Method, device, energy storage system and equipment for determining charge and discharge model

Abstract

An embodiment of the present application provides a method, device, energy storage system and equipment for determining a charge-discharge model. The method for determining the charge-discharge model includes: obtaining a first correspondence and a second correspondence obtained by testing an energy storage battery; the first correspondence represents the correspondence between the temperature and the state of charge of the energy storage battery during the charging process, and the second correspondence represents the correspondence between the temperature and the state of charge of the energy storage battery during the discharging process; based on the first correspondence and the second correspondence, determining a first target charge-discharge interval of the energy storage battery; in the first correspondence and the second correspondence, the temperature corresponding to the energy storage battery within the first target charge-discharge interval satisfies the target temperature condition; based on the first target charge-discharge interval, establishing a charge-discharge model of the energy storage battery. In this way, a more reasonable charge-discharge model can be established for the energy storage battery to better meet the cyclic energy efficiency requirements of the energy storage battery in the energy storage system.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and particularly to a method and device for determining a charge-discharge model, an energy storage system, and a device. Background Art

[0002] This section aims to provide background or context for the embodiments of the present application. The descriptions herein are not admitted to be prior art merely because they are included in this section.

[0003] New energy batteries are increasingly widely used in life and industries. For example, new energy vehicles equipped with batteries have been widely used. In addition, batteries are also increasingly used in the energy storage field, etc.

[0004] In the application scenario of new energy vehicles, in order to provide more charge-discharge capacity, batteries often open as wide an upper and lower limit voltage range as possible to obtain a high capacity density. This approach is economical and competitive in vehicle batteries. However, in energy storage batteries, charge and discharge are more concerned with the available cycle energy of the battery, and this indicator can be measured by the round trip efficiency (RTE). In the energy storage systems of related technologies, the charge-discharge model of energy storage batteries is not reasonable enough to meet the requirements of the cycle energy efficiency of energy storage batteries. Summary of the Invention

[0005] In view of this, embodiments of the present application are expected to provide a method and device for determining a charge-discharge model, an energy storage system, and a device, which can establish a more reasonable charge-discharge model for energy storage batteries to better meet the requirements of the cycle energy efficiency of energy storage batteries in the energy storage system.

[0006] The technical solution of the embodiments of the present application is implemented as follows:

[0007] The embodiments of the present application provide a method for determining a charge-discharge model, including:

[0008] Obtaining a first correspondence and a second correspondence obtained by testing an energy storage battery; the first correspondence represents the correspondence between the temperature and the state of charge of the energy storage battery during the charging process, and the second correspondence represents the correspondence between the temperature and the state of charge of the energy storage battery during the discharging process;

[0009] Based on the first correspondence and the second correspondence, determining a first target charge-discharge interval of the energy storage battery; in the first correspondence and the second correspondence, the temperature corresponding to the energy storage battery within the first target charge-discharge interval satisfies a target temperature condition;

[0010] Based on the first target charge-discharge interval, establishing a charge-discharge model of the energy storage battery.

[0011] In the method for determining the charge-discharge model according to the embodiments of the present application, first, a first correspondence and a second correspondence obtained by testing a energy storage battery are acquired. The first correspondence represents the correspondence between the temperature and the state of charge of the energy storage battery during the charging process, and the second correspondence represents the correspondence between the temperature and the state of charge of the energy storage battery during the discharging process. Then, based on the first correspondence and the second correspondence, a first target charge-discharge interval of the energy storage battery is determined. In the first correspondence and the second correspondence, the temperature corresponding to the energy storage battery within the first target charge-discharge interval satisfies the target temperature condition. Finally, based on the first target charge-discharge interval, a charge-discharge model of the energy storage battery is established. In this way, since the heat generation situation of the energy storage battery is different under different states of charge during the charge-discharge process, and thus the energy loss caused by heat generation is different. By comprehensively considering the correspondence between the temperature and the state of charge of the energy storage battery during the charge-discharge process and the target temperature condition, a more reasonable first target charge-discharge interval can be quickly determined for the energy storage battery. Furthermore, based on the first target charge-discharge interval, a more reasonable charge-discharge model can be established for the energy storage battery to better meet the cyclic energy efficiency requirements of the energy storage battery in the energy storage system.

[0012] In some embodiments, the target temperature condition includes at least one of the following: the temperature is within a target temperature range; the temperature change rate is less than a target change rate threshold.

[0013] In the above embodiments, when the target temperature condition includes that the temperature is within a target temperature range, the established charge-discharge model can control the temperature of the energy storage battery during the charge-discharge process within a suitable temperature range. When the target temperature condition includes that the temperature change rate is less than a target change rate threshold, the established charge-discharge model can make the temperature change of the energy storage battery during the charge-discharge process relatively gentle. In this way, the energy loss caused by heat generation of the energy storage battery during the charge-discharge process can be reduced, the cyclic energy efficiency of the energy storage battery can be improved, the damage to the energy storage battery caused by heat generation can be reduced, and the aging of the energy storage battery can be delayed. In addition, due to the reduction of heat generation of the energy storage battery, the energy consumption and cost required for cooling the energy storage battery can also be reduced.

[0014] In some embodiments, determining the first target charge-discharge interval of the energy storage battery based on the first correspondence and the second correspondence includes: determining a first candidate charge-discharge interval of the energy storage battery based on the first correspondence, where, in the first correspondence, the temperature corresponding to the energy storage battery within the first candidate charge-discharge interval satisfies the target temperature condition; determining a second candidate charge-discharge interval of the energy storage battery based on the second correspondence, where, in the second correspondence, the temperature corresponding to the energy storage battery within the second candidate charge-discharge interval satisfies the target temperature condition; and determining the first target charge-discharge interval based on the first candidate charge-discharge interval and the second candidate charge-discharge interval.

[0015] In the above embodiments, based on the first correspondence relationship, a first candidate charge-discharge interval of the energy storage battery is determined; in the first correspondence relationship, the temperature corresponding to the energy storage battery within the first candidate charge-discharge interval satisfies the target temperature condition; based on the second correspondence relationship, a second candidate charge-discharge interval of the energy storage battery is determined; in the second correspondence relationship, the temperature corresponding to the energy storage battery within the second candidate charge-discharge interval satisfies the target temperature condition; based on the first candidate charge-discharge interval and the second candidate charge-discharge interval, a first target charge-discharge interval is determined. In this way, by comprehensively considering the first candidate charge-discharge interval in which the corresponding temperature in the first correspondence relationship satisfies the target temperature condition and the second candidate charge-discharge interval in which the corresponding temperature in the second correspondence relationship satisfies the target temperature condition, a more reasonable first target charge-discharge interval can be determined, so that the energy storage battery can well meet the target temperature condition during both the charging and discharging processes, and further better meet the cyclic energy efficiency requirement of the energy storage battery.

[0016] In some embodiments, determining the first target charge-discharge interval based on the first candidate charge-discharge interval and the second candidate charge-discharge interval includes: determining the intersection between the first candidate charge-discharge interval and the second candidate charge-discharge interval as the first target charge-discharge interval.

[0017] In the above embodiments, the intersection between the first candidate charge-discharge interval and the second candidate charge-discharge interval is determined as the first target charge-discharge interval. In this way, it can be further ensured that the energy storage battery can better meet the target temperature condition during both the charging and discharging processes, and further better meet the cyclic energy efficiency requirement of the energy storage battery.

[0018] In some embodiments, the method for determining the above charge-discharge model further includes: obtaining a third correspondence relationship and a fourth correspondence relationship obtained by testing the energy storage battery; the third correspondence relationship represents the correspondence relationship between the upper limit of the charge-discharge interval of the energy storage battery and the cyclic energy efficiency, and the fourth correspondence relationship represents the correspondence relationship between the lower limit of the charge-discharge interval of the energy storage battery and the cyclic energy efficiency; based on the third correspondence relationship and the fourth correspondence relationship, a second target charge-discharge interval is determined;

[0019] Establishing a charge-discharge model of the energy storage battery based on the first target charge-discharge interval includes: determining a third target charge-discharge interval of the energy storage battery based on the first target charge-discharge interval and the second target charge-discharge interval; establishing a charge-discharge model of the energy storage battery based on the third target charge-discharge interval.

[0020] In the above embodiments, the third corresponding relationship and the fourth corresponding relationship obtained from the test of the energy storage battery are acquired; the third corresponding relationship represents the corresponding relationship between the upper limit of the charge-discharge interval of the energy storage battery and the cycle energy efficiency, and the fourth corresponding relationship represents the corresponding relationship between the lower limit of the charge-discharge interval of the energy storage battery and the cycle energy efficiency; based on the third corresponding relationship and the fourth corresponding relationship, the second target charge-discharge interval is determined, and based on the first target charge-discharge interval and the second target charge-discharge interval, the third target charge-discharge interval of the energy storage battery is determined; based on the third target charge-discharge interval, a charge-discharge model of the energy storage battery is established. In this way, by comprehensively considering the temperature condition during the charge-discharge process of the energy storage battery and the corresponding relationship between the upper and lower limits of the charge-discharge interval and the cycle energy efficiency, a more reasonable third target charge-discharge interval can be obtained, a more reasonable charge-discharge model can be established for the energy storage battery, and thus the cycle energy efficiency requirement of the energy storage battery can be better met.

