Control method and control device of energy storage system

Abstract

The embodiment of the invention provides a control method and a control device of an energy storage system, the energy storage system is coupled to an energy generation system and a power grid, the energy storage system comprises a plurality of energy storage units, and the method comprises the following steps: obtaining discharge power information of the energy generation system, charging power information of the power grid and state information of the energy storage system, the state information of the energy storage system comprises time information of the energy storage unit in a preset DOD interval; and determining an energy management strategy of the energy storage system according to the discharging power information of the energy generation system, the charging power information of the power grid and the state information of the energy storage system. According to the control method and the control device of the energy storage system, energy management of the energy storage system can be reasonably carried out, the performance of the energy storage system is improved, and the service life of the energy storage system is prolonged.

Description

Control method and control device of energy storage system Technical Field

[0001] The present application relates to the field of energy storage technology, and in particular to a control method and control device for an energy storage system. Background Art

[0002] With the rapid development of the new energy industry, a large number of renewable energy systems, such as wind power and photovoltaics, have been connected to the power grid. Renewable energy systems suffer from large power fluctuations, which cause dramatic fluctuations in grid voltage and frequency, affecting grid stability.

[0003] By connecting a renewable energy system to an energy storage system, fluctuations in output power can be effectively mitigated. When the renewable energy system outputs excessive energy, the renewable energy system can be controlled to charge the energy storage system, avoiding energy waste. If the renewable energy system generates insufficient energy, the energy storage system can be controlled to discharge energy to the grid to ensure smooth overall power output. A common charging and discharging method for energy storage systems is to allocate power based on the state of charge (SOC), charging and discharging all batteries in the energy storage system during each charge and discharge. This charging method affects the performance and service life of the energy storage system.

[0004] Summary of the Invention

[0005] The embodiments of the present application provide a control method and a control device for an energy storage system, which can reasonably manage the energy of the energy storage system and improve the performance and service life of the energy storage system.

[0006] In a first aspect, a control method for an energy storage system is provided, wherein the energy storage system is coupled to an energy generation system and a power grid, and the energy storage system includes multiple energy storage units. The method includes: obtaining discharge power information of the energy generation system, charging power information of the power grid, and status information of the energy storage system, wherein the status information of the energy storage system includes time information of the energy storage unit in a preset DOD interval; and determining an energy management strategy of the energy storage system based on the discharge power information of the energy generation system, the charging power information of the power grid, and the status information of the energy storage system.

[0007] The control scheme for the energy storage system provided in the embodiment of the present application comprehensively considers the discharge power information of the energy generation system, the charging power information of the power grid, and the status information of the energy storage system, including the time information of the energy storage unit in the preset DOD interval. It can more reasonably determine the energy management strategy of the energy storage system and flexibly manage the energy of the energy storage system, thereby improving the performance and service life of the energy storage system.

[0008] In one possible implementation, determining the energy management strategy of the energy storage system includes: charging the first energy storage unit when the discharge power of the energy generation system is greater than the charging power of the power grid and there is a first energy storage unit in the energy storage system, wherein the first energy storage unit is an energy storage unit whose time in the preset DOD interval is greater than or equal to a preset time.

[0009] The control scheme for the energy storage system provided in the embodiment of the present application gives priority to charging the energy storage units that have been in the preset DOD interval for a longer time when charging the energy storage system. This can avoid the problem of inaccurate SOC caused by the energy storage units being in the DOD interval for a longer time, and can avoid overcharging or over-discharging caused by inaccurate SOC, thereby improving the performance and service life of the energy storage system.

[0010] In one possible implementation, determining the energy management strategy of the energy storage system includes: charging the second energy storage unit when the discharge power of the energy generation system is greater than the charging power of the power grid and there is a second energy storage unit in the energy storage system, wherein the second energy storage unit is an energy storage unit other than the first energy storage unit and the SOC is less than or equal to a first charging threshold, and the charging priority of the second energy storage unit is lower than that of the first energy storage unit.

[0011] The control scheme for the energy storage system provided in the embodiment of the present application also takes into account the SOC of the energy storage unit. When charging the energy storage units in the energy storage system other than the first energy storage unit that has been in the preset DOD interval for a longer period of time, the energy storage units with relatively smaller SOCs can be charged first. This ensures that the energy storage units with smaller SOCs are charged first, avoids over-discharge of the energy storage units with smaller SOCs, and improves the performance and service life of the energy storage system.

[0012] In one possible implementation, determining the energy management strategy of the energy storage system includes: when the discharge power of the energy generation system is greater than the charging power of the power grid and there is a third energy storage unit in the energy storage system, charging the third energy storage unit, wherein the third energy storage unit is an energy storage unit other than the first energy storage unit and the second energy storage unit and whose SOC is less than or equal to a second charging threshold, the second charging threshold is greater than the first charging threshold, and the charging priority of the third energy storage unit is lower than that of the first energy storage unit or the second energy storage unit.

[0013] The control scheme for the energy storage system provided in the embodiments of the present application can control the energy generation system to charge the energy storage units in a certain priority order based on the time the energy storage units are in a preset DOD interval and the SOC of the energy storage units. This allows the energy storage system to be charged reasonably, avoids the problem of overcharging or over-discharging of the energy storage units due to inaccurate SOC of the energy storage units, and to a certain extent reduces the number of charging times of the energy storage units, thereby improving the performance and service life of the energy storage system.

[0014] In one possible implementation, determining the energy management strategy of the energy storage system includes: when the discharge power of the energy generation system is less than the charging power of the power grid and there is a fourth energy storage unit in the energy storage system, discharging the fourth energy storage unit, wherein the fourth energy storage unit is an energy storage unit whose time in the preset DOD interval is greater than or equal to a preset time.

[0015] The control scheme for the energy storage system provided in the embodiments of the present application prioritizes discharging energy storage units that have been in a preset DOD interval for a longer period of time when controlling the energy storage system to discharge to the grid. This can avoid the problem of inaccurate SOC caused by the energy storage units being in the DOD interval for a longer period of time, thereby avoiding the problem of overcharging or over-discharging of the energy storage units due to inaccurate SOC, thereby improving the performance and service life of the energy storage system.

[0016] In one possible implementation, determining the energy management strategy of the energy storage system includes: when the discharge power of the energy generation system is less than the charging power of the power grid and there is a fifth energy storage unit in the energy storage system, discharging the fifth energy storage unit, wherein the fifth energy storage unit is an energy storage unit other than the fourth energy storage unit and the SOC of which is greater than or equal to a first discharge threshold, and the discharge priority of the fifth energy storage unit is lower than that of the fourth energy storage unit.

[0017] The control scheme for the energy storage system provided in the embodiment of the present application also takes into account the SOC of the energy storage unit. When discharging the energy storage units in the energy storage system other than the energy storage units that have been in the preset DOD interval for a long time, the energy storage units with relatively large SOCs can be discharged first. This can ensure that the energy storage units with large SOCs are discharged first, avoid overcharging of the energy storage units with large SOCs, and improve the performance and service life of the energy storage system.

