Method for controlling grid-connected power of energy storage system and electronic equipment

Abstract

The invention relates to a grid-connected power control method of an energy storage system and electronic equipment. The energy storage system comprises an inverter and a battery, the inverter is connected with the battery and a photovoltaic module, and the method comprises the steps that the total current value of the energy storage system is obtained, and the total current value is the sum of the maximum current value of an alternating current port of the inverter, the maximum current value of the battery and the maximum current value of the photovoltaic module; determining the limiting sequence of the current of each module in the energy storage system, and determining the maximum current value of each module in sequence by using the total current value according to the limiting sequence; and controlling the current of each module by using the maximum current value of each module. According to the invention, the technical problems of bus voltage fluctuation and relatively long dynamic response time caused by a power limiting mode of a current energy storage inverter are solved.

Description

Technical Field

[0001] The present application relates to the field of energy storage system control, and in particular to a method and electronic equipment for controlling the grid-connected power of an energy storage system. Background Art

[0002] In order to comply with grid-connected regulations in relevant regions and save photovoltaic energy, it is necessary to quickly control the power at the output port of the energy storage inverter.

[0003] There are two current ways to limit the power of energy storage inverters: directly limiting the power of the AC output port or limiting the power of the DC input port. Limiting the power of the AC output port will cause bus voltage fluctuations, while limiting the power of the DC input port will take a long time in terms of dynamic response. Summary of the invention

[0004] The embodiments of the present application provide a method for controlling the grid-connected power of an energy storage system and an electronic device, which at least solve the problem that the power limiting method of the current energy storage inverter will cause bus voltage fluctuations and a long dynamic response time.

[0005] According to one aspect of an embodiment of the present application, a method for controlling the grid-connected power of an energy storage system is provided, wherein the energy storage system comprises: an inverter and a battery, wherein the inverter is connected to the battery and a photovoltaic module, respectively, and the method comprises: obtaining a total current value of the energy storage system, wherein the total current value is the sum of the maximum current value of the inverter AC port, the maximum current value of the battery, and the maximum current value of the photovoltaic module; determining a current limiting order of each module in the energy storage system, and determining the maximum current value of each module in turn according to the limiting order using the total current value; and controlling the current of each module using the maximum current value of each module.

[0006] Optionally, obtaining the total current value of the energy storage system includes: inputting the power of the energy storage system load and the target power of the load into a linear controller to obtain the total current value.

[0007] Optionally, when the battery current is limited preferentially, the total current value is used to determine the maximum current value of each module in turn, including: when the battery is in a discharging state, the difference obtained by subtracting the rated current value of the inverter AC port, the rated current value of the battery during charging, and the rated current value of the photovoltaic module from the total current value is determined as the maximum current value of the battery; the rated current value of the photovoltaic module is determined as the maximum current value of the photovoltaic module; and the rated current value of the inverter AC port is determined as the maximum current value of the inverter AC port.

[0008] Optionally, when the battery current is limited preferentially, the total current value is used to determine the maximum current value of each module in turn, including: when the battery is in a charging state, the difference obtained by subtracting the rated current value of the inverter AC port and the rated current value of the photovoltaic module from the total current value is determined as the maximum current value of the battery; the rated current value of the photovoltaic module is determined as the maximum current value of the photovoltaic module; and the rated current value of the inverter AC port is determined as the maximum current value of the inverter AC port.

[0009] Optionally, when the battery current is limited preferentially, the total current value is used to determine the maximum current value of each module in turn, including: when the battery is in a fully charged state, determining that the maximum current value of the battery is equal to the rated current value of the battery when charging, but opposite in direction; subtracting the rated current value of the inverter AC port from the total current value to determine the maximum current value of the photovoltaic module; and determining the rated current value of the inverter AC port as the maximum current value of the inverter AC port.

[0010] Optionally, when the battery current is limited preferentially, the total current value is used to determine the maximum current value of each module in turn, including: when the battery is fully charged and the current of the photovoltaic module is uncontrolled, determining that the maximum current value of the battery is the same in magnitude but opposite in direction to the rated current value when the battery is charged; determining that the maximum current value of the photovoltaic module is zero; and determining the total current value as the maximum current value of the inverter AC port.

