Detailed Description
In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular system structures, techniques, etc. in order to provide a thorough understanding of the embodiments of the present application. It will be apparent, however, to one skilled in the art that the present application may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary detail.
In order to explain the technical means of the present invention, the following description will be given by way of specific examples.
Fig. 1 is a schematic diagram of an application environment of an energy storage method of an energy storage system according to an embodiment of the present invention, referring to fig. 1, the energy storage method is applied to the energy storage system 1 to the energy storage system n shown in fig. 1; the number of the energy storage systems is n, and n is a positive integer greater than or equal to 2.
In this embodiment, each energy storage system may include a controller, a photovoltaic boosting module, a conversion module, a charge and discharge control module, and an energy storage module (not shown). The photovoltaic boosting module is used for boosting the direct current generated by the corresponding photovoltaic unit and transmitting the boosted electric energy to the bus; the charging and discharging control module is used for absorbing electric energy from the bus to charge the energy storage module or paying off the electric energy stored by the energy storage module to the bus; the conversion module is used for converting the direct current of the bus into alternating current and then supplying power to a power grid or a load, or converting the alternating current sent by other energy storage systems into direct current and sending the direct current to the bus. The controller can obtain the stored electric energy size and the charging and discharging current size of the energy storage module of the current energy storage system and other information sent by the controller of the energy storage system.
The controller can control the charging and discharging control module to discharge the electric energy stored in the energy storage module to the bus, and control the conversion module to convert the direct current of the bus into alternating current and then send the alternating current to the conversion modules of other energy storage systems; the controller can control the conversion module to receive alternating current sent by the conversion modules of other energy storage systems, convert the alternating current into direct current and supply the direct current to the bus, and control the charging and discharging control module to obtain electric energy from the bus to charge the energy storage module.
The charge-discharge process between the energy storage system 1 and the energy storage system n is described below.
For example, when the energy storage system 1 discharges the energy storage system n, the photovoltaic boosting module 1 boosts the direct current generated by the photovoltaic unit 1 and sends the boosted direct current to the bus 1, the conversion module 1 obtains the direct current from the bus 1 and converts the direct current into alternating current and sends the alternating current to the conversion module n, the conversion module n converts the alternating current into the direct current and sends the direct current to the bus n, and the charge and discharge control module n absorbs electric energy from the bus n to charge the energy storage module n.
For example, when the energy storage system n discharges the energy storage system 1, the path of the current is that the photovoltaic boosting module n boosts the direct current generated by the photovoltaic unit n and sends the boosted direct current to the bus n, the conversion module n obtains the direct current from the bus n and converts the direct current into alternating current and then sends the alternating current to the conversion module 1, the conversion module 1 converts the alternating current into the direct current and then sends the direct current to the bus 1, and the charging and discharging control module 1 absorbs electric energy from the bus 1 to charge the energy storage module 1.
In this embodiment, each energy storage system may be connected to an external power grid, the energy storage systems and the external power grid are controlled by a switch S, and the switch S may be disposed at a position where each energy storage system converges, or at both positions, which does not limit the number of the switches S.
Fig. 2 is a schematic flow chart of an implementation of an energy storage method of an energy storage system according to an embodiment of the present invention, and for convenience of description, only a part related to the embodiment of the present invention is shown.
As shown in fig. 2, the energy storage method of the energy storage system may include the following steps:
step 201, obtaining current parameters of energy storage modules of each energy storage system.
In this step, each energy storage system corresponds to one energy storage module, and the current parameters of the energy storage module may include the size of stored electric energy and/or the size of charge and discharge current.
For example, the stored electrical energy level and/or the charging current level of the energy storage module may be obtained by a controller in the energy storage system, for example, the stored electrical energy level may be a percentage of the stored electrical energy to a rated capacity of the energy storage module.
Step 202, when the current parameter of the first energy storage module of the current energy storage system meets a first preset condition, determining a target energy storage system of which the current parameter of the energy storage module meets a second preset condition in each energy storage system.
The current energy storage system is any one of the energy storage systems, and the target energy storage system is an energy storage system of each energy storage system except the current energy storage system.
As illustrated in step 201, the current parameter of the energy storage module may be the stored electric energy, or may be the stored electric energy and the charging current, and the following describes in detail whether the current parameter of the first energy storage module satisfies the first preset condition in combination with these cases.
In a possible implementation manner, if the electric energy stored in the first energy storage module is greater than or equal to the first threshold, the current parameter of the first energy storage module of the current energy storage system satisfies the first preset condition.