[0018] In one possible implementation, determining the energy management strategy of the energy storage system includes: when the discharge power of the energy generation system is less than the charging power of the power grid and there is a sixth energy storage unit in the energy storage system, discharging the sixth energy storage unit, wherein the sixth energy storage unit is an energy storage unit other than the fourth energy storage unit and the fifth energy storage unit and whose SOC is greater than or equal to a second discharge threshold, the second discharge threshold is less than the first discharge threshold, and the discharge priority of the sixth energy storage unit is lower than that of the fourth energy storage unit or the fifth energy storage unit.

[0019] The control scheme for the energy storage system provided in the embodiments of the present application can control the energy storage units to discharge into the grid in a certain priority order based on the time information of the energy storage units in the preset DOD interval and the SOC information of the energy storage units. This enables the energy storage system to discharge more rationally, avoids the problem of overcharging or overdischarging of the energy storage units due to inaccurate SOC of the energy storage units, and can also reduce the number of discharges of the energy storage units to a certain extent, thereby improving the performance and service life of the energy storage system.

[0020] In one possible implementation, determining the energy management strategy of the energy storage system includes: when there is an undervoltage energy storage unit in the energy storage system, charging the undervoltage energy storage unit, the charging priority of the undervoltage energy storage unit is higher than the non-undervoltage energy storage unit in the power grid or the energy storage system, and the SOC of the undervoltage energy storage unit is less than or equal to the undervoltage threshold.

[0021] The control scheme of the energy storage system provided in the embodiment of the present application can preferentially charge the undervoltage energy storage unit when there is an undervoltage energy storage unit in the energy storage system, thereby avoiding excessive discharge of the undervoltage energy storage unit and improving the performance and service life of the energy storage system.

[0022] In a second aspect, a control device is provided, wherein the control device is coupled to an energy storage system, the energy storage system is coupled to an energy generation system and a power grid, the energy storage system includes multiple energy storage units, and the device includes: an acquisition unit for acquiring discharge power information of the energy generation system, charging power information of the power grid and status information of the energy storage system, the status information of the energy storage system including time information of the energy storage unit in a preset DOD interval; a control unit for determining an energy management strategy of the energy storage system based on the discharge power information of the energy generation system, the charging power information of the power grid and the status information of the energy storage system.

[0023] In one possible implementation, the control unit is specifically used to charge the first energy storage unit when the discharge power of the energy generation system is greater than the charging power of the power grid and there is a first energy storage unit in the energy storage system, wherein the first energy storage unit is an energy storage unit whose time in the preset DOD interval is greater than or equal to a preset time.

[0024] In one possible implementation, the control unit is specifically used to charge the second energy storage unit when the discharge power of the energy generation system is greater than the charging power of the power grid and there is a second energy storage unit in the energy storage system, wherein the second energy storage unit is an energy storage unit other than the first energy storage unit and the SOC is less than or equal to a first charging threshold, and the charging priority of the second energy storage unit is lower than that of the first energy storage unit.

[0025] In one possible implementation, the control unit is specifically used to: when the discharge power of the energy generation system is greater than the charging power of the power grid and there is a third energy storage unit in the energy storage system, charge the third energy storage unit, wherein the third energy storage unit is an energy storage unit other than the first energy storage unit and the second energy storage unit and whose SOC is less than or equal to a second charging threshold, the second charging threshold is greater than the first charging threshold, and the charging priority of the third energy storage unit is lower than that of the first energy storage unit or the second energy storage unit.

[0026] In one possible implementation, the control unit is specifically used to: discharge the fourth energy storage unit when the discharge power of the energy generation system is less than the charging power of the power grid and there is a fourth energy storage unit in the energy storage system, wherein the fourth energy storage unit is an energy storage unit whose time in the preset DOD interval is greater than or equal to the preset time.

[0027] In one possible implementation, the control unit is specifically used to: when the discharge power of the energy generation system is less than the charging power of the power grid and there is a fifth energy storage unit in the energy storage system, discharge the fifth energy storage unit, wherein the fifth energy storage unit is an energy storage unit outside the fourth energy storage unit and the SOC is greater than or equal to the first discharge threshold, and the discharge priority of the fifth energy storage unit is lower than that of the fourth energy storage unit.

[0028] In one possible implementation, the control unit is specifically used to: when the discharge power of the energy generation system is less than the charging power of the power grid and there is a sixth energy storage unit in the energy storage system, discharge the sixth energy storage unit, wherein the sixth energy storage unit is an energy storage unit other than the fourth energy storage unit and the fifth energy storage unit and whose SOC is greater than or equal to a second discharge threshold, the second discharge threshold is less than the first discharge threshold, and the discharge priority of the sixth energy storage unit is lower than that of the fourth energy storage unit or the fifth energy storage unit.

[0029] In one possible implementation, the control unit is specifically configured to: when there is an undervoltage energy storage unit in the energy storage system, charge the undervoltage energy storage unit, the charging priority of the undervoltage energy storage unit being higher than the non-undervoltage energy storage unit in the power grid or the energy storage system, and the SOC of the undervoltage energy storage unit being less than or equal to the undervoltage threshold.

[0030] In a third aspect, an energy storage system is provided, which is coupled to an energy generation system and a power grid, and includes multiple energy storage units and a control device as in the above-mentioned second aspect and any possible implementation of the second aspect.

[0031] In a fourth aspect, a control device for an energy storage system is provided, the control device comprising a memory and a processor, the memory being used to store instructions, the processor being used to read the instructions and execute the method in the first aspect and any possible implementation of the first aspect according to the instructions.

[0032] In a fifth aspect, a chip is provided, comprising: a processor for calling and running a computer program from a memory, so that a device equipped with the chip executes the method in the first aspect and any possible implementation of the first aspect.

[0033] In a sixth aspect, a computer program is provided, characterized in that when the computer program is executed by a computer, the computer implements the method in the first aspect and any possible implementation of the first aspect.

[0034] In the seventh aspect, a computer-readable storage medium is provided, which is used to store a computer program. When the computer program is executed by a computer, the computer implements the method as in the first aspect and any possible implementation of the first aspect.

[0035] In an eighth aspect, a computer program product is provided, comprising computer program instructions, which, when executed by a computer, enable the computer to implement the method as in the first aspect and any possible implementation manner of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] FIG1 is a schematic architecture diagram of an application scenario of an energy storage system to which an embodiment of the present application is applicable.

[0037] FIG2 is a schematic architecture diagram of a photovoltaic storage DC coupling system applicable to an embodiment of the present application.

[0038] FIG3 is a schematic flow chart of a control method for an energy storage system according to an embodiment of the present application.

[0039] FIG4 is a schematic flow chart of a control method for an energy storage system according to an embodiment of the present application.

[0040] FIG5 is a schematic flow chart of a control method for an energy storage system according to an embodiment of the present application.

[0041] FIG6 is a schematic block diagram of a control device for an energy storage system according to an embodiment of the present application.

