Energy storage module control method and control terminal

Abstract

The present invention provides a control method and control terminal for an energy storage module. The control method includes: obtaining the voltage of a DC bus and the voltage of a battery; subtracting the battery voltage from the battery given voltage to obtain a battery voltage error, and inputting the battery voltage error into a first voltage loop to obtain a first reference current; subtracting the DC bus voltage from the bus given voltage to obtain a bus voltage error, and inputting the bus voltage error into a second voltage loop to obtain a second reference current; according to preset conditions, recording the first reference current or the second reference current as a target reference current; inputting the target reference current into a current loop to obtain a target control quantity, and controlling the bidirectional converter according to the target control quantity. The present invention integrates charging control and discharging control, and can achieve charging and discharging through only one control method. There is no need to switch the control method according to the battery charging and discharging conditions, and the control process is simple.

Description

Technical Field

[0001] The present invention relates to the technical field of power supplies, and in particular to a control method and a control terminal for an energy storage module. Background Art

[0002] As global energy and environmental challenges grow, photovoltaic power generation technology has become a hot topic of research and development worldwide. Due to the intermittent and fluctuating nature of photovoltaic power, directly connecting it to the grid can degrade grid power quality. Therefore, energy storage modules are often installed on the photovoltaic side to mitigate grid fluctuations through their charge and discharge levels.

[0003] In the prior art, the charging and discharging of energy storage modules are usually controlled separately, with one control mode used during charging and another control mode used during discharging. Constant switching between the two control modes is required, making the control process complex. Summary of the Invention

[0004] The embodiments of the present invention provide a control method and a control terminal for an energy storage module to solve the problem in the prior art that the charging and discharging of energy storage batteries are controlled separately and the control process is complicated.

[0005] In a first aspect, an embodiment of the present invention provides a control method for an energy storage module, the energy storage module comprising: a battery and a bidirectional converter, wherein the battery is connected to a DC bus via the bidirectional converter; when the battery is discharged, the bidirectional converter boosts the voltage; the control method comprises:

[0006] Get the voltage of the DC bus and the battery;

[0007] Subtracting the battery voltage from the battery given voltage to obtain a battery voltage error, and inputting the battery voltage error into the first voltage loop to obtain a first reference current;

[0008] Subtracting the DC bus voltage from the bus given voltage to obtain a bus voltage error, and inputting the bus voltage error into the second voltage loop to obtain a second reference current;

[0009] According to a preset condition, recording the first reference current or the second reference current as a target reference current;

[0010] The target reference current is input into the current loop to obtain the target control quantity, and the bidirectional converter is controlled according to the target control quantity.

[0011] In a second aspect, an embodiment of the present invention provides a control terminal comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the method for controlling the energy storage module according to the first aspect or any possible implementation of the first aspect are implemented.

[0012] The embodiment of the present invention provides a control method and control terminal for an energy storage module. The energy storage module includes: a battery and a bidirectional converter, wherein the battery is connected to the DC bus through the bidirectional converter; when the battery is discharged, the bidirectional converter boosts the voltage; the above-mentioned control method includes: obtaining the voltage of the DC bus and the voltage of the battery; subtracting the battery voltage from the battery given voltage to obtain the battery voltage error, and inputting the battery voltage error into the first voltage loop to obtain the first reference current; subtracting the DC bus voltage from the bus given voltage to obtain the bus voltage error, and inputting the bus voltage error into the second voltage loop to obtain the second reference current; according to preset conditions, the first reference current or the second reference current is recorded as the target reference current; the target reference current is input into the current loop to obtain the target control quantity, and the bidirectional converter is controlled according to the target control quantity. In the embodiment of the present invention, the charging control and the discharging control are integrated, and charging and discharging can be achieved through only one control method, without switching the control method according to the battery charging and discharging conditions, and the control process is simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0014] Figure 1 It is a topological diagram of an energy storage module;

[0015] Figure 2 This is a flow chart of an implementation method of a control method for an energy storage module provided by an embodiment of the present invention;

[0016] Figure 3 This is a topological diagram of the connection between an energy storage module and a power grid provided by an embodiment of the present invention;

[0017] Figure 4 This is a PI control block diagram of an energy storage module provided by an embodiment of the present invention;

[0018] Figure 5 1 is a schematic structural diagram of a control device for an energy storage module provided by an embodiment of the present invention;

[0019] Figure 6 is a schematic diagram of a control terminal provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0020] In the following description, specific details such as particular system structures and techniques are provided for purposes of illustration, not limitation, to facilitate a thorough understanding of the embodiments of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

[0021] In order to make the purpose, technical solutions and advantages of the present invention more clear, specific embodiments will be described below with reference to the accompanying drawings.