The first threshold may be a preset value, such as a percentage. Specifically, after the controller acquires the stored electric energy of the energy storage module, the controller may compare the acquired value with the rated capacity of the storage module to obtain the percentage of the stored electric energy of the energy storage module, then compare the percentage of the stored electric energy of the energy storage module with a first threshold, and if the percentage of the stored electric energy of the energy storage module is greater than or equal to the first threshold, the current parameter of the first energy storage module meets a first preset condition; otherwise, the current parameter of the first energy storage module does not meet the first preset condition.
The first threshold value may be a numerical value in the same unit as the rated capacity of the memory module. At the moment, after the controller acquires the stored electric energy of the first energy storage module, the controller directly compares the stored electric energy of the first energy storage module with a first threshold value, and if the stored electric energy of the first energy storage module is greater than or equal to the first threshold value, the current parameter of the first energy storage module meets a first preset condition; otherwise, the current parameter of the first energy storage module does not meet the first preset condition. In another possible implementation manner, if the electric energy stored in the first energy storage module reaches a first threshold and the charging current of the first energy storage module is greater than a current threshold, the current parameter of the first energy storage module meets a first preset condition.
After the controller acquires the current charging current of the first energy storage module, the current charging current of the first energy storage module is compared with a current threshold, if the current charging current of the first energy storage module is greater than or equal to the current threshold, it is indicated that the electric energy stored by the first energy storage module is about to exceed the rated capacity and the charging current is large, the current parameter of the first energy storage module meets a first preset condition, and the electric energy collected by the current energy storage system can be transferred to other energy storage systems; otherwise, the current parameter of the first energy storage module does not meet the first preset condition.
In another possible implementation manner, if the electric energy stored in the first energy storage module is greater than or equal to the first threshold and the photovoltaic unit corresponding to the current energy storage system is still generating the electric energy, the current parameter of the first energy storage module meets the first preset condition.
Specifically, under the condition that the electric energy stored in the first energy storage module is greater than or equal to the first threshold, if the photovoltaic unit corresponding to the current energy storage system does not generate electric energy any more, the electric energy acquired by the current energy storage system does not need to be sent to the target energy storage system for storage, and under the condition that the photovoltaic unit corresponding to the current energy storage system is still generating electric energy, the electric energy acquired by the current energy storage system is sent to the target energy storage system for storage.
In the above embodiments, the first threshold value may be a value slightly smaller than the rated capacity or a value slightly smaller than 100%, and the first threshold value may also be a value equal to the rated capacity or 100%.
How to determine the target energy storage system is described below in conjunction with several scenarios.
In a possible implementation manner, if the electric energy stored by the energy storage module of the energy storage system is smaller than a second threshold, the current parameter of the energy storage system meets the second preset condition, and the energy storage system is the target energy storage system.
The second threshold may be a preset value, such as a percentage. Specifically, after the controller acquires the stored electric energy of the energy storage module, the controller may compare the acquired value with the rated capacity of the storage module to obtain the percentage of the stored electric energy of the energy storage module, then compare the percentage of the stored electric energy of the energy storage module with a second threshold, if the percentage of the stored electric energy of the energy storage module is smaller than the second threshold, the current parameter of the energy storage system meets a second preset condition, and the energy storage system is the target energy storage system; otherwise, the current parameter of the energy storage system does not meet the second preset condition.
The second threshold value may be a numerical value in the same unit as the rated capacity of the memory module. At this time, after the controller acquires the stored electric energy of the second energy storage module, the controller directly compares the stored electric energy of the energy storage module with a second threshold value, if the stored electric energy of the energy storage module is smaller than the second threshold value, the current parameter of the energy storage module meets a second preset condition, and the energy storage system is the target energy storage system; otherwise, the current parameter of the energy storage module does not meet the second preset condition.
In another possible implementation manner, if there is a difference between the charging current of the energy storage module of the energy storage system and the charging current of the current energy storage module that is greater than or equal to a third threshold, the current parameter of the energy storage system meets the second preset condition, and the energy storage system is the target energy storage system.
The current energy storage system can obtain the charging current of the energy storage modules of other energy storage systems through the controller, the charging current of the energy storage modules of the current energy storage system is compared with the charging current of the energy storage modules of other energy storage systems to obtain a current difference, and if the current difference is larger than a third threshold value, the other energy storage systems are target energy storage systems. In particular, the photovoltaic cells of the target energy storage system may be aged more severely, resulting in a lower electrical energy storage efficiency of the energy storage modules of the target energy storage system.