[0042] FIG7 is another schematic block diagram of a control device for an energy storage system according to an embodiment of the present application. DETAILED DESCRIPTION

[0043] The following detailed description of the embodiments of the present application is provided in conjunction with the accompanying drawings and examples. The following detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of the present application, but are not intended to limit the scope of the present application, that is, the present application is not limited to the described embodiments.

[0044] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0045] The directional words appearing in the following description are all directions shown in the figures, and do not limit the specific structure of this application. In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connected" 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 directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0046] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0047] In the embodiment of the present application, A charging B can be understood as A outputting power to B, or it can be understood as A discharging B. That is, A is the output end / discharging end, and B is the input end / charging end.

[0048] Currently, new energy is developing rapidly, with a large number of renewable energy systems such as wind power and photovoltaics connected to the power grid. Renewable energy systems suffer from large power fluctuations, which cause dramatic fluctuations in grid voltage and frequency, affecting grid stability.

[0049] Connecting a renewable energy system to an energy storage system can effectively mitigate fluctuations in output power. When the renewable energy system outputs excessive energy, the renewable energy system can be controlled to charge the energy storage system, preventing energy waste. If the renewable energy system generates insufficient energy, the energy storage system can be controlled to discharge to ensure smooth overall power output. Currently, the most common charging and discharging method for energy storage systems distributes power proportionally based on the SOC level. This requires charging and discharging all batteries in the energy storage system during each charge and discharge, impacting the performance and lifespan of the energy storage system.

[0050] In view of this, the present application proposes a control scheme for an energy storage system, which can determine the energy management strategy of the energy storage system based on the obtained discharge power information of the renewable energy system, the charging power information of the power grid, and the status information of the energy storage system, wherein the status information of the energy storage system includes the time information of the energy storage unit in a preset depth of discharge (DOD) interval. By comprehensively considering the discharge power information of the renewable energy system, the charging power information of the power grid, and the status information of the energy storage system including the time information of the energy storage unit in the preset DOD interval, the energy management strategy of the energy storage system can be reasonably determined, and the charging and discharging energy management of the energy storage system can be more flexible, thereby improving the performance and service life of the energy storage system.

[0051] FIG1 shows an architecture diagram of an application scenario of an energy storage system to which an embodiment of the present application is applicable.

[0052] As shown in FIG1 , the energy storage system 110 may be connected to an energy generation system 120 . Optionally, the energy storage system 110 may also be connected to a power grid 130 .

[0053] The energy generation system 120 can convert solar energy, wind energy, nuclear energy, etc. into electrical energy, and the energy storage system 110 internally stores electrical energy. Both the energy generation system 120 and the energy storage system 110 are connected to the power grid 130 and can output power to the power grid 130. Optionally, the energy generation system 120 can output power to the power grid 130 alone, the energy storage system 110 can output power to the power grid 130 alone, or the energy storage system 110 and the energy generation system 120 can output power to the power grid 130 together.

[0054] In the embodiment of the present application, the energy generation system 120 and the power grid 130 can also output power to the energy storage system 110. Optionally, the energy generation system 120 can output power to the energy storage system 110 alone, the power grid 130 can output power to the energy storage system 110 alone, or the energy generation system 120 and the power grid 130 can output power to the energy storage system 110 together.

[0055] In the embodiment of the present application, the energy storage system 110 may include multiple energy storage units. Optionally, each energy storage unit may include at least one battery. Each energy storage unit is designed with a battery management system (BMS) to monitor battery information such as the battery's SOC, temperature, and current, and to exchange information with an upper-layer energy management system (EMS) or power conversion system (PCS) in real time to implement energy management of the entire energy storage system.

[0056] Optionally, in embodiments of the present application, energy generation system 120 may be a renewable energy system such as a wind power generation system, a solar power generation system, or a tidal power generation system. Alternatively, energy generation system 120 may be a nuclear power generation system, a thermal power generation system, or a hydropower generation system. For example, energy generation system 120 may be a photovoltaic power generation system. For another example, energy generation system 120 may be a power generation system that combines a wind power generation system and a thermal power generation system. This application does not limit the power generation form of energy generation system 120.

[0057] Optionally, in the embodiment of the present application, the power grid 130 may be a distribution network or a regional power grid, which is not limited in the present application.

[0058] Optionally, in this embodiment of the present application, power grid 130 may be replaced by user-side electrical equipment, which may not output power to energy storage system 110. Alternatively, user-side electrical equipment may receive power output by energy storage system 110 and / or energy generation system 120. Alternatively, energy storage system 110 may receive power output by energy generation system 120.

[0059] It should be understood that in the embodiments of the present application, the energy storage system is connected to the energy generation system, the energy storage system is connected to the power grid, and the energy generation system is connected to the power grid, which can also be understood as the energy storage system is coupled to the energy generation system, the energy storage system is coupled to the power grid, and the energy generation system is coupled to the power grid.

[0060] Figure 2 is a schematic flow chart of a photovoltaic-storage DC-coupled system applicable to an embodiment of the present application. The following, in conjunction with Figure 2, illustrates an exemplary application scenario of an energy storage system when the energy generation system is a photovoltaic power generation system. The photovoltaic power generation system 220 in Figure 2 may be the energy generation system 120 in Figure 1 , and the energy storage system 210 in Figure 2 may be the energy storage system 110 in Figure 1 .

[0061] In an optional embodiment of the present application, the energy storage system 210 can be connected to one end of the first DC converter 211, the other end of the first DC converter 211 is connected to one end of the second DC converter 221 and one end of the converter 231, such as a bidirectional inverter, the other end of the second DC converter 221 is connected to the photovoltaic power generation system 220, and the other end of the converter 231 is connected to the power grid 230.

[0062] In an optional embodiment of the present application, the output power of the second DC converter 221 is provided by the photovoltaic power generation system 220, and the second DC converter 221 can control the output power of the photovoltaic power generation system 220. The output power of the first DC converter 211 is provided by the energy storage system 210. The converter 231 can receive the power output by the first DC converter 211 and the second DC converter 221. Optionally, the first DC converter 211 can receive the power output by the second DC converter 221 and the converter 231.

[0063] In an optional embodiment of the present application, the energy storage system 210, the photovoltaic power generation system 220, and the power grid 230 can be connected via a converter module. The power grid 230 can receive the output power of the energy storage system 210 and the photovoltaic power generation system 220 via the converter module. Alternatively, the energy storage system 210 can receive the power output of the photovoltaic power generation system 220 and the power grid 230 via the converter module.

[0064] In an optional embodiment of the present application, the energy storage system 210 may include multiple energy storage units, and the charge and discharge power of each energy storage unit may be the minimum of the charge and discharge power allowed by the energy storage unit and the charge and discharge power allowed by the first DC converter 211. The charging power of the grid side 230 may be the minimum of the charging power allowed by the grid side issued by the EMS and the charging power allowed by the converter 231. The discharge power of the grid side may be the minimum of the discharge power allowed by the grid side issued by the EMS, the discharge power allowed by the converter 231, and the charging power of the energy storage system 210.

