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

Abstract

The invention provides a control method and a control device of an energy storage system and the energy storage system. The energy storage system is coupled to the energy generation system, the energy storage system comprises a plurality of energy storage units, and the control method of the energy storage system comprises the following steps: in a first stage, the energy generation system is controlled to charge a first energy storage unit of the plurality of energy storage units, and the first stage is a charging stage of a charging period of the first energy storage unit; and in a second stage, the first energy storage unit is controlled to discharge to a second energy storage unit of the plurality of energy storage units, and the second stage is a discharge stage of the charging cycle of the first energy storage unit. According to the technical scheme, the performance and the service life of the energy storage system can be improved.

Description

Energy storage system control method, control device and energy storage system Technical Field

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

[0002] With the rapid development of the new energy industry, a large number of energy generation systems, such as wind power and photovoltaic power, have been connected to the power grid. To avoid wasting excessive energy output from these energy generation systems, energy storage systems are often installed to store excess energy.

[0003] However, during the use of energy storage systems, the energy generation system continuously charges the energy storage system. After long-term charge and discharge cycles, the batteries in the energy storage system will produce lithium deposition and heat generation, which affects the performance and service life of the batteries. Therefore, how to provide a control method for energy storage systems to improve their performance and service life is a technical problem that needs to be solved urgently.

[0004] Summary of the Invention

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

[0006] In a first aspect, the present application provides a method for controlling an energy storage system, wherein the energy storage system includes multiple energy storage units, the energy storage system is coupled to an energy generation system and a power grid, and the energy storage system is used to store electrical energy obtained from the energy generation system and release electrical energy to the power grid. The method includes: in a first stage, controlling the energy generation system to charge a first energy storage unit of the multiple energy storage units, the first stage being the charging stage of the charging cycle of the first energy storage unit; and in a second stage, controlling the first energy storage unit to discharge to a second energy storage unit of the multiple energy storage units, the second stage being the discharging stage of the charging cycle of the first energy storage unit.

[0007] In the embodiment of the present application, during the first phase of the first energy storage unit's charging cycle, the energy generation system is controlled to charge the first energy storage unit, which can fully utilize the electrical energy output by the energy generation system and avoid energy waste. During the second phase of the first energy storage unit's charging cycle, the first energy storage unit is controlled to discharge to the second energy storage unit, which can reduce the occurrence of lithium deposition and heat generation in the batteries of the energy storage system, thereby improving the performance and service life of the batteries. Therefore, the solution of the present application can improve the performance and service life of the energy storage system.

[0008] In one possible implementation, controlling the energy generation system to charge a first energy storage unit among the multiple energy storage units in the first stage includes controlling the energy generation system to charge the first energy storage unit among the multiple energy storage units based on at least one of the dispatching state of the power grid, the output power of the energy generation system, the charging power of the first energy storage unit, the remaining capacity of the first energy storage unit, and the remaining capacity of the second energy storage unit. This facilitates determining a strategy for the energy generation system to charge the first energy storage unit based on different usage scenarios.

[0009] In one possible implementation, controlling the energy generation system to charge the first energy storage unit of the multiple energy storage units based on at least one of the dispatching state of the power grid, the output power of the energy generation system, the charging power of the first energy storage unit, the remaining capacity of the first energy storage unit, and the remaining capacity of the second energy storage unit includes: controlling the energy generation system to charge the first energy storage unit when the remaining capacity of the first energy storage unit is less than a maximum preset capacity. In this way, the remaining capacity of the first energy storage unit can be maintained within an appropriate range, avoiding overcharging caused by charging the first energy storage unit when the remaining capacity of the first energy storage unit is high.

[0010] In one possible implementation, controlling the energy generation system to charge the first energy storage unit of the multiple energy storage units based on at least one of the dispatching state of the power grid, the output power of the energy generation system, the charging power of the first energy storage unit, the remaining capacity of the first energy storage unit, and the remaining capacity of the second energy storage unit includes: when the dispatching state of the power grid includes the absence of energy dispatching demand, controlling the energy generation system to charge the first energy storage unit based on the output power of the energy generation system, the charging power of the first energy storage unit, and the remaining capacity of the second energy storage unit. In this way, when there is no dispatching demand from the power grid, a strategy for charging the first energy storage unit can be determined based on the corresponding information.

[0011] In one possible implementation, controlling the energy generation system to charge a first energy storage unit of the multiple energy storage units includes: when the output power of the energy generation system is less than the charging power of the first energy storage unit, controlling the energy generation system to charge the first energy storage unit, and controlling at least one of the second energy storage unit and the power grid to charge the first energy storage unit, wherein the remaining capacity of the second energy storage unit is greater than or equal to a minimum preset capacity. In this way, the second energy storage unit and / or the power grid can charge the first energy storage unit simultaneously with the energy generation system in the first phase to meet the first energy storage unit's demand for charging power, thereby facilitating the extension of the service life of the first energy storage unit.

[0012] In one possible implementation, controlling the energy generation system to charge the first energy storage unit of the multiple energy storage units includes: controlling the output power of the energy generation system to be the same as the charging power of the first energy storage unit when the output power of the energy generation system is greater than or equal to the charging power of the first energy storage unit; after controlling the output power of the energy generation system to be the same as the charging power of the first energy storage unit, controlling the energy generation system to charge the first energy storage unit.

[0013] In this implementation, when the output power of the energy generation system is greater than or equal to the charging power of the first energy storage unit, the output power of the energy generation system is controlled to be equal to the charging power of the first energy storage unit. After the output power of the energy generation system is controlled to be equal to the charging power of the first energy storage unit, only the energy generation system is controlled to charge the first energy storage unit. This implementation can meet the charging power requirement of the first energy storage unit, which is conducive to extending the service life of the first energy storage unit. It is also simple and easy to implement.

[0014] In one possible implementation, controlling the energy generation system to charge a first energy storage unit of the multiple energy storage units includes controlling the energy generation system and / or the power grid to charge the second energy storage unit if the remaining capacity of the second energy storage unit is less than a minimum preset capacity. This facilitates flexible selection of a charging strategy for the second energy storage unit based on actual conditions. Furthermore, after the second energy storage unit is charged to a certain level, the second energy storage unit can be used to charge the first energy storage unit in subsequent processes.

[0015] In one possible implementation, controlling the energy generation system and / or the power grid to charge the second energy storage unit includes: when the output power of the energy generation system is less than the charging power of the first energy storage unit, controlling the energy generation system and the power grid to charge the first energy storage unit, and controlling the power grid to charge the second energy storage unit. In this way, while charging the first energy storage unit, the second energy storage unit is also charged, facilitating the use of the second energy storage unit to charge the first energy storage unit after the second energy storage unit is charged to an appropriate level.

[0016] In one possible implementation, controlling the energy generation system and / or the power grid to charge the second energy storage unit includes: when the output power of the energy generation system is equal to the charging power of the first energy storage unit, controlling the energy generation system to charge the first energy storage unit and controlling the power grid to charge the second energy storage unit; when the output power of the energy generation system is greater than the charging power of the first energy storage unit, controlling the energy generation system to charge the first energy storage unit and controlling the energy generation system and / or the power grid to charge the second energy storage unit. This facilitates selecting an appropriate control method based on actual conditions to achieve charging of the first energy storage unit and replenishment of the power of the second energy storage unit.