[0011] Optionally, when the current of the photovoltaic module is preferentially limited, the total current value is used to determine the maximum current value of each module in turn, including: when the battery is discharged at full power and the current of the photovoltaic module is controlled, the difference obtained by subtracting the rated current value of the inverter AC port, the rated current value of the battery during charging, and the rated current value of the battery during discharge from the total current value is determined as the maximum current value of the photovoltaic module; the rated current value of the battery during discharge is determined as the maximum current value of the battery; and the rated current value of the inverter AC port is determined as the maximum current value of the inverter AC port.

[0012] Optionally, when the current of the photovoltaic module is preferentially limited, the total current value is used to determine the maximum current value of each module in turn, including: when the battery discharge is controlled and the current of the photovoltaic module is not controlled, the maximum current value of the photovoltaic module is determined to be zero; the difference obtained by subtracting the rated current value of the inverter AC port and the rated current value during battery charging from the total current value is determined as the maximum current value of the battery; and the rated current value of the battery is determined as the maximum current value of the inverter AC port.

[0013] Optionally, when the current of the photovoltaic module is preferentially limited, the total current value is used to determine the maximum current value of each module in turn, including: when the battery charging is controlled and the current of the photovoltaic module is not controlled, determining that the maximum current value of the photovoltaic module is zero; determining that the maximum current value of the battery and the difference obtained by subtracting the rated current value of the inverter AC port from the total current value are equal in magnitude and opposite in direction; and determining the rated current value of the inverter AC port as the maximum current value of the inverter AC port.

[0014] Optionally, when the current of the photovoltaic module is limited preferentially, the total current value is used to determine the maximum current value of each module in turn, including: when the battery is charged at full power and the current of the photovoltaic module is uncontrolled, determining that the maximum current value of the photovoltaic module is zero; determining that the maximum current value of the battery is equal to the rated current value of the battery during charging, but opposite in direction; and determining the total current value as the maximum current value of the inverter AC port.

[0015] Optionally, the maximum current value of each module is used to control the current of each module, including: determining a minimum current value from the maximum current value of each module and the target current value of each module; using the minimum current value and the current current value of each module as inputs of a linear controller; and controlling the current of each module using the output of the linear controller.

[0016] According to another aspect of an embodiment of the present application, there is also provided an electronic device, including: a processor, and a memory storing a program, wherein the program includes instructions, and when the instructions are executed by the processor, the processor executes the above method.

[0017] According to another aspect of the embodiments of the present application, a non-transitory machine-readable medium storing computer instructions is also provided, where the computer instructions are used to enable a computer to execute the above method.

[0018] According to another aspect of the embodiments of the present application, a computer program product is provided, including a computer program, which is used to enable the computer to execute the above method when the computer program is executed by a processor of the computer.

[0019] Beneficial effects of the embodiments of the present application:

[0020] In the embodiment of the present application, a load power control loop is designed to obtain the maximum current of each module in the energy storage system through closed-loop control, and then the maximum current of the PV side, BAT side and AC side of the energy storage system is limited by the maximum current of each module, thereby achieving the technical effect of quickly controlling the grid-connected power of the energy storage system.

[0021] Details of one or more embodiments of the present application are set forth in the following drawings and description to make other features, objects, and advantages of the present application more readily apparent. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other embodiments can be obtained based on these drawings without creative work.

