the control device controls the valve device corresponding to the branch pipe where the battery device with that temperature is located to reduce the opening degree, wherein the heat exchange medium is used to cool the battery device.

[0020] Therefore, by reducing the opening of the valve device and reducing the flow rate of the heat exchange medium in the branch pipe that needs to be heated, all battery devices with temperatures below the specified temperature range can be heated, and the temperatures of each battery device in the same battery cluster can be quickly made to be consistent; moreover, it also helps to prevent the battery devices from being overcooled.

[0021] In some embodiments, for the valve devices corresponding to the branch pipes where multiple battery devices with a temperature difference of less than 0 are located, the valve devices are controlled to reduce their opening degree simultaneously; or, for the valve devices corresponding to the branch pipes where multiple battery devices with a temperature difference of less than 0 are located, the valve devices are controlled to reduce their opening degree sequentially according to the order of battery device temperature from low to high.

[0022] Therefore, the opening degree of multiple valve devices can be controlled at one time to quickly cool down multiple battery devices with high temperatures; or, the battery devices with relatively high temperatures can be cooled down first, which can suppress the adverse effects of excessive temperature as early as possible, and also help reduce the impact of flow regulation on the flow in other pipelines.

[0023] In some embodiments, the specified temperature includes: the lowest temperature among all or some of the battery devices in the same battery cluster during the same temperature detection; the control device is configured to determine the temperature difference between the temperature of each battery device in the same battery cluster and the lowest temperature, and, if the temperature is higher than the lowest temperature and the temperature difference exceeds a specified range, control the opening of the valve device based on the temperature difference to reduce the temperature of the battery device to a temperature difference with the lowest temperature that does not exceed a specified range.

[0024] Therefore, it is possible to quickly bring the temperature of the battery devices in the same battery cluster to a uniform level while minimizing the temperature of each individual battery device, which helps to extend the lifespan of the battery devices. Moreover, even without specifically setting the operating temperature range of the battery devices, the battery devices can operate in a uniform temperature environment.

[0025] In some embodiments, the specified temperature includes: any temperature other than the lowest and highest temperatures among the temperatures of each battery device in the same battery cluster during the same temperature detection; the control device is configured to determine the temperature difference between the temperature of each battery device in the same battery cluster and the specified temperature; if the temperature is higher than the specified temperature and the temperature difference exceeds a specified range, control the opening of a valve device based on the temperature difference to reduce the temperature of the battery device to a temperature difference not exceeding a specified range; if the temperature is lower than the specified temperature and the absolute value of the temperature difference exceeds a specified range, control the opening of a valve device based on the temperature difference to raise the temperature of the battery device to a temperature difference not exceeding a specified range.

[0026] Therefore, the ability to quickly equalize the temperature of battery devices within the same battery cluster helps extend the lifespan of the battery devices; moreover, even without specifically setting the operating temperature range of the battery devices, they can operate in a more uniform temperature environment. Additionally, it helps prevent the battery devices from being overcooled.

[0027] In some embodiments, the specified temperature range is from 0 degrees Celsius to 3 degrees Celsius.

[0028] This improves the temperature consistency among battery devices within the same battery cluster.

[0029] In some embodiments, the specified temperature range is from 0 degrees Celsius to 0.5 degrees Celsius.

[0030] This allows for further improvement in temperature consistency among battery devices within the same battery cluster.

[0031] In some embodiments, the control device determines the lowest temperature among the temperatures of each battery device in the same battery cluster, determines whether the temperature difference between each temperature other than the lowest temperature and the lowest temperature exceeds a specified range, and controls the valve device corresponding to the branch pipe where the battery device with that temperature is located to increase its opening degree when the temperature is higher than the lowest temperature and the temperature difference exceeds the specified range, wherein the heat exchange medium is used to cool the battery device.

[0032] Therefore, by increasing the opening of the valve device and increasing the flow rate of the heat exchange medium in the branch pipe that needs to be cooled, the battery device with a relatively high temperature can be cooled down as quickly as possible and approach the lowest temperature. This makes the temperature of the battery devices in the same battery cluster more consistent and approach the lowest temperature. This not only improves the temperature consistency of the battery devices, but also helps the battery devices to perform well and extend their service life.

[0033] In some embodiments, for the valve devices corresponding to the branch pipes where multiple battery devices have temperatures higher than the minimum temperature and temperature differences exceeding a specified range, the valve devices are all controlled to increase their opening degree; or...

[0034] For the valve devices corresponding to the branch pipes where multiple battery devices are located, with temperatures higher than the minimum temperature and temperature differences exceeding the specified range, the valve devices are sequentially controlled to increase their opening degree in order of battery device temperature from high to low.

[0035] Therefore, the opening degree of multiple valve devices can be controlled at one time to quickly cool down multiple battery devices with high temperatures; or, the battery devices with relatively high temperatures can be cooled down first, which can suppress the adverse effects of excessive temperature as early as possible, and also help reduce the impact of flow regulation on the flow in other pipelines.

[0036] In some embodiments, if there is an excessively low temperature in the temperature of each battery device in the same battery cluster that is lower than a specified temperature and the absolute value of the temperature difference exceeds a specified range, the control device controls the valve device corresponding to the branch pipe where the battery device with the excessively low temperature is located to reduce the opening degree, so that the temperature of the battery device rises to a temperature difference from the lowest temperature that does not exceed the specified range, wherein the heat exchange medium is used to cool the battery device.

[0037] Therefore, by reducing the opening of the valve device and reducing the flow rate of the heat exchange medium in the branch pipe that needs to be heated, the battery device with an excessively low temperature can be heated up, and the temperature of each battery device in the same battery cluster can be quickly made to be consistent; in addition, it is also beneficial to prevent the battery device from being overcooled.

[0038] In some embodiments, the valve device includes a switching valve, and controlling the valve device to increase the opening degree includes controlling the switching valve to switch from closed to open.

[0039] In some embodiments, the valve device includes a switching valve, and controlling the valve device to increase the opening degree includes controlling the switching valve to be turned on, and controlling the valve device to decrease the opening degree includes controlling the switching valve to switch from being turned on to being turned off.

[0040] Because the valve device uses an on / off valve, it is beneficial to simplify the pipeline structure and control the valve, and it is also beneficial to quickly adjust the temperature.

[0041] In some embodiments, the valve device includes a proportional valve, and controlling the valve device to increase the opening degree includes controlling the proportional valve to increase the opening degree relative to the current opening degree.

[0042] In some embodiments, the valve device includes a proportional valve, and controlling the valve device to increase the opening degree includes controlling the proportional valve to increase the opening degree relative to the current opening degree, and controlling the valve device to decrease the opening degree includes controlling the proportional valve to decrease the opening degree relative to the current opening degree.

[0043] Because the valve device uses a proportional valve, it is beneficial to accurately control the valve opening and the flow rate of the heat exchange medium in the branch pipe, which in turn is beneficial to accurately adjust the temperature of the battery device. Moreover, the use of a proportional valve also helps to ensure that each battery device in the battery cluster operates in a relatively low temperature environment, which is beneficial to the performance of the battery device and extends its service life.

[0044] In some embodiments, the proportional valve increases or decreases its opening by a predetermined opening change range each time, with the predetermined opening change range being within the range of 3% to 10% of the opening.

[0045] Therefore, it is possible to adjust the flow rate of the heat exchange medium in the branch pipe to be adjusted while maintaining a continuous supply of heat exchange medium to each battery device. Moreover, it is possible to flexibly increase or decrease the opening of the valve device with high precision according to the temperature of the battery device. This is beneficial for quickly achieving temperature uniformity and enables each battery device in the battery cluster to work in a relatively low temperature environment, which is conducive to the performance of the battery device and extends its service life.

[0046] In some embodiments, the control device is configured to acquire the temperature of each battery device from the temperature detection device at predetermined time intervals, determine a temperature difference in response to each acquired temperature, and control the opening of the valve device based on the temperature difference so that the temperature difference does not exceed a predetermined range.

[0047] Therefore, the temperature of the battery device can be monitored in real time, and the flow rate of the heat exchange medium in the branch pipeline can be adjusted in a timely manner according to the temperature difference, so as to adjust the temperature of the battery device in a timely manner.

[0048] In some embodiments, the main pipeline includes an input main pipeline and an output main pipeline, and the branch pipeline includes an input branch pipeline and an output branch pipeline. Each input branch pipeline is used to input the heat exchange medium from the input main pipeline into the battery device, and each output branch pipeline is used to output the heat exchange medium that has exchanged heat with the battery device from the battery device to the output main pipeline.

[0049] This makes it easy to form a circulating flow path for the heat exchange medium.

[0050] In some embodiments, along the flow direction of the heat exchange medium, the valve device is connected between the upstream end of the input branch and the input main branch, and / or, along the flow direction of the heat exchange medium, the valve device is connected between the downstream end of the output branch and the output main branch, and / or, the valve device is connected in the middle of the input branch, and / or, the valve device is connected in the middle of the output branch.

[0051] Therefore, valve devices can be flexibly selected or combined according to pipeline structure, flow resistance, etc.

[0052] In some embodiments, in each battery cluster, multiple battery devices are stacked in layers along a first direction, wherein the first direction is perpendicular to the bearing surface, and the bearing surface is used to support the energy storage system.