[0017] In one possible implementation, when the output power of the energy generation system is greater than the charging power of the first energy storage unit, controlling the energy generation system to charge the first energy storage unit and controlling the energy generation system and / or the power grid to charge the second energy storage unit includes: when the difference between the output power of the energy generation system and the charging power of the first energy storage unit is less than the maximum charging power of the second energy storage unit, controlling the energy generation system and the power grid to charge the second energy storage unit. This facilitates rapid charging of the second energy storage unit.

[0018] In one possible implementation, the energy generation system is controlled to charge the first energy storage unit of the multiple energy storage units based on at least one of the dispatching state of the power grid, the output power of the energy generation system, the charging power of the first energy storage unit, the remaining capacity of the first energy storage unit, and the remaining capacity of the second energy storage unit, including: when the dispatching state of the power grid includes the existence of energy dispatching demand and the output power of the energy generation system is greater than the required power of the power grid, the energy generation system is controlled to charge the first energy storage unit based on the output power of the energy generation system, the charging power of the first energy storage unit, and the remaining capacity of the second energy storage unit.

[0019] In this implementation, when the grid has a dispatching demand and the energy generation system's output power exceeds the grid's required power, the energy generation system is controlled to charge the first energy storage unit. This allows the first energy storage unit to be charged while meeting the grid's demand, preventing the charging of the first energy storage unit from affecting the grid's stability.

[0020] In one possible implementation, controlling the energy generation system to charge a first energy storage unit of the multiple energy storage units includes: when the remaining capacity of the second energy storage unit is greater than or equal to a minimum preset capacity, controlling the energy generation system to charge the first energy storage unit, or controlling the energy generation system and the second energy storage unit to charge the first energy storage unit. In this way, the second energy storage unit and / or the energy generation system can simultaneously charge the first energy storage unit in the first phase to meet the first energy storage unit's demand for charging power, thereby facilitating extending the service life of the first energy storage unit.

[0021] In one possible implementation, controlling the energy generation system to charge a first energy storage unit of the multiple energy storage units includes: controlling the energy generation system to charge the second energy storage unit if the remaining capacity of the second energy storage unit is less than a minimum preset capacity; and after controlling the energy generation system to charge the second energy storage unit, controlling the energy generation system and / or the second energy storage unit to charge the first energy storage unit. In this way, the remaining capacity of the second energy storage unit can be made greater than the minimum preset capacity, so that when charging the first energy storage unit, the charging power requirement of the first energy storage unit is met.

[0022] In one possible implementation, controlling the first energy storage unit to discharge into the second energy storage unit of the plurality of energy storage units in the second stage includes controlling the first energy storage unit to discharge into the second energy storage unit of the plurality of energy storage units in the second stage based on at least one of a dispatching state of the power grid and a remaining capacity of the second energy storage unit. This facilitates flexible configuration of different discharge strategies for the first energy storage unit during a charging cycle based on actual conditions.

[0023] In one possible implementation, controlling the first energy storage unit to discharge into the second energy storage unit of the plurality of energy storage units based on at least one of the dispatching state of the power grid and the remaining capacity of the second energy storage unit includes controlling the first energy storage unit to discharge into the second energy storage unit if the remaining capacity of the second energy storage unit is less than a maximum preset capacity. This can avoid overcharging of the second energy storage unit due to excessive power being received.

[0024] In one possible implementation, controlling the first energy storage unit to discharge into the second energy storage unit of the plurality of energy storage units based on at least one of a grid dispatch state and a remaining capacity of the second energy storage unit includes: if the grid dispatch state includes an energy dispatch demand, controlling the output power of the energy generation system to zero and controlling the first energy storage unit to discharge into the second energy storage unit. This prevents the first energy storage unit from discharging into the grid and affecting grid stability.

[0025] In one possible implementation, controlling the first energy storage unit to discharge energy to the second energy storage unit of the multiple energy storage units based on at least one of the grid's dispatch status and the remaining capacity of the second energy storage unit includes: if the grid's dispatch status includes an energy dispatch demand, controlling the energy generation system's output power to be equal to the grid's required power, and controlling the first energy storage unit to discharge energy to the second energy storage unit. This implementation is simple and easy, and can simultaneously meet both the grid's demand and the need for the first energy storage unit to discharge energy to the second energy storage unit.

[0026] In one possible implementation, the method further includes: controlling the first energy storage unit to switch from the first stage to the second stage when the charge capacity of the first energy storage unit reaches a first preset capacity; and controlling the first energy storage unit to switch from the second stage to the first stage when the discharge capacity of the first energy storage unit reaches a second preset capacity. In this way, the first energy storage unit is charged by continuously switching between the first stage and the second stage during the charging cycle of the first energy storage unit.

[0027] In one possible implementation, the method further includes controlling the energy generation system to stop charging the first energy storage unit when the remaining capacity of the first energy storage unit reaches a maximum preset capacity. In this way, the remaining capacity of the first energy storage unit does not exceed the maximum preset capacity, and after the energy generation system finishes charging the first energy storage unit, the first energy storage unit can serve as an energy absorption device to receive power discharged by other energy storage units in the plurality of energy storage units.

[0028] In a second aspect, the present application provides a control device, which is coupled to an energy storage system, which is coupled to an energy generation system and a power grid, and the energy storage system is used to store electrical energy obtained from the energy generation system and release electrical energy to the power grid. The energy storage system includes multiple energy storage units, and the control device includes a control unit, which is used to: in a first stage, control the energy generation system to charge a first energy storage unit of the multiple energy storage units, and the first stage is the charging stage of the charging cycle of the first energy storage unit; in a second stage, control the first energy storage unit to discharge to a second energy storage unit of the multiple energy storage units, and the second stage is the discharging stage of the charging cycle of the first energy storage unit.

[0029] In one possible implementation, the control unit is further used to: in the first stage, control the energy generation system to charge the first energy storage unit of the multiple energy storage units based on at least one of the dispatching status of the power grid, the output power of the energy generation system, the charging power of the first energy storage unit, the remaining capacity of the first energy storage unit, and the remaining capacity of the second energy storage unit.

[0030] In a third aspect, the present application provides an energy storage system, which is coupled to an energy generation system and a power grid, and is used to store electrical energy obtained from the energy generation system and release electrical energy to the power grid. The energy storage system includes multiple energy storage units and the second aspect and any one of the control devices described in the second aspect.

[0031] In a fourth aspect, the present application provides a control device for an energy storage system, 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 first aspect and any one of the methods in the first aspect according to the instructions.

[0032] In the embodiment of the present application, during the first phase of the first energy storage unit's charging cycle, the energy generation system is controlled to charge the first energy storage unit, which can fully utilize the electrical energy output by the energy generation system and avoid energy waste. During the second phase of the first energy storage unit's charging cycle, the first energy storage unit is controlled to discharge to the second energy storage unit, which can reduce the occurrence of lithium deposition and heat generation in the batteries of the energy storage system, thereby improving the performance and service life of the batteries. Therefore, the solution of the present application can improve the performance and service life of the energy storage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the drawings without creative work.