[0065] It should be understood that the charging power allowed by the converter 231 can be understood as the power allowed by the converter when outputting power to the grid 230. Similarly, the discharging power allowed by the converter 231 can be understood as the power allowed by the converter 231 when the grid 230 outputs power to the energy storage system 210.

[0066] FIG3 is a schematic flow chart of a control method for an energy storage system provided in an embodiment of the present application.

[0067] The energy storage system may be the energy storage system 110 in Figure 1 or the energy storage system 210 in Figure 2. The control method of the energy storage system provided in the embodiment of the present application is exemplarily introduced below by coupling the energy storage system to a renewable energy system.

[0068] 310 , obtaining discharge power information of the renewable energy system, charging power information of the power grid, and status information of the energy storage system.

[0069] The energy storage system is coupled to the renewable energy system and the grid, which can be understood as the energy storage system being able to connect to both the renewable energy system and the grid. Optionally, through the connection between the energy storage system and the renewable energy system, the renewable energy system can output power to the energy storage system, that is, the renewable energy system can charge the energy storage system. Optionally, through the connection between the energy storage system and the grid, the energy storage system can output power to the grid, or the grid can output power to the energy storage system, that is, the energy storage system can discharge power to the grid, or the grid can charge the energy storage system.

[0070] The energy storage system may include multiple energy storage units. Optionally, the renewable energy system may output power to the energy storage unit, i.e., the renewable energy system may charge the energy storage unit. Optionally, the energy storage unit may output power to the power grid, i.e., the energy storage unit may charge the power grid. Optionally, the power grid may output power to the energy storage unit, i.e., the power grid may charge the energy storage unit.

[0071] Optionally, in an embodiment of the present application, the status information of the energy storage system includes time information of the energy storage unit in a preset DOD interval.

[0072] Optionally, in the embodiment of the present application, the energy storage unit can be charged and discharged in a preset DOD interval, and the preset DOD interval can be set within the range of the fully discharged (full discharge) state and the fully charged (full charge) state of the energy storage unit. The SOC value of the fully discharged state of the energy storage unit is SOC min , the SOC value of the fully charged state is SOC max , the lower limit of the preset DOD range is SOC Dmin , the upper limit of the preset DOD range is SOC Dmax , then, SOC min ≤SOC Dmin <SOC Dmax ≤SOC max .

[0073] 320 , determining an energy management strategy for the energy storage unit based on the discharge power information of the renewable energy system, the charging power information of the power grid, and the status information of the energy storage system.

[0074] The control scheme of the energy storage system provided in the embodiment of the present application can determine the energy management strategy of the energy storage system based on the obtained discharge power information of the renewable energy system, the charging power information of the power grid, and the status information of the energy storage system including the time information of the energy storage unit in the preset DOD interval. The scheme of the present application comprehensively considers the discharge power information of the renewable energy system, the charging power information of the power grid, and the status information of the energy storage system including the time information of the energy storage unit in the preset DOD interval, and can more reasonably determine the energy management strategy of the energy storage system, flexibly perform the energy management of the energy storage system, thereby improving the performance and service life of the energy storage system.

[0075] Optionally, in an embodiment of the present application, when the discharge power of the renewable energy system is greater than or equal to the charging power of the power grid, the renewable energy system is controlled to charge the energy storage system.

[0076] That is, in this embodiment, the renewable energy system may output power to the grid first, and the remaining power of the renewable energy system may be output to the energy storage system.

[0077] FIG4 is a schematic flow chart of a method for controlling an energy storage system according to an embodiment of the present application. The following describes, in conjunction with FIG4 , a method for controlling a renewable energy system to charge an energy storage system.

[0078] 410. If a first energy storage unit exists in the energy storage system, charge the first energy storage unit.

[0079] Optionally, in an embodiment of the present application, the first energy storage unit is an energy storage unit whose time in the preset DOD interval is greater than or equal to a preset time.

[0080] The energy storage unit can be charged and discharged in a preset DOD interval, which can be set within the range of the fully discharged (full discharge) state and the fully charged (full charge) state of the energy storage unit. The SOC value of the fully discharged state of the energy storage unit is SOC min , the SOC value of the fully charged state is SOC max , the lower limit of the preset DOD range is SOC Dmin , the upper limit of the preset DOD range is SOC Dmax , then, SOC min ≤SOC Dmin <SOC Dmax ≤SOC max .

[0081] If an energy storage unit is charged and discharged within the preset DOD range for a long period of time, it can easily lead to an inaccurate SOC of the energy storage unit, which can cause overcharging or over-discharging of the energy storage unit. Therefore, a renewable energy system can be used to charge the first energy storage unit that has been charged and discharged within the preset DOD range for a long period of time. If the renewable energy system has sufficient energy, the first energy storage unit can be charged to a fully charged state.

[0082] The control scheme for the energy storage system provided in the embodiment of the present application gives priority to charging the energy storage units that have been in the preset DOD interval for a longer time when charging the energy storage system. This can avoid the problem of inaccurate SOC caused by the energy storage units being in the DOD interval for a longer time, thereby avoiding overcharging or over-discharging of the energy storage units due to inaccurate SOC, and improving the performance and service life of the energy storage system.

[0083] 420. If a second energy storage unit exists in the energy storage system, charge the second energy storage unit.

[0084] Optionally, in an embodiment of the present application, the second energy storage unit is an energy storage unit other than the first energy storage unit and whose SOC is less than or equal to the first charging threshold, and the charging priority of the second energy storage unit is lower than that of the first energy storage unit.

[0085] In this embodiment, the state information of the energy storage system also includes SOC information of the energy storage unit.

[0086] The second energy storage unit can also be understood as an energy storage unit with a relatively smaller SOC value among the other energy storage units in the energy storage system except the first energy storage unit. The upper limit of the SOC of the second energy storage unit depends on the size of the first charging threshold. Optionally, in this embodiment, the first charging threshold SOC char1 It can be set within the range of the preset DOD interval, that is, SOC Dmin ≤SOC charg1≤SOC Dmax Optionally, in this embodiment, the first charging threshold SOC charg1 It can be set outside the range of the preset DOD interval, that is, SOC charg1 <SOC Dmin or SOC charg1 >SOC Dmax .

[0087] Optionally, in this embodiment, when the energy storage system includes a first energy storage unit and a second energy storage unit, when controlling the renewable energy system to charge the energy storage system, the first energy storage unit is preferentially charged. If there is surplus power when the renewable energy system charges the first energy storage unit, the surplus power is used to charge the second energy storage unit.

[0088] Optionally, in this embodiment, when the first energy storage unit does not exist in the energy storage system and the second energy storage unit exists, when controlling the renewable energy system to charge the energy storage system, the second energy storage unit is charged first.