[0022] See also Figure 2 , which shows a flow chart of an implementation method of a control method for an energy storage module provided by an embodiment of the present invention, and also refers to Figure 4 , as detailed below:

[0023] Figure 1 The topology diagram of the energy storage module 11 is shown. The energy storage module 11 includes: a battery 111 and a bidirectional converter 112. The battery 111 is connected to the DC bus through the bidirectional converter 112. When the battery 111 discharges, the bidirectional converter 112 boosts the voltage. The above control method includes:

[0024] S101: Obtain the voltage Ubusfb of the DC bus and the voltage Ubatfb of the battery 111;

[0025] S102: Subtract the voltage Ubatfb of the battery 111 from the given battery voltage Ubatref to obtain a battery voltage error, and input the battery voltage error into a first voltage loop to obtain a first reference current;

[0026] S103: Subtracting the DC bus voltage Ubusfb from the bus given voltage Ubusref to obtain a bus voltage error, and inputting the bus voltage error into a second voltage loop to obtain a second reference current;

[0027] S104: Recording the first reference current or the second reference current as the target reference current Iref according to a preset condition;

[0028] S105: Input the target reference current Iref into the current loop to obtain a target control variable, and control the bidirectional converter 112 according to the target control variable.

[0029] In an embodiment of the present invention, two voltage loops are provided, and the battery voltage error and the bus voltage error are input into the two voltage loops, respectively, to obtain two reference currents. A reference current is selected according to preset conditions and input into the current loop to control the bidirectional converter 112. For example, when the battery 111 is charging, the voltage Ubatfb of the battery 111 changes continuously, the first voltage loop is activated, and the first reference current is input into the current loop to perform charging control; and vice versa. The embodiment of the present invention integrates charging and discharging control, and only one control method is used to perform charging control and discharging control. There is no need to switch the control mode according to the battery charging and discharging conditions, and the control process is simple.

[0030] Since bidirectional converter 112 is connected to the DC bus, the bus reference voltage Ubusref is the rated output voltage of bidirectional converter 112 when battery 111 is discharging. The DC bus voltage Ubusfb is the actual output voltage of bidirectional converter 112 obtained by actual sampling when battery 111 is discharging. The battery 111 voltage Ubatfb is the actual voltage between the positive and negative electrodes of battery 112 obtained by actual sampling.

[0031] In a possible implementation, before S105, the control method may further include:

[0032] S106: Determine the difference between the DC bus voltage Ubusfb and the bus reference voltage Ubusref, which is recorded as a first difference;

[0033] S107: If the first difference is greater than the first preset value and the target reference current Iref is greater than 0, turning off the driving of the bidirectional converter 112;

[0034] S108: Otherwise, execute step S105.

[0035] Similar to the existing control method, when the target reference current Iref of the input current loop is less than 0, the battery 111 is charged; when the target reference current Iref is greater than 0, the battery 111 is discharged. However, for example, when the energy storage module 11 is applied to a photovoltaic system, when the photovoltaic system is turned on, the control method of steps S101 or at least S105 may fail. In an embodiment of the present invention, when the voltage Ubusfb of the DC bus is greater than the given bus voltage Ubusref (the first difference is greater than the first preset value), it indicates that the voltage Ubusfb of the DC bus is too high and the battery 111 cannot continue to discharge. However, if the target reference current Iref is greater than 0 at this time, it still indicates that the battery 111 is discharging, indicating that the above-mentioned control method fails at this time, and the drive of the bidirectional converter 112 is turned off to prevent the battery 111 from continuing to discharge.

[0036] In a possible implementation, the first preset voltage may be 15V.

[0037] Specifically, the value of the first preset voltage can be set according to actual application requirements.