[0023] Figure 1 It is a schematic diagram of an energy storage system;

[0024] Figure 2 It is a schematic diagram of an energy storage system;

[0025] Figure 3 is a flow chart of a method for controlling grid-connected power of an energy storage system according to an embodiment of the present application;

[0026] Figure 4 is a schematic diagram of a load power closed-loop control system according to an embodiment of the present application;

[0027] Figure 5 is a schematic diagram of controlling PV side current using a closed-loop control system according to an embodiment of the present application;

[0028] Figure 6 is a schematic diagram of controlling the BAT side current by using a closed-loop control system according to an embodiment of the present application;

[0029] Figure 7 is a schematic diagram of controlling the current of the AC output port of the inverter by using a closed-loop control system according to an embodiment of the present application;

[0030] Figure 8 Schematic diagram of the structure of the electronic device of this embodiment. DETAILED DESCRIPTION

[0031] Embodiments of the present embodiment will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present embodiment are shown in the accompanying drawings, it should be understood that the present embodiment can be implemented in various forms and should not be construed as being limited to the embodiments set forth herein, which are instead provided for a more thorough and complete understanding of the present embodiment. It should be understood that the drawings and embodiments of the present embodiment are only for exemplary purposes and are not intended to limit the scope of protection of the present embodiment.

[0032] In order to better understand the embodiments of the present application, the technical terms involved in the embodiments of the present application are explained as follows:

[0033] PCC is the abbreviation of "Point of Common Coupling", which is usually translated into Chinese as "public connection point" or "public coupling point". In the power system, PCC refers to the connection point between the power source (usually the power grid) and the user's facilities.

[0034] Figure 1 is a schematic diagram of an energy storage system, such as Figure 1 As shown in the figure, the control object is the PCC point power, and the control target value is Ppcc_ref. Figure 1 In the state shown, in order to meet the control target, the output power Pac1=Pload+Ppcc_ref of the inverter AC output port, and ignoring the loss, Pac1=Ppv1+Pbat1, where Pload is the load power, Ppv1 is the power of the photovoltaic module PV, and Pbat1 is the battery power.

[0035] When the load is Figure 1 The state is switched to Figure 2 In the state shown, the load is removed and the previous balance relationship is broken. At this time, in order to meet the control target, the inverter output power must satisfy Pac2 = Ppcc_ref. After ignoring the loss, the relationship between the DC side and the AC side is Pac2 = Ppv2 + Pbat2. At this time, in order to meet the requirements of grid-connected regulations in some regions, it is necessary to quickly limit the grid-connected power within the specified time.

[0036] There are two current ways to limit the power of energy storage inverters: directly limiting the power of the AC output port or limiting the power of the DC input port. Limiting the power of the AC output port will cause bus voltage fluctuations, while limiting the power of the DC input port will take a long time in terms of dynamic response.

[0037] In order to solve the above problems, relevant solutions are provided in the embodiments of the present application, which are described in detail below.

[0038] Figure 3 The present invention is a flow chart of a method for controlling the grid-connected power of an energy storage system according to an embodiment of the present application. The energy storage system includes an inverter and a battery. The inverter is connected to the battery and the photovoltaic module respectively. The method includes the following steps:

[0039] Step S302, obtaining a total current value of the energy storage system, wherein the total current value is the sum of the maximum current value of the inverter AC port, the maximum current value of the battery, and the maximum current value of the photovoltaic module.

[0040] According to an optional embodiment of the present application, step S302 is executed to obtain the total current value of the energy storage system, which is achieved by the following method: the power of the energy storage system load and the target power of the load are input into the linear controller to obtain the total current value.

[0041] The above linear controller is a PI controller, which forms a control deviation based on a given value and an actual output value, and forms a control quantity by linearly combining the proportion and integral of the deviation to control the controlled object.

[0042] Figure 4 is a schematic diagram of a load power closed-loop control system according to an embodiment of the present application, such as Figure 4 As shown, the load power (P load ) and the target power of the load (P load_ref ) input PI controller, output the total current value of the energy storage system (I sys_total ).

[0043] I sys_total =(kp+ki / s)*(P load_ref -P load ), where kp and ki are the basic parameters of the PI controller.

[0044] As mentioned above, the total current value is the sum of the maximum current value of the inverter AC port, the maximum current value of the battery, and the maximum current value of the PV module, which is expressed by the following formula:

[0045] I sys_total =I ac_max +I bat_max +I pv_max , I ac_max is the maximum current value of the inverter AC port, I bat_max is the maximum current value of the battery, I pv_max is the maximum current value of the PV module.