[0053] Because multiple battery devices are stacked in layers along a direction perpendicular to the support surface, it is beneficial to save floor space; moreover, even if the battery devices on the top layer tend to heat up due to sunlight, rising heat, etc., temperature uniformity of battery devices in the battery cluster can be achieved.

[0054] In some embodiments, the heat exchange medium includes a coolant.

[0055] In some embodiments, the energy storage system further includes a thermal management device, which includes a heat exchange pipeline connected to the thermal management pipeline. The thermal management device is used to exchange heat with the heat exchange medium flowing from the thermal management pipeline into the heat exchange pipeline and to provide the heat-exchanged heat exchange medium to the thermal management pipeline.

[0056] Therefore, the heat exchange medium that has exchanged heat with the battery device can be restored to a suitable temperature through the thermal management device so that it can be recycled for heat exchange with the battery device again.

[0057] In some embodiments, the energy storage system includes multiple battery clusters, with the main pipelines of the multiple battery clusters connected in parallel to each other in a heat exchange pipeline; or, the energy storage system includes multiple battery clusters and a main heat exchange medium pipeline, with the main pipelines of the multiple battery clusters connected in parallel to each other in the main heat exchange medium pipeline, and the main heat exchange medium pipeline connected to the heat exchange pipeline.

[0058] Therefore, it is possible not only to perform thermal management on each battery device in the battery cluster and improve the temperature uniformity of each battery device, but also to flexibly arrange the flow paths. When the main pipelines of multiple battery clusters are connected in parallel to each other to the heat exchange pipeline, the circulation of the heat exchange medium in each battery cluster is relatively independent, which helps to reduce the interference of flow changes between them; when the main pipelines of multiple battery clusters are connected in parallel to each other through the main flow path of the heat exchange medium to the heat exchange pipeline, it helps to simplify the pipeline structure in the energy storage system.

[0059] A second aspect of this disclosure provides a temperature control method for an energy storage system, comprising: acquiring the temperature of each battery device; determining the temperature difference between each temperature and a specified temperature; determining whether each temperature difference is within a specified range; maintaining the valve device corresponding to the battery device whose temperature difference does not exceed the specified range at its current opening state when the temperature difference does not exceed the specified range; and controlling the opening of the valve device corresponding to the battery device whose temperature difference exceeds the specified range when the temperature difference exceeds the specified range, so that the temperature difference does not exceed the specified range.

[0060] Because the opening of these valves is controlled based on the temperature difference of the battery devices, precise temperature adjustment can be applied to battery devices that significantly affect temperature uniformity, which helps to quickly bring the temperatures of the battery devices together.

[0061] The beneficial effects of the embodiments disclosed herein include: improving the temperature uniformity between battery devices, which is conducive to the battery cluster performing well and extending its service life. Attached Figure Description

[0062] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this disclosure. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0063] Figure 1 is a schematic diagram of the structure of an energy storage system provided in some embodiments of this disclosure;

[0064] Figure 2 is a schematic diagram of the structure of a battery cluster provided in some embodiments of this disclosure;

[0065] Figure 3 is a schematic diagram of the structure of a battery cluster provided in some other embodiments of this disclosure;

[0066] Figure 4 is a schematic diagram of the structure of a battery cluster provided in some further embodiments of this disclosure;

[0067] Figure 5 is a schematic diagram of the structure of a battery cluster provided in some other embodiments of this disclosure;

[0068] Figure 6 is a schematic diagram of the structure of a battery cluster provided in some further embodiments of this disclosure;

[0069] Figure 7 is a schematic diagram of the structure of a two-way valve provided in some embodiments of this disclosure;

[0070] Figure 8 is a structural schematic diagram of a three-way valve provided in some embodiments of this disclosure;

[0071] Figure 9 is a schematic diagram of a valve device controlling the opening and closing of a flow path according to some embodiments of this disclosure;

[0072] Figure 10 is a schematic diagram of a valve device controlling the opening and closing of a flow path according to some other embodiments of this disclosure;

[0073] Figure 11 is a schematic diagram of a valve device controlling the opening and closing of a flow path according to some other embodiments of this disclosure;

[0074] Figure 12 is a schematic diagram of valve device for opening adjustment provided in some embodiments of this disclosure;

[0075] Figure 13 is a schematic diagram of valve device opening adjustment provided in some other embodiments of this disclosure;

[0076] Figure 14 is a schematic diagram of the structure of an energy storage system provided in some other embodiments of this disclosure;

[0077] Figure 15 is a schematic flowchart of a temperature control method for an energy storage system provided in some embodiments of this disclosure;

[0078] Figure 16 is a schematic diagram of the structure of an energy storage system provided in some embodiments of this disclosure.

[0079] Explanation of reference numerals in the attached drawings: 1. Prefabricated housing; 10. Control device; 11. Thermal management pipeline; 110. Main flow path; 110a. Main supply flow path; 110b. Main return flow path; 111. Main pipe; 111a. Input main pipe; 111b. Output main pipe; 112. Branch pipe; 112a. Input branch pipe; 112b. Output branch pipe; 12. Battery cluster; 120. First battery cluster; 121. Second battery cluster; 122. Third battery cluster; 123. Fourth battery cluster; 12 4. Fifth battery cluster; 13. Battery unit; 14. Two-way valve; 141. First valve port; 142. Second valve port; 143. Two-way valve core; 144. Two-way valve control interface; 15. Three-way valve; 151. First port; 152. Second port; 153. Third port; 154. Three-way valve core; 155. Three-way valve control interface; 16. Exhaust device; 17. Temperature detection device; 18. Pump; 19. Temperature sensor; 2. Thermal management device; 100. Energy storage system. Detailed Implementation

[0080] The embodiments of the technical solutions disclosed herein will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solutions disclosed herein and are therefore intended to limit the scope of protection of this disclosure.

[0081] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure; the terms “comprising” and “having”, and any variations thereof, in the specification and the foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0082] In the description of the embodiments of this disclosure, technical terms such as "first," "second," "third," and "fourth" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary or secondary relationship of the indicated technical features. In the description of the embodiments of this disclosure, "a plurality of" means two or more, unless otherwise explicitly defined.

[0083] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this disclosure. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0084] In the description of the embodiments of this disclosure, the term "and / or" 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 document generally indicates that the preceding and following related objects are in an "or" relationship.

[0085] In the description of the embodiments of this disclosure, the technical terms "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "circumferential," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this disclosure and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed, operated, or used in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this disclosure.

[0086] In the description of the embodiments of this disclosure, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this disclosure according to the specific circumstances.

[0087] In the description of the embodiments of this disclosure, unless otherwise expressly specified and limited, the technical term "contact" should be interpreted broadly, and can be direct contact, contact through an intermediate medium layer, contact between two contacting parties with substantially no interaction force, or contact between two contacting parties with interaction force.

[0088] The embodiments of this disclosure will now be described in detail.

[0089] The application of new energy technologies in daily life and industry is becoming increasingly widespread. For example, new energy technologies are widely used in the automotive industry, and they are also increasingly being applied to energy storage. An energy storage system may include a prefabricated enclosure 1, battery clusters (including multiple battery devices) located within the prefabricated enclosure 1, and thermal management piping for supplying heat exchange media to thermal management components of these battery devices. In the prefabricated enclosure 1, sometimes to save floor space, the battery devices within the battery clusters are stacked in layers. The energy storage system may also include thermal management devices, which may be entirely or partially located within the prefabricated enclosure 1, or entirely located outside the prefabricated enclosure 1.

[0090] In some application scenarios, energy storage systems are placed outdoors. The battery units on the top layer and near the top layer of the system are susceptible to the effects of sunlight and rising heat from the prefabricated enclosure. Consequently, there is a phenomenon where the temperature of the top-layer battery units within the same battery cluster is significantly higher than that of the units on other layers. Temperature monitoring of several battery clusters revealed instances where the temperature of the top-layer battery units was more than 3 degrees Celsius higher than that of the bottom-layer units.

[0091] On the one hand, excessively high temperatures can cause battery devices to malfunction. On the other hand, large temperature differences between battery devices within the same battery cluster can also affect the cluster's performance and potentially shorten its lifespan. Therefore, improving temperature consistency among multiple battery devices using thermal management systems is a key research topic in the industry.

[0092] To address the aforementioned technical challenges, it is desirable to provide a solution that can effectively cool, for example, the top or near-top battery devices and reduce temperature differences between battery devices.

[0093] Therefore, embodiments of this disclosure provide an energy storage system comprising at least one battery cluster and a control device. Each battery cluster includes: multiple battery devices; a thermal management pipeline for providing a heat exchange medium to each battery device, the thermal management pipeline including multiple valve devices and interconnected main pipelines and branch pipelines, the branch pipelines being connected in parallel, each battery device being connected to the main pipeline via a branch pipeline, and a valve device configured for each branch pipeline for controlling the flow rate of each branch pipeline; a temperature detection device for detecting the temperature of each battery device; and a control device configured to determine the temperature difference between the temperature of each battery device and a specified temperature based on the detected temperature of the battery device, and to control the opening degree of the valve devices based on the temperature difference so that the temperature difference does not exceed the specified range.

[0094] Because each branch pipe in the parallel configuration is equipped with a valve device, and these valve devices can control the flow rate of each branch pipe, and control the opening degree of these valve devices according to the temperature difference between the battery device temperature and the specified temperature, it is possible to accurately adjust the temperature of the battery device that significantly affects temperature uniformity. This helps to quickly bring the temperature of the battery devices to uniformity, and improved temperature uniformity among the battery devices helps to extend the service life of the battery devices.

