WO2023040642A1

WO2023040642A1 - Energy storage system and management method

Info

Publication number: WO2023040642A1
Application number: PCT/CN2022/115497
Authority: WO
Inventors: 杨洋; 高文凯; 江法洋; 徐中华
Original assignee: 远景能源有限公司
Priority date: 2021-09-16
Filing date: 2022-08-29
Publication date: 2023-03-23
Also published as: CN113794217A; CN113794217B

Abstract

The present application provides an energy storage system and a management method. The energy storage system comprises an energy storage converter, a battery manager, and a battery pack. The battery pack comprises at least two groups of battery clusters. The energy storage converter is used for executing a charging and discharging current transmitted by the battery manager. The battery manager is used for acquiring the present current of each group of battery clusters, determining, according to the preset current of each group of battery clusters and a corresponding limiting current of each group of battery clusters, an allowable charging and discharging current of the battery pack, and transmitting to the energy storage converter the acquired allowable charging and discharging current of the battery pack in a next cycle, so that the current flowing through each group of battery clusters in the next cycle is less than the corresponding limiting current. The allowable charging and discharging current of the battery pack is acquired by repeated iteration until the current flowing through each group of battery clusters in the next cycle is less than the corresponding limiting current, so that overcurrent will not occur, thereby ensuring the safety of the energy storage system.

Description

An energy storage system and management method

technical field

The present application relates to the field of power systems, in particular, to an energy storage system and a management method.

Background technique

With the development of society and the progress of science, energy plays an important role in people's life. As the energy most closely related to people's life, electric energy is widely used in all walks of life and fields. The supply capacity of electric energy is closely related to people's life.

Due to living habits and working hours, the current power supply network has peaks and troughs in power consumption. In order to supplement the remaining electric energy during the valley of electricity consumption to the power supply network during the peak of electricity consumption, the electric energy storage system came into being. It can be understood that the power energy storage system is used to store the remaining electric energy during the valley of electricity consumption, and supplement the stored electric energy to the power supply network during the peak of electricity consumption.

In the prior art, the electric energy storage system includes a plurality of battery clusters, and the battery clusters are used to store and release electric energy. How to ensure the safety of each battery cluster during the charging and discharging process has become a difficult problem for those skilled in the art.

Contents of the invention

The purpose of this application is to provide an energy storage system and a management method to at least partially improve the above problems.

In order to achieve the above purpose, the technical solution adopted in the embodiment of the present application is as follows:

In the first aspect, an embodiment of the present application provides an energy storage system. The energy storage system includes an energy storage converter, a battery manager, and a battery pack. The battery pack includes at least two groups of battery clusters, and each group of battery clusters The positive terminals of each battery cluster are connected to the first terminal of the energy storage converter, the negative terminals of each battery cluster are connected to the second terminal of the energy storage converter, and each battery cluster is connected to the energy storage converter. A battery manager is connected, and the battery manager is connected to the energy storage converter;

The energy storage converter is used to execute the charging and discharging current transmitted by the battery manager;

The battery manager is used to obtain the current current of each group of battery clusters, determine the allowable charging and discharging current of the battery group according to the current current of each group of battery clusters and the corresponding limit current of each group of battery clusters, and obtain The allowable charge and discharge current of the battery pack is transmitted to the energy storage converter, so that the current flowing through each battery cluster is less than the corresponding limit current.

In a possible implementation manner, the battery manager is used to obtain the current current of each group of battery clusters, and repeatedly determine the next cycle according to the current current of each group of battery clusters and the corresponding limit current of each group of battery clusters. The allowable charge and discharge current of the battery pack in the next cycle, so that the current flowing through each set of battery clusters in the next cycle is less than the corresponding limit current, and the allowable charge and discharge current of the battery pack in the next cycle will be obtained transmitting current to the energy storage converter;

In a possible implementation manner, the battery manager is further configured to acquire the current limited current of each group of battery clusters.