[0038] In a possible implementation, before S105, the control method may further include:

[0039] S109: Determine the difference between the voltage Ubatfb of the battery 111 and the given battery voltage Ubatref, which is recorded as a second difference;

[0040] S1010: If the second difference is greater than the second preset value and the target reference current Iref is less than 0, turning off the driving of the bidirectional converter 112;

[0041] S1011: Otherwise, the target reference current Iref is input into the current loop to obtain a target control variable, and the bidirectional converter 112 is controlled according to the target control variable.

[0042] Similarly, when the voltage Ubatfb of battery 111 is greater than the given battery voltage Ubatref (the second difference is greater than the second preset value), it indicates that the voltage Ubatfb of battery 111 is already very high. Continuing to charge battery 111 will result in overcharging, and further charging is impossible. If the target reference current Iref is less than 0 at this time, and the battery 111 is still instructed to charge, it indicates that the above control method has failed. The bidirectional converter 112 is turned off to prevent overcharging and damage to battery 111.

[0043] In a possible implementation, the second preset voltage may be 2V.

[0044] Specifically, the value of the second preset voltage can be set according to actual application requirements.

[0045] In one possible implementation, reference Figure 3 The DC bus is also connected to the first end of the inverter module 13 and the photovoltaic module 12; the second end of the inverter module 13 is connected to the grid; wherein the bus given voltage Ubusref when the energy storage module 11 is charging is different from the bus given voltage Ubusref when the energy storage module 11 is discharging;

[0046] The rated DC output voltage of the inverter module 13 is greater than the bus reference voltage Ubusref when the energy storage module 11 is charging;

[0047] The busbar given voltage Ubusref when the energy storage module 11 is discharging is greater than the rated output voltage of the photovoltaic module 12;

[0048] The rated output voltage of the photovoltaic module 12 is greater than the rated DC output voltage of the inverter module 13 .

[0049] In an embodiment of the present invention, the energy storage module 11 is applied to a photovoltaic system, and the power circuit is determined by setting the rated output voltage of each module. When the battery 111 is charging, the rated output voltage of the photovoltaic module 12 is the largest, and the rated DC output voltage of the inverter module 13 is second. It can be seen that when the battery 111 is charging, the photovoltaic module 12 and the power grid jointly supply power to the battery 111, with the photovoltaic module 12 providing power first, followed by the power grid. When the battery 111 is discharging, the battery 111 is provided with power first, followed by photovoltaics. In an embodiment of the present invention, photovoltaic energy is used first, and the energy storage module 11 is combined to smooth out power grid fluctuations, fully utilize renewable energy, save energy, and ensure the stability of the power grid.

[0050] In a possible implementation manner, the busbar given voltage Ubusref=A-10 when the energy storage module 11 is charging; the busbar given voltage Ubusref=A+20 when the energy storage module 11 is discharging;

[0051] InvBusRef=A; PVBusRef=A+10; BatBusRef=A+20;

[0052] Wherein, InvBusRef is the rated DC output voltage of the inverter module 13 , PVBusRef is the rated output voltage of the photovoltaic module 12 , and A is a constant.

[0053] Specifically, the value of each parameter can be set according to application requirements.

[0054] In a possible implementation, the above method may further include:

[0055] S1012: If the energy storage module 11 is charging and the output power of the photovoltaic module 12 is less than the charging power of the energy storage module 11, control the inverter module 13 to supply power to the DC bus;

[0056] S1013: If the energy storage module 11 is charging and the output power of the photovoltaic module 12 is not less than the charging power of the energy storage module 11, control the inverter module 13 to be connected to the grid according to the first power;

[0057] S1014: If the energy storage module 11 is discharged, the inverter module 13 is controlled to be grid-connected according to the second power.

[0058] In this embodiment of the present invention, when the energy storage module 11 is charging, if the output power of the photovoltaic module 12 is insufficient, the grid will supply energy through the inverter module 13 to supplement the energy deficit. If the output power of the photovoltaic module 12 exceeds the power required to charge the energy storage module 11, the inverter module 13 can be connected to the grid to feed the excess energy back to the grid. When the energy storage module 11 is discharging, the energy storage module 11 and the photovoltaic module 12 are connected to the grid to feed energy back to the grid.