[0021] In some embodiments, determining the second target charge-discharge interval based on the third corresponding relationship and the fourth corresponding relationship includes: based on the third corresponding relationship, determining the second target upper limit of the charge-discharge interval; wherein, in the third corresponding relationship, when the upper limit of the charge-discharge interval is greater than the second target upper limit, the cycle energy efficiency is inversely proportional to the upper limit of the charge-discharge interval; based on the fourth corresponding relationship, determining the second target lower limit of the charge-discharge interval; wherein, in the fourth corresponding relationship, when the lower limit of the charge-discharge interval is less than the second target lower limit, the cycle energy efficiency is directly proportional to the lower limit of the charge-discharge interval; based on the second target upper limit and the second target lower limit, determining the second target charge-discharge interval.

[0022] In the above embodiments, in the third corresponding relationship, when the upper limit of the charge-discharge interval is greater than the second target upper limit, the cycle energy efficiency is inversely proportional to the upper limit of the charge-discharge interval; in the fourth corresponding relationship, when the lower limit of the charge-discharge interval is less than the second target lower limit, the cycle energy efficiency is directly proportional to the lower limit of the charge-discharge interval. In this way, if the upper limit of the charge-discharge interval is greater than the second target upper limit, the cycle energy efficiency of the energy storage battery will decrease, and if the lower limit of the charge-discharge interval is less than the second target lower limit, the cycle energy efficiency of the energy storage battery will also decrease. Therefore, based on the second target upper limit and the second target lower limit, a more reasonable second target charge-discharge interval can be determined to improve the cycle energy efficiency of the energy storage battery.

[0023] In some embodiments, determining the third target charge-discharge interval of the energy storage battery based on the first target charge-discharge interval and the second target charge-discharge interval includes: determining the intersection between the first target charge-discharge interval and the second target charge-discharge interval as the third target charge-discharge interval of the energy storage battery.

[0024] In the above embodiments, the intersection between the first target charge-discharge interval and the second target charge-discharge interval is determined as the third target charge-discharge interval of the energy storage battery. In this way, the temperature condition during the charge-discharge process of the energy storage battery and the corresponding relationship between the upper and lower limits of the charge-discharge interval and the cycle energy efficiency can be more fully considered, thereby further improving the rationality of the charge-discharge model of the energy storage battery, and further better meeting the cycle energy efficiency requirements of the energy storage battery.

[0025] An embodiment of the present application provides a device for determining a charge-discharge model, including:

[0026] A first acquisition module, configured to acquire a first corresponding relationship and a second corresponding relationship obtained by testing an energy storage battery; the first corresponding relationship represents the corresponding relationship between the temperature and the power state of the energy storage battery during the charging process, and the second corresponding relationship represents the corresponding relationship between the temperature and the power state of the energy storage battery during the discharging process;

[0027] A first determination module, configured to determine a first target charge-discharge interval of the energy storage battery based on the first corresponding relationship and the second corresponding relationship; in the first corresponding relationship and the second corresponding relationship, the temperature corresponding to the energy storage battery within the first target charge-discharge interval satisfies the target temperature condition;

[0028] A building module, configured to build a charge-discharge model of the energy storage battery based on the first target charge-discharge interval.

[0029] In the device for determining the charge-discharge model according to the embodiment of the present application, since the heat generation situation of the energy storage battery in different power states during the charge-discharge process is different, and thus the energy loss caused by heat generation is different, by comprehensively considering the corresponding relationship between the temperature and the power state during the charge-discharge process of the energy storage battery and the target temperature condition, a more reasonable first target charge-discharge interval can be quickly determined for the energy storage battery, and then a more reasonable charge-discharge model can be built for the energy storage battery based on the first target charge-discharge interval to better meet the cycle energy efficiency requirements of the energy storage battery in the energy storage system.

[0030] An embodiment of the present application provides an energy storage system, which includes an energy storage battery and a battery management system. The battery management system controls the charging and discharging of the energy storage battery based on the charge-discharge model of the energy storage battery, and the charge-discharge model is determined by using the above-mentioned method for determining the charge-discharge model.

[0031] An embodiment of the present application provides a computer device, including a memory and a processor. The memory stores a computer program that can run on the processor, and the processor implements the steps in the above-mentioned method for determining the charge-discharge model when executing the program.

[0032] An embodiment of the present application provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method for determining the charge-discharge model are implemented.

[0033] An embodiment of the present application provides a computer program product, including a computer program or instruction. When the computer program or instruction is executed by a processor, the steps in the above-mentioned method for determining the charge-discharge model are implemented. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Schematic diagram of the implementation process of a method for determining a charge-discharge model provided by an embodiment of the present application Figure 1 ;

[0035] Figure 2 Schematic diagram of the relationship curve between DCR and SOC during the battery discharge process provided by an embodiment of the present application;

[0036] Figure 3 Schematic diagram of the first change curve of the battery temperature with respect to SOC during the charging process provided by an embodiment of the present application;

[0037] Figure 4 Schematic diagram of the second change curve of the battery temperature with respect to SOC during the discharging process provided by an embodiment of the present application;

[0038] Figure 5 Schematic diagram of the third correspondence relationship between the charge-discharge SOC upper limit and RTE provided by an embodiment of the present application;

[0039] Figure 6 Schematic diagram of the fourth correspondence relationship between the charge-discharge SOC lower limit and RTE provided by an embodiment of the present application;

[0040] Figure 7 Schematic diagram of the implementation process of using a BMS to control the available SOC range of the battery provided by an embodiment of the present application;

[0041] Figure 8 Schematic diagram of the composition structure of a device for determining a charge-discharge model provided by an embodiment of the present application;

[0042] Figure 9 Schematic diagram of the composition structure of an energy storage system provided by an embodiment of the present application;

[0043] Figure 10 Schematic diagram of a hardware entity of a computer device in an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0044] It should be noted that, without conflict, the embodiments in the present application and the technical features in the embodiments may be combined with each other. The detailed description in the specific implementation manners should be understood as an explanatory illustration of the gist of the present application and should not be regarded as an improper limitation to the present application.

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in this application are intended to cover non-exclusive inclusion.

[0046] In the description of the embodiments of the present application, the technical terms "first", "second", "third", etc. are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity, specific order or primary-secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality" is more than two, unless otherwise specifically defined.

[0047] Referring to "embodiments" herein means that the specific features, structures or characteristics described in connection with the embodiments may be included in at least one embodiment of the present application. The phrase appearing at various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein may be combined with other embodiments.

[0048] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of associated objects, indicating that there may be three relationships, for example, A and / or B, which may mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " herein generally indicates that the associated objects before and after are in an "or" relationship.

[0049] In the description of the embodiments of the present application, the orientation or positional relationship indicated by technical terms such as "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "circumferential", "height direction", "first direction", "second direction", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments of the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed, operated or used in a specific orientation, and therefore cannot be understood as a limitation to the embodiments of the present application.

[0050] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0051] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, the technical term "contact" should be understood in a broad sense, and may be direct contact or contact through an intermediate medium layer. It may be contact with essentially no interaction force between the two contacting parties, or it may be contact with interaction force between the two contacting parties.

[0052] With the development of clean energy, more and more devices use electric energy as driving energy, and then power batteries that can store more electric energy and can be charged and discharged repeatedly are developing rapidly, such as lithium-ion batteries. Among them, power batteries are not only used in energy storage power supply systems such as hydropower, thermal power, wind power and solar power stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as aerospace and other fields. With the continuous expansion of the application field of power batteries, the market demand is also constantly expanding.

[0053] In the embodiment of the present application, the battery pack can be made of battery cells and / or battery modules. A battery cell refers to a basic unit that can realize the mutual conversion of chemical energy and electrical energy, and can be used to make a battery module or a battery pack, so as to supply power to an electrical device. A battery cell can be a primary battery or a secondary battery. A secondary battery refers to a battery cell that can be activated by charging the active material after the battery cell is discharged and can continue to be used. The battery cell can be a lithium-ion battery, a sodium-ion battery, a sodium-lithium-ion battery, a lithium metal battery, a sodium metal battery, a lithium-sulfur battery, a magnesium-ion battery, a nickel-hydrogen battery, a nickel-cadmium battery, or a lead-acid battery, etc., and the embodiment of the present application is not limited to this. The battery cell can be cylindrical, rectangular, or in other shapes.

[0054] The battery cell includes an electrode assembly and an electrolyte. The electrode assembly consists of a positive electrode plate, a negative electrode plate, and a separator. The battery cell mainly operates by the movement of metal ions between the positive electrode plate and the negative electrode plate. The positive electrode plate includes a positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode current collector. The positive electrode current collector without the coated positive electrode active material layer protrudes from the positive electrode current collector with the coated positive electrode active material layer. The positive electrode current collector without the coated positive electrode active material layer serves as the positive electrode tab. Taking a lithium-ion battery as an example, the material of the positive electrode current collector can be aluminum, and the positive electrode active material can be lithium cobaltate, lithium iron phosphate, ternary lithium, or lithium manganate, etc. The negative electrode plate includes a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode current collector. The negative electrode current collector without the coated negative electrode active material layer protrudes from the negative electrode current collector with the coated negative electrode active material layer. The negative electrode current collector without the coated negative electrode active material layer serves as the negative electrode tab. The material of the negative electrode current collector can be copper, and the negative electrode active material can be carbon or silicon, etc. In order to ensure passing a large current without fusing, the number of positive electrode tabs is multiple and stacked together, and the number of negative electrode tabs is multiple and stacked together. The material of the separator can be PP (Polypropylene) or PE (Polyethylene), etc.

[0055] RTE is one of the important indicators to measure the performance of an energy storage system, which represents the energy conversion efficiency of the energy storage system during the charge and discharge process. The higher the RTE value, the smaller the energy loss of the energy storage system, and the higher the energy conversion and storage efficiency of the system. In practical applications, the level of the RTE value directly affects the economy and feasibility of the energy storage system.