[0095] The energy storage system disclosed in this embodiment can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems, or temporary power supply systems, etc. The energy storage system can store electrical energy as needed and output it at appropriate times. For example, the energy storage system can store electrical energy during off-peak hours and provide power to relevant users or electrical equipment during peak hours.

[0096] In some embodiments, the energy storage system is an energy storage container or an energy storage cabinet.

[0097] In some embodiments, one or more battery clusters may be arranged in the battery compartment of the energy storage system. Each battery cluster may include multiple battery devices, which may be connected in series to increase the voltage of the energy storage system. When the energy storage system includes multiple battery clusters, the multiple battery clusters are connected in parallel to increase the capacity of the energy storage system.

[0098] In some embodiments, a battery apparatus may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells connected in series, parallel, or in a mixed configuration via a busbar.

[0099] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells.

[0100] As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells together to form an independent module. As another example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0101] In some embodiments, the battery device may be a battery pack, which includes an outer casing and one or more individual battery cells housed within the outer casing.

[0102] As an example, the battery cell assembly can be a battery module, which can be housed in an outer casing by fixing the battery module in the casing.

[0103] As an example, battery cell assemblies can also be housed in an outer casing by directly fixing multiple battery cells to the outer casing.

[0104] As an example, the outer casing may include a first outer casing and a second outer casing. The first and second outer casings are fastened together to form a closed space inside the outer casing to house the individual battery cells. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first outer casing may be a top cover or a bottom plate.

[0105] In some embodiments, the energy storage system may include modules such as a main control module, a central control module, a power distribution module, and a fire protection system. A thermal management device may also be provided for the energy storage system.

[0106] As an example, the thermal management device may include a cooling unit that supplies a cooling medium via piping to each battery device for regulating the temperature of the battery device. For instance, the cooling unit may be a liquid-cooled unit, and the cooling medium may be a coolant.

[0107] As an example, the main control module can serve as the battery management unit for the battery cluster, used to monitor and manage the battery cluster. The main control module can monitor information such as the current, voltage, power, or temperature of the battery cluster. For instance, it can control the charging and discharging current and voltage of the battery cluster. The main control module includes modules such as an auxiliary battery management unit (SBMU) and a fusion switch.

[0108] As an example, the central control module can serve as the battery management unit of an energy storage system, used for monitoring and managing the system. The central control module can monitor information such as current, voltage, power, state of charge, and temperature of the energy storage system. For example, it can control the charging and discharging current and voltage of the energy storage system. As an example, the central control module includes modules such as an Insulation Monitoring Module (IMM), a Master Battery Management Unit (MBMU), an Ethernet (ETH) module, and a fiber optic conversion module. Exemplarily, the central control module may include input / output devices for control, such as switches and panels, which can be arranged in the central control box.

[0109] As an example, a power distribution module can be used to distribute power to electrical devices in an energy storage system. Exemplarily, the power distribution module may include input / output devices for control, such as switches, panels, etc., which may be arranged in a distribution box or cabinet.

[0110] As an example, a fire protection system includes fire protection components, control panels, detectors, alarm devices, etc., used to detect, alarm, or extinguish fires in energy storage systems.

[0111] The embodiments of this disclosure will now be described in detail with reference to Figures 1 to 16.

[0112] Figure 1 is a schematic diagram of the structure of an energy storage system provided in some embodiments of the present disclosure; Figure 2 is a schematic diagram of the structure of a battery cluster provided in some embodiments of the present disclosure; Figure 3 is a schematic diagram of the structure of a battery cluster provided in some other embodiments of the present disclosure; Figure 4 is a schematic diagram of the structure of a battery cluster provided in some further embodiments of the present disclosure; Figure 5 is a schematic diagram of the structure of a battery cluster provided in yet another embodiment of the present disclosure; Figure 6 is a schematic diagram of the structure of a battery cluster provided in yet another embodiment of the present disclosure; Figure 7 is a schematic diagram of the structure of a two-way valve provided in some embodiments of the present disclosure; Figure 8 is a schematic diagram of the structure of a three-way valve provided in some embodiments of the present disclosure; Figure 9 is a schematic diagram of the structure of a three-way valve provided in some embodiments of the present disclosure. Figure 10 is a schematic diagram of a valve device controlling the flow path opening and closing provided in some embodiments of this disclosure; Figure 11 is a schematic diagram of a valve device controlling the flow path opening and closing provided in yet another embodiment of this disclosure; Figure 12 is a schematic diagram of a valve device adjusting the opening degree provided in some embodiments of this disclosure; Figure 13 is a schematic diagram of a valve device adjusting the opening degree provided in some embodiments of this disclosure; Figure 14 is a structural schematic diagram of an energy storage system provided in some embodiments of this disclosure; Figure 15 is a flowchart of a temperature control method for an energy storage system provided in some embodiments of this disclosure; Figure 16 is a structural schematic diagram of an energy storage system provided in some embodiments of this disclosure.

[0113] As shown in Figure 1, the energy storage system provided in this embodiment includes at least one battery cluster 12 and a control device 10. Each battery cluster includes multiple battery devices 13, a thermal management pipeline 11, and a temperature detection device 17. The thermal management pipeline 11 provides a heat exchange medium to each battery device 13. The thermal management pipeline 11 includes multiple valve devices and interconnected main pipeline 111 and branch pipelines 112. The branch pipelines 112 are connected in parallel. Each battery device 13 is connected to the main pipeline 111 via a branch pipeline 112. A valve device is configured for each branch pipeline 112 to control the flow rate of each branch pipeline 112. The temperature detection device 17 detects the temperature of each battery device 13. The control device 10 is configured to determine the temperature difference between the detected temperatures of the battery devices 13 and a specified temperature, and control the opening degree of the valve devices based on the temperature difference to ensure that the temperature difference does not exceed the specified range.

[0114] As shown in Figures 1 and 16, the energy storage system 100 may include one or more battery clusters 12. In the embodiment shown in Figure 1, the energy storage system includes a first battery cluster 120, a second battery cluster 121, a third battery cluster 122, a fourth battery cluster 123, and a fifth battery cluster 124 as an example for explanation.

[0115] Each battery cluster 12 may include multiple battery devices 13. The number of battery devices 13 can be determined according to specific circumstances. Here, eight battery devices 13 are schematically shown in the figure. The battery devices 13 in the same battery cluster can be connected in series, parallel, or mixed.

[0116] For example, the energy storage system can be an energy storage container, the battery cluster 12 can be multiple energy storage cabinets arranged in the energy storage container, the battery cluster 12 can also be multiple battery devices arranged in the energy storage container, and the battery device 13 can be multiple battery devices in the energy storage cabinet.

[0117] For multiple battery devices 13 in the same battery cluster 12, for example, the multiple battery devices 13 can be arranged in layers along a first direction (a direction perpendicular to the energy storage system bearing surface); or, the multiple battery devices 13 can be arranged in a flat arrangement along the energy storage system bearing surface; or, the multiple battery devices 13 can be arranged in two or more layers.

[0118] For multiple battery devices 13 in the same battery cluster 12, for example, multiple battery devices 13 electrically connected in series can be regarded as a cluster.

[0119] In some specific embodiments, within the same battery cluster 12, eight battery devices 13 are arranged in layers along a first direction and are electrically connected in series. In other specific embodiments, within the same battery cluster 12, eight battery devices 13 are arranged in two layers along the first direction, with four devices in each layer and electrically connected in series. In still other specific embodiments, within the same battery cluster 12, eight battery devices 13 are arranged in two layers along the first direction, with different numbers in each layer (e.g., five in one layer and three in the other), and are electrically connected in series.

[0120] For each battery device 13, a temperature detection device 17 is provided so that each temperature detection device 17 can independently detect the temperature of the battery device 13. One temperature detection device 17 or several temperature detection devices 17 can be provided for each battery device 13. When several temperature detection devices 17 are provided for one battery device 13, the temperature detection devices 17 can be arranged at different locations on the battery device 13 to sample the temperature of the same battery device 13 from multiple locations. The temperature detection device 17 can be, for example, a temperature sensor. The temperature detection device 17 can be electrically connected to the control device 10, so that the control device 10 can acquire the detection results of the temperature detection device 17.

[0121] Each battery cluster 12 also includes a thermal management pipeline 11 for supplying a heat exchange medium for temperature regulation to each battery device within the battery cluster 12. The thermal management pipeline 11 includes a main pipeline 111 and multiple branch pipelines 112 branching from the main pipeline 111 and connected in parallel. The main pipeline 111 may be connected to a main flow path 110. The main flow path 110 may be thermally coupled to a thermal management device 2 (e.g., a cooling unit). For example, the thermal management device 2 may cool the heat exchange medium exchanging heat with the battery device 13 so that the heat exchange medium can be recycled. Alternatively, the main flow path 110 may be connected to a heat exchange medium supply source (e.g., a reservoir, lake, etc.), which continuously supplies cooling heat exchange medium to the main flow path 110, the main pipeline 111, and the branch pipelines 112. It should be noted that the following description uses a cooling heat exchange medium as an example of an embodiment of this disclosure; however, it is understood that the heat exchange medium may also be a heating heat exchange medium depending on the temperature regulation requirements of the battery device 13. For example, a heating device for heating the heat exchange medium can be connected to the main path 110.