In a possible implementation manner, the battery manager is further configured to reduce the total current of the current cycle when the current current of any group of battery clusters is greater than the corresponding limit current, so as to determine the The charging and discharging current allowed by the battery pack;

The battery manager is also used for increasing the total current of the current cycle when the current current of each battery group is lower than the corresponding limit current, so as to determine the allowable charging and discharging current of the battery group in the next cycle.

In a possible implementation manner, the battery manager determines the allowable charging and discharging current of the battery pack in the next cycle through the following formula;

I _pre-total =|I _total |-n*max{|I ₁ |-I _1limit ,|I ₂ |-I _2limit ,...,|I _n |-I _nlimit };

Among them, _Itotal represents the total current of the current cycle, _Ipretotal represents the charge and discharge current allowed by the battery pack in the next cycle, _Ix represents the current current of the xth battery cluster, and _Ixlimit represents the limit of the xth battery cluster Current, n represents the total number of battery clusters.

In a possible implementation manner, the battery manager includes at least two groups of battery management units and a group of comprehensive management units, the number of the battery management units is the same as the number of the battery clusters, and each group of battery management units They are respectively connected to corresponding battery clusters, each group of battery management units is connected to the comprehensive management unit, and the comprehensive management unit is connected to the energy storage converter.

In the second aspect, an embodiment of the present application provides an energy storage system management method, which is applied to an energy storage system. The energy storage system includes an energy storage converter, a battery manager, and a battery pack. The battery pack includes at least two The positive terminal of each battery cluster is connected to the first terminal of the energy storage converter, and the negative terminal of each battery cluster is connected to the second terminal of the energy storage converter. A group of battery clusters are all connected to the battery manager, and the battery manager is connected to the energy storage converter;

The energy storage converter executes the charging and discharging current transmitted by the battery manager;

The battery manager acquires the current current of each battery cluster, determines the allowable charge and discharge current of the battery pack according to the current current of each battery cluster and the current limit corresponding to each battery cluster, and obtains The charge and discharge current allowed by the battery pack is transmitted to the energy storage converter, so that the current flowing through each battery cluster is less than the corresponding limit current.

In a possible implementation, the battery manager acquires the current current of each battery cluster, and determines the current current of each battery cluster in the next cycle according to the current current of each battery cluster and the current limit corresponding to each battery cluster. The allowable charging and discharging current of the battery pack, so that the current flowing through each group of battery clusters in the next cycle is less than the corresponding limit current, and transfer the obtained charging and discharging current allowed by the battery pack in the next cycle to the energy storage converter;

The battery manager repeatedly obtains the current current of each group of battery clusters, and determines the allowable charging and discharging current of the battery group in the next cycle according to the current current of each group of battery clusters and the corresponding limit current of each group of battery clusters .

In a possible implementation manner, before determining the charge and discharge current allowed by the battery pack in the next cycle, the method further includes:

The battery manager acquires the current limited current of each battery cluster.

In a possible implementation manner, the step of determining the allowable charging and discharging current of the battery pack in the next cycle according to the current current of each battery cluster and the corresponding limit current of each battery cluster includes:

When the current current of any group of battery clusters is greater than the corresponding limit current, the battery manager reduces the total current of the current cycle to determine the allowable charge and discharge current of the battery group in the next cycle;

When the current current of each group of battery clusters is less than the corresponding current limit, the battery manager increases the total current of the current cycle to determine the allowable charging and discharging current of the battery group in the next cycle.