[0059] In a possible implementation, S1013 may include:

[0060] 1. If the difference between the output power of the photovoltaic module 12 and the charging power of the energy storage module 11 is not greater than the preset power, the first power is equal to the difference between the output power of the photovoltaic module 12 and the charging power of the energy storage module 11;

[0061] 2. If the difference between the output power of the photovoltaic module 12 and the charging power of the energy storage module 11 is greater than the preset power, the first power is equal to the preset power;

[0062] 3. Control the inverter module 13 to be connected to the grid according to the first power;

[0063] S1014 may include:

[0064] 1. If the sum of the output power of the photovoltaic module 12 and the discharge power of the energy storage module 11 is not greater than the preset power, the second power is equal to the sum of the output power of the photovoltaic module 12 and the charging power of the energy storage module 11;

[0065] 2. If the sum of the output power of the photovoltaic module 12 and the discharge power of the energy storage module 11 is greater than the preset power, the second power is equal to the preset power;

[0066] 3. Control the inverter module 13 to be connected to the grid according to the second power.

[0067] In this embodiment of the present invention, to prevent reverse flow, a grid-connected power limit (preset power) is set. If the grid-connected power exceeds the preset power, the grid is fed in at the preset power to prevent reverse flow caused by excessive grid-connected power. The preset power value can be set according to actual application requirements.

[0068] In one possible implementation, reference Figure 4 , S102 may include:

[0069] S1021: Inputting the battery voltage error into the first PI controller to obtain a first initial reference current; inputting the first initial reference current into the first limiter controller, and multiplying the output of the first limiter controller by -1 to obtain a first reference current.

[0070] The battery voltage error is input into the first PI controller to obtain a first initial reference current, which is multiplied by −1 to implement constant voltage charging control of the battery 111 .

[0071] In one possible implementation, reference Figure 4 , S103 may include:

[0072] S1022: Input the bus voltage error into the second PI controller to obtain a second initial reference current, and input the second initial reference current into the second limiter controller to obtain a second reference current.

[0073] In an embodiment of the present invention, the bus voltage error (i.e., the difference between the rated output voltage and the actual output voltage of the bidirectional converter 112 when the battery 111 is discharged) is input into the second PI controller to obtain a second initial reference current to achieve constant voltage discharge of the battery 111.

[0074] The first limiter controller and the second limiter are both used for current limiting, and limit the maximum charging current and the maximum discharging current allowed by the battery 111 .

[0075] In one possible implementation, reference Figure 4 , the preset condition may be: selecting the larger value of the first reference current and the second reference current as the target reference current Iref.

[0076] Based on the above, the first voltage loop and the second voltage loop both adopt a constant voltage control method, and the larger value of the first reference current and the second reference current can be directly selected as the target reference current Iref.

[0077] For example, when battery 111 is discharging, the battery set voltage Ubatref is typically greater than the battery 111 voltage Ubatfb, and the first reference current is negative. Due to the discharge of battery 111, the DC bus voltage Ubusfb is typically higher, greater than the bus set voltage Ubusref, and thus the second reference current is also negative. However, the battery 111 voltage is typically much lower than the DC bus voltage Ubusfb. Therefore, the first reference current is greater than the second reference current, and the first reference current is the target reference current Iref, and the charging of battery 111 is controlled via the first voltage loop. Similarly, when battery 111 is discharging, the first reference current is typically less than the second reference current, and the discharge of battery 111 is controlled via the second voltage loop.

[0078] In one possible implementation, reference Figure 4 , S105 may include:

[0079] Obtaining the current Ifb of the bidirectional converter 112;

[0080] Subtract the current Ifb of the bidirectional converter 112 from the target reference current Iref to obtain a current difference;

[0081] The current difference is input into the third PI controller to obtain a current control variable, and a PWM wave is generated according to the current control variable to control the bidirectional converter.

[0082] The current loop may also include a limiter to limit the magnitude of the current.

[0083] The current Ifb of the bidirectional converter 112 is the actual sampled charging current or discharging current flowing through the bidirectional converter 112. The current Ifb of the bidirectional converter 112 is positive or negative, indicating the direction of the current.

[0084] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0085] The following are device embodiments of the present invention. For details not fully described therein, reference may be made to the corresponding method embodiments described above.