[0122] Battery unit 13 is connected in branch pipe 112. Exemplarily, battery unit 13 includes thermal management components (e.g., water-cooled plates), the heat exchange medium inlets and outlets of which are connected in series to branch pipe 112. Within the same battery cluster 12, multiple thermal management components are connected in parallel flow paths to each other.

[0123] The thermal management piping 11 also includes multiple valve devices disposed within the piping. Each branch pipe 112 can have its flow rate independently regulated by the multiple valve devices, thereby allowing the battery device 13 connected to each branch pipe 112 to have its temperature independently regulated. Flow rate regulation is achieved by adjusting the opening degree of the valve devices. The valve devices can be on / off valves, proportional valves, or other valve devices capable of flow regulation. This embodiment uses a two-way valve 14 and a three-way valve 15 as examples for illustration, as detailed below.

[0124] In some embodiments, the temperature detection device 17 collects the current temperature of each battery device 13, and the control device 10 determines the temperature difference between the temperature of each battery device and a predetermined temperature based on these collected temperatures. If these temperature differences exceed a predetermined range, the control device 10 controls the opening degree of the valve devices based on the temperature differences to keep the temperature differences within the predetermined range. When the opening degrees of multiple valve devices need to be adjusted based on temperature differences, this adjustment can be performed simultaneously, in batches, or individually. Similarly, when it is necessary to control the opening degree of some valve devices to increase while controlling the opening degree of other valve devices to decrease, this can also be performed simultaneously or separately.

[0125] The control device 10 can be implemented by the main control module, the general control module, or both.

[0126] Because each branch pipe 112 in parallel is equipped with a valve device, and these valve devices can control the flow rate of each branch pipe 112, and control the opening degree of these valve devices according to the temperature difference between the temperature of the battery device 13 and the specified temperature, the temperature of the battery device 13 that significantly affects temperature uniformity can be precisely adjusted. This is beneficial to make the temperature of the battery devices 13 quickly become uniform, and the improved temperature uniformity between the battery devices is conducive to improving the service life of the battery devices.

[0127] In some embodiments, the control device 10 is configured to determine the temperature difference between the temperature of each battery device 13 and a predetermined temperature based on the temperature of each battery device 13 in the same battery cluster 12, and control the opening of the valve device based on the temperature difference, wherein the valve device corresponding to the branch pipe 112 where the battery device 13 with the higher temperature is located is preferentially controlled.

[0128] For example, temperature can be detected and temperature difference determined on a per-cell battery cluster 12 basis, and flow control can be performed by adjusting the opening of the valve device based on the temperature difference. In the case where the energy storage system includes multiple battery clusters 12, temperature detection, temperature difference determination, and flow control can be performed sequentially for each battery cluster 12, or in parallel for each battery cluster 12.

[0129] In addition, the valve devices corresponding to the branch pipe 112 where the battery device 13 with the high temperature is located are preferentially controlled. This includes preferentially controlling the valve opening of the battery device 13 that needs to be cooled down. For example, the valve opening of the battery device 13 that needs to be cooled down is controlled first, and then the valve opening of the battery device 13 that needs to be heated is controlled. Alternatively, the valve opening of the battery device 13 with the highest temperature is controlled first to cool it down, and then the valve opening of the battery device 13 with the second highest temperature is controlled. For example, the valve opening can be controlled in descending order of temperature to cool down the battery device 13.

[0130] For example, within the same battery cluster 12, after collecting the temperatures of each battery device 13, the temperature difference can be determined for the battery device 13 with the highest temperature. It can then be determined whether the temperature difference exceeds a specified range, and if it does, the opening degree of the valve device can be controlled based on that temperature difference. Alternatively, after collecting the temperatures of each battery device 13, the temperature difference can be determined for each battery device 13. It can then be determined whether the temperature difference exceeds a specified range, and if any temperature difference exceeds the specified range, the opening degree of the valve device is controlled first for the battery device 13 with the highest temperature.

[0131] Because the temperature of the battery device 13 with the highest temperature in the same battery cluster 12 is adjusted first, the adverse effects of the excessively high temperature of the battery device 13 can be suppressed as soon as possible, and the temperature of the battery devices 13 can be made to be uniform quickly.

[0132] In some embodiments, the specified temperature includes an upper or lower limit of a specified temperature range. If the temperature difference between the temperature of the battery device 13 and the upper limit of the temperature range is greater than 0, or if the temperature difference between the temperature of the battery device 13 and the lower limit of the temperature range is less than 0, the control device 10 determines that the temperature difference exceeds the specified range.

[0133] The specified temperature can be a specific temperature value. When it is desired that the battery device 13 operates within a suitable temperature range (i.e., the specified temperature range), the upper and lower limits of the temperature range can be used as comparison standards when determining the temperature difference.

[0134] The specified temperature range can be preset according to the operating conditions of the battery cluster 12. The temperature consistency among the battery devices 13 can be improved by reducing the difference between the upper and lower limits of the set temperature range. For example, the difference between the upper and lower limits can be set to 3 degrees, 2 degrees, or 1 degree, or other suitable differences.

[0135] This allows the temperature of each battery device 13 to be within a specified temperature range, which not only improves the temperature consistency among the battery devices 13, but also helps each battery device 13 to operate in a suitable temperature environment; moreover, a suitable temperature range can be set according to the operating conditions of the energy storage system.

[0136] In some embodiments, the specified temperature range is a temperature range of 20 degrees Celsius to 23 degrees Celsius.

[0137] This allows for improved temperature uniformity among battery devices while enabling each device to operate in a suitable temperature environment.

[0138] In other embodiments, the specified temperature range is a portion or all of the temperature range defined by the temperature of each battery device 13 in the same battery cluster, excluding the highest and lowest temperatures.

[0139] For example, in the same battery cluster 12 having 8 battery devices 13, the temperature of each of the 8 battery devices 13 is sampled and sorted in order of temperature from high to low. The temperature of the third-ranked device is taken as the upper limit of the specified temperature range, and the temperature of the sixth-ranked device is taken as the lower limit of the specified temperature range.

[0140] In some embodiments, when the temperature difference between the temperature of the battery device 13 and the upper limit of the temperature range is greater than 0, the opening of the temperature difference control valve device is used to reduce the temperature of the battery device 13 to a level not exceeding the temperature range; or, when the temperature difference between the temperature of the battery device 13 and the lower limit of the temperature range is less than 0, the opening of the temperature difference control valve device is used to raise the temperature of the battery device to a level not exceeding the temperature range.

[0141] The opening degree of the valve device can be increased or decreased according to whether the heat exchange medium is for cooling or heating, thereby controlling the flow rate of the heat exchange medium and adjusting the temperature of the battery device 13. Here, increasing the opening degree of the valve device includes gradually increasing (e.g., gradually increasing by 5% each time) and also includes changing from closed to open; decreasing the opening degree of the valve device includes gradually decreasing (e.g., gradually decreasing by 5% each time) and also includes changing from open to closed.

[0142] Therefore, it is possible to specifically adjust the temperature of battery devices 13 that exceed the predetermined temperature range, and to quickly bring the temperature of each battery device 13 to the predetermined temperature range. Moreover, it takes into account not only the case where the temperature of the battery device is too high, but also the case where the temperature of the battery device is too low, so that the battery device can operate in a suitable temperature environment while making the temperature of the battery device more uniform.

[0143] In some embodiments, when the temperature difference is greater than 0, the control device 10 controls the valve device corresponding to the branch pipe where the battery device with the temperature is located to increase the opening degree, wherein the heat exchange medium is used for cooling.

[0144] It is possible to control the valve opening degree of each valve device corresponding to the branch pipe where the battery device with a temperature difference greater than 0 is located.

[0145] In some specific embodiments, if the temperature of a battery device 13 (e.g., the top-level battery device 13) in a battery cluster 12 is higher than the upper limit of a predetermined temperature range (i.e., the temperature difference is greater than 0), the control device 10 determines that the battery device 13 needs to be cooled down. This means controlling the opening of the valve device corresponding to the branch pipe 112 where the battery device 13 is located, for example, by increasing the coolant flow rate. If the valve device is an on / off valve, it can be controlled to be in the on state; if the valve device is a proportional valve, it can be controlled to increase the opening of the proportional valve from its current opening by a certain amount. If the temperature of the battery device 13 is lower than the lower limit (i.e., the temperature difference is less than 0 (but the absolute value of the temperature difference is greater than 0), the control device 10 determines that the battery device 13 needs to be heated up. This means controlling the opening of the valve device corresponding to the branch pipe 112 where the battery device 13 is located, for example, by reducing the coolant flow rate or even suspending coolant circulation. If the valve device is an on / off valve, it can be controlled to be in the off state; if the valve device is a proportional valve, it can be controlled to decrease the opening of the proportional valve from its current opening by a certain amount.

[0146] For example, the temperature detection device 17 collects the temperature of the battery device 13 at predetermined intervals (e.g., every 1 second). After controlling the opening based on the temperature difference as described above, the temperature difference can be determined based on the temperature detected again by the temperature detection device 17 to see if it is within a predetermined range (e.g., whether the temperature difference with the upper limit is greater than 0, and whether the temperature difference with the lower limit is less than 0). If the temperature difference with the upper limit is still greater than 0, the corresponding valve device can be controlled to maintain the current flow rate of the coolant or to further increase the flow rate of the coolant. When the valve device is an on / off valve, the on / off valve can be controlled to remain open; when the valve device is a proportional valve, the proportional valve can be controlled to further increase its opening from the current opening. Of course, the proportional valve can also be controlled to continue to maintain its current opening based on the magnitude of the temperature difference.