[0034] FIG1 is a schematic diagram of an application scenario of an energy storage system in one embodiment of the present application;

[0035] FIG2 is a schematic diagram of an architecture of an application scenario of an energy storage system according to an embodiment of the present application;

[0036] FIG3 is a schematic diagram of a control method for an energy storage system according to an embodiment of the present application;

[0037] FIG4 is a schematic diagram of a charging cycle of a first energy storage unit according to an embodiment of the present application;

[0038] FIG5 is a schematic diagram of a control method according to an embodiment of the present application;

[0039] FIG6 is a schematic diagram of a control method according to an embodiment of the present application;

[0040] FIG7 is a schematic diagram of a control device according to an embodiment of the present application;

[0041] FIG8 is a schematic diagram of an energy storage system according to an embodiment of the present application;

[0042] FIG9 is a schematic diagram of a control device according to an embodiment of the present application.

[0043] In the drawings, the drawings are not drawn to scale. DETAILED DESCRIPTION

[0044] 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.

[0045] In the description of this application, it should be noted that, unless otherwise specified, "multiple" means more than two; the terms "upper", "lower", "left", "right", "inside", "outside", etc., indicating directions or positional relationships, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on this application. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. "Vertical" is not strictly perpendicular, but is within the allowable error range. "Parallel" is not strictly parallel, but is within the allowable error range.

[0046] 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 "installed", "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.

[0047] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0048] With the rapid development of the new energy industry, a large number of energy generation systems, such as wind power and photovoltaic power, are connected to the power grid to provide electricity. When these energy generation systems generate a large amount of energy, energy storage systems are often installed to store excess energy to avoid wasting it.

[0049] Researchers found that during the use of the energy storage system, the energy generation system charges the energy storage system in a continuous charging manner. After a long period of charge and discharge cycles, the batteries in the energy storage system produce lithium deposition, heat generation and other phenomena, affecting the performance and service life of the battery.

[0050] Based on this, the present application provides a control method for an energy storage system, wherein the energy storage system includes multiple energy storage units, the energy storage system is coupled with an energy generation system and a power grid, and the energy storage system is used to store electrical energy obtained from the energy generation system and release electrical energy to the power grid. The control method includes: in a first stage, controlling the energy generation system to charge the first energy storage unit of the multiple energy storage units, and the first stage is the charging stage of the charging cycle of the first energy storage unit; in a second stage, controlling the first energy storage unit to discharge to the second energy storage unit of the multiple energy storage units, and the second stage is the discharging stage of the charging cycle of the first energy storage unit. In this way, by introducing a discharge stage in the charging cycle of the first energy storage unit, the first energy storage unit is charged to a certain amount of electricity in the first stage of the charging cycle, and then discharges to the second energy storage unit in the second stage, thereby reducing the occurrence of lithium plating and heat generation in the battery of the first energy storage unit in the energy storage system, which is beneficial to improving the performance and service life of the battery, thereby improving the performance and service life of the energy storage system.

[0051] FIG1 is a schematic diagram of an application scenario of an energy storage system according to an embodiment of the present application.

[0052] As shown in FIG1 , the energy generation system 120 is connected to the energy storage system 110 and the power grid 130 , and the energy generation system 120 can transmit power to the energy storage system 110 and the power grid 130 .

[0053] Energy generation system 120 can convert solar energy, wind energy, nuclear energy, and the like into electrical energy. Energy generation system 120 can be a renewable energy system such as a wind power generation system, a photovoltaic power generation system, or a tidal power generation system. It can also be a nuclear power generation system, a thermal power generation system, or a hydropower generation system. It can also be a power generation system that combines wind power generation systems and thermal power generation systems. This application does not limit the power generation form of energy generation system 120.

[0054] The energy storage system 110 is used to store electrical energy and 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 state of charge (SOC), temperature, current, voltage, and state of health (SOH). The BMS also exchanges information with the upper-layer energy management system (EMS) or power conversion system (PCS) in real time to implement energy management of the entire energy storage system 110. The battery's SOC can also be referred to as the battery's remaining capacity.

[0055] A battery may include multiple battery cells, which are connected in series, in parallel, or in mixed series to form a battery. A battery cell may be the smallest unit of a battery.

[0056] Optionally, the energy storage system 110 may also output power to an electrical device, which may be an electric vehicle or the like.

[0057] Optionally, the energy storage system 110 is connected to a power grid 130. The power grid 130 may be a distribution grid, a regional grid, or a power grid, which is not limited in this application. The power grid 130 may receive power output by the energy storage system 110 or may transmit power to the energy storage system 110.

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

[0059] It should be understood that in the embodiment of the present application, the energy storage system 110 is connected to the energy generation system 120, the energy storage system 110 is connected to the power grid 130, and the energy generation system 120 is connected to the power grid 130. It can also be understood that the energy storage system 110 is coupled to the energy generation system 120, the energy storage system 110 is coupled to the power grid 130, and the energy generation system 120 is coupled to the power grid 130.

[0060] FIG2 is a schematic diagram of the architecture of an energy storage system according to an embodiment of the present application. As shown in FIG2 , FIG2 illustrates an example of an energy generation system 120 being a photovoltaic power generation system. It should be noted that the energy generation system 120 is not limited to a photovoltaic power generation system.

[0061] The output power of energy generation system 120 is the power output after passing through the first controller. For example, for a photovoltaic power generation system, the first controller can be a maximum power point tracking (MPTT) solar controller. MPTT can control the output power of energy generation system 120 and whether energy generation system 120 outputs power to energy storage system 110 or grid 130. For example, the power of energy generation system 120 is output to bus 140 through MPPT. In other words, energy generation system 120 can output DC to bus 104 under the control of MPPT.

[0062] The power output from grid 130 can be delivered to bus 140 via an alternating current-direct current (AC / DC) converter. This AC / DC converter is a bidirectional AC / DC converter that supports fast charge / discharge switching. The AC generated by grid 130 can be converted to DC by the bidirectional AC / DC converter and then delivered to bus 140.

[0063] The energy storage system 110 includes multiple energy storage units, each of which includes a battery and a direct current-direct current (DCDC) converter. The DCDC converter is a bidirectional DCDC converter that can support fast charging and discharging switching functions and can also convert the current or power to meet the charging and discharging power of the battery. Each energy storage unit can output power to the bus 140 through DCDC, and can also output power to other energy storage units through DCDC. In addition, the current or power of the bus 140 can also be delivered to each energy storage unit through DCDC.

[0064] In each energy storage unit, the charging or discharging of the energy storage unit can be controlled to be turned on and off by a DCDC converter.

[0065] The DCDC converter may be an isolated DCDC converter or a non-isolated DCDC converter.

[0066] Figure 3 is a schematic diagram of a control method for an energy storage system according to an embodiment of the present application. In the embodiment of the present application, as shown in Figure 3, the control method 300 includes the following steps.