[0089] The control scheme for the energy storage system provided in the embodiment of the present application also needs to consider the SOC of the energy storage unit. When charging the energy storage units in the energy storage system other than the first energy storage unit that has been in the preset DOD interval for a longer time, the energy storage units with relatively smaller SOCs can be charged first. This can ensure that the energy storage units with smaller SOCs are charged first, avoid over-discharge of the energy storage units with smaller SOCs, and improve the performance and service life of the energy storage system.

[0090] 430. If a third energy storage unit exists in the energy storage system, charge the third energy storage unit.

[0091] Optionally, in an embodiment of the present application, the third energy storage unit is an energy storage unit other than the first energy storage unit and the second energy storage unit and whose SOC is less than or equal to the second charging threshold, the second charging threshold is greater than the first charging threshold, and the charging priority of the third energy storage unit is lower than that of the first energy storage unit or the second energy storage unit.

[0092] If the SOC of the energy storage unit is less than or equal to the second charging threshold, the energy storage unit can be charged. This rechargeable energy storage unit can be called a rechargeable energy storage unit. Otherwise, the energy storage unit cannot be charged. The third energy storage unit can also be understood as an energy storage unit with a higher SOC value among the rechargeable energy storage units in the energy storage system other than the first energy storage unit.

[0093] Optionally, in this embodiment, when the energy storage system includes a first energy storage unit, a second energy storage unit, and a third energy storage system, when controlling the renewable energy system to charge the energy storage system, the first energy storage unit is prioritized for charging, followed by the second energy storage system, and finally the third energy storage system. That is, when charging the first energy storage system, if the renewable energy system has surplus power, the second energy storage system is charged with this surplus power. When charging the first and second energy storage systems using the renewable energy system, if the renewable energy system has surplus power, the third energy storage unit is charged with this surplus power.

[0094] Optionally, in this embodiment, when the energy storage system includes the first and third energy storage units but does not include the second energy storage unit, when controlling the renewable energy system to charge the energy storage system, the first energy storage unit is charged first, and the third energy storage unit is charged secondarily. In other words, when the renewable energy system is used to charge the first energy storage unit first, if the renewable energy system has surplus power, the surplus power is used to charge the third energy storage unit.

[0095] Optionally, in this embodiment, when the energy storage system includes a second energy storage unit and a third energy storage unit, and does not include the first energy storage unit, when controlling the renewable energy system to charge the energy storage system, the second energy storage system is charged first, and the third energy storage system is charged secondarily. That is, when the renewable energy system is used to charge the second energy storage unit first, if the renewable energy system has surplus power, the surplus power is used to charge the third energy storage unit.

[0096] The control scheme for the energy storage system provided in the embodiment of the present application comprehensively considers the time information of the energy storage unit in the preset DOD interval and the SOC information of the energy storage unit, thereby being able to control the renewable energy system to charge the energy storage unit according to a certain priority order, making the charging of the energy storage unit more reasonable, avoiding the problem of overcharging or over-discharging of the energy storage unit due to inaccurate SOC of the energy storage unit, and also reducing the number of charging times of the energy storage unit to a certain extent, thereby improving the performance and service life of the energy storage system.

[0097] Optionally, in an embodiment of the present application, when the discharge power of the renewable energy system is less than the charging power of the grid, the energy storage system is controlled to discharge to the grid.

[0098] That is, in this embodiment, the renewable energy system is preferentially controlled to output power to the grid. When the output power of the renewable energy system cannot meet the grid's demand, the energy storage system can also be controlled to output power to the grid, that is, the energy storage system can be controlled to discharge to the grid.

[0099] Figure 5 is a schematic flow chart of a method for controlling an energy storage system according to an embodiment of the present application. The method for controlling the energy storage system to discharge to the power grid will be schematically described below with reference to Figure 5 .

[0100] 510. If a fourth energy storage unit exists in the energy storage system, discharge the fourth energy storage unit.

[0101] Optionally, in an embodiment of the present application, the fourth energy storage unit is an energy storage unit whose time in the preset DOD interval is greater than or equal to a preset time.

[0102] The energy storage unit can be charged and discharged in a preset DOD interval, which can be set within the range of the fully discharged (full discharge) state and the fully charged (full charge) state of the energy storage unit. The SOC value of the fully discharged state of the energy storage unit is SOC min , the SOC value of the fully charged state is SOC max , the lower limit of the preset DOD range is SOC Dmin , the upper limit of the preset DOD range is SOC Dmax , then SOC min ≤SOC Dmin <SOC Dmax ≤SOC max If the energy storage unit is charged and discharged within the preset DOD range for a long time, it is easy to cause the SOC of the energy storage unit to be inaccurate, which may cause the energy storage unit to be overcharged or over-discharged due to the inaccurate SOC. Therefore, when controlling the energy storage system to discharge to the grid, the fourth energy storage unit can be discharged first.

[0103] Optionally, in this embodiment, the fourth energy storage unit may be discharged to a fully discharged state.

[0104] The control scheme for the energy storage system provided in the embodiments of the present application prioritizes discharging energy storage units that have been in a preset DOD interval for a longer period of time when controlling the energy storage system to discharge to the grid. This can avoid the problem of inaccurate SOC caused by the energy storage units being in the DOD interval for a longer period of time, thereby avoiding overcharging or over-discharging of the energy storage units due to inaccurate SOC, thereby improving the performance and service life of the energy storage system.

[0105] S520: If there is a fifth energy storage unit in the energy storage system, discharge the fifth energy storage unit.

[0106] Optionally, in an embodiment of the present application, the fifth energy storage unit is an energy storage unit other than the fourth energy storage unit and has an SOC greater than or equal to the first discharge threshold, and the charging priority of the fifth energy storage unit is lower than that of the fourth energy storage unit.

[0107] The fifth energy storage unit can be understood as an energy storage unit with a relatively larger SOC value in the energy storage system except for the fourth energy storage unit. The lower limit of the SOC of the fifth energy storage unit depends on the size of the first discharge threshold. Optionally, the first discharge threshold SOC Discharg1 Can be set within the preset DOD range, i.e. SOC Dmin ≤SOC Discharg1 ≤SOC Dmax Optionally, the first discharge threshold can be set outside the range of the preset DOD interval, that is, SOC Discharg1 <SOC Dmin or SOC Discharg1 >SOC Dmax .

[0108] Optionally, in this embodiment, if the energy storage system includes a fourth energy storage unit and a fifth energy storage unit, when discharging the energy storage system, the fourth energy storage unit is preferentially controlled to discharge to the grid, followed by the fifth energy storage unit. In other words, when controlling the fourth energy storage unit to discharge to the grid, if the discharge power of the renewable energy system and the fourth energy storage unit still cannot meet the charging power requirement of the grid, the fifth energy storage unit may also be controlled to discharge to the grid.

[0109] Optionally, in this embodiment, when there is no fourth energy storage unit in the energy storage system and there is a fifth energy storage unit, when controlling the energy storage system to discharge to the grid, priority is given to controlling the fifth energy storage unit to discharge to the grid.