Compared with the prior art, an energy storage system provided in the embodiment of the present application includes an energy storage converter, a battery manager, and a battery pack. The battery pack includes at least two sets of battery clusters, and the positive terminals of each set of battery clusters are Connected to the first terminal of the energy storage converter, the negative terminal of each group of battery clusters is connected to the second terminal of the energy storage converter, each group of battery clusters is connected to the battery manager, and the battery manager and storage The energy converter is connected; the energy storage converter is used to execute the charging and discharging current transmitted by the battery manager, and the battery manager is used to obtain the current current of each group of battery clusters, according to the current current of each group of battery clusters and each group of batteries The limit current corresponding to the cluster, determine the charge and discharge current allowed by the battery pack, so that the current flowing through each battery cluster is less than the corresponding limit current, and transmit the obtained charge and discharge current allowed by the battery pack to the energy storage transformer streamer. After the charge and discharge current allowed by the battery pack changes, the current flowing through each battery cluster may change. Obtain the charge and discharge current allowed by the battery pack until the current flowing through each battery cluster is less than the corresponding limit current, and no overcurrent will occur, thus ensuring the safety of the energy storage system.

In order to make the above-mentioned purpose, features and advantages of the present application more comprehensible, preferred embodiments will be described in detail below together with the accompanying drawings.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the accompanying drawings used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, so It should be regarded as a limitation on the scope, and those skilled in the art can also obtain other related drawings based on these drawings without creative work.

Fig. 1 is a schematic structural diagram of an energy storage system provided by an embodiment of the present application;

FIG. 2 is a schematic structural diagram of a battery manager provided in an embodiment of the present application;

Fig. 3 is a schematic flowchart of an energy storage system management method provided by an embodiment of the present application;

FIG. 4 is a schematic diagram of sub-steps of S103 provided in the embodiment of the present application.

In the figure: 101-energy storage converter; 102-battery pack; 103-battery manager.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments It is a part of the embodiments of this application, not all of them. The components of the embodiments of the application generally described and illustrated in the figures herein may be arranged and designed in a variety of different configurations.

Accordingly, the following detailed description of the embodiments of the application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of the application. Based on the embodiments in this application, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of this application.

It should be noted that like numerals and letters denote similar items in the following figures, therefore, once an item is defined in one figure, it does not require further definition and explanation in subsequent figures. Meanwhile, in the description of the present application, the terms "first", "second" and the like are only used to distinguish descriptions, and cannot be understood as indicating or implying relative importance.

It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is a relationship between these entities or operations. There is no such actual relationship or order between them. Furthermore, the term "comprises", "comprises" or any other variation thereof is intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus comprising a set of elements includes not only those elements, but also includes elements not expressly listed. other elements of or also include elements inherent in such a process, method, article, or device. Without further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article or apparatus comprising said element.

In the description of the present application, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer" etc. is based on the orientation or positional relationship shown in the drawings, or the The usual orientation or positional relationship of the application product when used is only for the convenience of describing the application and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, therefore It should not be construed as a limitation of the application.

In the description of this application, it should also be noted that, unless otherwise clearly stipulated and limited, the terms "setting" and "connection" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection, or Integral connection; it can be mechanical connection or electrical connection; it can be direct connection or indirect connection through an intermediary, and it can be the internal communication of two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in this application in specific situations.

Some implementations of the present application will be described in detail below in conjunction with the accompanying drawings. In the case of no conflict, the following embodiments and features in the embodiments can be combined with each other.

The electric energy storage system includes multiple battery clusters, and the battery clusters are used to store and release electric energy. It is understandable that the internal resistance of each battery cluster cannot be exactly the same, and the length of the wiring between each battery cluster and the power conversion system (PCS for short) is not exactly the same, that is, the wiring resistance is not exactly the same. The same, but the battery clusters are connected in parallel, so the voltage of the battery clusters is the same. As a result, the values of the discharge current or the charge current of different battery clusters are different. Taking the energy storage system including 3 battery clusters as an example, the rated current corresponding to each battery cluster is 100 mA, and the total rated current of the energy storage system is 300 mA. If the discharge current is 300 mA, the current of each battery cluster is not exactly the same, there must be some battery clusters whose discharge current is greater than 100 mA, and some battery clusters whose discharge current is less than 100 mA. Therefore, there is an overcurrent phenomenon, which has potential safety hazards.