[0067] The control method 300 of an embodiment of the present application is applicable to the energy storage system 110 shown in Figures 1 and 2. The energy storage system 110 is coupled with the energy generation system 120 and the power grid 130. The energy storage system 110 is used to store the electrical energy obtained from the energy generation system 120 and release the electrical energy to the power grid 130. The energy storage system 110 includes multiple energy storage units.

[0068] The control method 300 of the embodiment of the present application is executed by a control device, which can be provided in the energy storage system 110, in the energy generation system 120, or independently provided outside the energy storage system 110 and the energy generation system 120. The specific configuration of the control device can be determined based on actual conditions and is not specifically limited in the embodiment of the present application.

[0069] Step 310 : In the first stage, the energy generation system 120 is controlled to charge the first energy storage unit 111 of the plurality of energy storage units. The first stage is the charging stage of the charging cycle of the first energy storage unit 111 .

[0070] Optionally, step 310 can be implemented by the following operations. For example, the control device controls the MPPT to output power from the energy generation system 120 to the bus 140 . Thereafter, the control device controls the DC-DC converter in the first energy storage unit 111 to convert the DC power on the bus 140 side into a charging current for the first energy storage unit 111 and output the charging current to the first energy storage unit 111 .

[0071] In step 310 , the energy generation system 120 is controlled to charge the first energy storage unit 111 , so as to fully utilize the electric energy generated by the energy generation system 120 and avoid energy waste.

[0072] Step 320 : In the second stage, the first energy storage unit 111 is controlled to discharge to the second energy storage unit 112 of the plurality of energy storage units. The second stage is the discharge stage of the charging cycle of the first energy storage unit 111 .

[0073] Optionally, step 320 may be implemented by the following operations: For example, the control device controls the DCDC of the first energy storage unit 111 and the DCDC of the second energy storage unit 112 to turn on, so as to output the power of the first energy storage unit 111 to the second energy storage unit 112 .

[0074] FIG4 is a schematic diagram of a charging cycle of the first energy storage unit according to an embodiment of the present application. As shown in FIG4 , the charging cycle of the first energy storage unit 111 includes multiple first and second stages that occur in a sequential manner. In the first stage, the first energy storage unit 111 is charged to replenish the power of the first energy storage unit 111. In the second stage, the first energy storage unit 111 is discharged to reduce or eliminate the polarization accumulation of the battery in the first energy storage unit 111, thereby reducing the generation of lithium plating and reducing the heat accumulation caused by charging the first energy storage unit 111.

[0075] In different first stages, the charging power of the first energy storage unit 111 may be different, and the amount of electricity replenished may also be different, which can be determined by the BMS based on the battery information of the first energy storage unit. Similarly, in different second stages, the discharging power and amount of electricity discharged by the first energy storage unit 111 may also be different.

[0076] The durations of different first stages and different second stages may be the same or different, and these may be specifically set according to actual conditions.

[0077] In step 320, controlling first energy storage unit 111 to discharge into second energy storage unit 112 can reduce lithium deposition and heating in the batteries of energy storage system 110, thereby improving battery performance and service life. Furthermore, controlling first energy storage unit 111 to discharge into second energy storage unit 112 is easier to implement than controlling first energy storage unit 111 to discharge into grid 130, and has less impact on grid 130, thus not affecting its stability.

[0078] An embodiment of the present application provides a control method 300. In the first stage, the energy generation system 120 is controlled to charge the first energy storage unit 111 of the multiple energy storage units. The first stage is the charging stage of the charging cycle of the first energy storage unit 111. In the second stage, the first energy storage unit 111 is controlled to discharge the second energy storage unit 112 of the multiple energy storage units. The second stage is the discharging stage of the charging cycle of the first energy storage unit 111. In this way, the electric energy generated by the energy generation system 120 can be fully utilized to avoid energy waste, and the occurrence of lithium plating and heat generation in the batteries in the energy storage system 110 can be reduced, which is beneficial to improving the performance and service life of the batteries. Therefore, the solution of the present application can improve the performance and service life of the energy storage system 110.

[0079] Optionally, in the first stage, only the energy storage units other than the first energy storage unit 111 in the energy storage system 110 may be controlled to charge the first energy storage unit 111. In this way, the first energy storage unit 111 may be charged by the other energy storage units, thereby heating the battery of the first energy storage unit 111.

[0080] FIG5 is a schematic diagram of a control method according to an embodiment of the present application. Optionally, in an embodiment of the present application, as shown in FIG5 , step 310 includes step 311 .

[0081] Step 311: In the first stage, the energy generation system 120 is controlled to charge the first energy storage unit 111 of the multiple energy storage units based on the dispatching status of the power grid 130, the output power of the energy generation system 120, the charging power of the first energy storage unit 111, the remaining capacity of the first energy storage unit 111 and at least one of the remaining capacity of the second energy storage unit 112.

[0082] The charging power of the first energy storage unit 111 can be determined based on the battery information of the batteries in the first energy storage unit 111. The battery information may include the voltage of each battery cell, the temperature of the battery cell, the state of health of the battery cell and the battery, and the state of charge of the battery cell and the battery. The battery management system (BMS) in the first energy storage unit 111 can determine the charging current and charging power of the first energy storage unit 111 based on the battery information. For example, the BMS can obtain battery information in real time and determine the most appropriate charging power for the first energy storage unit 111 based on the battery information.

[0083] After the BMS determines the charging power of the first energy storage unit 111, the BMS may send the charging power to the control device. For example, the BMS sends the charging power to the control device via a controller area network (CAN) communication.

[0084] The output power of the energy generation system 120 is the power at the output side of the energy generation system 120, for example, the output power at position a in Figure 2. The output power of the energy generation system 120 can be controlled by a first controller, such as an MPPT.

[0085] The remaining capacity of the first energy storage unit 111 and the remaining capacity of the second energy storage unit 112 refer to the SOC of the first energy storage unit 111 and the SOC of the second energy storage unit 112 , respectively.

[0086] In this embodiment, it is convenient to determine the strategy for the energy generation system 120 to charge the first energy storage unit 111 based on information such as the scheduling status of the power grid 130, the output power of the energy generation system 120, the charging power of the first energy storage unit 111, the remaining capacity of the first energy storage unit 111 and the remaining capacity of the second energy storage unit 112.

[0087] Optionally, before step 310, method 300 also includes: obtaining at least one of the dispatching status of the power grid 130, the output power of the energy generation system 120, the charging power of the first energy storage unit 111, the remaining capacity of the first energy storage unit 111, and the remaining capacity of the second energy storage unit 112.

[0088] Optionally, in an embodiment of the present application, step 311 includes: when the remaining capacity of the first energy storage unit 111 is less than a maximum preset capacity, controlling the energy generation system 120 to charge the first energy storage unit 111 .

[0089] The maximum preset capacity may be the maximum SOC of the battery of the first energy storage unit 111 , and the SOC may be specifically set according to actual needs, for example, the SOC may be 0.8, 0.9, etc.

