A method and device for constructing a distributed energy storage system

Abstract

The present invention relates to a construction method and device for a distributed energy storage system, and belongs to the field of energy storage technology. The construction method includes: obtaining the power demand and electricity demand of different users in the target area; clustering the power demands of different users, and obtaining the power value of the power unit according to the power demand corresponding to the cluster center in the power cluster with the most users; clustering the electricity demands of different users, and obtaining the electricity value of the capacity unit according to the electricity demand corresponding to the cluster center in the electricity cluster with the most users; constructing a distributed energy storage system for the target area according to the constructed power units and capacity units. The present invention proposes a modular construction concept, modularizes the power device and the capacity device, and obtains the smallest power unit and capacity unit, and the power unit and the capacity unit are obtained by clustering the users in the target area, which is more in line with the actual needs of the users.

Description

Technical Field

[0001] The invention relates to a construction method and device of a distributed energy storage system, belonging to the technical field of energy storage. Background Art

[0002] The application of distributed energy storage systems involves all aspects of the power distribution system and has broad application prospects. Giving full play to the role of distributed energy storage equipment can effectively improve the system's operating reliability, improve the system's power quality, increase the access capacity of renewable energy in the distribution network, increase the economic benefits of the power grid and users, and provide strong support for the development of smart distribution networks. Compared with large-scale, centralized energy storage power stations, distributed energy storage equipment has fewer restrictions on the environment and natural conditions of the access location, and the way to access the grid is more flexible. It can play a unique role in the distribution network, microgrid, distributed power supply side, and user side.

[0003] As a form of distributed energy storage, electrochemical energy storage has a wide variety of types. Due to its mature technology and relatively low cost, it has developed rapidly in various industries of the national economy, such as energy and electricity, transportation, communications, military, and aerospace. Among them, the electrochemical energy storage batteries suitable for application in the power field mainly include lithium-ion batteries, lead-acid batteries, nickel-hydrogen batteries, sodium-sulfur batteries, and flow batteries. Lithium iron phosphate batteries are a type of lithium-ion battery with a series of unique advantages such as high operating voltage, high energy density, long cycle life, low self-discharge rate, no memory effect, and green environmental protection. It has developed rapidly in recent years.

[0004] However, distributed energy storage equipment using lithium iron phosphate batteries is generally arranged in containers, which has the following defects:

[0005] 1. Limited by the energy density of lithium iron phosphate batteries, distributed energy storage equipment using lithium iron phosphate batteries is generally heavy, and the transportation process requires the configuration of special trucks, cranes, etc., which is difficult and difficult to adapt to the flexible requirements of future distributed energy storage.

[0006] 2. If mobile power vehicles are used to improve the flexibility of the energy storage system, the increase in flexibility will be far greater than the flexibility required for distributed energy storage, which will cause the cost to increase exponentially, and ultimately make it difficult to promote and apply distributed energy storage using lithium iron phosphate batteries on a large scale.

[0007] 3. Limited by the battery consistency factor, the power conversion device and the battery system are generally configured as a set. After the system power or battery energy demand changes, it is difficult to expand. After the system has been running for a period of time, if the energy demand changes, only increasing the capacity of the battery system will easily cause the new battery to be unable to fully play its role and the overall efficiency of the battery system to decrease. If only the power demand changes, a new power conversion module needs to be added to the container. In most cases, the space inside the container is limited and it is difficult to meet the capacity increase demand.

[0008] In summary, after the construction of distributed energy storage equipment using lithium iron phosphate batteries, it is difficult to transport the equipment, and it is difficult to adjust the power and energy. It is difficult to meet the basic requirements of efficient, flexible and economical distributed energy storage construction. There are disadvantages such as large workload for expansion and reconstruction and difficulty in movement. Therefore, it is necessary to propose a technical solution for a distributed energy storage system based on lithium iron phosphate batteries. Summary of the invention

[0009] The purpose of this application is to provide a method and device for constructing a distributed energy storage system, and to propose an effective technical solution for the distributed energy storage system of lithium iron phosphate batteries to meet the basic requirements of high efficiency, flexibility and economy.