[0056] In the energy storage systems of related technologies, the charge and discharge models of energy storage batteries usually do not consider the RTE of energy storage batteries. In the application scenarios of new energy vehicles, in order to provide more charge and discharge capacity, the battery often opens the upper and lower limit voltage ranges as wide as possible to obtain a high capacity density. This approach is economical and competitive in vehicle batteries. However, the current vehicle battery strategy may not be the optimal strategy in the energy storage scenario. The reason is that the high upper and low lower limit ranges of the state of charge during the battery charge and discharge process are often high-energy-consuming heat generation ranges. In addition, for an energy storage cooling system with an extremely large integration scale, active energy consumption is also required to dissipate heat into the environment. These two are uneconomical, and excessive heat generation also brings the problem of accelerated battery aging and loss. For example, when the RTE increases from 90% to 91%, a certain power station charges and stores 100 million kWh of electricity per month, and the discharge will increase from 90 million kWh to 91 million kWh. The additional 1 million kWh of discharge per month can bring considerable economic benefits, and the energy consumption and expenditure required for cooling the energy storage battery are also significantly reduced.

[0057] In view of this, an embodiment of the present application provides a method for determining a charge-discharge model, which can be executed by a computer device. When implemented, the computer device may include at least one of a server, a laptop computer, a tablet computer, a desktop computer, a large-screen device, a mobile device (such as a mobile phone, a portable video player, a personal digital assistant, a dedicated messaging device, a portable gaming device), etc.

[0058] Figure 1 Schematic implementation process of a method for determining a charge-discharge model provided by an embodiment of the present application Figure 1 , as Figure 1 shown, the method for determining the charge-discharge model includes the following steps S101 to step S103:

[0059] Step S101, obtaining a first correspondence and a second correspondence obtained by testing an energy storage battery; the first correspondence represents the correspondence between the temperature and the state of charge of the energy storage battery during the charging process, and the second correspondence represents the correspondence between the temperature and the state of charge of the energy storage battery during the discharging process;

[0060] Here, any suitable method can be used to perform charge-discharge tests on the energy storage battery to obtain the first correspondence and the second correspondence.

[0061] For example, during the charging test, the energy storage battery after being emptied can be continuously charged until the energy storage battery is fully charged, and the first correspondence between the temperature and the state of charge of the energy storage battery can be recorded during this charging process; during the discharging test, the fully charged energy storage battery can be continuously discharged until the energy storage battery is emptied, and the second correspondence between the temperature and the state of charge of the energy storage battery can be recorded during this discharging process.

[0062] In some embodiments, the first correspondence includes multiple correspondences between the state of charge and the temperature. The energy storage battery can be continuously charged, and the temperature and the state of charge of the energy storage battery during the charging process can be recorded to obtain the first correspondence.

[0063] In some embodiments, the second correspondence includes multiple correspondences between the state of charge and the temperature. The energy storage battery can be continuously discharged, and the temperature and the state of charge of the energy storage battery during the discharging process can be recorded to obtain the second correspondence.

[0064] In some embodiments, the first corresponding relationship includes a first curve of the temperature of the energy storage battery varying with the state of charge during the charging process; the energy storage battery can be continuously charged, and various states of charge during the charging process of the energy storage battery and the temperature corresponding to each state of charge are recorded; a curve fitting is performed according to the various states of charge during the charging process of the energy storage battery and the temperature corresponding to each state of charge, and the first curve can be obtained.

[0065] In some embodiments, the second corresponding relationship includes a second curve of the temperature of the battery varying with the state of charge during the discharging process; the energy storage battery can be continuously discharged, and various states of charge during the discharging process of the energy storage battery and the temperature corresponding to each state of charge are recorded; a curve fitting is performed according to the various states of charge during the charging process of the energy storage battery and the temperature corresponding to each state of charge, and the second curve can be obtained.

[0066] Among them, the state of charge may include at least one of, but not limited to, the state of charge (SOC), voltage, etc.

[0067] Step S102, based on the first corresponding relationship and the second corresponding relationship, determine the first target charge-discharge interval of the energy storage battery; in the first corresponding relationship and the second corresponding relationship, the temperature corresponding to the energy storage battery within the first target charge-discharge interval satisfies the target temperature condition;

[0068] Here, by analyzing the first corresponding relationship and the second corresponding relationship, the first target charge-discharge interval in which the corresponding temperature during the charge-discharge process of the energy storage battery satisfies the target temperature condition can be determined. Among them, the first target charge-discharge interval can be a charge-discharge voltage interval or a charge-discharge SOC interval.

[0069] In some embodiments, the first target upper limit and the first target lower limit of the charge-discharge interval of the energy storage battery can be determined based on the first corresponding relationship and the second corresponding relationship; based on the first target upper limit and the first target lower limit, the first target charge-discharge interval is determined. Among them, during the charging process and / or discharging process of the energy storage battery, the temperature corresponding to the state of charge of the energy storage battery in the interval higher than the first target upper limit does not satisfy the target temperature condition, the temperature corresponding to the state of charge of the energy storage battery in the interval lower than the first target lower limit does not satisfy the target temperature condition, and the temperature corresponding to the state of charge of the energy storage battery between the first target lower limit and the first target upper limit satisfies the target temperature condition.

[0070] The target temperature condition may include, but is not limited to, at least one of the following: the temperature corresponding to the energy storage battery within the first target charge-discharge interval is within the target temperature range, the temperature corresponding to the energy storage battery within the first target charge-discharge interval is lower than the target temperature threshold, the temperature change rate corresponding to the energy storage battery within the first target charge-discharge interval is less than the target change rate threshold, etc. Among them, the target temperature range, the target temperature threshold, the target change rate threshold, etc. can all be appropriate values set according to the actual situation, and the embodiments of the present application do not limit this.

[0071] Step S103, based on the first target charge-discharge interval, establish a charge-discharge model of the energy storage battery.

[0072] Here, the charge-discharge model can be used for charge-discharge control of the energy storage battery, and / or charge-discharge process simulation, etc.

[0073] In some embodiments, the first target charge-discharge interval can be used as the cyclic charge-discharge interval of the energy storage battery to establish the charge-discharge model of the energy storage battery.

[0074] In some embodiments, the charge-discharge model of the energy storage battery can be stored in a Battery Management System (BMS), and the BMS can use this charge-discharge model to control the charge and discharge of the energy storage battery.

[0075] It should be noted that the embodiments of the present application do not limit the chemical system of the above battery. For example, the battery may include, but is not limited to, at least one of lithium iron phosphate batteries, ternary lithium batteries, lithium manganate batteries, lithium cobalt oxide batteries, nickel-metal hydride batteries, etc.

[0076] In the method for determining the charge-discharge model according to the embodiments of the present application, first, a first correspondence and a second correspondence obtained by testing the energy storage battery are acquired. The first correspondence represents the correspondence between the temperature and the state of charge of the energy storage battery during the charging process, and the second correspondence represents the correspondence between the temperature and the state of charge of the energy storage battery during the discharging process. Then, based on the first correspondence and the second correspondence, a first target charge-discharge interval of the energy storage battery is determined. In the first correspondence and the second correspondence, the temperature corresponding to the energy storage battery within the first target charge-discharge interval satisfies the target temperature condition. Finally, based on the first target charge-discharge interval, a charge-discharge model of the energy storage battery is established. In this way, since the heat generation situation of the energy storage battery is different at different states of charge during the charge-discharge process, and thus the energy loss caused by heat generation is different, by comprehensively considering the correspondence between the temperature and the state of charge of the energy storage battery during the charge-discharge process and the target temperature condition, a more reasonable first target charge-discharge interval can be quickly determined for the energy storage battery, and then a more reasonable charge-discharge model can be established for the energy storage battery based on the first target charge-discharge interval to better meet the cyclic energy efficiency requirements of the energy storage battery in the energy storage system.

[0077] In some embodiments, the above-mentioned energy storage battery includes a lithium iron phosphate battery. Since the internal resistance of the lithium iron phosphate battery at both ends of the charge-discharge interval changes significantly with the state of charge during the charge-discharge process, and the internal resistance values at both ends of the charge-discharge interval are relatively high, in this way, by comprehensively considering the first correspondence between the temperature and the state of charge of the lithium iron phosphate battery during the charging process, the second correspondence between the temperature and the state of charge of the lithium iron phosphate battery during the discharging process, and the target temperature condition, a more reasonable first target charge-discharge interval can be quickly determined for the lithium iron phosphate battery, and then a more reasonable charge-discharge model can be established for the lithium iron phosphate battery based on the first target charge-discharge interval to better meet the cyclic energy efficiency requirements of the lithium iron phosphate battery.

[0078] In some embodiments, the target temperature condition includes at least one of the following:

[0079] The temperature is within the target temperature range;

[0080] The temperature change rate is less than the target change rate threshold.

[0081] Here, both the target temperature range and the target change rate threshold can be set according to the actual situation.

[0082] For example, the target temperature range can be 24.5°C to 26.5°C, 24.5°C to 26°C, or 25°C to 26°C, etc.

[0083] For another example, the target change rate threshold can be 0.1, 0.15, or 0.2, etc.