[0086] Figure 5 A schematic structural diagram of a control device for an energy storage module provided by an embodiment of the present invention is shown. For ease of explanation, only the portion related to the embodiment of the present invention is shown, which is described in detail as follows:

[0087] like Figure 1 As shown, the energy storage module 11 includes: a battery 111 and a bidirectional converter 112, the battery 111 is connected to the DC bus through the bidirectional converter 112; when the battery 111 is discharged, the bidirectional converter 112 boosts the voltage; Figure 5 , the above-mentioned control device includes:

[0088] The parameter acquisition module 21 is used to obtain the voltage Ubusfb of the DC bus and the voltage Ubatfb of the battery 111;

[0089] A first voltage loop control module 22 is configured to subtract the voltage Ubatfb of the battery 111 from the given battery voltage Ubatref to obtain a battery voltage error, and input the battery voltage error into the first voltage loop to obtain a first reference current;

[0090] A second voltage loop control module 23 is configured to subtract the DC bus voltage Ubusfb from the bus given voltage Ubusref to obtain a bus voltage error, and input the bus voltage error into a second voltage loop to obtain a second reference current;

[0091] The loop selection module 24 is configured to record the first reference current or the second reference current as the target reference current Iref according to a preset condition;

[0092] The current loop control module 25 is configured to input the target reference current Iref into the current loop to obtain a target control variable, and control the bidirectional converter 112 according to the target control variable.

[0093] In a possible implementation, the control device may further include:

[0094] A first difference determination module 26 is configured to determine a difference between the DC bus voltage Ubusfb and the bus reference voltage Ubusref, which is recorded as a first difference;

[0095] a first driving shut-down module 27 configured to shut down driving of the bidirectional converter 112 if the first difference is greater than a first preset value and the target reference current Iref is greater than 0;

[0096] The first jump module 28 is configured to execute the steps of inputting the target reference current Iref into the current loop to obtain a target control variable, and controlling the bidirectional converter 112 according to the target control variable.

[0097] In a possible implementation, the control device may further include:

[0098] A second difference determination module 29 is used to determine the difference between the voltage Ubatfb of the battery 111 and the given battery voltage Ubatref, which is recorded as a second difference;

[0099] a second driving shut-down module 210 , configured to shut down the driving of the bidirectional converter 112 if the second difference is greater than a second preset value and the target reference current Iref is less than 0;

[0100] The second jump module 211 is configured to execute the steps of inputting the target reference current Iref into the current loop to obtain a target control variable, and controlling the bidirectional converter 112 according to the target control variable.

[0101] In one possible implementation, reference Figure 3 The DC bus is also connected to the first end of the inverter module 13 and the photovoltaic module 12; the second end of the inverter module 13 is connected to the grid; wherein the bus given voltage Ubusref when the energy storage module 11 is charging is different from the bus given voltage Ubusref when the energy storage module 11 is discharging;

[0102] The rated DC output voltage of the inverter module 13 is greater than the bus reference voltage Ubusref when the energy storage module 11 is charging;

[0103] The busbar given voltage Ubusref when the energy storage module 11 is discharging is greater than the rated output voltage of the photovoltaic module 12;

[0104] The rated output voltage of the photovoltaic module 12 is greater than the rated DC output voltage of the inverter module 13 .

[0105] In a possible implementation, the control device may further include:

[0106] The first power control module 212 is configured to control the inverter module 13 to supply power to the DC bus if the energy storage module 11 is charging and the output power of the photovoltaic module 12 is less than the charging power of the energy storage module 11;

[0107] The second power control module 213 is configured to control the inverter module 13 to be grid-connected according to the first power if the energy storage module 11 is charging and the output power of the photovoltaic module 12 is not less than the charging power of the energy storage module 11;

[0108] The third power control module 214 is configured to control the inverter module 13 to be grid-connected at the second power if the energy storage module 11 is discharged.

[0109] In a possible implementation, the second power control module 213 may include:

[0110] The first judgment unit 2131 is configured to determine, if the difference between the output power of the photovoltaic module 12 and the charging power of the energy storage module 11 is not greater than a preset power, that the first power is equal to the difference between the output power of the photovoltaic module 12 and the charging power of the energy storage module 11;

[0111] The second judgment unit 2132 is configured to determine that the first power is equal to the preset power if the difference between the output power of the photovoltaic module 12 and the charging power of the energy storage module 11 is greater than a preset power;

[0112] A first grid-connected unit 2133, configured to control the inverter module 13 to be grid-connected according to a first power;

[0113] The third power control module 214 may include:

[0114] The third judgment unit 2141 is configured to determine, if the sum of the output power of the photovoltaic module 12 and the discharge power of the energy storage module 11 is not greater than a preset power, that the second power is equal to the sum of the output power of the photovoltaic module 12 and the charging power of the energy storage module 11;

[0115] The fourth judgment unit 2142 is configured to determine that the second power is equal to the preset power if the sum of the output power of the photovoltaic module 12 and the discharge power of the energy storage module 11 is greater than the preset power;

[0116] The second grid-connected unit 2143 is configured to control the inverter module 13 to be grid-connected according to the second power.