[0010] To achieve the above objectives, the present application proposes a technical solution for a method for constructing a distributed energy storage system, comprising the following steps:

[0011] 1) Obtaining electricity demand of different users in the target area, where the electricity demand includes power demand and electricity demand;

[0012] 2) Cluster the power demands of different users to form several power clusters, each of which contains several users with similar power demands, and obtain the power demand corresponding to the cluster center in the power cluster with the most users; Cluster the power demands of different users to form several power clusters, each of which contains several users with similar power demands, and obtain the power demand corresponding to the cluster center in the power cluster with the most users;

[0013] 3) obtaining the power value of the power unit according to the power demand corresponding to the cluster center in the power cluster with the most users in step 2); obtaining the power value of the capacity unit according to the power demand corresponding to the cluster center in the power cluster with the most users in step 2);

[0014] 4) Constructing a distributed energy storage system for the target area according to the power value of the power unit and the electric quantity value of the capacity unit in step 3).

[0015] In addition, the present application also proposes a technical solution for a distributed energy storage system construction device, including a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned distributed energy storage system construction method when executing the computer program.

[0016] The beneficial effects of the technical solution of the construction method and device of the distributed energy storage system of the present invention are as follows: the present invention proposes a modular construction concept, modularizes the power device and the capacity device, and obtains the smallest power unit and capacity unit. The power unit can facilitate the unified battery system to charge and discharge in different power ranges, and different types and batches of battery systems can simultaneously complete power output; the capacity unit can facilitate the expansion of users after the energy demand changes. And the power unit and the capacity unit are obtained by clustering the users in the target area, which is more in line with the actual needs of users.

[0017] Furthermore, in the construction method and device of the above-mentioned distributed energy storage system, in order to improve the accuracy of the power unit and the capacity unit, the power demand includes daily power demand and average power demand, and the smaller value of the daily power demand and the average power demand is taken as the power value of the power unit; the electricity demand includes daily electricity demand and average electricity demand, and the smaller value of the daily electricity demand and the average electricity demand is taken as the electricity value of the capacity unit.

[0018] Furthermore, in the above-mentioned distributed energy storage system construction method and device, the daily power demand includes the daily power demand of double-peak users and the daily power demand of single-peak users; the daily electricity demand includes the daily electricity demand of double-peak users and the daily electricity demand of single-peak users.

[0019] Furthermore, in the above-mentioned distributed energy storage system construction method and device, the calculation process of the daily power demand of the double peak users is:

[0020] P e2 =(P max -P min )*α;

[0021] Among them, P e2 is the daily power demand of the double-peak users; α is the demand coefficient of the double-peak users; P max is the maximum value of user power demand during the flat, peak and peak periods of a day; P min It is the minimum value of user power demand during the flat, peak and peak periods of a day.

[0022] Furthermore, in the above-mentioned distributed energy storage system construction method and device, the calculation process of the daily power demand of the double-peak users is:

[0023]

[0024] Among them, Q e2 is the daily electricity demand of the double-peak users; P is the power; P′2 is the power target value of the double-peak users; t1, t2, t3, t4 are the times corresponding to the power target values ​​of the double-peak users.

[0025] Furthermore, in the above-mentioned distributed energy storage system construction method and device, the calculation process of the daily power demand of a single peak user is:

[0026] P e1 =P max *β;

[0027] Among them, P e1 is the daily power demand of single peak users; β is the demand coefficient of single peak users; P max It is the maximum value of user power demand during the flat, peak and peak periods of a day.

[0028] Furthermore, in the above-mentioned distributed energy storage system construction method and device, the calculation process of the daily power demand of a single peak user is:

[0029]

[0030] Among them, Q e1 is the daily power demand of single peak users; β is the demand coefficient of single peak users; P′1 is the power target value of single peak users; t5 and t6 are the times corresponding to the power target values ​​of single peak users; P is power; P max It is the maximum value of user power demand during the flat, peak and peak periods of a day. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a flow chart of a method for constructing a distributed energy storage system of the present invention;

[0032] Figure 2 It is a power curve diagram of a double peak user in one day of the present invention;

[0033] Figure 3 It is a power curve diagram of a single peak user in one day of the present invention;

[0034] Figure 4 is a flow chart of the clustering algorithm of the present invention;

[0035] Figure 5 is a schematic diagram of a distributed energy storage system with high power output according to the present invention;

[0036] Figure 6 is a schematic diagram of a distributed energy storage system with large capacity requirements of the present invention;

[0037] Figure 7It is a structural schematic diagram of a construction device of a distributed energy storage system of the present invention. DETAILED DESCRIPTION

[0038] Example of a method for constructing a distributed energy storage system:

[0039] The main idea of ​​the construction method of the distributed energy storage system is to modularize the container-type layout mode, including the modularization of power devices and the modularization of capacity devices, and to construct the distributed energy storage system in the form of power units and capacity units, thereby avoiding the defects of the container-type. In addition, the power value of the power unit and the capacity value of the capacity unit are obtained by clustering the power demands and electricity demands of different users in the target area, which is more in line with the needs of users.