[0084] In the above embodiments, when the target temperature condition includes that the temperature is within the target temperature range, the established charge-discharge model can control the temperature during the charge-discharge process of the energy storage battery within a suitable temperature range; when the target temperature condition includes that the temperature change rate is less than the target change rate threshold, the established charge-discharge model can make the temperature change during the charge-discharge process of the energy storage battery relatively gentle. In this way, the energy loss caused by heat generation of the energy storage battery during the charge-discharge process can be reduced, the cycle energy efficiency of the energy storage battery can be improved, the damage to the energy storage battery caused by heat generation can be reduced, and the aging of the energy storage battery can be delayed. In addition, due to the reduction of heat generation of the energy storage battery, the energy consumption and cost required for cooling the energy storage battery can also be reduced.

[0085] In some embodiments, the above step S102 may include the following steps S111 to S113:

[0086] Step S111, based on the first correspondence, determine the first candidate charge-discharge interval of the energy storage battery; wherein, in the first correspondence, the temperature corresponding to the energy storage battery within the first candidate charge-discharge interval satisfies the target temperature condition.

[0087] Here, the first candidate charge-discharge interval in which the corresponding temperature in the first correspondence satisfies the target temperature condition can be determined by analyzing the change trend of the temperature of the energy storage battery with the state of charge in the first correspondence.

[0088] In some embodiments, the target temperature condition includes that the temperature is within the target temperature range. Based on the first correspondence, the state-of-charge interval in which the corresponding temperature is within the target temperature range can be determined, and this state-of-charge interval can be determined as the first candidate charge-discharge interval of the energy storage battery.

[0089] In some embodiments, the target temperature condition includes that the temperature change rate is less than the target change rate threshold. Based on the first correspondence, the state-of-charge interval in which the corresponding temperature change rate is within the target temperature range can be determined, and this state-of-charge interval can be determined as the first candidate charge-discharge interval of the energy storage battery. For example, if the first correspondence includes the first change curve of the temperature of the energy storage battery with the state of charge during the charging process, the state-of-charge interval in which the absolute value of the slope in the first change curve is less than the target change rate threshold can be determined as the first candidate charge-discharge interval.

[0090] In some embodiments, based on the first correspondence relationship, a first candidate upper limit and a first candidate lower limit of the charge-discharge interval of the energy storage battery may be determined; based on the first candidate upper limit and the first candidate lower limit, a first candidate charge-discharge interval may be determined. Among them, during the charging process of the energy storage battery, the temperature corresponding to the state of charge of the energy storage battery in the interval higher than the first candidate upper limit does not meet the target temperature condition, the temperature corresponding to the state of charge of the energy storage battery in the interval lower than the first candidate lower limit does not meet the target temperature condition, and the temperature corresponding to the state of charge of the energy storage battery between the first candidate lower limit and the first candidate upper limit meets the target temperature condition.

[0091] Step S112, based on the second correspondence relationship, determine the second candidate charge-discharge interval of the energy storage battery; among them, in the second correspondence relationship, the temperature corresponding to the energy storage battery in the second candidate charge-discharge interval meets the target temperature condition.

[0092] Here, by analyzing the change trend of the temperature of the energy storage battery with the state of charge in the second correspondence relationship, the second candidate charge-discharge interval in which the corresponding temperature in the second correspondence relationship meets the target temperature condition can be determined.

[0093] In some embodiments, the target temperature condition includes that the temperature is within a target temperature range. Based on the second correspondence relationship, the state-of-charge interval in which the corresponding temperature is within the target temperature range may be determined, and this state-of-charge interval may be determined as the second candidate charge-discharge interval of the energy storage battery.

[0094] In some embodiments, the target temperature condition includes that the temperature change rate is less than a target change rate threshold. Based on the second correspondence relationship, the state-of-charge interval in which the corresponding temperature change rate is within the target temperature range may be determined, and this state-of-charge interval may be determined as the second candidate charge-discharge interval of the energy storage battery. For example, the second correspondence relationship includes a second change curve of the temperature of the energy storage battery with the state of charge during the discharge process, and the state-of-charge interval in which the absolute value of the slope in this second change curve is less than the target change rate threshold may be determined as the second candidate charge-discharge interval.

[0095] In some embodiments, based on the second correspondence relationship, a second candidate upper limit and a second candidate lower limit of the charge-discharge interval of the energy storage battery may be determined; based on the second candidate upper limit and the second candidate lower limit, a second candidate charge-discharge interval may be determined. Among them, during the discharge process of the energy storage battery, the temperature corresponding to the state of charge of the energy storage battery in the interval higher than the second candidate upper limit does not meet the target temperature condition, the temperature corresponding to the state of charge of the energy storage battery in the interval lower than the second candidate lower limit does not meet the target temperature condition, and the temperature corresponding to the state of charge of the energy storage battery between the second candidate lower limit and the second candidate upper limit meets the target temperature condition.

[0096] Step S113, determine the first target charge-discharge interval based on the first candidate charge-discharge interval and the second candidate charge-discharge interval.

[0097] In some embodiments, the first target charge-discharge interval may be determined based on the intersection between the first candidate charge-discharge interval and the second candidate charge-discharge interval.

[0098] In some embodiments, the first target charge-discharge interval may be determined based on the union between the first candidate charge-discharge interval and the second candidate charge-discharge interval.

[0099] In some embodiments, one of the first candidate charge-discharge interval and the second candidate charge-discharge interval may be selected as the first target charge-discharge interval. For example, the one with the largest corresponding discharge energy among the first candidate charge-discharge interval and the second candidate charge-discharge interval may be determined as the first target charge-discharge interval.

[0100] In the above embodiments, the first candidate charge-discharge interval of the energy storage battery is determined based on the first correspondence; in the first correspondence, the temperature corresponding to the energy storage battery within the first candidate charge-discharge interval satisfies the target temperature condition; the second candidate charge-discharge interval of the energy storage battery is determined based on the second correspondence; in the second correspondence, the temperature corresponding to the energy storage battery within the second candidate charge-discharge interval satisfies the target temperature condition; the first target charge-discharge interval is determined based on the first candidate charge-discharge interval and the second candidate charge-discharge interval. In this way, by comprehensively considering the first candidate charge-discharge interval whose corresponding temperature satisfies the target temperature condition in the first correspondence and the second candidate charge-discharge interval whose corresponding temperature satisfies the target temperature condition in the second correspondence, a more reasonable first target charge-discharge interval can be determined, enabling the energy storage battery to well satisfy the target temperature condition during both the charge and discharge processes, and thus better meeting the cyclic energy efficiency requirements of the energy storage battery.

[0101] In some embodiments, the above step S113 may include the following step S121:

[0102] Step S121, determine the intersection between the first candidate charge-discharge interval and the second candidate charge-discharge interval as the first target charge-discharge interval.

[0103] For example, if the SOC interval corresponding to the first candidate charge-discharge interval is [2.7%, 90%] and the SOC interval corresponding to the second candidate charge-discharge interval is [7.8%, 97%], then the first target charge-discharge interval may be [7.8%, 90%].

[0104] For another example, if the SOC range corresponding to the first candidate charge-discharge range is [0%, 92%] and the SOC range corresponding to the second candidate charge-discharge range is [7.5%, 100%], then the first target charge-discharge range can be [7.5%, 92%].

[0105] In the above embodiments, the intersection between the first candidate charge-discharge range and the second candidate charge-discharge range is determined as the first target charge-discharge range. In this way, it can be further ensured that the energy storage battery can better meet the target temperature condition during both the charging and discharging processes, and thus better meet the requirements of the cyclic energy efficiency of the energy storage battery.

[0106] In some embodiments, the method for determining the above charge-discharge model further includes the following steps S131 to S132:

[0107] Step S131: Obtain a third correspondence and a fourth correspondence obtained by testing the energy storage battery; the third correspondence represents the correspondence between the upper limit of the charge-discharge range of the energy storage battery and the cyclic energy efficiency, and the fourth correspondence represents the correspondence between the lower limit of the charge-discharge range of the energy storage battery and the cyclic energy efficiency.

[0108] Here, any suitable method can be used to perform charge-discharge tests on the energy storage battery to obtain the third correspondence and the fourth correspondence. Among them, the charge-discharge range of the energy storage battery can be a charge-discharge voltage range or a charge-discharge SOC range.

[0109] In some embodiments, the third correspondence includes the correspondences between multiple third candidate upper limits of the charge-discharge range of the energy storage battery and the cyclic energy efficiency. For each third candidate upper limit, the energy storage battery can be subjected to charge-discharge cycle tests according to this third candidate upper limit, and the cyclic energy efficiency corresponding to the energy storage battery during the charge-discharge cycle tests using this third candidate upper limit can be calculated. In this way, the third correspondence can be obtained. For example, a third candidate upper limit can be selected, and the discharged energy storage battery can be continuously charged until the battery charge reaches this third candidate upper limit, and the charging energy CC_E_up during this charging process can be recorded; then the energy storage battery can be continuously discharged until the battery is completely discharged, and the discharging energy DC_E_up during this discharging process can be recorded; finally, the cyclic energy efficiency DC_E_up / CC_E_up corresponding to this third candidate upper limit can be calculated based on the recorded charging energy CC_E_up and discharging energy DC_E_up.

[0110] In some embodiments, the fourth correspondence relationship includes the correspondence relationship between various third candidate lower limits of the charge-discharge interval of the energy storage battery and the cycle energy efficiency. For each third candidate lower limit, the energy storage battery can be subjected to charge-discharge cycle tests according to the third candidate lower limit, and the corresponding cycle energy efficiency during the charge-discharge cycle tests of the energy storage battery using the third candidate lower limit can be calculated. In this way, the fourth correspondence relationship can be obtained. For example, a third candidate lower limit can be selected, and the fully charged energy storage battery can be continuously discharged until the power of the energy storage battery is discharged to the third candidate lower limit, and the discharge energy DC_E_low during the discharge process can be recorded; then the energy storage battery can be continuously charged until the energy storage battery is fully charged, and the charging energy CC_E_low during the charging process can be recorded; finally, the cycle energy efficiency DC_E_low / CC_E_low corresponding to the third candidate lower limit can be calculated according to the recorded discharge energy DC_E_low and charging energy CC_E_low.