[0090] In this embodiment, the remaining capacity of the first energy storage unit 111 can be maintained within a suitable range, thereby avoiding overcharging caused by charging the first energy storage unit 111 when the remaining capacity of the first energy storage unit 111 is high.

[0091] FIG6 is a schematic diagram of a control method according to an embodiment of the present application. Optionally, in an embodiment of the present application, as shown in FIG6 , step 311 includes step 312 .

[0092] Step 312: When the dispatching state of the power grid 130 includes the absence of energy dispatching demand, the energy generation system 120 is controlled to charge the first energy storage unit 111 according to the output power of the energy generation system 120, the charging power of the first energy storage unit 111 and the remaining capacity of the second energy storage unit 112.

[0093] When the dispatching state of the power grid 130 includes the absence of energy dispatching demand, it can be that the power grid 130 does not need the energy generation system 120 and the energy storage system 110 to transmit power to the power grid 130 .

[0094] In this embodiment, when there is no scheduling demand from the power grid 130, it is convenient to determine the strategy for charging the first energy storage unit 111 based on the relationship between the output power P2 of the energy generation system 120 and the charging power P1 of the first energy storage unit 111, and the remaining capacity of the second energy storage unit 112.

[0095] Optionally, in one embodiment of the present application, step 312 includes: when the output power of the energy generation system 120 is less than the charging power of the first energy storage unit 111, controlling the energy generation system 120 to charge the first energy storage unit 111, and controlling at least one of the second energy storage unit 112 and the power grid 130 to charge the first energy storage unit 111, wherein the remaining capacity of the second energy storage unit 112 is greater than or equal to the minimum preset capacity.

[0096] The minimum preset capacity can be specifically set according to actual needs. For example, the minimum preset capacity of the second energy storage unit 112 corresponds to an SOC of the battery in the second energy storage unit 112 of 0.5.

[0097] If the remaining capacity of the second energy storage unit 112 is greater than or equal to the minimum preset capacity, the second energy storage unit 112 can serve as an energy supplement device to charge the first energy storage unit. If the output power of the energy generation system 120 is less than the charging power of the first energy storage unit 111, in addition to the energy generation system 120, other devices are required to charge the first energy storage unit 111.

[0098] Optionally, during a low electricity consumption period, the energy generation system 120 and the grid 130 charge the first energy storage unit simultaneously, which is more economical.

[0099] Optionally, when the sum of the maximum output power P3 of the second energy storage unit 112 and the output power P2 of the energy generation system 120 is greater than or equal to the charging power P1 of the first energy storage unit 111, the energy generation system 120 and the second energy storage unit 112 simultaneously charge the first energy storage unit 111, and the power grid 130 does not charge the first energy storage unit 111. In this way, the power grid 130 does not need to charge the first energy storage unit 111. This charging strategy is simple and easy to implement and does not affect the normal operation and stability of the power grid 130.

[0100] Optionally, when the sum of the maximum output power P3 of the second energy storage unit 112 and the output power of the energy generation system 120 is less than the charging power of the first energy storage unit 111, the energy generation system 120, the power grid 130 and the second energy storage unit 112 charge the first energy storage unit 111 simultaneously.

[0101] Optionally, when the energy generation system 120, the grid 130, and the second energy storage unit 112 are simultaneously charging the first energy storage unit 111, this can be achieved through the following operations: the control device controls the first controller, such as the MPPT, to output the output power of the energy generation system 120 to the bus 104; the control device controls the DC / DC converter of the second energy storage unit 112 to output the power of the second energy storage unit 112 to the bus 104; the control device controls the AC / DC converter to output the power of the grid 130 to the bus 104; and the control device controls the DC / DC converter of the first energy storage unit 111 to convert the power (direct current) on the bus 104 side and output it to the first energy storage unit 111.

[0102] In this embodiment, the second energy storage unit 112 and / or the power grid 130 can charge the first energy storage unit 111 in the first stage simultaneously with the energy generation system 120 to meet the first energy storage unit 111's demand for charging power, thereby helping to extend the service life of the first energy storage unit 111.

[0103] Optionally, in one embodiment of the present application, step 312 includes: when the output power of the energy generation system 120 is greater than or equal to the charging power of the first energy storage unit 111, controlling the output power of the energy generation system 120 to be the same as the charging power of the first energy storage unit 111; after controlling the output power of the energy generation system 120 to be the same as the charging power of the first energy storage unit 111, controlling the energy generation system 120 to charge the first energy storage unit 111.

[0104] In this embodiment, when the output power of energy generation system 120 is greater than or equal to the charging power of first energy storage unit 111, the output power of energy generation system 120 is controlled to be equal to the charging power of first energy storage unit 111. After the output power of energy generation system 120 is controlled to be equal to the charging power of first energy storage unit 111, energy generation system 120 is controlled to only charge first energy storage unit 111. In this way, the charging power requirement of first energy storage unit 111 can be met, which helps to extend the service life of first energy storage unit 111. At the same time, this implementation is simple and easy to implement.

[0105] Optionally, in one embodiment of the present application, step 312 includes: when the remaining capacity of the second energy storage unit 112 is less than a minimum preset capacity, controlling the energy generation system 120 and / or the power grid 130 to charge the second energy storage unit 112. This facilitates flexible selection of a strategy for charging the second energy storage unit 112 based on actual conditions; furthermore, after the second energy storage unit 112 is charged to a certain amount of power, it is convenient to use the second energy storage unit 112 to charge the first energy storage unit 111 in subsequent processes.

[0106] Optionally, in one embodiment of the present application, when the remaining capacity of the second energy storage unit 112 is less than the minimum preset capacity, the energy generation system 120 and / or the power grid 130 are controlled to charge the second energy storage unit 112, including: when the output power of the energy generation system 120 is less than the charging power of the first energy storage unit 111, the energy generation system 120 and the power grid 130 are controlled to charge the first energy storage unit 111, and the power grid 130 is controlled to charge the second energy storage unit 112.

[0107] In this embodiment, while charging the first energy storage unit 111 , the second energy storage unit 112 is also charged, so that after the second energy storage unit 112 is charged to an appropriate amount of power, the first energy storage unit 111 can be charged using the second energy storage unit 112 .

[0108] Optionally, when the output power of the energy generation system 120 is less than the charging power of the first energy storage unit 111 , the energy generation system 120 and the power grid 130 are controlled to only charge the first energy storage unit 111 and not charge the second energy storage unit 112 .

[0109] Optionally, in one embodiment of the present application, when the remaining capacity of the second energy storage unit 112 is less than the minimum preset capacity, the energy generation system 120 and / or the power grid 130 are controlled to charge the second energy storage unit 112, including: when the output power of the energy generation system 120 is equal to the charging power of the first energy storage unit 111, the energy generation system 120 is controlled to charge the first energy storage unit 111, and the power grid 130 is controlled to charge the second energy storage unit 112; when the output power of the energy generation system 120 is greater than the charging power of the first energy storage unit 111, the energy generation system 120 is controlled to charge the first energy storage unit 111, and the energy generation system 120 and / or the power grid 130 are controlled to charge the second energy storage unit 112.