[0040] Specifically, the construction method of the distributed energy storage system is as follows: Figure 1 As shown, the following steps are included:

[0041] 1) Determine the target area and typical users in the target area.

[0042] The target area here is the application area with strong electricity demand. By investigating the load curves of each application area, the distributed energy storage application demand of the application area is classified into application areas with strong electricity demand, general electricity demand, and weak electricity demand. The classification basis is as follows:

[0043] Application areas with strong electricity demand: (P max0 -P min0 ) / P max0 ≥50% (or other given value);

[0044] Application areas with normal electricity demand: 50%>(P max0 -P min0 ) / P max0 ≥30% (or other given value);

[0045] Application areas with low electricity demand: (P max0 -P min0 ) / P max0 <30% (or other given value);

[0046] Among them, P max0 P is the maximum power demand of the application area in one day; min0 It is the minimum power demand of the application area in one day.

[0047] At the same time, different users in the target area are selected as typical users, specifically users with strong electricity demand and general users. By investigating the electricity demand characteristics of typical industrial, commercial, residential, and office users, the users' energy storage application needs are classified into users with strong electricity demand, general, and weak electricity demand. The classification basis is as follows:

[0048] Users with strong electricity demand: (P max -P min ) / P max ≥70% (or other given value)

[0049] Users with normal electricity demand: 70%>(P max -P min ) / P max ≥50% (or other given value)

[0050] Users with weak electricity demand: (P max -P min ) / P max <50%(or other given value)

[0051] Among them, P max is the maximum value of user power demand during the flat, peak and peak periods of a day; P min It is the minimum value of user power demand during the flat, peak and peak periods of a day.

[0052] Peak period: The period of time when the power company in a certain area sells the highest electricity prices throughout the year, generally the time period of the day with the highest load in the summer or winter months when the grid load is the highest.

[0053] Peak period: The period of time when the power company in a certain area sells electricity at the second highest price in the whole year. It is generally a certain time period every day when the daily load of the power grid is the largest throughout the year. When it overlaps with the peak period, the peak period electricity price will be applied.

[0054] Flat period: The period of time when the electricity price sold by a power company in a certain area is the second lowest in the whole year, generally a certain period of time every day when the daily load of the power grid is relatively stable throughout the year.

[0055] The physical meanings of the peak section, peak section, and flat section are technical terms in this field and will not be introduced in detail here.

[0056] 2) Calculate the daily electricity demand of a typical user on a certain day in step 1), where the daily electricity demand includes daily power demand and daily electricity demand.

[0057] The daily power demand is based on P max and P min Calculated and based on P max and P min Calculate the power target value.

[0058] The daily electricity demand is calculated based on the power target value.

[0059] By analyzing the electricity consumption of typical users, typical users are divided into two types: Figure 2 The double peak users shown and Figure 3 Single peak user shown.

[0060] The calculation process of daily power demand and daily electricity demand of double peak users is as follows:

[0061] P e2 =(P max -P min )*α;

[0062]

[0063] P′2=P e2 +P min ;

[0064] Among them, P e2 is the daily power demand of the double-peak users; α is the demand coefficient of the double-peak users, which is determined according to the needs and is generally 0.5; Q e2 is the daily electricity demand of the double-peak users; P is the power; P′2 is the power target value of the double-peak users; t1, t2, t3, t4 are the times corresponding to the power target values ​​of the double-peak users.

[0065] The calculation process of daily power demand and daily electricity demand of single peak users is as follows:

[0066] P e1 =P max *β;

[0067]

[0068] P′1=P max *(1-β);

[0069] Among them, P e1 is the daily power demand of single peak users; β is the demand coefficient of single peak users, which is determined according to needs and is generally 0.3; Q e1 is the daily power demand of the single peak user; P′1 is the power target value of the single peak user; t5 and t6 are the times corresponding to the power target values ​​of the single peak user.

[0070] 3) According to the method in step 2), the average electricity demand of a typical user in a certain period is calculated, and the average electricity demand includes the average power demand and the average electricity demand.

[0071] In this step, the stage can be divided according to season or month, and step 2) is repeated to calculate the power demand for each day in the stage, and the average power demand is obtained by averaging.

[0072] 5) Cluster the daily power demand and daily electricity demand of different typical users obtained in step 2) and the average power demand and average electricity demand of different typical users obtained in step 3) respectively, determine the daily power value of the power unit and the daily electricity value of the capacity unit, as well as the average power value of the power unit and the average electricity value of the capacity unit, and take the smaller value of the daily power value and the average power value as the power value of the power unit; take the smaller value of the daily electricity value and the average electricity value as the electricity value of the capacity unit.