[0147] If the temperature difference with the upper limit is not greater than 0 and the temperature difference with the lower limit is not less than 0, the corresponding valve device can be controlled to maintain its current opening, i.e., maintain the current flow rate of the coolant. When the valve device uses an on / off valve, it can be controlled to maintain its current state; when the valve device uses a proportional valve, it can be controlled to maintain its current opening.

[0148] If the temperature difference from the lower limit is less than 0, the corresponding valve device can be controlled to reduce the coolant flow or shut off. If the valve device is an on / off valve, it can be controlled to be in the off position; if the valve device is a proportional valve, it can be controlled to decrease its opening from the current degree. When the temperature of the battery device 13 approaches the same as the temperature of the battery device 13 with the higher temperature, the current opening of the valve device of the battery device 13 is kept consistent with the current opening of the valve device of the battery device 13 with the temperature of the battery device 13. The above-described detection, judgment, and flow control actions can be repeated to dynamically maintain the temperature of the battery device 13 within the specified temperature range.

[0149] The opening control of the valve device described above can be performed sequentially according to the temperature of the battery device 13 from high to low, or simultaneously.

[0150] Therefore, by increasing the opening of the valve device, the flow rate of the heat exchange medium in the branch pipe 112 that needs to be cooled is increased, and all battery devices 13 with temperatures higher than the specified temperature range can be cooled in a targeted manner, so that the temperatures of each battery device 13 in the same battery cluster 12 can quickly become consistent; moreover, prioritizing the cooling of battery devices 13 with relatively high temperatures can suppress the adverse effects that may be caused by excessively high temperatures as early as possible.

[0151] In some embodiments, when the temperature difference is less than 0, the control device 10 controls the valve device corresponding to the branch pipe where the battery device with that temperature is located to reduce the opening degree.

[0152] For the valve device corresponding to the branch pipe where the battery device has a temperature difference of less than 0, the valve device opening can be controlled to decrease sequentially according to the battery device temperature from low to high; or the valve device opening can be controlled to decrease simultaneously.

[0153] In some specific embodiments, if the temperature of a battery device 13 (e.g., the battery device 13 located at the bottom layer) in a battery cluster 12 is lower than the lower limit of a specified temperature range, i.e., the temperature difference is less than 0, the control device 10 determines that the battery device 13 needs to be heated, i.e., the valve device corresponding to the branch pipe 112 where the battery device 13 is located needs to be opened, for example, by reducing the flow rate of the coolant or even suspending the circulation of the coolant.

[0154] For example, the temperature detection device 17 collects the temperature of the battery device 13 at predetermined intervals (e.g., every 1 second). After controlling the opening based on the temperature difference as described above, the temperature difference can be determined based on the temperature detected again by the temperature detection device 17 to see if it is within the predetermined range (e.g., whether the temperature difference with the upper limit is greater than 0, and whether the temperature difference with the lower limit is less than 0). If the temperature difference with the lower limit is still less than 0, the corresponding valve device can be controlled to reduce the flow rate of the coolant or to close the valve device; if the temperature difference with the lower limit is not less than 0 and the temperature difference with the upper limit is not greater than 0, the corresponding valve device can be controlled to maintain the same opening as the valve devices corresponding to other battery devices 13 with relatively higher temperatures. The above-described detection, judgment, and flow rate control actions can be repeated to dynamically maintain the temperature of the battery device 13 within the predetermined temperature range.

[0155] The opening control of the valve device described above can be performed sequentially according to the temperature of the battery device 13 from high to low, or simultaneously.

[0156] Therefore, by reducing the opening of the valve device, the flow rate of the heat exchange medium in the branch pipe 112 that needs to be heated is reduced, which enables all battery devices 13 with temperatures below the specified temperature range to be heated, and the temperatures of each battery device 13 in the same battery cluster 12 to quickly become consistent; moreover, it also helps to prevent the battery device 13 from being overcooled.

[0157] The temperature difference can be determined not only based on the upper and lower limits of the specified temperature range as above, but also optionally based on the highest and lowest temperatures among multiple battery devices.

[0158] In some embodiments, the specified temperature includes: the lowest temperature among all battery devices 13 in the same battery cluster 12 in the same temperature detection; the control device 10 is configured to determine the temperature difference between the temperature of each battery device 13 in the same battery cluster 12 and the lowest temperature, and, if the temperature is higher than the lowest temperature and the temperature difference exceeds the specified range, control the opening of the valve device based on the temperature difference to reduce the temperature of the battery device 13 to a temperature difference with the lowest temperature that does not exceed the specified range.

[0159] For example, for each battery device 13 in the same battery cluster 12, the temperature detection device 17 collects the temperature, the control device 10 determines the lowest temperature among these temperatures, and determines the difference between the temperature of each battery device 13 and the lowest temperature, that is, determines the temperature difference. In addition, a specified range of temperature difference can be preset.

[0160] In determining the minimum temperature, it can be the lowest temperature among all battery devices 13 in the same battery cluster 12.

[0161] Therefore, while rapidly bringing the temperature of the battery devices 13 in the same battery cluster 12 to a uniform level, the temperature of each battery device 13 can be brought to the lowest possible temperature, which is beneficial to extending the service life of the battery devices 13. Moreover, even without specifically setting the operating temperature range of the battery devices 13, the battery devices can operate in a uniform temperature environment.

[0162] In some embodiments, the specified temperature includes: any temperature other than the lowest and highest temperatures among the temperatures of each battery device 13 in the same battery cluster 12 during the same temperature detection; the control device 10 is configured to determine the temperature difference between the temperature of each battery device 13 in the same battery cluster 12 and the specified temperature; if the temperature is higher than the specified temperature and the temperature difference exceeds a specified range, the control device 10 controls the opening of the temperature difference control valve to reduce the temperature of the battery device 13 to a temperature difference with the lowest temperature that does not exceed a specified range; if the temperature is lower than the specified temperature and the absolute value of the temperature difference exceeds a specified range, the control device 10 controls the opening of the temperature difference control valve to raise the temperature of the battery device 13 to a temperature difference with the specified temperature that does not exceed a specified range.

[0163] For example, the specified temperature can also be the lowest temperature among the battery devices 13 in the same battery cluster 12, excluding the highest and lowest temperatures. For instance, it could be the second lowest temperature, the third lowest temperature from the bottom, or another temperature. The heat exchange medium can be a fluid that heats the battery or a fluid that cools the battery device.

[0164] This allows the temperature of the battery devices 13 in the same battery cluster 12 to quickly become uniform.

[0165] In some embodiments, the specified temperature range is from 0 degrees Celsius to 3 degrees Celsius.

[0166] That is, if the temperature difference between the battery device 13 in the same battery cluster 12 and the minimum temperature (or the specified temperature as determined above) does not exceed 3 degrees Celsius, then the control device 10 can keep the valve device corresponding to each battery device 13 at its current opening; if the temperature difference between the temperature and the minimum temperature exceeds 3 degrees Celsius, then the control device 10 adjusts the opening of the valve device corresponding to those battery devices 13 with temperature differences exceeding 3 degrees Celsius, so as to reduce the temperature of the battery device 13.

[0167] This improves the temperature consistency among battery devices within the same battery cluster.

[0168] In some embodiments, the specified temperature range is from 0 degrees Celsius to 0.5 degrees Celsius.

[0169] Temperature consistency among battery devices 13 in the same battery cluster 12 can be improved by controlling the temperature difference between the temperature and the minimum temperature (or the specified temperature as determined above) within a small temperature range, such as not exceeding 0.5 degrees.

[0170] This allows for further improvement in temperature consistency among battery devices within the same battery cluster.

[0171] In some alternative embodiments, the control device 10 is configured to repeatedly control the opening of the valve device based on the temperature difference between the temperature and the specified temperature for the temperature of each battery device 13 in the same battery cluster 12, until the temperature difference between each battery device 13 in the same battery cluster 12 does not exceed the specified range.

[0172] In some specific embodiments, the temperature of each battery device 13 in the same battery cluster 12 is collected, and the temperatures of each battery device 13 are arranged in descending order from high to low. The temperature difference between each battery device 13 and the lowest temperature is then determined to be within a specified range, such as exceeding 3 degrees Celsius. For those battery devices 13 whose temperature differences exceed the specified range, such as exceeding 3 degrees Celsius, the opening of the valve device is adjusted in parallel or sequentially in descending order of temperature to cool down these battery devices 13.

[0173] For example, the temperature detection device 17 collects the temperature of the battery device 13 at predetermined intervals (e.g., every 1 second). After controlling the opening based on the temperature difference as described above, the temperature difference can be determined based on the temperature detected again by the temperature detection device 17 to see if it is within the predetermined range. If the temperature difference still exceeds the predetermined range, the valve device can be controlled to maintain its current opening or change its opening to cool down the battery devices 13; if the temperature difference does not exceed the predetermined range, the valve device can be controlled to maintain its current opening. The above-described actions of detection, judgment, and flow regulation can be repeated to dynamically maintain the temperature difference between the battery devices 13 within the predetermined range.

[0174] This allows the temperature of each battery device 13 in the same battery cluster to become more uniform and to the lowest possible temperature, which is beneficial for the performance of the battery device 13 and extends its service life.