[0111] Step S132, determine the second target charge-discharge interval based on the third correspondence relationship and the fourth correspondence relationship.

[0112] Here, the second target charge-discharge interval can be a charge-discharge voltage interval or a charge-discharge SOC interval.

[0113] In some embodiments, in the third correspondence relationship, the cycle energy efficiency corresponding to the second target charge-discharge interval satisfies the first target efficiency condition, and in the fourth correspondence relationship, the cycle energy efficiency corresponding to the second target charge-discharge interval satisfies the second target efficiency condition. Among them, the first target efficiency condition can include but is not limited to at least one of the cycle energy efficiency being higher than the first target efficiency threshold, the change rate of the cycle energy efficiency being lower than the first efficiency change rate threshold, etc.; the second target efficiency condition can include but is not limited to at least one of the cycle energy efficiency being higher than the second target efficiency threshold, the change rate of the cycle energy efficiency being lower than the second efficiency change rate threshold, etc. The first target efficiency threshold, the first efficiency change rate threshold, the second target efficiency threshold, and / or the second efficiency change rate threshold can all be set according to the actual situation. The first target efficiency threshold and the second target efficiency threshold can be the same or different, and the first efficiency change rate threshold and the second efficiency change rate threshold can be the same or different. For example, the first target efficiency threshold can be 91.7%, 91.8%, or 92%, etc., and the second target efficiency threshold can be 92.2%, 92.3%, or 92.1%, etc.; the first efficiency change rate threshold can be 0.01, or 0.015, etc.; the first efficiency change rate threshold can be 0.01, or 0.015, etc.

[0114] In some embodiments, the second target upper limit and the second target lower limit of the charge-discharge interval of the energy storage battery can be determined based on the third correspondence and the fourth correspondence; based on the second target upper limit and the second target lower limit, the second target charge-discharge interval can be determined. Among them, in the third correspondence, the cycle energy efficiency corresponding to the state of charge of the energy storage battery in the interval higher than the second target upper limit does not meet the target efficiency condition; in the fourth correspondence, the cycle energy efficiency corresponding to the state of charge of the energy storage battery in the interval lower than the second target lower limit does not meet the second target efficiency condition.

[0115] The above step S103 may include the following steps S133 to S134:

[0116] Step S133, determining the third target charge-discharge interval of the energy storage battery based on the first target charge-discharge interval and the second target charge-discharge interval.

[0117] In some embodiments, the third target charge-discharge interval can be determined based on the intersection between the first target charge-discharge interval and the second target charge-discharge interval.

[0118] In some embodiments, the third target charge-discharge interval can be determined based on the union between the first target charge-discharge interval and the second target charge-discharge interval.

[0119] In some embodiments, one of the first target charge-discharge interval and the second target charge-discharge interval can be selected as the third target charge-discharge interval. For example, the one with the largest discharge energy corresponding to the first target charge-discharge interval and the second target charge-discharge interval can be determined as the third target charge-discharge interval.

[0120] Step S134, establishing a charge-discharge model of the energy storage battery based on the third target charge-discharge interval.

[0121] Here, for the embodiment of establishing a charge-discharge model of the energy storage battery based on the third target charge-discharge interval, reference can be made to the embodiment of establishing a charge-discharge model of the energy storage battery based on the first target charge-discharge interval described in step S103 of the foregoing embodiments.

[0122] In the above embodiments, a third correspondence relationship and a fourth correspondence relationship obtained by testing the energy storage battery are acquired; the third correspondence relationship represents the correspondence relationship between the upper limit of the charge-discharge interval of the energy storage battery and the cycle energy efficiency, and the fourth correspondence relationship represents the correspondence relationship between the lower limit of the charge-discharge interval of the energy storage battery and the cycle energy efficiency; based on the third correspondence relationship and the fourth correspondence relationship, a second target charge-discharge interval is determined, and based on the first target charge-discharge interval and the second target charge-discharge interval, a third target charge-discharge interval of the energy storage battery is determined; based on the third target charge-discharge interval, a charge-discharge model of the energy storage battery is established. In this way, by comprehensively considering the temperature conditions during the charge-discharge process of the energy storage battery and the correspondence relationship between the upper and lower limits of the charge-discharge interval and the cycle energy efficiency, a more reasonable third target charge-discharge interval can be obtained, a more reasonable charge-discharge model can be established for the energy storage battery, and thus the cycle energy efficiency requirements of the energy storage battery can be better met.

[0123] In some embodiments, the above step S132 may include the following steps S141 to S143:

[0124] Step S141, based on the third correspondence relationship, determine the second target upper limit of the charge-discharge interval; wherein, in the third correspondence relationship, when the upper limit of the charge-discharge interval is greater than the second target upper limit, the cycle energy efficiency is inversely proportional to the upper limit of the charge-discharge interval.

[0125] Step S142, based on the fourth correspondence relationship, determine the second target lower limit of the charge-discharge interval; wherein, in the fourth correspondence relationship, when the lower limit of the charge-discharge interval is less than the second target lower limit, the cycle energy efficiency is directly proportional to the lower limit of the charge-discharge interval.

[0126] It can be understood that in the third correspondence relationship, when the upper limit of the charge-discharge interval is greater than the second target upper limit, the cycle energy efficiency decreases as the upper limit of the charge-discharge interval increases; in the fourth correspondence relationship, when the lower limit of the charge-discharge interval is less than the second target lower limit, the cycle energy efficiency increases as the lower limit of the charge-discharge interval increases.

[0127] Step S143, based on the second target upper limit and the second target lower limit, determine the second target charge-discharge interval.

[0128] In some embodiments, the second target upper limit and the second target lower limit may be respectively used as the upper and lower limits of the second target charge-discharge interval, so as to determine the second target charge-discharge interval.

[0129] In some embodiments, the upper limit of the second target charge-discharge interval may be selected from the interval between the second target upper limit and the upper limit of the theoretical charge-discharge interval of the energy storage battery; the lower limit of the second target charge-discharge interval may be selected from the interval between the lower limit of the theoretical charge-discharge interval of the energy storage battery and the second target lower limit; in this way, the second target charge-discharge interval can be determined.

[0130] In the above embodiments, in the third corresponding relationship, when the upper limit of the charge-discharge interval is greater than the second target upper limit, the cycle energy efficiency is inversely proportional to the upper limit of the charge-discharge interval; in the fourth corresponding relationship, when the lower limit of the charge-discharge interval is less than the second target lower limit, the cycle energy efficiency is directly proportional to the lower limit of the charge-discharge interval. In this way, if the upper limit of the charge-discharge interval is greater than the second target upper limit, the cycle energy efficiency of the energy storage battery will decrease, and if the lower limit of the charge-discharge interval is less than the second target lower limit, the cycle energy efficiency of the energy storage battery will also decrease. Therefore, based on the second target upper limit and the second target lower limit, a more reasonable second target charge-discharge interval can be determined to improve the cycle energy efficiency of the energy storage battery.

[0131] In some embodiments, the above step S133 may include the following step S151:

[0132] Step S151, determining the intersection between the first target charge-discharge interval and the second target charge-discharge interval as the third target charge-discharge interval of the energy storage battery.

[0133] For example, if the SOC interval corresponding to the first target charge-discharge interval is [7.8%, 90%], and the SOC interval corresponding to the second target charge-discharge interval is [10%, 90%], then the third target charge-discharge interval may be [10%, 90%].

[0134] For another example, if the SOC interval corresponding to the first target charge-discharge interval is [7.8%, 91%], and the SOC interval corresponding to the second target charge-discharge interval is [10%, 92%], then the third target charge-discharge interval may be [10%, 91%].

[0135] In the above embodiments, determining the intersection between the first target charge-discharge interval and the second target charge-discharge interval as the third target charge-discharge interval of the energy storage battery can more fully consider the temperature conditions during the charge-discharge process of the energy storage battery and the corresponding relationship between the upper and lower limits of the charge-discharge interval and the cycle energy efficiency. Therefore, the rationality of the charge-discharge model of the energy storage battery can be further improved, and the cycle energy efficiency requirements of the energy storage battery can be better met.

[0136] The following describes the application of the method for determining the charge-discharge model provided by the embodiments of the present application in an actual scenario.

[0137] In the related technologies, some technologies that use SOC to control the start and stop of battery charging and discharging are usually aimed at improving battery life and preventing overcharging and over-discharging, and do not involve RTE optimization and improvement of economic benefits.

[0138] On this basis, the embodiment of the present application provides a method for determining a charge and discharge model. On the one hand, based on the temperature, the SOC interval with high heat generation and energy consumption during the charge and discharge process of the energy storage battery is identified, and this part of the SOC interval is avoided during the cycle, which can improve the RTE in the energy storage system; on the other hand, based on the combined strategy of temperature and DOD test, the discharge depth (DOD) interval corresponding to the better RTE in the energy storage system can be quickly determined, that is, the charge and discharge SOC interval corresponding to the better RTE (corresponding to the first target charge and discharge interval or the third target charge and discharge interval in the aforementioned embodiment). It can be understood that the charge and discharge SOC interval can be the SOC interval that can be used for BMS to limit the charge and discharge of the battery, and the battery can be the energy storage battery in the above embodiment.