[0110] The control scheme for the energy storage system provided in the embodiment of the present application also needs to consider the SOC of the energy storage unit. When discharging the energy storage units in the energy storage system other than the energy storage units that have been in the preset DOD interval for a long time, the energy storage units with relatively large SOCs can be discharged first. This can ensure that the energy storage units with larger SOCs are discharged first, avoid overcharging of the energy storage units with large SOCs, and improve the performance and practical life of the energy storage system.

[0111] 530. If a sixth energy storage unit exists in the energy storage system, charge the sixth energy storage unit.

[0112] Optionally, in an embodiment of the present application, the sixth energy storage unit is an energy storage unit other than the fourth energy storage unit and the fifth energy storage unit and whose SOC is greater than or equal to the second discharge threshold, the second discharge threshold is less than the first charging threshold, and the charging priority of the sixth energy storage unit is lower than that of the fourth energy storage unit or the fifth energy storage unit.

[0113] If the SOC of an energy storage unit is greater than or equal to the second discharge threshold, the energy storage unit can be discharged. This energy storage unit that can be discharged can be called a dischargeable energy storage unit. Otherwise, the energy storage unit cannot be discharged. The sixth energy storage unit can be understood as an energy storage unit with a lower SOC value among the dischargeable energy storage units in the energy storage system, excluding the fourth energy storage unit.

[0114] Optionally, in this embodiment, when a fourth energy storage unit, a fifth energy storage unit, and a sixth energy storage system are present in the energy storage system, when controlling the energy storage system to discharge to the grid, priority is given to controlling the fourth energy storage unit to discharge, followed by controlling the fifth energy storage unit to discharge, and finally controlling the sixth energy storage unit to discharge. That is, when controlling the fourth energy storage unit to discharge to the grid, if the discharge power of the renewable energy system and the fourth energy storage unit cannot meet the charging power requirement of the grid, the fifth energy storage unit may also be controlled to discharge to the grid. When controlling the fourth and fifth energy storage units to discharge to the grid, if the discharge power of the renewable energy system, the fourth and fifth energy storage units still cannot meet the charging power requirement of the grid, the sixth energy storage unit may also be controlled to discharge to the grid.

[0115] Optionally, in this embodiment, if the energy storage system includes a fourth energy storage unit and a sixth energy storage unit, and does not include a fifth energy storage unit, when controlling the energy storage system to discharge to the grid, priority is given to controlling the fourth energy storage unit to discharge to the grid, and the sixth energy storage unit may be controlled to discharge to the grid as a secondary control. In other words, when controlling the fourth energy storage unit to discharge to the grid, if the discharge power of the renewable energy system and the fourth energy storage unit still cannot meet the charging power requirement of the grid, the sixth energy storage unit may also be controlled to discharge to the grid.

[0116] Optionally, in this embodiment, if the energy storage system includes a fifth energy storage unit and a sixth energy storage unit, and does not include a fourth energy storage unit, when controlling the energy storage system to discharge to the grid, priority is given to controlling the fifth energy storage unit to discharge to the grid, followed by controlling the sixth energy storage unit to discharge to the grid. In other words, when controlling the fifth energy storage unit to discharge to the grid, if the discharge power of the renewable energy system and the fifth energy storage unit still cannot meet the charging power requirement of the grid, the sixth energy storage unit may also be controlled to discharge to the grid.

[0117] When controlling the renewable energy system to charge the energy storage system, the embodiment of the present application comprehensively considers the time information of the energy storage unit in the preset DOD interval and the SOC information of the energy storage unit, thereby being able to control the energy storage units in the energy storage system to discharge to the power grid according to a certain priority, making the discharge of the energy storage system more reasonable, avoiding the problem of over-discharge of the energy storage unit due to inaccurate SOC of the energy storage unit, and at the same time reducing the number of discharges of the energy storage unit to a certain extent, which can improve the performance and service life of the energy storage system.

[0118] Optionally, in an embodiment of the present application, when there is an undervoltage energy storage unit in the energy storage system, the undervoltage energy storage unit is charged, and the charging priority of the undervoltage energy storage unit is higher than that of the non-undervoltage energy storage unit in the power grid or the energy storage system, and the SOC of the undervoltage energy storage unit is less than or equal to the undervoltage threshold.

[0119] Because the SOC of the undervoltage energy storage unit is lower than the undervoltage threshold, the voltage of the energy storage unit is lower than the rated voltage. If the undervoltage energy storage unit continues to discharge, it will cause over-discharge of the energy storage unit, thereby affecting the performance and service life of the energy storage system.

[0120] Therefore, if an undervoltage energy storage unit exists in the energy storage system, the undervoltage energy storage unit is prioritized for charging. The undervoltage energy storage unit can be charged using a renewable energy system, a dischargeable energy storage unit in the energy storage system, or the power grid. The SOC of the dischargeable energy storage unit in the energy storage system is greater than or equal to a predetermined threshold. For example, the SOC of the dischargeable energy storage unit is greater than or equal to the second discharge threshold.

[0121] Optionally, in an embodiment of the present application, the SOC of the undervoltage energy storage unit is less than or equal to a first undervoltage threshold. When the SOC of a certain energy storage unit in the energy storage system is less than or equal to the first undervoltage threshold, the energy storage unit is considered an undervoltage energy storage unit and is charged preferentially. The undervoltage energy storage unit can be charged using a renewable energy system, a dischargeable energy storage unit, or the power grid.

[0122] Optionally, in an embodiment of the present application, the undervoltage energy storage unit is an energy storage unit that provides a voltage that is less than or equal to a rated voltage.

[0123] Optionally, in an embodiment of the present application, when the undervoltage energy storage unit is charged using a renewable energy system or a dischargeable energy storage unit, the SOC of the undervoltage energy storage unit is less than or equal to a first undervoltage threshold; or, when the undervoltage energy storage unit is charged using a power grid, the SOC of the undervoltage energy storage unit is less than or equal to a second undervoltage threshold, and the second undervoltage threshold is less than the first undervoltage threshold.

[0124] If the SOC of an energy storage unit is less than or equal to the first undervoltage threshold and greater than the second undervoltage threshold, the energy storage unit can be charged using the renewable energy system or a dischargeable energy storage unit, but cannot be charged using the grid. If the SOC of an energy storage unit is less than or equal to the second undervoltage threshold, the energy storage unit can be charged using the renewable energy system, a dischargeable energy storage unit, or the grid.

[0125] That is, in this embodiment, only undervoltage energy storage units with lower SOCs can be charged from the grid. While charging undervoltage energy storage units, economic factors are taken into consideration, ensuring the performance and service life of the energy storage system while minimizing the cost of charging the undervoltage energy storage units.

[0126] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0127] The above describes in detail the control method of the energy storage system in the embodiment of the present application. The control device in the embodiment of the present application will be described in detail below in combination with Figures 6 and 7. The technical features described in the method embodiment are applicable to the following device embodiments.