Continuing to refer to the above example, the discharge current or charging current of the battery clusters is different, and there must be some battery clusters that discharge or charge quickly. Taking the discharge situation as an illustration, some battery clusters may have been fully discharged, and when the battery is empty, some battery clusters are still in a partially discharged state, and there is still a lot of remaining power. But in such a case, it is not possible to continue discharging, but it needs to be charged synchronously, which cannot make good use of the electric energy in other battery clusters, and will cause the capacity of the battery energy storage system to decline too quickly.

In order to overcome the above problems, an embodiment of the present application provides an energy storage system. Please refer to FIG. 1 . FIG. 1 is a schematic diagram of an energy storage system architecture provided by an embodiment of the present application. The energy storage system includes an energy storage converter 101 , a battery manager 103 and a battery pack 102 , and the battery pack 102 includes at least two groups of battery clusters. The battery clusters are Rack1, Rack2, Rack3 and Rackn in Figure 1. It should be noted that the number of battery clusters shown in FIG. 1 is 4, but it is not limited thereto, as long as there are two or more battery clusters.

Please continue to refer to FIG. 1, the positive terminal of each group of battery clusters is connected to the first terminal of the energy storage converter 101, and the negative terminal of each group of battery clusters is connected to the second terminal of the energy storage converter 101, Each group of battery clusters is connected to the battery manager 103, and the battery manager 103 is connected to the energy storage converter.

The energy storage converter 101 is used to implement the charging and discharging current transmitted by the battery manager 103 .

Specifically, after the energy storage converter 101 receives the charge and discharge current allowed by the battery pack 102 transmitted by the battery manager 103, the energy storage converter 101 can adjust the current of each battery cluster based on its own current distribution logic. , so that the sum of the currents flowing through the battery cluster is equal to the charge and discharge current allowed by the battery pack 102 .

The battery manager 103 is used to obtain the current current of each battery cluster, and determine the allowable charging and discharging current of the battery pack 102 according to the current current of each battery cluster and the corresponding limit current of each battery cluster, so that the battery pack 102 can flow through The current of each group of battery clusters is less than the corresponding limit current, and the acquired charging and discharging current allowed by the battery group 102 is transmitted to the energy storage converter 101 .

Understandably, the current current may be an actual charging current or discharging current. Specifically, when the energy storage system is in the charging state, the current current is the charging current, and when the energy storage system is in the discharging state, the current current is the discharging current.

It can be understood that after the allowable charging and discharging current of the battery pack 102 changes, the current flowing through each battery cluster may change. In a possible implementation, the charge and discharge current allowed by the battery group 102 is obtained repeatedly and iteratively until the current flowing through each group of battery clusters in the next cycle is less than the corresponding limit current. There will be an overcurrent situation, thus ensuring the safety of the energy storage system.

In summary, the embodiment of the present application provides an energy storage system including an energy storage converter, a battery manager, and a battery pack. The battery pack includes at least two sets of battery clusters, and the positive terminals of each set of battery clusters are connected to The first end of the energy storage converter, the negative end of each group of battery clusters are connected to the second end of the energy storage converter, each group of battery clusters is connected to the battery manager, and the battery manager is connected to the energy storage converter. The energy storage converter is used to execute the charging and discharging current transmitted by the battery manager, and the battery manager is used to obtain the current current of each group of battery clusters, according to the current current of each group of battery clusters and the corresponding The limit current of the battery pack is determined, so that the current flowing through each battery cluster is less than the corresponding limit current, and the obtained charge and discharge current allowed by the battery pack is transmitted to the energy storage converter . After the charge and discharge current allowed by the battery pack changes, the current flowing through each battery cluster may change. Obtain the charge and discharge current allowed by the battery pack until the current flowing through each battery cluster is less than the corresponding limit current, and no overcurrent will occur, thus ensuring the safety of the energy storage system.