[0139] The following first describes the principle of improving the cycle energy efficiency in the embodiments of the present application.

[0140] The RTE of the battery can be calculated as shown in the following formula 1-1:

[0141] (1-1);

[0142] in, is the discharge energy, To charge energy.

[0143] Due to the heat consumption inside the battery, the charging energy is always greater than the discharging energy. According to the energy conservation equation, charging energy = discharging energy + heat generation.

[0144] It can be seen that to improve the RTE of the battery, it is necessary to reduce the heat generated by the battery during charging and discharging. Battery heating is closely related to the battery DC internal resistance (DCR), but testing DCR is time-consuming and the process is complicated. Figure 2 A schematic diagram of a relationship curve between DCR and SOC during a battery discharge process provided in an embodiment of the present application is shown in FIG. Figure 2 As shown in the figure, the two ends of the SOC range are areas with higher DCR resistance. The best way to reduce the overall heat loss of the battery is to let the battery cycle in the middle area of ​​the SOC range (the SOC is about 0.1~0.9).

[0145] In the embodiments of the present application, by combining the temperature change rate of the battery during continuous charge and discharge, the SOC intervals with high heat generation can be quickly determined. During cycling, these SOC intervals can be avoided, enabling the rapid determination of the charge and discharge SOC intervals corresponding to high RTE.

[0146] In some embodiments, taking a lithium iron phosphate battery as an example, the battery can be tested through the following process, and the temperature of the battery during the test can be recorded:

[0147] 1) Stand still for 30 min;

[0148] 2) Discharge to 2.5 V at 0.33C, where C is the rated capacity of the battery;

[0149] 3) Stand still for 30 min;

[0150] 4) Charge to 3.65 V at 0.33C, and record the curve of the battery temperature versus SOC during this charging process (corresponding to the first change curve in the foregoing embodiments);

[0151] 5) Stand still for 30 min;

[0152] 6) Discharge to 2.5 V at 0.33C;

[0153] 7) Discharge to 2.5 V at 0.04C.

[0154] In steps 6) and 7) above, record the curve of the battery temperature versus SOC during the discharge process (corresponding to the second change curve in the foregoing embodiments).

[0155] Figure 3 Schematic diagram of the first change curve of the battery temperature versus SOC during charging provided by the embodiments of the present application, as Figure 3 shown. In the first change curve, the temperature change rate of the battery fluctuates with SOC. During the charging process, the temperature of the battery at both ends of the first change curve (the first region 31 and the second region 32) rises relatively fast, that is, the SOC regions corresponding to the first region 31 and the second region 32 are the regions with relatively fast heat generation.

[0156] Figure 4 Schematic diagram of the second change curve of the battery temperature versus SOC during discharge provided by the embodiments of the present application, as Figure 4 shown. In the second change curve, the temperature change rate of the battery fluctuates with SOC. During the discharge process, the temperature of the battery at both ends of the second change curve (the third region 41 and the fourth region 42) rises relatively fast, that is, the SOC regions corresponding to the third region 41 and the fourth region 42 are the regions with relatively fast heat generation.

[0157] For example, the SOC range corresponding to the first region 31 is 0 to 2.7%, the SOC range corresponding to the second region 32 is 90% to 100%, the SOC range corresponding to the third region 41 is 0 to 7.8%, and the SOC range corresponding to the fourth region 42 is 97% to 100%. Then, the SOC range with a lower heat generation rate can be obtained as 7.8% to 90%. Thus, 7.8% to 90% can be used as the charge-discharge SOC range of the battery to improve the RTE of the battery.

[0158] In some embodiments, taking a lithium iron phosphate battery as an example, the influence of different charge-discharge SOC upper and lower limits of the battery on the RTE can be determined by the method of controlling variables.

[0159] First, the batteries can be grouped as follows:

[0160] Group 1: The charge-discharge SOC lower limit is fixed at 0% or close to 0%, and the charge-discharge SOC upper limits (corresponding to the third candidate upper limits in the foregoing embodiments) are set to 90%, 95%, 97%, and 100% respectively. Among them, the charge-discharge SOC upper limit can be broadened according to the actual required range.

[0161] Group 2: The charge-discharge SOC upper limit is fixed at 100% or close to 100%, and the charge-discharge SOC lower limits (corresponding to the third candidate lower limits in the foregoing embodiments) are set to 3%, 5%, 7%, and 10% respectively. Among them, the charge-discharge SOC lower limit can be broadened according to the actual required range.

[0162] Then, for each battery, the following process can be used to test and record the capacity Cn of the battery:

[0163] 1) Stand still for 30 min;

[0164] 2) Discharge to 2.5 V at 0.33C;

[0165] 3) Stand still for 30 min;

[0166] 4) Charge to 3.65 V at 0.33C;

[0167] Among them, the SOC corresponding to 2.5 V is 0%, and the SOC corresponding to 3.65 V is 100%.

[0168] 5) Stand still for 30 min;

[0169] 6) Discharge to 2.5 V at 0.33C and record the measured capacity Cn of the battery.

[0170] Next, the following tests are respectively carried out on each battery in Group 1, the RTE is calculated, and the third corresponding relationship between the charge-discharge SOC upper limit and the RTE is recorded:

[0171] 1) Discharge to 2.5 V at 0.33C;

[0172] 2) Let it stand for 30 min;

[0173] 3) Charge at 0.33C to the upper limit of the charge-discharge SOC required, and record the charging energy CC_E_up;

[0174] Among them, each battery in Group 1 can be charged to the corresponding upper limit of the charge-discharge SOC. The measured capacity Cn of the recorded battery can be used to calculate the real-time SOC of the battery.

[0175] 4) Let it stand for 30 min;

[0176] 5) Discharge at 0.33C to 2.5V, and record the discharge energy DC_E_up.

[0177] Perform the following tests on each battery in Group 2 respectively, calculate the RTE, and record the fourth corresponding relationship between the lower limit of the charge-discharge SOC and the RTE:

[0178] 1) Charge at 0.33C to 3.65V;

[0179] 2) Let it stand for 30 min;

[0180] 3) Discharge at 0.33C to the lower limit of the charge-discharge SOC required, and record the discharge energy DC_E_low;

[0181] Among them, each battery in Group 2 can be charged to the corresponding lower limit of the charge-discharge SOC. The measured capacity Cn of the recorded battery can be used to calculate the real-time SOC of the battery.

[0182] 4) Let it stand for 30 min;

[0183] 5) Charge at 0.33C to 3.65V, and record the charging energy CC_E_low.

[0184] Finally, through the recorded charging energy CC_E_up, discharge energy DC_E_up, charging energy CC_E_low and discharge energy DC_E_low above, calculate the RTE in the manner shown in Formula 1-2 and Formula 1-3 below:

[0185] (1-2);

[0186] (1-3);

[0187] Among them, represents the RTE of the battery in Group 1, represents the RTE of the battery in Group 2.

[0188] Plot the RTE of each tested battery in the two groups, and the results are as follows:

[0189] Figure 5 This is a schematic diagram of the third correspondence between the charge-discharge SOC upper limit and RTE provided by the embodiments of the present application. As Figure 5 shown, when the charge-discharge SOC lower limit remains unchanged, as the charge-discharge SOC upper limit decreases, the RTE gradually increases. Figure 6 This is a schematic diagram of the fourth correspondence between the charge-discharge SOC lower limit and RTE provided by the embodiments of the present application. As Figure 6 shown, when the charge-discharge SOC upper limit remains unchanged, as the charge-discharge SOC lower limit increases, the RTE gradually increases.

[0190] Combining Figure 5 and Figure 6 it can be seen that as the charge-discharge SOC interval (i.e., the DOD interval) shrinks, the RTE gradually increases. The reason is that the reduced charge-discharge SOC interval avoids the high DCR region, and the heat generation energy consumption decreases. Using this rule, the available SOC interval of the battery can be controlled within a certain narrow range in the BMS to improve the RTE.

[0191] In some embodiments, as Figure 7 shown, the implementation process of controlling the available SOC interval of the battery by the BMS includes the following steps S701 to step S704:

[0192] Step S701, experimentally determine the third correspondence between the charge-discharge SOC upper limit and RTE, and the fourth correspondence between the charge-discharge SOC lower limit and RTE;

[0193] Step S702, determine the charge-discharge SOC interval according to the third correspondence and the fourth correspondence;

[0194] Here, according to the third correspondence and the fourth correspondence obtained from the above experiments, the charge-discharge SOC interval can be determined by using the method of controlling variables.

[0195] In some embodiments, the method for determining the charge-discharge SOC range may include: in the third corresponding relationship, when a certain charge-discharge SOC upper limit decreases and the RTE does not increase (or the increase in RTE is less than 0.01% per 1% SOC), determining the charge-discharge SOC upper limit as the boundary of the SOC upper limit; in the fourth corresponding relationship, when a certain charge-discharge SOC lower limit increases and the RTE does not increase (or the increase in RTE is less than 0.01% per 1% SOC), determining the charge-discharge SOC lower limit as the boundary of the SOC lower limit; selecting an SOC within the range of [0%, the boundary of the SOC lower limit] as the lower limit of the charge-discharge SOC range according to actual needs (such as in combination with the actual discharge amount requirement), and selecting an SOC within the range of [the boundary of the SOC upper limit, 100%] as the upper limit of the charge-discharge SOC range, so as to obtain the charge-discharge SOC range. For example, on the basis of meeting the discharge amount requirement, select the lower limit of the charge-discharge SOC range as high as possible and the upper limit of the charge-discharge SOC range as low as possible.