[0117] In a possible implementation, the first voltage loop control module 22 may include:

[0118] The first reference current output unit 221 is used to input the battery voltage error into the first PI controller to obtain a first initial reference current; input the first initial reference current into the first limit controller, and multiply the output of the first limit controller by -1 to obtain the first reference current.

[0119] In a possible implementation, the second voltage loop control module 23 may include:

[0120] The first reference current output unit 231 is configured to input the bus voltage error into the second PI controller to obtain a second initial reference current, and input the second initial reference current into the second limit controller to obtain a second reference current.

[0121] In a possible implementation, the condition may be: selecting a larger value of the first reference current and the second reference current as the target reference current Iref.

[0122] Figure 6 Schematic diagram of a control terminal provided by an embodiment of the present invention. Figure 6 As shown, the control terminal 5 of this embodiment includes: a processor 50 and a memory 51. The memory 51 is used to store a computer program 52, and the processor 50 is used to call and run the computer program 52 stored in the memory 51 to perform the steps in the above-mentioned control method embodiments of each energy storage module, such as Figure 2 Alternatively, the processor 50 is used to call and run the computer program 52 stored in the memory 51 to implement the functions of each module / unit in the above-mentioned device embodiments, such as Figure 5 The functions of modules 21 to 25 are shown.

[0123] For example, the computer program 52 may be divided into one or more modules / units, one or more modules / units being stored in the memory 51 and executed by the processor 50 to implement the present invention. One or more modules / units may be a series of computer program instruction segments capable of implementing specific functions, and the instruction segments are used to describe the execution process of the computer program 52 in the control terminal 5. For example, the computer program 52 may be divided into Figure 5 Modules / units 21 to 25 are shown.

[0124] The control terminal 5 can be a computing device such as a desktop computer, a notebook, a palmtop computer, or a cloud server. The control terminal 5 can include, but is not limited to, a processor 50 and a memory 51. Those skilled in the art will understand that Figure 6 It is only an example of the control terminal 5 and does not constitute a limitation of the control terminal 5. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the control terminal may also include input and output devices, network access devices, buses, etc.

[0125] The processor 50 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0126] The memory 51 can be an internal storage unit of the control terminal 5, such as the hard disk or memory of the control terminal 5. The memory 51 can also be an external storage device of the control terminal 5, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) card, a flash memory card, etc. equipped on the control terminal 5. Furthermore, the memory 51 can include both the internal storage unit of the control terminal 5 and an external storage device. The memory 51 is used to store computer programs and other programs and data required by the control terminal. The memory 51 can also be used to temporarily store data that has been output or is about to be output.

[0127] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0128] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0129] 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. Professionals and technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present invention.

[0130] In the embodiments provided by the present invention, it should be understood that the disclosed devices / control terminals and methods can be implemented in other ways. For example, the device / control terminal embodiments described above are merely illustrative. For example, the division of modules or units is merely a logical functional 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. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be through some interface, indirect coupling or communication connection of devices or units, and can be electrical, mechanical or other forms.

[0131] Units described as separate components may or may not be physically separate, and 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.

[0132] In addition, the functional units in the various embodiments of the present invention may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0133] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and when the computer program is executed by the processor, it can implement the steps of the above-mentioned various method embodiments. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form, etc. Computer-readable media may include: any entity or device that can carry computer program code, recording medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal and software distribution medium, etc.

[0134] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included in the scope of protection of the present invention.