[0046] Step S304 , determining a current limiting sequence of each module in the energy storage system, and determining the maximum current value of each module in turn using the total current value according to the limiting sequence.

[0047] In the embodiment of the present application, the current limiting order can be determined according to the power priority requirement.

[0048] Step S306, controlling the current of each module using the maximum current value of each module.

[0049] The above method provided in the embodiment of the present application designs a load power control loop, obtains the maximum value of the current of each module in the energy storage system through closed-loop control, and then limits the maximum current of the PV side, BAT side and AC side of the energy storage system through the maximum value of the current of each module, thereby achieving the technical effect of quickly controlling the grid-connected power of the energy storage system.

[0050] According to an optional embodiment of the present application, when the current of the battery is limited preferentially, step S304 is executed to determine the maximum current value of each module in turn using the total current value, including: when the battery is in a discharging state, the difference obtained by subtracting the rated current value of the inverter AC port, the rated current value of the battery during charging, and the rated current value of the photovoltaic module from the total current value is determined as the maximum current value of the battery; the rated current value of the photovoltaic module is determined as the maximum current value of the photovoltaic module; and the rated current value of the inverter AC port is determined as the maximum current value of the inverter AC port.

[0051] In this embodiment, the battery current is limited preferentially, and the battery is in a discharging state.

[0052] I bat_max =I sys_total -I ac_rated -I bat_chg_rated -I pv_rated

[0053] I pv_max =I pv_rated

[0054] I ac_max =I ac_rated

[0055] According to another optional embodiment of the present application, when the current of the battery is limited preferentially, step S304 is executed to determine the maximum current value of each module in turn using the total current value, and also includes: when the battery is in a charging state, the difference obtained by subtracting the rated current value of the inverter AC port and the rated current value of the photovoltaic module from the total current value is determined as the maximum current value of the battery; the rated current value of the photovoltaic module is determined as the maximum current value of the photovoltaic module; and the rated current value of the inverter AC port is determined as the maximum current value of the inverter AC port.

[0056] In this embodiment, the current of the battery is limited preferentially, and the battery is in a charging state.

[0057] I bat_max =I sys_total -I ac_rated -I pv_rated

[0058] I pv_max =I pv_rated

[0059] I ac_max =I ac_rated

[0060] In some optional embodiments of the present application, when the battery current is limited preferentially, step S304 is executed to determine the maximum current value of each module in turn using the total current value, and also includes: when the battery is in a fully charged state, determining that the maximum current value of the battery is equal to the rated current value of the battery when charging, but opposite in direction; determining the difference obtained by subtracting the rated current value of the inverter AC port from the total current value as the maximum current value of the photovoltaic module; and determining the rated current value of the inverter AC port as the maximum current value of the inverter AC port.

[0061] In this embodiment, the battery current is limited preferentially, and the battery is in a fully charged state.

[0062] I bat_max =–I bat_chg_rated

[0063] I pv_max =I sys_total -I ac_rated

[0064] I ac_max =I ac_rated

[0065] In other optional embodiments of the present application, when the battery current is limited preferentially, step S304 is executed to determine the maximum current value of each module in turn using the total current value, and also includes: when the battery is in a fully charged state and the current of the photovoltaic module is not controlled, determining that the maximum current value of the battery is the same in magnitude and opposite in direction to the rated current value when the battery is charged; determining that the maximum current value of the photovoltaic module is zero; and determining the total current value as the maximum current value of the inverter AC port.

[0066] In this embodiment, the battery current is limited preferentially, the battery is in a fully charged state, and the current of the photovoltaic module is not controlled (ie, the PV drive is turned off).

[0067] I bat_max =–I bat_chg_rated

[0068] I pv_max =0

[0069] I ac_max =I sys_total

[0070] The above are several situations where battery current is limited first. The following are several situations where PV current is limited first.