[0175] In some embodiments, the control device 10 controls each valve device corresponding to the branch pipe 112 where each battery device 13 in the same battery cluster 12 is located to be in an initial state, determines the highest temperature and the lowest temperature (the lowest temperature among all or part of the temperatures) of each battery device 13 in the same battery cluster 12, determines whether the temperature difference between the highest temperature and the lowest temperature exceeds a specified range, and if the temperature difference exceeds the specified range, controls the valve device corresponding to the branch pipe 112 where the battery device 13 with the highest temperature is located to increase the opening degree, wherein the heat exchange medium is used for cooling; the control device 10 is configured to repeatedly perform the above-mentioned control of the valve device opening degree based on the temperature difference between the highest temperature and the lowest temperature for each battery device 13 in the same battery cluster 12 until the temperature difference between each battery device 13 in the same battery cluster 12 does not exceed the specified range.

[0176] In some specific embodiments, the valve device may be in a closed state or have an initial opening degree in the initial state. Temperatures are collected for each battery device 13 in the same battery cluster 12 to determine the highest and lowest temperatures, and it is determined whether the temperature difference between the highest and lowest temperatures is within a specified range, such as exceeding 3 degrees Celsius. If the temperature difference exceeds the specified range, such as exceeding 3 degrees Celsius, the opening degree of the valve device corresponding to the battery device 13 with the highest temperature is adjusted to cool these battery devices 13 using coolant. If the valve device is an on / off valve, it is switched from the initial closed state to the open state; if the valve device is a proportional valve, its opening degree is increased from the initial opening degree.

[0177] For example, the temperature detection device 17 collects the temperature of the battery device 13 at predetermined intervals (e.g., every 1 second). After controlling the opening based on the temperature difference as described above, the temperature difference can be determined based on the temperature detected again by the temperature detection device 17 to see if it is within the predetermined range. If the temperature difference still exceeds the predetermined range, the valve device can be controlled to maintain its current opening or change its opening to allow the battery devices 13 to continue cooling. When the valve device is an on / off valve, the valve device is kept in the conducting state; when the valve device is a proportional valve, the valve device can be kept at its current opening or its opening can be further increased. The determination of whether to maintain the current opening or increase the opening, and the extent of the increase, can be based on the magnitude of the temperature difference.

[0178] If the temperature difference does not exceed the specified range, the valve device can be controlled to maintain its current opening. If the valve device is an on / off valve, it will remain in the conducting state; if the valve device is a proportional valve, it will maintain its current opening. The above-described detection, judgment, and flow regulation actions can be repeated to dynamically maintain the temperature difference between the battery devices 13 within the specified range.

[0179] In some embodiments, if there is an excessively low temperature in the temperature of each battery device 13 in the same battery cluster 12 that is lower than the minimum temperature and the absolute value of the temperature difference exceeds a specified range, the control device 10 controls the valve device corresponding to the branch pipe where the battery device 13 with the excessively low temperature is located to reduce the opening degree, so that the temperature of the battery device 13 rises to a temperature difference with the minimum temperature that does not exceed the specified range, wherein the heat exchange medium is used to cool the battery device 13.

[0180] For example, when the lowest temperature among the battery devices 13 in the same battery cluster is used as the lowest temperature, it is also necessary to control the valve opening of the battery device 13 with the actual lowest temperature (which can be considered as an excessively low temperature) in the same battery cluster. After its temperature rises to a suitable temperature range, the valve opening is made consistent with the valve opening of other relatively high temperature battery devices 13. For example, if other switching valves are in the conducting state, this switching valve is also in the conducting state.

[0181] Therefore, by increasing the valve opening, the flow rate of the heat exchange medium in the branch pipe 112 that needs cooling is increased, allowing the relatively high-temperature battery device 13 to cool down quickly and approach its minimum temperature. This ensures that the temperatures of the battery devices 13 within the same battery cluster 12 are consistent and all approach their minimum temperatures, improving temperature uniformity and enhancing battery performance, thus extending their lifespan. Conversely, by decreasing the valve opening, the flow rate of the heat exchange medium in the branch pipe that needs heating is reduced, allowing the excessively low-temperature battery device 13 to heat up, rapidly bringing the temperatures of all battery devices 13 within the same battery cluster 12 to a consistent level. Furthermore, this also helps prevent over-cooling of the battery devices.

[0182] In some embodiments, the valve device includes a switching valve, and controlling the valve device to increase the opening degree includes controlling the switching valve to switch from closed to open, and controlling the valve device to decrease the opening degree includes controlling the switching valve to switch from open to closed.

[0183] As a switching valve, a two-way valve or a three-way valve as shown in Figures 7 to 11 can be used.

[0184] Because the valve device uses an on / off valve, it is beneficial to simplify the pipeline structure and control the valve.

[0185] In some embodiments, the valve device includes a proportional valve, and controlling the valve device to increase the opening degree includes controlling the proportional valve to increase the opening degree relative to the current opening degree, and controlling the valve device to decrease the opening degree includes controlling the proportional valve to decrease the opening degree relative to the current opening degree.

[0186] As a proportional valve, a two-way valve or a three-way valve as shown in Figures 7 to 13 can be used, and the opening degree can be adjusted as shown in Figures 12 and 13.

[0187] Because the valve device uses a proportional valve, it is beneficial to accurately control the valve opening and the flow rate of the heat exchange medium in the branch pipe, which in turn is beneficial to accurately adjust the temperature of the battery device. Moreover, the use of a proportional valve also helps to ensure that each battery device in the battery cluster operates in a relatively low temperature environment, which is beneficial to the performance of the battery device and extends its service life.

[0188] In some embodiments, the initial opening degree of the proportional valve may be in the range of 40% to 60%; and / or, the proportional valve may increase or decrease its opening degree by a predetermined range of 3% to 10% each time.

[0189] For example, the proportional valve in its initial state can have an opening of 50%. For example, the proportional valve adjusts its opening in 5% increments each time. Of course, the opening increment can also be determined based on the magnitude of the temperature difference.

[0190] Therefore, the flow rate of the heat exchange medium in the branch pipe to be adjusted can be adjusted while maintaining a continuous supply of heat exchange medium to each battery device 13. Moreover, the opening of the valve device can be flexibly increased or decreased with high precision according to the temperature of the battery device 13. This is beneficial for quickly achieving temperature uniformity and enables each battery device 13 in the battery cluster 12 to work in a relatively low temperature environment, which is beneficial for the battery device 13 to perform well and extend its service life.

[0191] In some embodiments, the control device 10 is configured to acquire the temperature of each battery device 13 from the temperature detection device 17 at predetermined time intervals, determine a temperature difference in response to each acquired temperature, and control the opening of a valve device based on the temperature difference so that the temperature difference does not exceed a predetermined range.

[0192] For example, the specified time interval can be 0.5 seconds, 1 second, 2 seconds, 3 seconds, 10 seconds, 60 seconds, etc.

[0193] Therefore, the temperature of the battery device can be monitored in real time, and the flow rate of the heat exchange medium in the branch pipeline can be adjusted in a timely manner according to the temperature difference, so as to adjust the temperature of the battery device in a timely manner.

[0194] In some embodiments, as shown in Figures 2 to 6, the main pipeline 111 includes an input main pipeline 111a and an output main pipeline 111b, and the branch pipeline 112 includes an input branch pipeline 112a and an output branch pipeline 112b. Each input branch pipeline 112a is used to input the heat exchange medium from the input main pipeline 111a into the battery device 13, and each output branch pipeline 112b is used to output the heat exchange medium that has exchanged heat with the battery device 13 from the battery device 13 to the output main pipeline 111b.

[0195] As shown in Figure 1, the main flow path 110 includes a liquid supply main flow path 110a and a liquid return main flow path 110b. The input main flow path 111a is connected to the liquid supply main flow path 110a, and the output main flow path 111b is connected to the liquid return main flow path 110b. In the case where the energy storage system has multiple battery clusters (first battery cluster 120, second battery cluster 121, third battery cluster 122, fourth battery cluster 123, and fifth battery cluster 124) as shown in Figure 1, the input main flow paths 111a of each battery cluster are connected in parallel to the liquid supply main flow path 110a, and the output main flow paths 111b of each battery cluster are connected in parallel to the liquid return main flow path 110b. In Figure 1, the hollow arrows indicate the flow direction of the heat exchange medium.

[0196] In addition, an exhaust device 16 can be installed in the main pipeline 111 of each battery cluster to remove gas from the pipeline. A pump 18 for increasing the fluid circulation power can also be installed in the main pipeline 110, as well as a temperature sensor 19 for detecting the temperature of the heat exchange medium, and a heating device (not shown in the figure) for raising the temperature of the heat exchange medium.

[0197] This allows for easy formation of a circulating flow path for the heat exchange medium. Furthermore, since the flow paths of each battery cluster are connected in parallel, in case of replacement or maintenance, the flow path can be disconnected only for that specific battery cluster. Connections between the pipes can be made using fittings, including quick-connect fittings.

[0198] In some embodiments, as shown in Figures 1 to 6, along the flow direction of the heat exchange medium, a valve device is connected between the upstream end of the input branch pipe 112a and the input main pipe 111a, and / or, along the flow direction of the heat exchange medium, a valve device is connected between the downstream end of the output branch pipe 112b and the output main pipe 111b, and / or, a valve device is connected along the input branch pipe 112a, and / or, a valve device is connected along the output branch pipe 112b.