[0073] The principle of cluster analysis is Figure 4 As shown:

[0074] (1) Specify the number k of clusters to be divided;

[0075] (2) Randomly select k initial data object points as the initial clustering centers;

[0076] (3) Calculate the distances from the remaining data objects to the k initial cluster centers, and assign the data pair to the cluster that contains the center closest to it;

[0077] (4) Adjust the new class and recalculate the center of the new class;

[0078] (5) Calculate the clustering criterion function E. If E does not meet the convergence condition, repeat (2), (3), and (4);

[0079] (6) If the convergence condition is met, the clustering results are output.

[0080] Specifically, the process of determining the daily power value of the power unit is as follows: the daily power demands of different typical users are clustered. Assuming that they are divided into three categories, three daily power clusters are formed. Each daily power cluster contains several users with similar daily power demands. The daily power demand corresponding to the cluster center in the daily power cluster with the most users is found as the daily power value.

[0081] The process of determining the daily electricity value of the capacity unit is as follows: the daily electricity demand rows of different typical users are clustered. Assume that they are divided into three categories to form three daily electricity clusters. Each daily electricity cluster contains several users with similar daily electricity demands. The daily electricity demand corresponding to the cluster center in the daily electricity cluster with the most users is found as the daily electricity value.

[0082] Similarly, the process of determining the average power value of the power unit is as follows: the average power demands of different typical users are clustered. Assuming that they are divided into three categories, three average power clusters are formed. Each average power cluster contains several users with similar average power demands. The average power demand corresponding to the cluster center in the average power cluster with the most users is found as the average power value.

[0083] The process of determining the average power value of the capacity unit is as follows: the average power demand rows of different typical users are clustered. Assuming that they are divided into three categories, three average power clusters are formed. Each average power cluster contains several users with similar average power demands. The average power demand corresponding to the cluster center in the average power cluster with the most users is found as the average power value.

[0084] 5) Flexibly construct a distributed energy storage system in the target area based on the power unit (ie, power module) and capacity unit (ie, battery module) of step 4).

[0085] Each unit can be arranged in an independent box, or the power unit and capacity unit can be combined and arranged in one box according to the actual construction conditions and application requirements of the application scenario. Figure 5 The configuration scheme of the distributed energy storage system with high power output is shown in FIG. 1 , in which the interface of the battery module is expanded through an industrial connector to achieve high power output; or Figure 6 The distributed energy storage system configuration scheme with large power demand shown in the figure achieves large power output through different battery modules.

[0086] In the above embodiment, in order to obtain power units and capacity units more accurately, the daily electricity demands and average electricity demands of different users are clustered respectively. As other implementation methods, only the daily electricity demands may be clustered, or only the average electricity demands may be clustered.

[0087] In the above embodiment, the power unit and the capacity unit are obtained by combining the double peak users and the single peak users. As another implementation method, the power unit and the capacity unit may be obtained only for the double peak users or only for the single peak users.

[0088] The power unit in the present invention can facilitate the unified battery system to charge and discharge in different power ranges, and different types and batches of battery systems can simultaneously complete power output; the capacity unit can facilitate easier expansion after the user's energy demand changes. Not only can the power and energy of the energy storage system be flexibly configured for different users and different energy consumption stages of the same user; it can also achieve the maximum function and economic benefits of the energy storage system under the constraint of limited calendar life, and the utilization efficiency of the energy storage system under the same application scenario can be greatly improved; and during the power and energy adjustment process of the energy storage system, the required transformation time, workload and cost can be reduced by more than 80%. It is of great significance to improve the efficiency and flexibility of distributed energy storage, promote the widespread promotion and application of energy storage systems, and improve the utilization efficiency of energy storage systems.

[0089] Example of a construction device for a distributed energy storage system:

[0090] Distributed energy storage system building devices, such as Figure 7 As shown, it includes a processor, a memory, and a computer program stored in the memory and executable on the processor, and the processor implements a method for constructing a distributed energy storage system when executing the computer program.

[0091] The specific implementation process and effects of the distributed energy storage system construction method are introduced in the above-mentioned distributed energy storage system construction method embodiment, which will not be repeated here.

[0092] That is to say, the method in the above embodiment of the method for constructing a distributed energy storage system should be understood to be able to implement the process of the method for constructing a distributed energy storage system by computer program instructions. These computer program instructions can be provided to a processor (such as a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device, etc.), so that the processor executes these instructions to generate functions specified in the above method flow.