[0196] In some embodiments, [the boundary of the SOC lower limit, the boundary of the SOC upper limit] can be selected as the charge-discharge SOC range and used as the available SOC range for the BMS to control the battery, so as to improve the RTE.

[0197] In some embodiments, the third corresponding relationship includes a third change curve of the RTE with respect to the charge-discharge SOC upper limit, and the fourth corresponding relationship includes a fourth change curve of the RTE with respect to the charge-discharge SOC lower limit. The charge-discharge SOC range is determined by the curve slope of the third change curve and the curve slope of the fourth change curve.

[0198] Step S703, convert the charge-discharge SOC range into a charge-discharge voltage range;

[0199] In some embodiments, if some types of BMS control the available range of the battery based on voltage, the charge-discharge SOC range can be converted into a charge-discharge voltage range by the method of open circuit voltage (OCV) test, so as to achieve the effect of the BMS controlling the battery charge-discharge process through the voltage range to improve the RTE.

[0200] In some embodiments, the following OCV test process is used to obtain the charge-discharge voltage range corresponding to the charge-discharge SOC range:

[0201] 1) Fully charge and discharge to record the battery capacity;

[0202] 2) Charge the battery fully;

[0203] 3) Discharge and adjust the SOC to the upper limit of the charge-discharge SOC range;

[0204] 4) Let it stand for 2 hours and record the voltage Vmax;

[0205] 5) Discharge and adjust the SOC to the lower limit of the charge-discharge SOC range;

[0206] 6) Let it stand for 2 hours and record the voltage Vmin.

[0207] Among them, the voltage Vmax and the voltage Vmin are the upper and lower limits of the charge-discharge voltage range corresponding to the charge-discharge SOC range, so that the charge-discharge voltage range can be determined.

[0208] Step S704, write the charge-discharge SOC range or the charge-discharge voltage range into the BMS, and the BMS restricts the battery to be used within the charge-discharge SOC range or the charge-discharge voltage range.

[0209] Take the charge-discharge SOC range or the charge-discharge voltage range as the control range for the BMS to control the charge and discharge of the battery. In this way, the RTE efficiency during the charge and discharge process of the battery can be improved.

[0210] In some embodiments, after determining the charge-discharge SOC range or the charge-discharge voltage range, a charge-discharge model of the battery can be established based on the charge-discharge SOC range or the charge-discharge voltage range, and the BMS can control the charge and discharge of the battery based on the charge-discharge model.

[0211] The embodiment of the present application provides a device for determining a charge-discharge model, as Figure 8 shown. The device 800 for determining the charge-discharge model includes a first acquisition module 810, a first determination module 820, and an establishment module 830, where:

[0212] The first acquisition module 810 is configured to acquire a first correspondence and a second correspondence obtained by testing an energy storage battery; the first correspondence represents the correspondence between the temperature and the state of charge of the energy storage battery during the charging process, and the second correspondence represents the correspondence between the temperature and the state of charge of the energy storage battery during the discharging process;

[0213] The first determination module 820 is configured to determine a first target charge-discharge range of the energy storage battery based on the first correspondence and the second correspondence; in the first correspondence and the second correspondence, the temperature corresponding to the energy storage battery within the first target charge-discharge range satisfies a target temperature condition;

[0214] The establishment module 830 is configured to establish a charge-discharge model of the energy storage battery based on the first target charge-discharge range.

[0215] In the device for determining the charge-discharge model according to the embodiments of the present application, since the heat generation of the energy storage battery is different at different state-of-charge during the charge-discharge process, the energy loss caused by heat generation will also be different. By comprehensively considering the correspondence between the temperature and the state-of-charge during the charge-discharge process of the energy storage battery and the target temperature condition, a more reasonable first target charge-discharge interval can be quickly determined for the energy storage battery. Furthermore, based on the first target charge-discharge interval, a more reasonable charge-discharge model can be established for the energy storage battery to better meet the cyclic energy efficiency requirements of the energy storage battery in the energy storage system.

[0216] In some embodiments, the target temperature condition includes at least one of the following: the temperature is within the target temperature range; the temperature change rate is less than the target change rate threshold.

[0217] In some embodiments, determining the first target charge-discharge interval of the energy storage battery based on the first correspondence and the second correspondence includes: determining a first candidate charge-discharge interval of the energy storage battery based on the first correspondence; wherein, in the first correspondence, the temperature corresponding to the energy storage battery within the first candidate charge-discharge interval satisfies the target temperature condition; determining a second candidate charge-discharge interval of the energy storage battery based on the second correspondence; wherein, in the second correspondence, the temperature corresponding to the energy storage battery within the second candidate charge-discharge interval satisfies the target temperature condition; determining the first target charge-discharge interval based on the first candidate charge-discharge interval and the second candidate charge-discharge interval.

[0218] In some embodiments, determining the first target charge-discharge interval based on the first candidate charge-discharge interval and the second candidate charge-discharge interval includes: determining the intersection between the first candidate charge-discharge interval and the second candidate charge-discharge interval as the first target charge-discharge interval.

[0219] In some embodiments, the method further includes: obtaining a third correspondence and a fourth correspondence obtained by testing the energy storage battery; the third correspondence characterizes the correspondence between the upper limit of the charge-discharge interval of the energy storage battery and the cyclic energy efficiency, and the fourth correspondence characterizes the correspondence between the lower limit of the charge-discharge interval of the energy storage battery and the cyclic energy efficiency; determining a second target charge-discharge interval based on the third correspondence and the fourth correspondence;

[0220] Establishing the charge-discharge model of the energy storage battery based on the first target charge-discharge interval includes: determining a third target charge-discharge interval of the energy storage battery based on the first target charge-discharge interval and the second target charge-discharge interval; establishing the charge-discharge model of the energy storage battery based on the third target charge-discharge interval.

[0221] In some embodiments, determining the second target charge-discharge interval based on the third correspondence relationship and the fourth correspondence relationship includes: determining the second target upper limit of the charge-discharge interval based on the third correspondence relationship; wherein, in the third correspondence relationship, when the upper limit of the charge-discharge interval is greater than the second target upper limit, the cycle energy efficiency is inversely proportional to the upper limit of the charge-discharge interval; determining the second target lower limit of the charge-discharge interval based on the fourth correspondence relationship; wherein, in the fourth correspondence relationship, when the lower limit of the charge-discharge interval is less than the second target lower limit, the cycle energy efficiency is directly proportional to the lower limit of the charge-discharge interval; determining the second target charge-discharge interval based on the second target upper limit and the second target lower limit.

[0222] In some embodiments, determining the third target charge-discharge interval of the energy storage battery based on the first target charge-discharge interval and the second target charge-discharge interval includes: determining the intersection between the first target charge-discharge interval and the second target charge-discharge interval as the third target charge-discharge interval of the energy storage battery.

[0223] An embodiment of the present application provides an energy storage system, as Figure 9 shown, the energy storage system 900 includes an energy storage battery 910 and a battery management system 920. The battery management system controls the charging and discharging of the energy storage battery based on the charge-discharge model of the energy storage battery, and the charge-discharge model is determined by using the determination method of the above-mentioned charge-discharge model.

[0224] The descriptions of the above device embodiments and energy storage system embodiments are similar to the descriptions of the above method embodiments and have similar beneficial effects to those of the method embodiments. In some embodiments, the functions or modules included in the device provided by the embodiments of the present application can be used to execute the methods described in the above method embodiments. For the technical details not disclosed in the device embodiments of the present application, please refer to the descriptions of the method embodiments of the present application for understanding.

[0225] It should be noted that in the embodiments of the present application, if the above method is implemented in the form of software function modules and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the embodiments of the present application, in essence or the part that contributes to the related technology, can be embodied in the form of a software product. The software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the methods of the various embodiments of the present application. The aforementioned storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROMs), magnetic disks, or optical discs that can store program codes. In this way, the embodiments of the present application are not limited to any specific hardware, software, or firmware, or any combination among hardware, software, and firmware.

[0226] The embodiments of the present application provide a computer device, including a memory and a processor. The memory stores a computer program that can run on the processor. When the processor executes the program, it implements some or all of the steps in the above method for determining the charge-discharge model.

[0227] The embodiments of the present application provide a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by the processor, it implements some or all of the steps in the above method for determining the charge-discharge model. The computer-readable storage medium can be transient or non-transient.

[0228] The embodiments of the present application provide a computer program, including computer-readable code. When the computer-readable code runs in a computer device, the processor in the computer device executes to implement some or all of the steps in the above method.

[0229] The embodiments of the present application provide a computer program product. The computer program product includes a non-transient computer-readable storage medium storing a computer program. When the computer program is read and executed by a computer, it implements some or all of the steps in the above method. The computer program product can be specifically implemented in the form of hardware, software, or a combination thereof. In some embodiments, the computer program product is specifically embodied as a computer storage medium. In other embodiments, the computer program product is specifically embodied as a software product, such as a software development kit (SDK), etc.

[0230] The embodiments of the present application provide a computer program product, including a computer program or instructions. When the computer program or instructions are executed by a processor, they implement some or all of the steps in the above method for determining the charge-discharge model.

[0231] It should be noted here that: the above descriptions of the various embodiments tend to emphasize the differences between the various embodiments, and their similarities can be referred to each other. The above descriptions of the device, storage medium, computer program, and computer program product embodiments are similar to the descriptions of the above method embodiments and have beneficial effects similar to those of the method embodiments. For the technical details not disclosed in the device, storage medium, computer program, and computer program product embodiments of the present application, please refer to the descriptions of the method embodiments of the present application for understanding.