[0071] According to an optional embodiment of the present application, when the current of the photovoltaic module is preferentially limited, step S304 is executed to determine the maximum current value of each module in turn using the total current value, including: when the battery is discharged at full power and the current of the photovoltaic module is controlled, the difference obtained by subtracting the rated current value of the inverter AC port, the rated current value when the battery is charged, and the rated current value when the battery is discharged from the total current value is determined as the maximum current value of the photovoltaic module; the rated current value when the battery is discharged is determined as the maximum current value of the battery; and the rated current value of the inverter AC port is determined as the maximum current value of the inverter AC port.

[0072] This embodiment is a situation where the current of the photovoltaic module is limited preferentially, the battery is discharged at full power, and the current of the photovoltaic module is controlled.

[0073] I pv_max =I sys_total -I ac_rated -I bat_chg_rated -I bat_dchg_rated

[0074] I bat_max =I bat_dchg_rated

[0075] I ac_max =I ac_rated

[0076] According to another optional embodiment of the present application, when the current of the photovoltaic module is preferentially limited, step S304 is executed to determine the maximum current value of each module in turn using the total current value, and also includes: when the battery discharge is controlled and the current of the photovoltaic module is not controlled, determining that the maximum current value of the photovoltaic module is zero; subtracting the rated current value of the inverter AC port and the rated current value of the battery during charging from the total current value to obtain the difference as the maximum current value of the battery; and determining the rated current value of the battery as the maximum current value of the inverter AC port.

[0077] This embodiment is a situation where the current of the photovoltaic module is limited preferentially, the battery discharge is controlled, and the current of the photovoltaic module is not controlled (ie, the PV drive is turned off).

[0078] I pv_max =0

[0079] I bat_max =I sys_total -I ac_rated -I bat_chg_rated

[0080] I ac_max =I bat_rated

[0081] In some optional embodiments of the present application, when the current of the photovoltaic module is preferentially limited, step S304 is executed to determine the maximum current value of each module in turn using the total current value, and also includes: when the battery charging is controlled and the current of the photovoltaic module is not controlled, determining that the maximum current value of the photovoltaic module is zero; determining that the maximum current value of the battery and the difference obtained by subtracting the rated current value of the inverter AC port from the total current value are equal in magnitude and opposite in direction; and determining the rated current value of the inverter AC port as the maximum current value of the inverter AC port.

[0082] This embodiment is a situation where the current of the photovoltaic module is limited preferentially, the battery charging is controlled, and the current of the photovoltaic module is not controlled (ie, the PV drive is turned off).

[0083] I pv_max =0

[0084] I bat_max =-(I sys_total -I ac_rated )

[0085] I ac_max =I ac_rated

[0086] In other optional embodiments of the present application, when the current of the photovoltaic module is limited preferentially, step S304 is executed to determine the maximum current value of each module in turn using the total current value, and also includes: when the battery is charged at full power and the current of the photovoltaic module is not controlled, determining that the maximum current value of the photovoltaic module is zero; determining that the maximum current value of the battery is equal to the rated current value of the battery during charging, but opposite in direction; and determining the total current value as the maximum current value of the inverter AC port.

[0087] This embodiment is to prioritize limiting the current of the photovoltaic module, the battery is charged at full power, and the current of the photovoltaic module is not controlled (that is, the PV drive is turned off).

[0088] I pv_max =0

[0089] I bat_max =-I bat_chg_rated

[0090] I ac_max =I sys_total

[0091] I sys_total The output zero point can be adjusted as required.

[0092] As an optional embodiment of the present application, executing step S306 uses the maximum current value of each module to control the current of each module, which is achieved by the following method: determining a minimum current value from the maximum current value of each module and the target current value of each module; using the minimum current value and the current current value of each module as inputs of a linear controller; and using the output of the linear controller to control the current of each module.

[0093] pass Figure 4 The respective maximum current values ​​of the power loop output shown limit the maximum currents on the PV side, the BAT side and the AC side.

[0094] Figure 5 is a schematic diagram of controlling the PV side current by using a closed-loop control system according to an embodiment of the present application, such as Figure 5 As shown, first, from the maximum current value of the photovoltaic module (I Pv_max ) and the target current value of the PV module (I pv_ref ) to determine a minimum value, and then compare this minimum value with the current current value (I pv ) as the input of the PI controller and output a duty cycle (duty_pv). The duty cycle output by the PI controller is used to limit the maximum current of the photovoltaic module.