[0110] In this embodiment, it is convenient to select a suitable control method according to actual conditions to realize charging of the first energy storage unit 111 and replenishment of the power of the second energy storage unit 112 .

[0111] Optionally, in one embodiment of the present application, when the output power of the energy generation system 120 is greater than the charging power of the first energy storage unit 111, controlling the energy generation system 120 to charge the first energy storage unit 111 and controlling the energy generation system 120 and / or the power grid 130 to charge the second energy storage unit 112 includes: when the difference between the output power of the energy generation system 120 and the charging power of the first energy storage unit 111 is less than the maximum charging power of the second energy storage unit 112, controlling the energy generation system 120 and the power grid 130 to charge the second energy storage unit 112. In this way, rapid charging of the second energy storage unit 112 is facilitated.

[0112] Optionally, in one embodiment of the present application, step 311 includes: when the scheduling state of the power grid 130 includes the existence of energy scheduling demand and the output power of the energy generation system 120 is greater than the required power of the power grid 130, controlling the energy generation system 120 to charge the first energy storage unit 111 according to the output power of the energy generation system 120, the charging power of the first energy storage unit 111 and the remaining capacity of the second energy storage unit 112.

[0113] Grid 130 has an energy dispatch demand, and grid 130 may send the energy dispatch demand to at least one of energy generation system 120 and energy storage system 110. Optionally, grid 130 preferentially sends the energy dispatch demand to energy generation system 120. Optionally, if the output power of energy generation system 120 cannot meet the dispatch demand of grid 130, grid 130 may also send the dispatch demand to energy storage system 110.

[0114] In this embodiment, when the power grid 130 has a scheduling demand and the output power of the energy generation system 120 is greater than the power demand of the power grid 130, the energy generation system 120 is controlled to charge the first energy storage unit 111. In this way, the first energy storage unit 111 can be charged while the demand of the power grid 130 is met, avoiding the situation where the demand of the power grid 130 cannot be met due to the charging of the first energy storage unit 111, thereby preventing the stability of the power grid 130 from being affected.

[0115] Optionally, in one embodiment of the present application, controlling the energy generation system 120 to charge the first energy storage unit 111 of the multiple energy storage units includes: when the remaining capacity of the second energy storage unit 112 is greater than or equal to a minimum preset capacity, controlling the energy generation system 120 to charge the first energy storage unit 111, or controlling the energy generation system 120 and the second energy storage unit 112 to charge the first energy storage unit 111. In this way, the second energy storage unit 112 and / or the energy generation system 120 can simultaneously charge the first energy storage unit 111 in the first phase to meet the charging power requirement of the first energy storage unit 111, thereby facilitating extending the service life of the first energy storage unit 111.

[0116] Optionally, when the difference between the output power of the energy generation system 120 and the required power of the power grid 130 is greater than or equal to the charging power of the first energy storage unit 111, it is only necessary to control the energy generation system 120 to charge the first energy storage unit 111.

[0117] Optionally, when the difference between the output power P2 of energy generation system 120 and the power demand P4 of power grid 130 is less than the charging power P1 of first energy storage unit 111, second energy storage unit 112 and energy generation system 120 are controlled to simultaneously charge first energy storage unit 111 in the first stage. In this case, the power delivered by energy generation system 120 to first energy storage unit 111 is P2-P4, and the power delivered by second energy storage unit 112 to first energy storage unit 111 is P1-(P2-P4).

[0118] Optionally, in one embodiment of the present application, controlling the energy generation system 120 to charge the first energy storage unit 111 of the multiple energy storage units includes: controlling the energy generation system 120 to charge the second energy storage unit 112 when the remaining capacity of the second energy storage unit 112 is less than a minimum preset capacity; and after controlling the energy generation system 120 to charge the second energy storage unit 112, controlling the energy generation system 120 and / or the second energy storage unit 112 to charge the first energy storage unit 111. In this way, the remaining capacity of the second energy storage unit 112 can be made greater than the minimum preset capacity, so that when charging the first energy storage unit 111, the charging power requirement of the first energy storage unit 111 is met.

[0119] Optionally, when the remaining capacity of the second energy storage unit 112 is less than the minimum preset capacity, the energy generation system 120 can be controlled to simultaneously charge the first energy storage unit 111 and the second energy storage unit 112. It should be noted that the charging power of the first energy storage unit 111 is the appropriate charging power calculated by the BMS, and the charging power of the second energy storage unit 112 does not need to exceed the maximum charging power of the second energy storage unit 112.

[0120] Optionally, in one embodiment of the present application, controlling the first energy storage unit 111 to discharge to the second energy storage unit 112 of the plurality of energy storage units in the second phase includes: in the second phase, controlling the first energy storage unit 111 to discharge to the second energy storage unit 112 of the plurality of energy storage units based on at least one of the dispatch status of the power grid 130 and the remaining capacity of the second energy storage unit 112. This facilitates flexible setting of different discharge strategies for the first energy storage unit 111 during a charging cycle based on actual conditions.

[0121] Optionally, in one embodiment of the present application, based on at least one of the dispatching state of the power grid 130 and the remaining capacity of the second energy storage unit 112, controlling the first energy storage unit 111 to discharge to the second energy storage unit 112 of the plurality of energy storage units includes: when the remaining capacity of the second energy storage unit 112 is less than a maximum preset capacity, controlling the first energy storage unit 111 to discharge to the second energy storage unit 112. In this way, overcharging caused by excessive power received by the second energy storage unit 112 can be avoided.

[0122] Optionally, in one embodiment of the present application, controlling the first energy storage unit 111 to discharge to the second energy storage unit 112 of the plurality of energy storage units based on at least one of the dispatching state of the power grid 130 and the remaining capacity of the second energy storage unit 112 includes: when the dispatching state of the power grid 130 includes the absence of energy dispatching demand, controlling the output power of the energy generation system 120 to 0, and controlling the first energy storage unit 111 to discharge to the second energy storage unit 112. In this way, the discharge of the first energy storage unit 111 to the power grid 130 and the impact on the stability of the power grid 130 can be avoided.

[0123] Optionally, in one embodiment of the present application, controlling the first energy storage unit 111 to discharge to the second energy storage unit 112 of the plurality of energy storage units based on at least one of the dispatching status of the power grid 130 and the remaining capacity of the second energy storage unit 112 includes: when the dispatching status of the power grid 130 includes the presence of an energy dispatch demand, controlling the output power of the energy generation system 120 to be equal to the power demand of the power grid 130, and controlling the first energy storage unit 111 to discharge to the second energy storage unit 112. This implementation is simple and easy, and can simultaneously meet the demand of the power grid 130 and the demand of the first energy storage unit 111 to discharge to the second energy storage unit 112.

[0124] Optionally, in an embodiment of the present application, the method further includes: controlling the first energy storage unit 111 to switch from the first stage to the second stage when the charge capacity of the first energy storage unit 111 reaches a first preset capacity; and controlling the first energy storage unit 111 to switch from the second stage to the first stage when the discharge capacity of the first energy storage unit 111 reaches a second preset capacity. In this way, by continuously switching between the first stage and the second stage during the charging cycle of the first energy storage unit 111, the first energy storage unit 111 is charged.