Claims

1. A control method for an energy storage module, characterized in that: The energy storage module includes: a battery and a bidirectional converter, wherein the battery is connected to a DC bus through the bidirectional converter; when the battery is discharged, the bidirectional converter boosts the voltage; and the control method includes: Obtaining the voltage of the DC bus and the voltage of the battery; subtracting the battery voltage from the battery given voltage to obtain a battery voltage error, and inputting the battery voltage error into a first voltage loop to obtain a first reference current; subtracting the DC bus voltage from the bus given voltage to obtain a bus voltage error, and inputting the bus voltage error into a second voltage loop to obtain a second reference current; According to a preset condition, recording the first reference current or the second reference current as a target reference current; Inputting the target reference current into the current loop to obtain a target control variable, and controlling the bidirectional converter according to the target control variable; The DC bus is also connected to the first end of the inverter module and the photovoltaic module; the second end of the inverter module is connected to the power grid; the bus given voltage when the energy storage module is charging is different from the bus given voltage when the energy storage module is discharging; The rated DC output voltage of the inverter module is greater than the bus given voltage when the energy storage module is charged; The busbar given voltage when the energy storage module is discharged is greater than the rated output voltage of the photovoltaic module; The rated output voltage of the photovoltaic module is greater than the rated DC output voltage of the inverter module.

2. The control method of the energy storage module according to claim 1, characterized in that: Before inputting the target reference current into the current loop to obtain a target control variable and controlling the bidirectional converter according to the target control variable, the control method further includes: Determine a difference between the voltage of the DC bus and the given bus voltage, and record it as a first difference; If the first difference is greater than a first preset value and the target reference current is greater than 0, turning off the driving of the bidirectional converter; Otherwise, the step of inputting the target reference current into the current loop to obtain a target control variable and controlling the bidirectional converter according to the target control variable is performed.

3. The control method of the energy storage module according to claim 1, characterized in that: Before inputting the target reference current into the current loop to obtain a target control variable and controlling the bidirectional converter according to the target control variable, the control method further includes: Determine a difference between the voltage of the battery and a given voltage of the battery, and record the difference as a second difference; If the second difference is greater than a second preset value and the target reference current is less than 0, turning off the driving of the bidirectional converter; Otherwise, the step of inputting the target reference current into the current loop to obtain a target control variable and controlling the bidirectional converter according to the target control variable is performed.

4. The control method of the energy storage module according to claim 1, characterized in that: The control method further includes: If the energy storage module is charged and the output power of the photovoltaic module is less than the charging power of the energy storage module, controlling the inverter module to supply power to the DC bus; If the energy storage module is charged and the output power of the photovoltaic module is not less than the charging power of the energy storage module, controlling the inverter module to be grid-connected according to the first power; If the energy storage module is discharged, the inverter module is controlled to be connected to the grid according to the second power.

5. The control method of the energy storage module according to claim 4, characterized in that: The controlling the inverter module to be connected to the grid according to the first power comprises: If the difference between the output power of the photovoltaic module and the charging power of the energy storage module is not greater than a preset power, the first power is equal to the difference between the output power of the photovoltaic module and the charging power of the energy storage module; If the difference between the output power of the photovoltaic module and the charging power of the energy storage module is greater than the preset power, the first power is equal to the preset power; Controlling the inverter module to be connected to the grid according to the first power; The controlling the inverter module to be grid-connected according to the second power comprises: If the sum of the output power of the photovoltaic module and the discharge power of the energy storage module is not greater than the preset power, the second power is equal to the sum of the output power of the photovoltaic module and the charging power of the energy storage module; If the sum of the output power of the photovoltaic module and the discharge power of the energy storage module is greater than the preset power, the second power is equal to the preset power; The inverter module is controlled to be connected to the grid according to the second power.

6. The control method of the energy storage module according to any one of claims 1 to 3, characterized in that: Inputting the battery voltage error into a first voltage loop to obtain a first reference current includes: The battery voltage error is input into a first PI controller to obtain a first initial reference current; the first initial reference current is input into a first limiter controller, and the output of the first limiter controller is multiplied by -1 to obtain the first reference current.

7. The control method of the energy storage module according to claim 6, characterized in that: Inputting the bus voltage error into a second voltage loop to obtain a second reference current includes: The bus voltage error is input into a second PI controller to obtain a second initial reference current, and the second initial reference current is input into a second limiter controller to obtain the second reference current.

8. The control method of the energy storage module according to claim 7, characterized in that: The preset condition is: selecting the larger value of the first reference current and the second reference current as the target reference current.

9. A control terminal, characterized in that: The system comprises a processor and a memory, wherein the memory is used to store a computer program, and the processor is used to call and run the computer program stored in the memory to execute the control method of the energy storage module according to any one of claims 1 to 8.

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