[0095] Figure 6 is a schematic diagram of controlling the BAT side current by using a closed-loop control system according to an embodiment of the present application, such as Figure 6 As shown, first, the maximum current value of the battery (I bat_max ) and the target current value of the battery (I bat_ref ) to determine a minimum value, and then compare this minimum value with the current current value of the battery collected in real time (I bat ) is used as the input of the PI controller and outputs a duty cycle (duty_bat). The duty cycle output by the PI controller is used to limit the maximum current of the battery.

[0096] Figure 7 is a schematic diagram of controlling the current of the inverter AC output port by using a closed-loop control system according to an embodiment of the present application, such as Figure 7 As shown, first, the maximum current value (I ac_max ) and the target current value of the inverter AC port (I ac_ref ) to determine a minimum value, and then compare this minimum value with the current current value (I ac ) is used as the input of the PI controller and outputs a duty cycle (duty_ac). The duty cycle output by the PI controller is used to limit the maximum current of the inverter AC port.

[0097] The above technical solution proposed in this application not only realizes the rapid control of the grid-connected power of the energy storage system, but also ensures the stability of the bus voltage and has good dynamic response performance.

[0098] The embodiment of the present application also provides an electronic device, comprising: at least one processor; and a memory connected to the at least one processor in communication. The memory stores a computer program executable by the at least one processor, and the computer program is used to enable the electronic device to perform the method of the embodiment of the present application when executed by the at least one processor.

[0099] An embodiment of the present application also provides a non-transitory machine-readable medium storing a computer program, wherein the computer program, when executed by a processor of a computer, is used to cause the computer to execute the method of the embodiment of the present application.

[0100] The embodiment of the present application also provides a computer program product, including a computer program, wherein the computer program, when executed by a processor of a computer, is used to cause the computer to execute the method of the embodiment of the present application.

[0101] refer to Figure 8 , the structural block diagram of the electronic device that can be used as the server or client of the embodiment of the present application will now be described, which is an example of the hardware device that can be applied to various aspects of the present application. The electronic device is intended to represent various forms of digital electronic computer equipment, such as laptop computers, desktop computers, workbenches, personal digital assistants, servers, blade servers, mainframe computers and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices and other similar computing devices. The components shown herein, their connections and relationships, and their functions are only examples, and are not intended to limit the implementation of the present application described and / or required herein.

[0102] like Figure 8 As shown, the electronic device includes a computing unit 801, which can perform various appropriate actions and processes according to a computer program stored in a read-only memory (ROM) 802 or a computer program loaded from a storage unit 808 into a random access memory (RAM) 803. In the RAM 803, various programs and data required for the operation of the electronic device can also be stored. The computing unit 801, the ROM 802, and the RAM 803 are connected to each other via a bus 804. An input / output (I / O) interface 805 is also connected to the bus 804.

[0103] Multiple components in the electronic device are connected to the I / O interface 805, including: an input unit 806, an output unit 807, a storage unit 808, and a communication unit 809. The input unit 806 can be any type of device that can input information to the electronic device, and the input unit 806 can receive input digital or character information, and generate key signal input related to user settings and / or function control of the electronic device. The output unit 807 can be any type of device that can present information, and can include but is not limited to a display, a speaker, a video / audio output terminal, a vibrator, and / or a printer. The storage unit 808 can include but is not limited to a disk, an optical disk. The communication unit 809 allows the electronic device to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks, and can include but is not limited to a modem, a network card, an infrared communication device, a wireless communication transceiver, and / or a chipset, such as a Bluetooth device, a WiFi device, a WiMax device, a cellular communication device, and / or the like.