[0199] As shown in Figure 2, a valve device is connected along the output branch pipe 112b. In this specific embodiment, the valve device is a two-way valve 14. For example, the two-way valve 14 shown in Figures 7 and 12 can be used. As shown in Figures 7 and 12, the two-way valve 14 has a first valve port 141 and a second valve port 142. The flow path between the first valve port 141 and the second valve port 142 can be opened or closed by the action of the valve core 143. Alternatively, the valve opening of the two-way valve 14 can be adjusted by adjusting the rotational position of the valve core 143, thereby controlling the flow rate of the fluid passing through the two-way valve 14. The two-way valve 14 also has a two-way valve control interface 144 for adjusting the valve opening under the control of the control device 10.

[0200] As shown in Figure 3, the downstream end of each output branch pipe 112b is connected to the main output pipe 111b via a valve device. In this specific embodiment, the valve device is a three-way valve 15. For example, a three-way valve 15 as shown in Figures 8 to 11 and 13 can be used. As shown in Figures 8 to 11 and 13, the three-way valve 15 has a first port 151, a second port 152, and a third port 153. The flow path between the first port 151, the second port 152, and the third port 153 can be opened or closed by the action of the valve core 154. For example, as shown in Figure 9, closing the second port 152 allows the first port 151 to connect with the third port 153; as shown in Figure 10, closing the third port 153 allows the first port 151 to connect with the second port 152; and as shown in Figure 11, closing both the second port 152 and the third port 153 constitutes a shut-off valve device. Alternatively, as shown in Figure 13, the valve opening of the three-way valve 15 can be adjusted by changing the rotational position of the valve core 154, thereby controlling the flow rate of fluid passing through the three-way valve 15. As shown in Figure 8, the three-way valve 15 is also provided with a three-way valve control interface 155 for adjusting the valve opening under the control of the control device 10.

[0201] As shown in Figure 4, the upstream end of each input branch pipe 112a is connected to the input main pipe 111a via a valve device. In this specific embodiment, the valve device is a three-way valve 15. For example, the three-way valve 15 shown in Figures 8 to 11 and Figure 13 can be used. In addition, in the embodiment shown in Figure 3, the downstream end of the topmost output branch pipe 112b is connected to the output main pipe 111b via a second valve device (three-way valve 15).

[0202] As shown in Figure 5, a valve device is connected along the input branch line 112a. In this specific embodiment, the valve device is a two-way valve 14. For example, a two-way valve 14 as shown in Figures 7 and 12 can be used.

[0203] As shown in Figure 6, a valve device (two-way valve 14) is connected to the input branch pipe 112a of the top and second-to-bottom layers, and the downstream end of each output branch pipe 112b of other layers is connected to the output main pipe 111b via a valve device (three-way valve 15).

[0204] As shown in Figures 2 to 6, within the same battery cluster, one or a combination of two or more of the valve devices located at different pipeline positions can be used. As shown in Figure 1, when the energy storage system has multiple battery clusters, the arrangement of the valve devices used in each battery cluster may not be the same.

[0205] Therefore, valve devices can be flexibly selected or combined according to pipeline structure, flow resistance, etc.

[0206] In some embodiments, the energy storage system includes multiple battery clusters, with the main circuits of each battery cluster connected in parallel to each other.

[0207] Therefore, even when the energy storage system includes multiple battery clusters, it is possible to achieve thermal management of the battery devices in each battery cluster, and also to improve the temperature consistency of each battery device in the same battery cluster and even between battery devices in different battery clusters.

[0208] In some embodiments, as shown in Figures 1 to 6, in each battery cluster, multiple battery devices 13 are stacked in layers along a first direction, wherein the first direction is perpendicular to the bearing surface, and the bearing surface is used to support the energy storage system.

[0209] Because multiple battery devices are stacked in layers along a direction perpendicular to the support surface, it is beneficial to save floor space; moreover, even if the battery devices on the top layer tend to heat up due to sunlight, rising heat, etc., temperature uniformity of battery devices in the battery cluster can be achieved.

[0210] In some embodiments, the heat exchange medium includes a coolant. Exemplarily, the coolant includes ethylene glycol or water or other media suitable for use as a battery coolant, and this disclosure does not particularly limit this aspect.

[0211] In some embodiments, the energy storage system further includes a thermal management device, which includes a heat exchange pipeline connected to the thermal management pipeline. The thermal management device is used to exchange heat with the heat exchange medium flowing from the thermal management pipeline into the heat exchange pipeline and to provide the heat-exchanged heat exchange medium to the thermal management pipeline.

[0212] For example, a thermal management device may include a cooling unit.

[0213] Therefore, the heat exchange medium that has exchanged heat with the battery device can be restored to a suitable temperature through the thermal management device so that it can be recycled for heat exchange with the battery device again.

[0214] In some embodiments, as shown in FIG14, the energy storage system includes a plurality of battery clusters 12, and the main pipelines 111 of the plurality of battery clusters 12 are connected in parallel to each other to a heat exchange pipeline; or, as shown in FIG1, the energy storage system includes a plurality of battery clusters 12 and a main pipeline 110 of the heat exchange medium, the main pipelines 111 of the plurality of battery clusters 12 are connected in parallel to each other to the main pipeline 110 of the heat exchange medium, and the main pipeline 110 of the heat exchange medium is connected to a heat exchange pipeline.

[0215] Therefore, not only can thermal management be performed on each battery device 13 in the battery cluster 12, improving the temperature uniformity of each battery device 13, but also the flow path can be flexibly arranged. When the main pipelines 111 of multiple battery clusters 12 are connected to the heat exchange pipeline in parallel, the heat exchange medium circulation of each battery cluster 12 is relatively independent, which helps to reduce the interference of flow changes between them; when the main pipelines 111 of multiple battery clusters 12 are connected to the heat exchange pipeline in parallel through the main flow path of the heat exchange medium, it helps to simplify the pipeline structure in the energy storage system.

[0216] The second aspect of this disclosure provides a temperature control method for an energy storage system, as shown in FIG15, which includes: acquiring the temperature of each battery device; determining the temperature difference between each temperature and a specified temperature; determining whether each temperature difference is within a specified range; maintaining the valve device corresponding to the battery device whose temperature difference does not exceed the specified range at its current opening state when the temperature difference does not exceed the specified range; and controlling the opening of the valve device corresponding to the battery device whose temperature difference exceeds the specified range when the temperature difference exceeds the specified range, so as to prevent the temperature difference from exceeding the specified range.

[0217] Because the opening of these valves is controlled based on the temperature difference of the battery devices, precise temperature adjustment can be applied to battery devices that significantly affect temperature uniformity, which helps to quickly bring the temperatures of the battery devices together.

[0218] The following is a specific example of this disclosure, illustrated with reference to the accompanying drawings.

[0219] As shown in Figure 1, the energy storage system includes a prefabricated housing 1 (battery prefabrication compartment) and a thermal management device 2. Multiple battery clusters 12 are arranged within the battery prefabrication compartment, and these clusters are connected to the thermal management device 2 via thermal management pipelines 11. Multiple temperature sampling sensors (temperature detection devices 17) are arranged within the prefabricated housing 1 to collect the temperature of the battery units 13. A temperature sensor 19 is installed in the main flow path 110 to collect the inlet and outlet water temperatures of the thermal management device. The pipelines within the battery clusters can be flexibly arranged with electrically controlled two-way valves 14 or electrically controlled three-way valves 15 for flow control of each battery pack layer, depending on the structure and space available. The pipelines also include a power pump (pump 18) for flow transmission and an exhaust valve (exhaust device 16) for venting the pipeline system.

[0220] To achieve flow control across different layers within the battery cluster, as shown in Figures 1 to 6, electrically controlled switching valves can be installed at the inlets of each layer's battery devices (e.g., battery packs). Alternatively, electrically controlled three-way valves can be installed at the outlets of each layer's battery devices (e.g., battery packs). And / or, one type of electrically controlled valve can be installed at either the inlet or outlet of each layer's battery devices (e.g., battery packs), with the number of two-way and three-way valves determined based on pipeline structure, flow resistance performance, and other suitable factors.

[0221] Temperature data from various sampling points is aggregated and analyzed by the BMS (Battery Management System, Control Device 10) to determine the temperature of different battery layers. These layers are then sorted by temperature from highest to lowest. For battery layers with higher temperatures, the control valves are opened more, while those with lower temperatures are opened less. The remaining layers maintain their default openings. This improves the temperature consistency of the entire battery pack's cells under all operating conditions, thereby extending product lifespan.

[0222] If a switching valve is used, the valve with the higher battery layer temperature will open, delivering the maximum coolant flow rate. The valve with the lower battery layer temperature will close until the battery layer temperature and the higher battery layer temperature are similar. If the valve with the higher battery layer temperature is open, the valve with the lower battery layer temperature will also be open; otherwise, it will be closed.

[0223] Using a proportional valve allows the battery temperature to be regulated to match or lower than the average battery layer temperature. Using an on / off valve allows the battery layer temperature to be regulated to match a higher battery layer temperature. The proportional valve approach results in lower absolute battery temperature, longer battery life, and more precise temperature control.

[0224] The above embodiments are merely illustrative of the technical solutions of this disclosure and are not intended to limit it. Although this disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this disclosure, and all should be covered within the scope of this disclosure. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. This disclosure is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of this disclosure.