[0128] Figure 6 shows a schematic block diagram of a control device 600 according to an embodiment of the present application. The control device is coupled to an energy storage system, which is coupled to an energy generation system and a power grid. The energy storage system includes multiple energy storage units. As shown in Figure 6, the control device includes some or all of the following:

[0129] an acquisition unit 610 configured to acquire discharge power information of the energy generation system, charging power information of the power grid, and status information of the energy storage system, wherein the status information of the energy storage system includes time information of the energy storage unit in a preset DOD interval;

[0130] The control unit 620 is configured to determine an energy management strategy for the energy storage system based on the discharge power information of the energy generation system, the charging power information of the power grid, and the status information of the energy storage system.

[0131] Optionally, in an embodiment of the present application, the control unit is specifically used to: charge the first energy storage unit when the discharge power of the energy generation system is greater than the charging power of the power grid and there is a first energy storage unit in the energy storage system, wherein the first energy storage unit is an energy storage unit whose time in the preset DOD interval is greater than or equal to a preset time.

[0132] Optionally, in an embodiment of the present application, the control unit is specifically used to: charge the second energy storage unit when the discharge power of the energy generation system is greater than the charging power of the power grid and there is a second energy storage unit in the energy storage system, wherein the second energy storage unit is an energy storage unit other than the first energy storage unit and the SOC is less than or equal to a first charging threshold, and the charging priority of the second energy storage unit is lower than that of the first energy storage unit.

[0133] Optionally, in an embodiment of the present application, the control unit is specifically used to: charge the third energy storage unit when the discharge power of the energy generation system is greater than the charging power of the power grid and there is a third energy storage unit in the energy storage system, wherein the third energy storage unit is an energy storage unit other than the first energy storage unit and the second energy storage unit and whose SOC is less than or equal to a second charging threshold, the second charging threshold is greater than the first charging threshold, and the charging priority of the third energy storage unit is lower than that of the first energy storage unit or the second energy storage unit.

[0134] Optionally, in an embodiment of the present application, the control unit is specifically used to: discharge the fourth energy storage unit when the discharge power of the energy generation system is less than the charging power of the power grid and there is a fourth energy storage unit in the energy storage system, wherein the fourth energy storage unit is an energy storage unit whose time in the preset DOD interval is greater than or equal to a preset time.

[0135] Optionally, in an embodiment of the present application, the control unit is specifically used to: when the discharge power of the energy generation system is less than the charging power of the power grid and there is a fifth energy storage unit in the energy storage system, discharge the fifth energy storage unit, wherein the fifth energy storage unit is an energy storage unit outside the fourth energy storage unit and the SOC is greater than or equal to the first discharge threshold, and the discharge priority of the fifth energy storage unit is lower than that of the fourth energy storage unit.

[0136] Optionally, in an embodiment of the present application, the control unit is specifically used to: discharge the sixth energy storage unit when the discharge power of the energy generation system is less than the charging power of the power grid and there is a sixth energy storage unit in the energy storage system, wherein the sixth energy storage unit is an energy storage unit other than the fourth energy storage unit and the fifth energy storage unit and whose SOC is greater than or equal to a second discharge threshold, the second discharge threshold is less than the first discharge threshold, and the discharge priority of the sixth energy storage unit is lower than that of the fourth energy storage unit or the fifth energy storage unit.

[0137] Optionally, in an embodiment of the present application, the control unit is specifically used to: when there is an undervoltage energy storage unit in the energy storage system, charge the undervoltage energy storage unit, the charging priority of the undervoltage energy storage unit is higher than the non-undervoltage energy storage unit in the power grid or the energy storage system, and the SOC of the undervoltage energy storage unit is less than or equal to the undervoltage threshold.

[0138] It should be understood that the above and other operations and / or functions of each module in the control device 600 of the energy storage system are for implementing the corresponding processes in each method of Figures 3 to 5, and for the sake of brevity, they are not repeated here.

[0139] Optionally, an embodiment of the present application also provides an energy storage system, which is coupled to an energy generation system and a power grid. The energy storage system includes multiple energy storage units and a control device 600 provided in the various embodiments above, which is used to determine the energy management strategy of the energy storage system.

[0140] Figure 7 shows a schematic block diagram of a control device 1000 for an energy storage system according to an embodiment of the present application. As shown in Figure 7, the control device 1000 includes a processor 1010 and a memory 1020, wherein the memory 1020 is used to store instructions, and the processor 1010 is used to read the instructions and execute the methods of the various embodiments of the present application described above based on the instructions.

[0141] The memory 1020 may be a separate device independent of the processor 1010 , or may be integrated into the processor 1010 .

[0142] Optionally, as shown in FIG7 , the control device 1000 of the energy storage system may further include a transceiver 1030 , and the processor 1010 may control the transceiver 1030 to communicate with other devices, specifically, to send information or data to other devices, or to receive information or data sent by other devices.

[0143] It should be understood that the processor of the embodiments of the present application may be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above method embodiment can be completed by hardware integrated logic circuits in the processor or software instructions. The above processor can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. The various methods, steps, and logic block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in the embodiments of the present application can be directly embodied as being executed by a hardware decoding processor, or can be executed by a combination of hardware and software modules in the decoding processor. The software module can be located in a storage medium mature in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, etc. The storage medium is located in the memory, and the processor reads the information in the memory and completes the steps of the above method in combination with its hardware.

[0144] It is understood that the memory in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct RAM bus random access memory (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0145] An embodiment of the present application also provides a computer-readable storage medium for storing a computer program.

[0146] Optionally, the computer-readable storage medium can be applied to the control device of the energy storage system in the embodiment of the present application, and when the computer program runs on the computer, it enables the computer to execute the corresponding processes implemented by the control device in the various methods of the embodiment of the present application. For the sake of brevity, it will not be repeated here.

[0147] An embodiment of the present application also provides a computer program product, including computer program instructions.

[0148] Optionally, the computer program product can be applied to the control device of the energy storage system in the embodiment of the present application, and when the computer program instructions are run on a computer, the computer executes the corresponding processes implemented by the control device of the energy storage system in the various methods of the embodiment of the present application. For the sake of brevity, they are not repeated here.

[0149] The embodiment of the present application also provides a computer program.

[0150] Optionally, the computer program can be applied to the control device of the energy storage system in the embodiment of the present application. When the computer program runs on a computer, the computer executes the corresponding processes implemented by the control device of the energy storage system in the various methods of the embodiment of the present application. For the sake of brevity, they are not repeated here.

[0151] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0152] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0153] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0154] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0155] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0156] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a ROM, a RAM, a magnetic disk, or an optical disk.

[0157] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A control method for an energy storage system, characterized in that: The energy storage system is coupled to an energy generation system and a power grid, the energy storage system includes a plurality of energy storage units, and the method includes: Obtaining discharge power information of the energy generation system, charging power information of the power grid, and status information of the energy storage system, wherein the status information of the energy storage system includes time information of the energy storage unit in a preset DOD interval; An energy management strategy of the energy storage system is determined according to the discharge power information of the energy generation system, the charging power information of the power grid, and the status information of the energy storage system.