[0104] The computing unit 801 can be various general and / or special processing components with processing and computing capabilities. Some examples of the computing unit 801 include, but are not limited to, CPUs, graphics processing units (GPUs), various dedicated artificial intelligence (AI) computing chips, various computing units that run machine learning model algorithms, digital signal processors (DSPs), and any appropriate processors, controllers, microcontrollers, etc. The computing unit 801 performs the various methods and processes described above. For example, in some embodiments, the method embodiments of the present application may be implemented as a computer program, which is tangibly contained in a machine-readable medium, such as a storage unit 808. In some embodiments, part or all of the computer program can be stored in a ROM.

[0105] 802 and / or the communication unit 809 are loaded and / or installed on the electronic device. In some embodiments, the computing unit 801 can be configured to execute the above method in any other appropriate manner (for example, by means of firmware).

[0106] The computer program for implementing the method of the embodiment of the present application can be written in any combination of one or more programming languages. These computer programs can be provided to a processor or controller of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that when the computer program is executed by the processor or controller, the functions / operations specified in the flow chart and / or block diagram are implemented. The computer program can be executed entirely on the machine, partially on the machine, partially on the machine as a stand-alone software package and partially on a remote machine, or entirely on a remote machine or server.

[0107] In the context of the present application embodiment, machine-readable medium can be a tangible medium that can contain or store a program for use by an instruction execution system, device or equipment or used in combination with an instruction execution system, device or equipment. Machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. Machine-readable signal medium can include but is not limited to electronic, magnetic, optical, electromagnetic or infrared systems, devices or equipment, or any suitable combination of the above. More specific examples of machine-readable storage media can include electrical connections based on one or more lines, portable computer disks, hard disks, random access memories (RAM), read-only memories (ROM), erasable programmable read-only memories (EPROM or flash memory), optical fibers, portable compact disk read-only memories (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the above.

[0108] It should be noted that the term "including" and its variations used in the embodiments of the present application are open inclusions, that is, "including but not limited to". The term "based on" means "based at least in part on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments". The modifications of "one" and "multiple" mentioned in the embodiments of the present application are illustrative and not restrictive. Those skilled in the art should understand that unless otherwise clearly indicated in the context, it should be understood as "one or more".

[0109] The user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in the embodiments of the present application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant laws, regulations and standards of relevant countries and regions, and provide corresponding operation entrances for users to choose to authorize or refuse.

[0110] The various steps described in the method implementation methods provided in the embodiments of the present application can be performed in different orders and / or in parallel. In addition, the method implementation methods may include additional steps and / or omit the steps shown. The scope of protection of the present application is not limited in this respect.

[0111] The term "embodiment" in this specification refers to specific features, structures or characteristics described in conjunction with the embodiment that can be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily mean the same embodiment, nor does it mean that it is mutually exclusive with other embodiments and is independent or optional. The various embodiments in this specification are described in a related manner, and the same or similar parts between the various embodiments refer to each other. In particular, for the device, equipment, and system embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts refer to the partial description of the method embodiment.

[0112] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of patent protection. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the scope of protection of the present application. Therefore, the scope of protection of the present application shall be subject to the attached claims.

Claims

1. A method for controlling the grid-connected power of an energy storage system, It is characterized in that The energy storage system comprises: an inverter and a battery, wherein the inverter is connected to the battery and the photovoltaic module respectively, and the method comprises: Obtaining a total current value of the energy storage system, wherein the total current value is the sum of the maximum current value of the inverter AC port, the maximum current value of the battery, and the maximum current value of the photovoltaic module; Determine a current limiting order of each module in the energy storage system, and determine the maximum current value of each module in sequence according to the limiting order using the total current value; The current of each module is controlled by utilizing the maximum current value of each module.

2. The method according to claim 1, It is characterized in that Get the total current value of the energy storage system, including: The power of the energy storage system load and the target power of the load are input into a linear controller to obtain the total current value.

3. The method according to claim 1, It is characterized in that When limiting the current of the battery first, determining the maximum current value of each module in sequence by using the total current value includes: When the battery is in a discharging state, the difference obtained by subtracting the rated current value of the inverter AC port, the rated current value of the battery when charging, and the rated current value of the photovoltaic module from the total current value is determined as the maximum current value of the battery; Determining the rated current value of the photovoltaic module as the maximum current value of the photovoltaic module; The rated current value of the inverter AC port is determined as the maximum current value of the inverter AC port.