For example, the third threshold may be a preset value set according to actual needs.
In another possible implementation manner, if the stored electric energy of the energy storage module of some other energy storage system is smaller than the second threshold, and the difference between the charging current of the energy storage module of the other energy storage system and the charging current of the energy storage module of the current energy storage system is greater than or equal to the third threshold, the other energy storage system is the target energy storage system.
It should be noted that each energy storage system has its own maximum charging parameter limit, and the charging energy may come from its own photovoltaic unit and other energy storage systems, so that when the target energy storage system receives charging, the maximum charging parameter limit of the target energy storage system should not be exceeded, so as to ensure safe use of the target energy storage system.
And 203, under the condition that the target energy storage system exists, controlling the current energy storage system to be disconnected with an external power grid, and sending the electric energy acquired by the current energy storage system to the target energy storage system for storage.
For example, the current energy storage system may include a first photovoltaic boosting module, a first bus, a first conversion module, a first charge and discharge control module, and a first energy storage module, and the target energy storage system includes a second photovoltaic boosting module, a second bus, a second conversion module, a second charge and discharge control module, and a second energy storage module;
in step 203, sending the electric energy acquired by the current energy storage system to the target energy storage system for storage may specifically include:
the first photovoltaic boosting module performs boosting processing on direct current generated by the corresponding photovoltaic unit and sends the direct current to the first bus;
the first conversion module obtains direct current from the first bus, converts the direct current into alternating current and sends the alternating current to the second conversion module;
the second conversion module converts the alternating current into direct current and then sends the direct current to the second bus;
the second charging and discharging control module absorbs electric energy from the second bus to charge the second energy storage module.
The charge-discharge process between the energy storage system 1 and the energy storage system n is described below with reference to fig. 1.
For example, when the energy storage system 1 discharges the energy storage system n, the photovoltaic boosting module 1 boosts the direct current generated by the photovoltaic unit 1 and sends the boosted direct current to the bus 1, the conversion module 1 obtains the direct current from the bus 1 and converts the direct current into alternating current and sends the alternating current to the conversion module n, the conversion module n converts the alternating current into the direct current and sends the direct current to the bus n, and the charge and discharge control module n absorbs electric energy from the bus n to charge the energy storage module n.
For example, when the energy storage system n discharges the energy storage system 1, the path of the current is that the photovoltaic boosting module n boosts the direct current generated by the photovoltaic unit n and sends the boosted direct current to the bus n, the conversion module n obtains the direct current from the bus n and converts the direct current into alternating current and then sends the alternating current to the conversion module 1, the conversion module 1 converts the alternating current into the direct current and then sends the direct current to the bus 1, and the charging and discharging control module 1 absorbs electric energy from the bus 1 to charge the energy storage module 1.
Optionally, the sending the electric energy acquired by the current energy storage system to the target energy storage system for storage in step 203 may include: and the current energy storage system sends all or part of surplus electric energy obtained after meeting the first preset condition to a target energy storage system for storage.
When the stored electric energy of the energy storage module of the current energy storage system reaches the rated capacity, the current energy storage system sends all surplus electric energy obtained after the first preset condition is met to the target energy storage system for storage; or when the stored electric energy of the energy storage module of the current energy storage system does not reach the rated capacity, the current energy storage system sends the surplus electric energy part obtained after the first preset condition is met to the first energy storage system for storage, and the rest part is stored through the energy storage module of the current energy storage system.
For example, when the number of the target energy storage systems is more than two, the current energy storage system allocates the surplus electric energy according to the current parameters of the second energy storage modules of the target energy storage systems, and respectively sends the allocated surplus electric energy to the corresponding target energy storage systems for storage.
When the number of the first storage systems is more than two, the current energy storage system may allocate surplus electric energy obtained after the first preset condition is met according to the current parameters of the energy storage modules of each target storage system, and send the surplus electric energy to the corresponding target storage system.
For example, the stored electric energy of the energy storage modules of the first storage systems is sorted, the first storage system with less stored electric energy is allocated with more electric energy, and the first storage system with more stored electric energy is allocated with less electric energy.
Specifically, the current energy storage system may allocate the surplus electric energy according to a proportional relationship between current parameters of each second energy storage module.
In addition, electric energy distribution can be performed by combining the magnitude of the charging current of the energy storage modules of each first storage system, more electric energy is distributed to the first storage system with less stored electric energy and smaller charging current, and less electric energy is distributed to the first storage system with more stored electric energy and larger charging current.