Claims

1. An energy storage system, comprising at least one battery cluster and a control device, Each of the battery clusters includes: Multiple battery devices; A thermal management pipeline is used to provide heat exchange medium to each of the battery devices. The thermal management pipeline includes multiple valve devices and interconnected main pipelines and branch pipelines. Each of the branch pipelines is connected in parallel. Each of the battery devices is connected to the main pipeline via a branch pipeline. Each of the branch pipelines is equipped with a valve device, which is used to control the flow rate of each branch pipeline. A temperature detection device, wherein the temperature detection device is used to detect the temperature of each of the battery devices; The control device is configured to determine the temperature difference between the temperature of each battery device and a specified temperature based on the detected temperature of the battery device, and control the opening degree of the valve device based on the temperature difference so that the temperature difference does not exceed the specified range.

2. The energy storage system according to claim 1, wherein, The control device is configured to determine the temperature difference between the temperature of each battery device and the predetermined temperature based on the temperature of each battery device in the same battery cluster, and to control the opening degree of the valve device based on the temperature difference, wherein the valve device corresponding to the branch pipe where the battery device with the higher temperature is located is preferentially controlled.

3. The energy storage system according to claim 2, wherein, The specified temperature includes the upper or lower limit of the specified temperature range. If the temperature difference between the battery device and the upper limit of the temperature range is greater than 0, or if the temperature difference between the battery device and the lower limit of the temperature range is less than 0, the control device determines that the temperature difference exceeds the specified range.

4. The energy storage system according to claim 3, wherein, The specified temperature range is a temperature range of 20 degrees Celsius to 23 degrees Celsius; or... The specified temperature range is a range defined by part or all of the temperatures of each battery device in the same battery cluster, excluding the highest and lowest temperatures.

5. The energy storage system according to claim 3 or 4, wherein, When the temperature difference is greater than 0, the control device controls the valve device corresponding to the branch pipe where the battery device with that temperature is located to increase the opening degree, wherein the heat exchange medium is used to cool the battery device.

6. The energy storage system according to claim 5, wherein, For the valve devices corresponding to the branch pipes where multiple battery devices have a temperature difference greater than 0, control the valve devices to increase their opening degree simultaneously; or, For the valve devices corresponding to the branch pipes where multiple battery devices have a temperature difference greater than 0, the valve devices are sequentially controlled to increase their opening degree in order of the battery device temperature from high to low.

7. The energy storage system according to any one of claims 3 to 6, wherein, When the temperature difference is less than 0, the control device controls the valve device corresponding to the branch pipe where the battery device with that temperature is located to reduce the opening degree, wherein the heat exchange medium is used to cool the battery device.

8. The energy storage system according to claim 7, wherein, For the valve devices corresponding to the branch pipes where multiple battery devices have a temperature difference of less than 0, control the valve devices to reduce their opening degree simultaneously; or, For the valve devices corresponding to the branch pipes where multiple battery devices have a temperature difference of less than 0, the valve devices are controlled to reduce their opening degree in sequence according to the battery device temperature from low to high.

9. The energy storage system according to claim 2, wherein, The specified temperature includes: the lowest temperature among all the battery devices in the same battery cluster during the same temperature measurement. The control device is configured to determine the temperature difference between the temperature of each battery device in the same battery cluster and the minimum temperature, and, when the temperature is higher than the minimum temperature and the temperature difference exceeds the specified range, control the opening of the valve device based on the temperature difference so that the temperature of the battery device is reduced to a temperature difference with the minimum temperature that does not exceed the specified range.

10. The energy storage system according to claim 2, wherein, The specified temperature includes: any temperature other than the lowest and highest temperatures among the temperatures of each battery device in the same battery cluster during the same temperature detection. The control device is configured to determine the temperature difference between the temperature of each battery device in the same battery cluster and the specified temperature; when the temperature is higher than the specified temperature and the temperature difference exceeds the specified range, control the opening of the valve device based on the temperature difference to reduce the temperature of the battery device to a temperature difference not exceeding the specified range; when the temperature is lower than the specified temperature and the absolute value of the temperature difference exceeds the specified range, control the opening of the valve device based on the temperature difference to increase the temperature of the battery device to a temperature difference not exceeding the specified range.

11. The energy storage system according to claim 9 or 10, wherein, The specified range is a temperature range from 0 degrees Celsius to 3 degrees Celsius.

12. The energy storage system according to claim 9 or 10, wherein, The specified range is a temperature range of 0 degrees Celsius to 0.5 degrees Celsius.

13. The energy storage system according to any one of claims 9 to 12, wherein, The control device determines the lowest temperature among the temperatures of each battery device in the same battery cluster, determines whether the temperature difference between each temperature other than the lowest temperature and the lowest temperature exceeds the specified range, and if the temperature is higher than the lowest temperature and the temperature difference exceeds the specified range, controls the valve device corresponding to the branch pipe where the battery device with the specified temperature is located to increase the opening degree, wherein the heat exchange medium is used to cool the battery device.

14. The energy storage system according to claim 13, wherein, For the valve devices corresponding to the branch pipes where multiple battery devices are located, where the temperature is higher than the minimum temperature and the temperature difference exceeds the specified range, the valve devices are simultaneously controlled to increase their opening degree; or... For the valve devices corresponding to the branch pipes where the temperature of the multiple battery devices is located, which are higher than the minimum temperature and the temperature difference exceeds the specified range, the valve devices are sequentially controlled to increase their opening degree in order of the battery device temperature from high to low.

15. The energy storage system according to claim 10, wherein, If, in the same battery cluster, there is an excessively low temperature among the battery devices that is lower than the specified temperature and the absolute value of the temperature difference exceeds the specified range, the control device controls the valve device corresponding to the branch pipe where the battery device with the excessively low temperature is located to reduce the opening, so that the temperature of the battery device rises to a temperature difference from the minimum temperature that does not exceed the specified range, wherein the heat exchange medium is used to cool the battery device.

16. The energy storage system according to claim 5, 6, 13, or 14, wherein, The valve device includes a switching valve, and controlling the valve device to increase its opening degree includes controlling the switching valve to switch from closed to open; or... The valve device includes a proportional valve, and controlling the valve device to increase its opening degree includes controlling the proportional valve to increase its opening degree relative to the current opening degree.

17. The energy storage system according to claim 7, 8, or 15, wherein, The valve device includes a switching valve, and controlling the valve device to reduce its opening degree includes controlling the switching valve to switch from open to closed; or... The valve device includes a proportional valve, and controlling the valve device to reduce its opening degree includes controlling the proportional valve to reduce its opening degree relative to the current opening degree.

18. The energy storage system according to claim 16 or 17, wherein, The proportional valve increases or decreases its opening by a specified range of 3% to 10% each time.

19. The energy storage system according to any one of claims 1 to 18, wherein, The control device is configured to acquire the temperature of each of the battery devices from the temperature detection device at predetermined time intervals, determine the temperature difference in response to each acquired temperature, and control the opening of the valve device based on the temperature difference so that the temperature difference does not exceed a predetermined range.

20. The energy storage system according to any one of claims 1 to 19, wherein, The main pipeline includes an input main pipeline and an output main pipeline, and the branch pipelines include input branch pipelines and output branch pipelines. Each input branch is used to input the heat exchange medium from the input main line into the battery device, and each output branch is used to output the heat exchange medium that has exchanged heat with the battery device from the battery device to the output main line.

21. The energy storage system according to claim 20, wherein, Along the flow direction of the heat exchange medium, the valve device is connected between the upstream end of the input branch pipe and the input main pipe, and / or, Along the flow direction of the heat exchange medium, the valve device is connected between the downstream end of the output branch pipe and the main output pipe, and / or, The valve device is connected along the input branch line, and / or, The valve device is connected to the output branch line.

22. The energy storage system according to any one of claims 1 to 21, wherein, In each of the battery clusters, multiple battery devices are stacked in layers along a first direction, wherein the first direction is perpendicular to a supporting surface, the supporting surface being used to support the energy storage system; and / or, The heat exchange medium includes a coolant.

23. The energy storage system according to any one of claims 1 to 22, wherein, The energy storage system further includes a thermal management device, which includes a heat exchange pipeline connected to the thermal management pipeline. The thermal management device is used to exchange heat with the heat exchange medium flowing from the thermal management pipeline into the heat exchange pipeline, and to provide the heat exchange medium that has undergone heat exchange to the thermal management pipeline.

24. The energy storage system according to claim 23, wherein The energy storage system includes multiple battery clusters, and the main pipelines of the multiple battery clusters are connected in parallel to the heat exchange pipeline; or, The energy storage system includes multiple battery clusters and a main heat exchange medium flow path. The main flow paths of the multiple battery clusters are connected in parallel to each other to the main heat exchange medium flow path, and the main heat exchange medium flow path is connected to the heat exchange pipeline.

25. A temperature control method for an energy storage system, comprising: Obtain the temperature of each battery device; Determine the temperature difference between each of the stated temperatures and the specified temperature; Determine whether the temperature differences described are within the specified range; If the temperature difference does not exceed the specified range, the valve device corresponding to the battery device that maintains the temperature difference within the specified range shall remain in its current opening state. If the temperature difference exceeds the specified range, the opening degree of the valve device corresponding to the battery device whose temperature difference exceeds the specified range is controlled so that the temperature difference does not exceed the specified range.

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