[0093] The processor referred to in this embodiment refers to a processing device such as a microprocessor MCU or a programmable logic device FPGA;

[0094] The memory referred to in this embodiment is used to store computer program instructions formed by the construction method of implementing a distributed energy storage system, including a physical device for storing information, which usually digitizes the information and then stores it in a medium using electrical, magnetic or optical methods. For example: various memories that use electrical energy to store information, such as RAM, ROM, etc.; various memories that use magnetic energy to store information, such as hard disks, floppy disks, magnetic tapes, magnetic core memories, bubble memories, and U disks; various memories that use optical methods to store information, such as CDs or DVDs. Of course, there are other types of memories, such as quantum memories, graphene memories, and so on.

[0095] The distributed energy storage system construction device is composed of the memory and processor that store the computer program instructions formed by the above-mentioned distributed energy storage system construction method, and the processor executes the corresponding program instructions in the computer to implement it. The computer can use the Windows operating system, Linux system, or others, such as Android, iOS system programming language to implement it in a smart terminal, and based on the processing logic of a quantum computer.

[0096] As other implementations, the construction device of the distributed energy storage system may also include other processing hardware, such as a database or multi-level cache, GPU, etc. The present invention does not specifically limit the structure of the construction device of the distributed energy storage system.

[0097] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0098] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0099] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0100] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0101] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for constructing a distributed energy storage system, characterized in that: The following steps are involved: 1) Obtaining electricity demand of different users in the target area, where the electricity demand includes power demand and electricity demand; 2) Cluster the power demands of different users to form several power clusters, each of which contains several users with similar power demands, and obtain the power demand corresponding to the cluster center in the power cluster with the most users; Cluster the power demands of different users to form several power clusters, each of which contains several users with similar power demands, and obtain the power demand corresponding to the cluster center in the power cluster with the most users; 3) Obtain the power value of the power unit according to the power demand corresponding to the cluster center in the power cluster with the most users in step 2); obtain the power value of the capacity unit according to the power demand corresponding to the cluster center in the power cluster with the most users in step 2); the power demand includes the daily power demand and the average power demand, and the smaller value of the daily power demand and the average power demand is taken as the power value of the power unit; the power demand includes the daily power demand and the average power demand, and the smaller value of the daily power demand and the average power demand is taken as the power value of the capacity unit; 4) Constructing a distributed energy storage system for the target area according to the power value of the power unit and the electric quantity value of the capacity unit in step 3).

2. The method for constructing a distributed energy storage system according to claim 1, characterized in that: The daily power demand includes the daily power demand of dual-peak users and the daily power demand of single-peak users; the daily electricity demand includes the daily electricity demand of dual-peak users and the daily electricity demand of single-peak users.

3. The method for constructing a distributed energy storage system according to claim 2, characterized in that: The calculation process of the daily power demand of double peak users is: P e2 =(P max -P min )*α; Among them, P e2 is the daily power demand of the double-peak users; α is the demand coefficient of the double-peak users; P max is the maximum value of user power demand during the flat, peak and peak periods of a day; P min It is the minimum value of user power demand during the flat, peak and peak periods of a day.

4. The method for constructing a distributed energy storage system according to claim 3, characterized in that: The calculation process of the daily electricity demand of double peak users is: Among them, Q e2 is the daily electricity demand of the double-peak users; P is the power; P′2 is the power target value of the double-peak users; t1, t2, t3, t4 are the times corresponding to the power target values ​​of the double-peak users.

5. The method for constructing a distributed energy storage system according to claim 2, characterized in that: The calculation process of the daily power demand of a single peak user is: P e1 =P max *b; Among them, P e1 is the daily power demand of single peak users; β is the demand coefficient of single peak users; P max It is the maximum value of user power demand during the flat, peak and peak periods of a day.

6. The method for constructing a distributed energy storage system according to claim 2, characterized in that: The calculation process of the daily electricity demand of a single peak user is: Among them, Q e1 is the daily power demand of single peak users; β is the demand coefficient of single peak users; P′1 is the power target value of single peak users; t5 and t6 are the times corresponding to the power target values ​​of single peak users; P is power; P max It is the maximum value of user power demand during the flat, peak and peak periods of a day.

7. A device for constructing a distributed energy storage system, characterized in that: The invention comprises a processor, a memory and a computer program stored in the memory and executable on the processor, wherein the processor implements the construction method of the distributed energy storage system as described in any one of claims 1 to 6 when executing the computer program.

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