Optionally, before disconnecting the current energy storage system from the external power grid, the energy storage method of the energy storage system may further include:
and obtaining grid-connected electricity price, and if the grid-connected electricity price is smaller than a third threshold value, executing the step of disconnecting the current energy storage system from the external power grid.
The grid-connected electricity price can be set according to the current grid-connected electricity price, and for example, the grid-connected electricity price is written into a controller of the energy storage system. When the grid-connected electricity price is low (namely the grid-connected electricity price is less than a third threshold), distributing redundant electric energy of the current energy storage system to other energy storage systems; when the grid-connected electricity price is high (namely, the grid-connected electricity price is greater than or equal to the third threshold), the redundant electric energy of the current energy storage system is transferred to an external power grid, so that higher economic benefit is achieved.
In the embodiment of the invention, the current parameters of the energy storage modules of each energy storage system are firstly obtained, when the current parameters of the first energy storage module of the current energy storage system meet the first preset condition, the target energy storage system of which the current parameters of the energy storage modules meet the second preset condition is determined in each energy storage system, the current energy storage system is controlled to be disconnected with an external power grid under the condition that the target energy storage system exists, the electric energy obtained by the current energy storage system is sent to the target energy storage system for storage, and part of the electric energy generated by the current energy storage system can be transferred to the target energy storage system meeting the second preset condition for storage, wherein the target energy storage system can be the energy storage system with less current energy storage, so that the redundant electric energy generated by the energy storage system with faster charging is stored in the energy storage system with slower charging, and the low-price redundant electric energy is avoided, the profit maximization is realized as far as possible, and the power generation benefit is improved.
It should be understood that, the sequence numbers of the steps in the foregoing embodiments do not imply an execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.
Fig. 3 shows a schematic diagram of an energy storage device 300 of the energy storage system according to the embodiment of the invention, corresponding to the energy storage method of the storage system according to the above embodiment. For convenience of explanation, only the portions related to the present embodiment are shown.
Referring to fig. 3, the energy storage device 300 of the energy storage system may include a first obtaining module 301, a second obtaining module 302, and a control module 303.
The parameter obtaining module 301 is configured to obtain current parameters of energy storage modules of each energy storage system; each energy storage system corresponds to one energy storage module;
a determining module 302, configured to determine, when a current parameter of a first energy storage module of a first energy storage system satisfies a first preset condition, a second energy storage system of the energy storage systems, where the current parameter of the energy storage module satisfies a second preset condition; the first energy storage system is any one of the energy storage systems, and the second energy storage system is one of the energy storage systems except the first energy storage system;
the control module 303 is configured to control the first energy storage system to be disconnected from an external power grid and send the electric energy acquired by the first energy storage system to the second energy storage system for storage in the presence of the second energy storage system.
Optionally, if the electric energy stored in the first energy storage module is greater than or equal to a first threshold, the current parameter of the first energy storage module meets the first preset condition.
Optionally, if the electric energy stored in the energy storage module of the energy storage system is smaller than a second threshold, the current parameter of the energy storage system meets the second preset condition, and the energy storage system is the target energy storage system; or
If the difference between the charging current of the energy storage module of the energy storage system and the charging current of the first energy storage module is larger than or equal to a third threshold value, the current parameter of the energy storage system meets the second preset condition, and the energy storage system is the target energy storage system.
Optionally, the current energy storage system includes a first photovoltaic boosting module, a first bus, a first conversion module, a first charge and discharge control module, and a first energy storage module, and the target energy storage system includes a second photovoltaic boosting module, a second bus, a second conversion module, a second charge and discharge control module, and a second energy storage module;
the control module 303 is specifically configured to:
the first photovoltaic boosting module is used for boosting the direct current generated by the corresponding photovoltaic unit and sending the boosted direct current to the first bus;
acquiring direct current from the first bus through the first conversion module, converting the direct current into alternating current and sending the alternating current to the second conversion module;
the alternating current is converted into direct current through the second conversion module and then is sent to the second bus;
and the second energy storage module is charged by absorbing electric energy from the second bus through the second charge-discharge control module.
Optionally, the control module 303 is specifically configured to:
and sending all or part of surplus electric energy obtained after the first preset condition is met to the target energy storage system for storage.