[0125] The first preset capacity and the second preset capacity can be set according to actual needs, and this application does not impose any specific restrictions on this.

[0126] Optionally, the first preset capacity is greater than the second preset capacity. Optionally, the duration of the first stage is less than the duration of the second stage.

[0127] Optionally, in different first stages, the charging power of the first energy storage unit 111 may be different, or may be determined according to battery information of the first energy storage unit 111 .

[0128] Optionally, in one embodiment of the present application, the method further includes: when the remaining capacity of the first energy storage unit 111 reaches a maximum preset capacity, controlling the energy generation system 120 to stop charging the first energy storage unit 111. In this way, the remaining capacity of the first energy storage unit 111 does not exceed the maximum preset capacity, and after the energy generation system 120 finishes charging the first energy storage unit 111, the first energy storage unit 111 can serve as an energy absorption device to receive electricity discharged by other energy storage units of the plurality of energy storage units.

[0129] In the present application, after the remaining capacity of the first energy storage unit 111 reaches the maximum preset capacity and the control energy generation system 120 ends charging the first energy storage unit 111, the control device no longer controls the energy generation system 120 to charge the first energy storage unit 111. That is, the first energy storage unit 111 only serves as an energy absorption device to absorb the electricity released by the remaining energy storage units during the discharge phase of the charging cycle; at the same time, the first energy storage unit 111 will not charge the remaining energy storage battery units.

[0130] The above description, in conjunction with Figures 1 to 6 , details the method embodiment of the present application. The following description will detail the control device embodiment of the present application. It should be understood that the method embodiment and the control device embodiment correspond to each other, and similar descriptions can refer to the method embodiment, which will not be repeated here.

[0131] FIG7 is a schematic diagram of a control device according to an embodiment of the present application. As shown in FIG7 , the present application provides a control device 500, which is coupled to an energy storage system 110. The energy storage system 110 is coupled to an energy generation system 120 and a power grid 130. The energy storage system 110 is used to store electrical energy obtained from the energy generation system 120 and release electrical energy to the power grid 130. The energy storage system 110 includes multiple energy storage units. The control device 500 includes a control unit 510. The control unit 510 is used to: in a first phase, control the energy generation system 120 to charge a first energy storage unit 111 of the multiple energy storage units. The first phase is the charging phase of the charging cycle of the first energy storage unit 111; and in a second phase, control the first energy storage unit 111 to discharge to a second energy storage unit 112 of the multiple energy storage units. The second phase is the discharging phase of the charging cycle of the first energy storage unit 111.

[0132] Optionally, in one embodiment of the present application, the control unit 510 is further used to: in the first stage, control the energy generation system 120 to charge the first energy storage unit 111 of the multiple energy storage units based on the dispatching status of the power grid 130, the output power of the energy generation system 120, the charging power of the first energy storage unit 111, the remaining capacity of the first energy storage unit 111 and at least one of the remaining capacity of the second energy storage unit 112.

[0133] Optionally, the control unit 510 is further configured to execute any one of the control methods described above. Similar descriptions can be found above and will not be repeated here.

[0134] Figure 8 is a schematic diagram of an energy storage system according to an embodiment of the present application. As shown in Figure 8 , the present application provides an energy storage system 110 coupled to an energy generation system 120 and a power grid 130. Energy storage system 110 is configured to store electrical energy obtained from energy generation system 120 and release electrical energy to power grid 130. Energy storage system 110 includes multiple energy storage units and the control device 500 described above.

[0135] The energy storage system 110 includes multiple energy storage units, for example, two energy storage units, namely a first energy storage unit 111 and a second energy storage unit 112, which are connected in parallel. Optionally, the energy storage system 110 may also include three or more energy storage units.

[0136] The control device 500 can be connected to multiple energy storage units in a wireless or wired manner, and this embodiment of the present application does not impose any specific restrictions on this.

[0137] FIG9 is a schematic diagram of a control device according to an embodiment of the present application. As shown in FIG9 , the present application provides a control device 600 for an energy storage system 110 . The control device 600 includes a memory 610 and a processor 620 . The memory 610 is configured to store instructions, and the processor 620 is configured to read the instructions and execute the method described above according to the instructions.

[0138] The processor 620 in the embodiment of the present application can 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 and steps 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 implemented and executed by a hardware decoding processor, or 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.

[0139] The memory 610 of the embodiment of the present application can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can 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 can 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.

[0140] The present application also provides a computer-readable storage medium for storing a computer program.

[0141] 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.

[0142] An embodiment of the present application also provides a computer program product, including computer program instructions.

[0143] 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.

[0144] The embodiment of the present application also provides a computer program.

[0145] 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.

[0146] 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.

[0147] 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.

[0148] 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.

[0149] 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.

[0150] 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.

[0151] 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.

[0152] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and components may be substituted with equivalents without departing from the scope of the present application. In particular, the various technical features described in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present application is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions within the scope of the claims.

Claims

1. A control method for an energy storage system, characterized in that: The energy storage system includes a plurality of energy storage units, the energy storage system is coupled to an energy generation system and a power grid, the energy storage system is used to store electrical energy obtained from the energy generation system and release electrical energy to the power grid, and the method includes: In a first stage, controlling the energy generation system to charge a first energy storage unit of the plurality of energy storage units, the first stage being a charging stage of a charging cycle of the first energy storage unit; In the second stage, the first energy storage unit is controlled to discharge to the second energy storage unit of the plurality of energy storage units. The second stage is a discharge stage of the charging cycle of the first energy storage unit.

2. The control method according to claim 1, characterized in that: The controlling the energy generation system to charge the first energy storage unit of the plurality of energy storage units in the first stage includes: In the first stage, the energy generation system is controlled to charge the first energy storage unit of the multiple energy storage units based on at least one of the dispatching status of the power grid, the output power of the energy generation system, the charging power of the first energy storage unit, the remaining capacity of the first energy storage unit, and the remaining capacity of the second energy storage unit.

3. The control method according to claim 2, characterized in that: The controlling the energy generation system to charge the first energy storage unit of the plurality of energy storage units according to at least one of a dispatching state of a power grid, an output power of the energy generation system, a charging power of the first energy storage unit, a remaining capacity of the first energy storage unit, and a remaining capacity of the second energy storage unit comprises: When the remaining capacity of the first energy storage unit is less than a maximum preset capacity, the energy generation system is controlled to charge the first energy storage unit.

4. The control method according to claim 2 or 3, characterized in that: The controlling the energy generation system to charge the first energy storage unit of the plurality of energy storage units according to at least one of a dispatching state of a power grid, an output power of the energy generation system, a charging power of the first energy storage unit, a remaining capacity of the first energy storage unit, and a remaining capacity of the second energy storage unit comprises: When the dispatching state of the power grid includes the absence of energy dispatching demand, the energy generation system is controlled to charge the first energy storage unit according to the output power of the energy generation system, the charging power of the first energy storage unit and the remaining capacity of the second energy storage unit.