2. The method according to claim 1, characterized in that Determining the energy management strategy of the energy storage system includes: When the discharge power of the energy generation system is greater than the charging power of the power grid and there is a first energy storage unit in the energy storage system, the first energy storage unit is charged, wherein the first energy storage unit is an energy storage unit whose time in the preset DOD interval is greater than or equal to the preset time.

3. The method according to claim 2, characterized in that Determining the energy management strategy of the energy storage system includes: When the discharge power of the energy generation system is greater than the charging power of the power grid and a second energy storage unit exists in the energy storage system, the second energy storage unit is charged, wherein the second energy storage unit is an energy storage unit other than the first energy storage unit and has a state of charge (SOC) less than or equal to a first charging threshold, and the charging priority of the second energy storage unit is lower than that of the first energy storage unit.

4. The method according to claim 3, characterized in that Determining the energy management strategy of the energy storage system includes: When the discharge power of the energy generation system is greater than the charging power of the power grid and there is a third energy storage unit in the energy storage system, the third energy storage unit is charged, wherein the third energy storage unit is an energy storage unit other than the first energy storage unit and the second energy storage unit and whose SOC is less than or equal to a second charging threshold, the second charging threshold is greater than the first charging threshold, and the charging priority of the third energy storage unit is lower than that of the first energy storage unit or the second energy storage unit.

5. The method according to any one of claims 1 to 4, characterized in that Determining the energy management strategy of the energy storage system includes: When the discharge power of the energy generation system is less than the charging power of the power grid and there is a fourth energy storage unit in the energy storage system, the fourth energy storage unit is discharged, wherein the fourth energy storage unit is an energy storage unit whose time in the preset DOD interval is greater than or equal to the preset time.

6. The method according to claim 5, characterized in that Determining the energy management strategy of the energy storage system includes: When the discharge power of the energy generation system is less than the charging power of the power grid and there is a fifth energy storage unit in the energy storage system, the fifth energy storage unit is discharged, wherein the fifth energy storage unit is an energy storage unit other than the fourth energy storage unit and the SOC of which is greater than or equal to the first discharge threshold, and the discharge priority of the fifth energy storage unit is lower than that of the fourth energy storage unit.

7. The method according to claim 6, characterized in that Determining the energy management strategy of the energy storage system includes: When the discharge power of the energy generation system is less than the charging power of the power grid and there is a sixth energy storage unit in the energy storage system, the sixth energy storage unit is discharged, wherein the sixth energy storage unit is an energy storage unit other than the fourth energy storage unit and the fifth energy storage unit and whose SOC is greater than or equal to a second discharge threshold, the second discharge threshold is less than the first discharge threshold, and the discharge priority of the sixth energy storage unit is lower than that of the fourth energy storage unit or the fifth energy storage unit.

8. The method according to any one of claims 1 to 7, characterized in that Determining the energy management strategy of the energy storage system includes: In the event that there is an undervoltage energy storage unit in the energy storage system, the undervoltage energy storage unit is charged, the charging priority of the undervoltage energy storage unit is higher than the non-undervoltage energy storage unit in the power grid or the energy storage system, and the SOC of the undervoltage energy storage unit is less than or equal to the undervoltage threshold.

9. A control device, characterized in that: The control device is coupled to an energy storage system, the energy storage system is coupled to an energy generation system and a power grid, the energy storage system includes a plurality of energy storage units, and the device includes: an acquisition unit, configured to acquire discharge power information of the energy generation system, charging power information of the power grid, and status information of the energy storage system, wherein the status information of the energy storage system includes time information of the energy storage unit in a preset DOD interval; A control unit is used to determine an energy management strategy for the energy storage system based on the discharge power information of the energy generation system, the charging power information of the power grid, and the status information of the energy storage system.

10. The device according to claim 9, characterized in that The control unit is specifically used for: When the discharge power of the energy generation system is greater than the charging power of the power grid and there is a first energy storage unit in the energy storage system, the first energy storage unit is charged, wherein the first energy storage unit is an energy storage unit whose time in the preset DOD interval is greater than or equal to the preset time.

11. The device according to claim 10, characterized in that The control unit is specifically used for: When the discharge power of the energy generation system is greater than the charging power of the power grid and a second energy storage unit exists in the energy storage system, the second energy storage unit is charged, wherein the second energy storage unit is an energy storage unit other than the first energy storage unit and the SOC of the second energy storage unit is less than or equal to a first charging threshold, and the charging priority of the second energy storage unit is lower than that of the first energy storage unit.

12. The device according to claim 11, characterized in that The control unit is specifically used for: When the discharge power of the energy generation system is greater than the charging power of the power grid and there is a third energy storage unit in the energy storage system, the third energy storage unit is charged, wherein the third energy storage unit is an energy storage unit other than the first energy storage unit and the second energy storage unit and whose SOC is less than or equal to a second charging threshold, the second charging threshold is greater than the first charging threshold, and the charging priority of the third energy storage unit is lower than that of the first energy storage unit or the second energy storage unit.

13. The device according to any one of claims 9 to 12, characterized in that The control unit is specifically used for: When the discharge power of the energy generation system is less than the charging power of the power grid and there is a fourth energy storage unit in the energy storage system, the fourth energy storage unit is discharged, wherein the fourth energy storage unit is an energy storage unit whose time in the preset DOD interval is greater than or equal to the preset time.

14. The device according to claim 13, characterized in that The control unit is specifically used for: When the discharge power of the energy generation system is less than the charging power of the power grid and there is a fifth energy storage unit in the energy storage system, the fifth energy storage unit is discharged, wherein the fifth energy storage unit is an energy storage unit other than the fourth energy storage unit and the SOC of which is greater than or equal to the first discharge threshold, and the discharge priority of the fifth energy storage unit is lower than that of the fourth energy storage unit.

15. The device according to claim 14, characterized in that The control unit is specifically used for: When the discharge power of the energy generation system is less than the charging power of the power grid and there is a sixth energy storage unit in the energy storage system, the sixth energy storage unit is discharged, wherein the sixth energy storage unit is an energy storage unit other than the fourth energy storage unit and the fifth energy storage unit and whose SOC is greater than or equal to a second discharge threshold, the second discharge threshold is less than the first discharge threshold, and the discharge priority of the sixth energy storage unit is lower than that of the fourth energy storage unit or the fifth energy storage unit.

16. The device according to any one of claims 9 to 15, characterized in that The control unit is specifically used for: In the event that there is an undervoltage energy storage unit in the energy storage system, the undervoltage energy storage unit is charged, the charging priority of the undervoltage energy storage unit is higher than the non-undervoltage energy storage unit in the power grid or the energy storage system, and the SOC of the undervoltage energy storage unit is less than or equal to the undervoltage threshold.

17. An energy storage system, characterized in that: The energy storage system is coupled to an energy generation system and a power grid, and includes a plurality of energy storage units and a control device according to any one of claims 9 to 16.

18. A control device for an energy storage system, characterized in that: The control device includes a memory and a processor, wherein the memory is used to store instructions, and the processor is used to read the instructions and execute the method according to any one of claims 1 to 8 according to the instructions.

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