Optionally, the sending, by the current energy storage system, all or part of surplus electric energy obtained after meeting the first preset condition to the target energy storage system for storage includes:
and under the condition that the number of the target energy storage systems is more than two, the current energy storage system distributes the surplus electric energy according to the current parameters of the second energy storage modules of the target energy storage systems, and respectively sends the distributed electric energy to the corresponding target storage systems for storage.
Optionally, the allocating, by the current energy storage system, the surplus electric energy according to the current parameter of the second energy storage module of each target energy storage system includes:
and the current energy storage system distributes the surplus electric energy according to the proportional relation among the current parameters of the second energy storage modules.
Fig. 4 is a schematic diagram of a terminal device according to an embodiment of the present invention. As shown in fig. 4, the terminal device 400 of this embodiment includes: a processor 401, a memory 402 and a computer program 403, such as a power storage program of a power storage system, stored in the memory 402 and executable on the processor 401. The processor 401, when executing the computer program 403, implements the steps in the various method embodiments described above, such as the steps 201 to 203 shown in fig. 2. Alternatively, the processor 80, when executing the computer program 82, implements the functions of each module/unit in each device embodiment described above, for example, the functions of the modules 301 to 303 shown in fig. 3.
Illustratively, the computer program 403 may be partitioned into one or more modules/units that are stored in the memory 402 and executed by the processor 401 to implement the present invention. The one or more modules/units may be a series of computer program instruction segments capable of performing specific functions, which are used to describe the execution of the computer program 403 in the storage system 400.
The storage system 400 may include, but is not limited to, a processor 80, a memory 81. Those skilled in the art will appreciate that fig. 4 is merely an example of a storage system 400 and is not intended to limit the storage system 400 and may include more or fewer components than those shown, or some components may be combined, or different components, for example, the end devices may also include input output devices, network access devices, buses, displays, etc.
The Processor 401 may be a Central Processing Unit (CPU), other general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf Programmable Gate Array (FPGA) or other Programmable logic device, discrete Gate or transistor logic, discrete hardware components, etc. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.
The storage 402 may be an internal storage unit of the storage system 400, such as a hard disk or a memory of the storage system 400. The memory 402 may also be an external storage device of the storage system 400, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card), etc. provided on the storage system 400. Further, the memory 402 may also include both internal storage units and external storage devices of the storage system 400. The memory 402 is used for storing the computer programs and other programs and data required by the terminal device. The memory 402 may also be used to temporarily store data that has been output or is to be output.
It will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-mentioned division of the functional units and modules is illustrated, and in practical applications, the above-mentioned function distribution may be performed by different functional units and modules according to needs, that is, the internal structure of the apparatus is divided into different functional units or modules to perform all or part of the above-mentioned functions. Each functional unit and module in the embodiments may be integrated in one processing unit, or each unit may exist alone physically, or two or more units are integrated in one unit, and the integrated unit may be implemented in a form of hardware, or in a form of software functional unit. In addition, specific names of the functional units and modules are only for convenience of distinguishing from each other, and are not used for limiting the protection scope of the present application. The specific working processes of the units and modules in the system may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.
In the above embodiments, the descriptions of the respective embodiments have respective emphasis, and reference may be made to the related descriptions of other embodiments for parts that are not described or illustrated in a certain embodiment.
Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.
In the embodiments provided in the present invention, it should be understood that the disclosed apparatus/terminal device and method may be implemented in other ways. For example, the above-described embodiments of the apparatus/terminal device are merely illustrative, and for example, the division of the modules or units is only one logical division, and there may be other divisions when actually implemented, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.
The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.
In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.
The integrated modules/units, if implemented in the form of software functional units and sold or used as separate products, may be stored in a computer readable storage medium. Based on such understanding, all or part of the flow of the method according to the embodiments of the present invention may also be implemented by a computer program, which may be stored in a computer-readable storage medium, and when the computer program is executed by a processor, the steps of the method embodiments may be implemented. Wherein the computer program comprises computer program code, which may be in the form of source code, object code, an executable file or some intermediate form, etc. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, usb disk, removable hard disk, magnetic disk, optical disk, computer Memory, Read-Only Memory (ROM), Random Access Memory (RAM), electrical carrier wave signals, telecommunications signals, software distribution medium, and the like. It should be noted that the computer readable medium may contain other components which may be suitably increased or decreased as required by legislation and patent practice in jurisdictions, for example, in some jurisdictions, computer readable media which may not include electrical carrier signals and telecommunications signals in accordance with legislation and patent practice.
The above-mentioned embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present invention, and are intended to be included within the scope of the present invention.