5. The control method according to claim 4, characterized in that: The controlling the energy generation system to charge the first energy storage unit of the plurality of energy storage units includes: When the output power of the energy generation system is less than the charging power of the first energy storage unit, the energy generation system is controlled to charge the first energy storage unit, and at least one of the second energy storage unit and the power grid is controlled to charge the first energy storage unit, wherein the remaining capacity of the second energy storage unit is greater than or equal to the minimum preset capacity.

6. The control method according to claim 4, characterized in that: The controlling the energy generation system to charge the first energy storage unit of the plurality of energy storage units comprises: When the output power of the energy generation system is greater than or equal to the charging power of the first energy storage unit, controlling the output power of the energy generation system to be the same as the charging power of the first energy storage unit; After controlling the output power of the energy generation system to be the same as the charging power of the first energy storage unit, controlling the energy generation system to charge the first energy storage unit.

7. The control method according to claim 4, characterized in that: The controlling the energy generation system to charge the first energy storage unit of the plurality of energy storage units comprises: When the remaining capacity of the second energy storage unit is less than a minimum preset capacity, the energy generation system and / or the power grid is controlled to charge the second energy storage unit.

8. The control method according to claim 7, characterized in that: The controlling the energy generation system and / or the power grid to charge the second energy storage unit includes: When the output power of the energy generation system is less than the charging power of the first energy storage unit, the energy generation system and the power grid are controlled to charge the first energy storage unit, and the power grid is controlled to charge the second energy storage unit.

9. The control method according to claim 7, characterized in that: The controlling the energy generation system and / or the power grid to charge the second energy storage unit includes: When the output power of the energy generation system is equal to the charging power of the first energy storage unit, controlling the energy generation system to charge the first energy storage unit and controlling the power grid to charge the second energy storage unit; When the output power of the energy generation system is greater than the charging power of the first energy storage unit, the energy generation system is controlled to charge the first energy storage unit, and the energy generation system and / or the power grid is controlled to charge the second energy storage unit.

10. The control method according to claim 9, characterized in that: When the output power of the energy generation system is greater than the charging power of the first energy storage unit, controlling the energy generation system to charge the first energy storage unit, and controlling the energy generation system and / or the power grid to charge the second energy storage unit, includes: When the difference between the output power of the energy generation system and the charging power of the first energy storage unit is less than the maximum charging power of the second energy storage unit, the energy generation system and the power grid are controlled to charge the second energy storage unit.

11. The control method according to claim 2 or 3, characterized in that: The controlling the energy generation system to charge the first energy storage unit of the plurality of energy storage units according to at least one of a dispatching state of a power grid, an output power of the energy generation system, a charging power of the first energy storage unit, a remaining capacity of the first energy storage unit, and a remaining capacity of the second energy storage unit comprises: When the dispatching state of the power grid includes an energy dispatching demand and the output power of the energy generation system is greater than the required power of the power grid, the energy generation system is controlled to charge the first energy storage unit according to the output power of the energy generation system, the charging power of the first energy storage unit and the remaining capacity of the second energy storage unit.

12. The control method according to claim 11, characterized in that: The controlling the energy generation system to charge the first energy storage unit of the plurality of energy storage units comprises: When the remaining capacity of the second energy storage unit is greater than or equal to the minimum preset capacity, the energy generation system is controlled to charge the first energy storage unit, or the energy generation system and the second energy storage unit are controlled to charge the first energy storage unit.

13. The control method according to claim 11, characterized in that: The controlling the energy generation system to charge the first energy storage unit of the plurality of energy storage units comprises: When the remaining capacity of the second energy storage unit is less than a minimum preset capacity, controlling the energy generation system to charge the second energy storage unit; After controlling the energy generation system to charge the second energy storage unit, controlling the energy generation system and / or the second energy storage unit to charge the first energy storage unit.

14. The control method according to any one of claims 1 to 13, characterized in that: In the second stage, controlling the first energy storage unit to discharge to the second energy storage unit of the plurality of energy storage units includes: In the second stage, the first energy storage unit is controlled to discharge to the second energy storage unit of the plurality of energy storage units according to at least one of a dispatching state of the power grid and a remaining capacity of the second energy storage unit.

15. The control method according to claim 14, characterized in that: The step of controlling the first energy storage unit to discharge to the second energy storage unit of the plurality of energy storage units according to at least one of a dispatching state of the power grid and a remaining capacity of the second energy storage unit comprises: When the remaining capacity of the second energy storage unit is less than a maximum preset capacity, the first energy storage unit is controlled to discharge to the second energy storage unit.

16. The control method according to claim 14 or 15, characterized in that: The step of controlling the first energy storage unit to discharge to the second energy storage unit of the plurality of energy storage units according to at least one of a dispatching state of the power grid and a remaining capacity of the second energy storage unit comprises: When the dispatching state of the power grid includes an energy dispatching demand, the output power of the energy generation system is controlled to be 0, and the first energy storage unit is controlled to discharge to the second energy storage unit.

17. The control method according to claim 14 or 15, characterized in that: The step of controlling the first energy storage unit to discharge to the second energy storage unit of the plurality of energy storage units according to at least one of a dispatching state of the power grid and a remaining capacity of the second energy storage unit comprises: When the dispatching state of the power grid includes an energy dispatching demand, the output power of the energy generation system is controlled to be equal to the required power of the power grid, and the first energy storage unit is controlled to discharge to the second energy storage unit.

18. The control method according to any one of claims 1 to 17, characterized in that: The method further comprises: When the charge amount of the first energy storage unit reaches a first preset capacity, controlling the first energy storage unit to switch from the first stage to the second stage; When the discharge capacity of the first energy storage unit reaches a second preset capacity, the first energy storage unit is controlled to switch from the second stage to the first stage.

19. The control method according to any one of claims 1 to 18, characterized in that: The method further comprises: When the remaining capacity of the first energy storage unit reaches a maximum preset capacity, the energy generation system is controlled to stop charging the first energy storage unit.

20. A control device coupled to an energy storage system, characterized in that: The energy storage system is coupled to the energy generation system and the power grid. The energy storage system is used to store electrical energy obtained from the energy generation system and release electrical energy to the power grid. The energy storage system includes multiple energy storage units. The control device includes a control unit. The control unit is used to: In a first stage, controlling the energy generation system to charge a first energy storage unit of the plurality of energy storage units, the first stage being a charging stage of a charging cycle of the first energy storage unit; In the second stage, the first energy storage unit is controlled to discharge to the second energy storage unit of the plurality of energy storage units. The second stage is a discharge stage of the charging cycle of the first energy storage unit.

21. The control device according to claim 20, characterized in that The control unit is further configured to: In the first stage, the energy generation system is controlled to charge the first energy storage unit of the multiple energy storage units based on at least one of the dispatching status of the power grid, the output power of the energy generation system, the charging power of the first energy storage unit, the remaining capacity of the first energy storage unit, and the remaining capacity of the second energy storage unit.

22. 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 is used to store electrical energy obtained from the energy generation system and release electrical energy to the power grid. The energy storage system includes multiple energy storage units and a control device as described in claim 20 or 21.

23. 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 19 according to the instructions.

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