[0232] It should be noted that Figure 10 is a schematic diagram of a hardware entity of a computer device in an embodiment of the present application. As Figure 10 shown, the hardware entity of the computer device 1000 includes: a processor 1001, a communication interface 1002, and a memory 1003, where: the processor 1001 generally controls the overall operation of the computer device 1000. The communication interface 1002 can enable the computer device to communicate with other terminals or servers through a network. The memory 1003 is configured to store instructions and applications executable by the processor 1001, and can also cache data to be processed or already processed by the processor 1001 and each module in the computer device 1000 (for example, image data, audio data, voice communication data, and video communication data), and can be implemented by flash memory (FLASH) or random access memory (Random Access Memory, RAM). Data transmission can be performed between the processor 1001, the communication interface 1002, and the memory 1003 through a bus 1004.

[0233] It should be understood that the "one embodiment" or "an embodiment" mentioned throughout the specification means that the specific features, structures, or characteristics related to the embodiment are included in at least one embodiment of the present application. Therefore, the "in one embodiment" or "in an embodiment" that appears throughout the specification does not necessarily refer to the same embodiment. In addition, these specific features, structures, or characteristics can be combined in one or more embodiments in any suitable manner. It should be understood that in various embodiments of the present application, the magnitude of the sequence numbers of the above steps / processes does not mean the order of execution, and the order of execution of each step / process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application. The sequence numbers of the embodiments of the present application above are only for description and do not represent the advantages and disadvantages of the embodiments.

[0234] It should be noted that in this text, the term "including", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements not only includes those elements but also includes other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the phrase "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising such element.

[0235] In several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined, or can be integrated into another system, or some features can be ignored or not executed. Additionally, the couplings, direct couplings, or communication connections between the various components shown or discussed may be through some interfaces. The indirect couplings or communication connections of devices or units can be electrical, mechanical, or in other forms.

[0236] The units described above as separate components may or may not be physically separated. The components shown as units may or may not be physical units; they can be located in one place or distributed across multiple network units; some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment. Additionally, in each embodiment of this application, the various functional units can all be integrated in one processing unit, or each unit can be separately a unit by itself, or two or more units can be integrated in one unit; the above-mentioned integrated units can be implemented in the form of hardware, or in the form of hardware plus software functional units.

[0237] Those of ordinary skill in the art can understand that all or part of the steps of implementing the above method embodiments can be completed by hardware related to program instructions. The foregoing program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps including the above method embodiments; and the foregoing storage medium includes various media that can store program codes, such as removable storage devices, read-only memory (ROM), magnetic disks, or optical discs.

[0238] Alternatively, if the above integrated units of the present application are implemented in the form of software functional modules and sold or used as independent products, they can also be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, in essence or the part that contributes to the related technology, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the methods of the various embodiments of the present application. The aforementioned storage medium includes: various media that can store program codes, such as removable storage devices, ROMs, magnetic disks, or optical discs.

[0239] The above are only exemplary embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application are all included within the protection scope of the present application.

Claims

1. A method for determining a charge and discharge model, characterized in that: The method comprises: Acquire a first corresponding relationship and a second corresponding relationship obtained by testing an energy storage battery; the first corresponding relationship represents a corresponding relationship between the temperature and the state of charge of the energy storage battery during a charging process, and the second corresponding relationship represents a corresponding relationship between the temperature and the state of charge of the energy storage battery during a discharging process; Based on the first corresponding relationship and the second corresponding relationship, determining a first target charge and discharge interval of the energy storage battery; in the first corresponding relationship and the second corresponding relationship, the temperature corresponding to the energy storage battery in the first target charge and discharge interval meets the target temperature condition; Based on the first target charge and discharge interval, establishing a charge and discharge model of the energy storage battery; The first corresponding relationship is obtained based on multiple first power states of the energy storage battery and the temperature corresponding to each of the first power states of the energy storage battery, and the multiple first power states and the temperature corresponding to each of the first power states are recorded during the charging process of the energy storage battery; The second corresponding relationship is obtained based on multiple second power states of the energy storage battery and the temperature corresponding to the energy storage battery in each second power state, and the multiple second power states and the temperature corresponding to each second power state are recorded during the discharge process of the energy storage battery.

2. The method for determining a charge and discharge model according to claim 1, characterized in that: The target temperature condition includes at least one of the following: The temperature is within the target temperature range; The temperature change rate is less than the target change rate threshold.

3. The method for determining a charge and discharge model according to claim 1, characterized in that: The determining, based on the first corresponding relationship and the second corresponding relationship, a first target charge and discharge interval of the energy storage battery includes: Based on the first corresponding relationship, determining a first candidate charge and discharge interval of the energy storage battery; wherein, in the first corresponding relationship, the temperature corresponding to the energy storage battery in the first candidate charge and discharge interval satisfies the target temperature condition; Based on the second corresponding relationship, determining a second candidate charge and discharge interval of the energy storage battery; wherein, in the second corresponding relationship, the temperature corresponding to the energy storage battery in the second candidate charge and discharge interval meets the target temperature condition; The first target charge and discharge interval is determined based on the first candidate charge and discharge interval and the second candidate charge and discharge interval.

4. The method for determining the charge and discharge model according to claim 3, characterized in that: The determining the first target charge and discharge interval based on the first candidate charge and discharge interval and the second candidate charge and discharge interval includes: The intersection of the first candidate charge and discharge interval and the second candidate charge and discharge interval is determined as the first target charge and discharge interval.

5. The method for determining a charge and discharge model according to any one of claims 1 to 4, characterized in that: The method further comprises: Acquire a third corresponding relationship and a fourth corresponding relationship obtained by testing the energy storage battery; the third corresponding relationship represents the corresponding relationship between the upper limit of the charge and discharge interval of the energy storage battery and the cycle energy efficiency, and the fourth corresponding relationship represents the corresponding relationship between the lower limit of the charge and discharge interval of the energy storage battery and the cycle energy efficiency; Determining a second target charge-discharge interval based on the third corresponding relationship and the fourth corresponding relationship; The establishing the charge and discharge model of the energy storage battery based on the first target charge and discharge interval includes: Determining a third target charge and discharge interval of the energy storage battery based on the first target charge and discharge interval and the second target charge and discharge interval; Based on the third target charge and discharge interval, a charge and discharge model of the energy storage battery is established.

6. The method for determining the charge and discharge model according to claim 5, characterized in that: The determining of the second target charge-discharge interval based on the third corresponding relationship and the fourth corresponding relationship includes: Based on the third corresponding relationship, determining a second target upper limit of the charge-discharge interval; wherein, in the third corresponding relationship, when the upper limit of the charge-discharge interval is greater than the second target upper limit, the cycle energy efficiency is inversely proportional to the upper limit of the charge-discharge interval; Based on the fourth corresponding relationship, determining a second target lower limit of the charge-discharge interval; wherein, in the fourth corresponding relationship, when the lower limit of the charge-discharge interval is less than the second target lower limit, the cycle energy efficiency is in direct proportion to the lower limit of the charge-discharge interval; A second target charge-discharge interval is determined based on the second target upper limit and the second target lower limit.

7. The method for determining a charge and discharge model according to claim 5, characterized in that: The determining, based on the first target charge and discharge interval and the second target charge and discharge interval, a third target charge and discharge interval of the energy storage battery includes: The intersection of the first target charge and discharge interval and the second target charge and discharge interval is determined as a third target charge and discharge interval of the energy storage battery.

8. A device for determining a charge and discharge model, characterized in that: include: A first acquisition module, used to acquire a first corresponding relationship and a second corresponding relationship obtained by testing the energy storage battery; The first corresponding relationship represents the corresponding relationship between the temperature and the state of charge of the energy storage battery during the charging process, and the second corresponding relationship represents the corresponding relationship between the temperature and the state of charge of the energy storage battery during the discharging process; A first determining module, configured to determine a first target charge and discharge interval of the energy storage battery based on the first corresponding relationship and the second corresponding relationship; In the first corresponding relationship and the second corresponding relationship, the temperature corresponding to the energy storage battery in the first target charge and discharge interval meets the target temperature condition; An establishing module, used to establish a charging and discharging model of the energy storage battery based on the first target charging and discharging interval; The first corresponding relationship is obtained based on multiple first power states of the energy storage battery and the temperature corresponding to each of the first power states of the energy storage battery, and the multiple first power states and the temperature corresponding to each of the first power states are recorded during the charging process of the energy storage battery; The second corresponding relationship is obtained based on multiple second power states of the energy storage battery and the temperature corresponding to the energy storage battery in each second power state, and the multiple second power states and the temperature corresponding to each second power state are recorded during the discharge process of the energy storage battery.

9. An energy storage system, characterized in that: The energy storage system includes an energy storage battery and a battery management system, and the battery management system controls the charging and discharging of the energy storage battery based on a charging and discharging model of the energy storage battery, and the charging and discharging model is determined by the method described in any one of claims 1 to 7.

10. A computer device comprising a memory and a processor, wherein the memory stores a computer program that can be run on the processor, characterized in that: When the processor executes the program, the steps in the method according to any one of claims 1 to 7 are implemented.

11. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps in the method according to any one of claims 1 to 7 are implemented.

12. A computer program product comprising a computer program or instructions, characterized in that When the computer program or instruction is executed by a processor, the steps in the method according to any one of claims 1 to 7 are implemented.

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