4. The method according to claim 1, It is characterized in that When limiting the current of the battery first, determining the maximum current value of each module in sequence by using the total current value includes: When the battery is in a charging state, a difference obtained by subtracting the rated current value of the inverter AC port and the rated current value of the photovoltaic module from the total current value is determined as the maximum current value of the battery; Determining the rated current value of the photovoltaic module as the maximum current value of the photovoltaic module; The rated current value of the inverter AC port is determined as the maximum current value of the inverter AC port.

5. The method according to claim 1, It is characterized in that When limiting the current of the battery first, determining the maximum current value of each module in sequence by using the total current value includes: When the battery is in a fully charged state, determining that the maximum current value of the battery is equal in magnitude and opposite in direction to the rated current value of the battery when it is charged; The difference obtained by subtracting the rated current value of the inverter AC port from the total current value is determined as the maximum current value of the photovoltaic module; The rated current value of the inverter AC port is determined as the maximum current value of the inverter AC port.

6. The method according to claim 1, It is characterized in that When limiting the current of the battery first, determining the maximum current value of each module in sequence by using the total current value includes: When the battery is in a fully charged state and the current of the photovoltaic module is not controlled, determining that the maximum current value of the battery is the same in magnitude and opposite in direction to the rated current value of the battery when it is charged; Determine that the maximum current value of the photovoltaic module is zero; The total current value is determined as the maximum current value of the inverter AC port.

7. The method according to claim 1, It is characterized in that When limiting the current of the photovoltaic assembly first, the maximum current value of each module is determined in sequence using the total current value, including: When the battery is discharged at full power and the current of the photovoltaic module is controlled, the difference obtained by subtracting the rated current value of the inverter AC port, the rated current value of the battery when charging, and the rated current value of the battery when discharging from the total current value is determined as the maximum current value of the photovoltaic module; Determine the rated current value of the battery during discharge as the maximum current value of the battery; The rated current value of the inverter AC port is determined as the maximum current value of the inverter AC port.

8. The method according to claim 1, It is characterized in that When limiting the current of the photovoltaic assembly first, the maximum current value of each module is determined in sequence using the total current value, including: When the discharge of the battery is controlled and the current of the photovoltaic assembly is not controlled, determining that the maximum current value of the photovoltaic assembly is zero; Determine the difference between the rated current value of the inverter AC port and the rated current value of the battery when charging, obtained by subtracting the rated current value of the battery from the total current value as the maximum current value of the battery; The rated current value of the battery is determined as the maximum current value of the inverter AC port.

9. The method according to claim 1, It is characterized in that When limiting the current of the photovoltaic assembly first, the maximum current value of each module is determined in sequence using the total current value, including: When the battery charging is controlled and the current of the photovoltaic assembly is not controlled, determining that the maximum current value of the photovoltaic assembly is zero; Determine that the maximum current value of the battery and the difference obtained by subtracting the rated current value of the inverter AC port from the total current value are equal in magnitude and opposite in direction; The rated current value of the inverter AC port is determined as the maximum current value of the inverter AC port.

10. The method according to claim 1, It is characterized in that When limiting the current of the photovoltaic assembly first, the maximum current value of each module is determined in sequence using the total current value, including: When the battery is charged at full power and the current of the photovoltaic assembly is not controlled, determining that the maximum current value of the photovoltaic assembly is zero; Determining that the maximum current value of the battery is equal in magnitude to the rated current value of the battery during charging, but opposite in direction; The total current value is determined as the maximum current value of the inverter AC port.

11. The method according to any one of claims 1 to 10, It is characterized in that The current of each module is controlled by using the maximum current value of each module, including: Determine a minimum current value from the maximum current value of each module and the target current value of each module; Using the minimum current value and the current current value of each module as input of a linear controller; The output of the linear controller is used to control the current of each module.

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