In a possible implementation, the battery manager 103 is used to acquire the current current of each group of battery clusters, and repeatedly determine the next cycle according to the current current of each group of battery clusters and the corresponding limit current of each group of battery clusters. The charging and discharging current allowed by the internal battery pack 102, so that the current flowing through each group of battery clusters in the next cycle is less than the corresponding limit current, and the obtained charging and discharging current allowed by the battery pack 102 in the next cycle is transmitted to energy storage converter 101.

In a possible implementation, if it is satisfied that the current flowing through each group of battery clusters in the current cycle is less than the corresponding limit current, and the subsequent limit current does not change, the battery manager 103 may not iterate temporarily, that is The allowable charging and discharging current of the battery pack 102 in the next cycle is not reacquired temporarily. The energy storage converter 101 can perform current conversion work according to the last received charging and discharging current.

Certainly, the battery manager 103 may repeatedly iterate the charging and discharging current allowed by the battery pack 102 in the next cycle.

In order to further improve the balance performance and security performance of the storage system, the embodiment of the present application also provides a possible implementation manner, please refer to the following.

The battery manager 103 is also used to acquire the current limited current of each battery cluster.

It can be understood that the discharge current or charging current of the battery clusters is different, and after a certain period of time, the remaining power (or, potential energy E) in the battery clusters will change, resulting in that the remaining power in each battery cluster is not completely the same. At this time, the limited current or rated current corresponding to each group of battery clusters will change. In order to further improve the balance performance and safety performance of the storage system, the battery manager 103 needs to obtain the current limited current of each battery cluster. In a possible implementation manner, the current limited current of each battery cluster may be determined according to the current remaining power of each battery cluster.

Regarding how to determine the allowable charging and discharging current of the battery pack in the next cycle, the embodiment of the present application also provides a possible implementation manner, please refer to the following.

The battery manager 103 is also used to reduce the total current of the current cycle when the current current of any group of battery clusters is greater than the corresponding limit current, so as to determine the allowable charging and discharging current of the battery group in the next cycle.

Please continue to refer to Figure 1, assuming that the battery clusters Rack1, Rack2, Rack3 and Rackn in Figure 1 respectively correspond to the current currents I ₁ , I ₂ , I ₃ and _In , and the corresponding current limits are I _1limit , I _2limit , I _3limit and _Inlimit . When any one of |I ₁ | greater than I _1limit , |I ₂ | greater than I _2limit , |I ₃ | greater than I _3limit and |I _n | greater than _Inlimit is satisfied, it indicates that there is an overcurrent phenomenon. Therefore, it is necessary to reduce the allowable charging and discharging current of the battery pack 102 in the next cycle. Specifically, the charging and discharging current allowed by the battery pack 102 in the current cycle is reduced. The allowable charging and discharging current of the battery pack 102 in the current cycle is the sum of I ₁ , I ₂ , I ₃ and _In .

The battery manager 103 is also used to increase the total current of the current cycle when the current current of each battery group is lower than the corresponding limit current, so as to determine the allowable charging and discharging current of the battery group in the next cycle.

Please continue to refer to the above example, when |I ₁ | is less than I _1limit , |I ₂ | _is less than I _2limit , |I ₃ | is less than I _3limit and |I _n | Therefore, it is necessary to increase the allowable charging and discharging current of the battery pack 102 in the next cycle. Specifically, it is increased on the basis of the charge and discharge current allowed by the battery pack 102 in the current cycle. The allowable charging and discharging current of the battery pack 102 in the current cycle is the sum of I ₁ , I ₂ , I ₃ and _In .

Regarding the formula for determining the allowable charging and discharging current of the battery pack in the next cycle, the embodiment of the present application also provides a possible implementation manner, please refer to the following.

The battery manager 103 determines the allowable charging and discharging current of the battery pack in the next cycle through the following formula;

Among them, I _total represents the total current of the current cycle, I _pre-total represents the charge and discharge current allowed by the battery pack in the next cycle, I _x represents the current current of the xth battery cluster, and I _xlimit represents the limit current of the xth battery cluster, n represents the total number of battery clusters.

Taking the number of battery clusters as 3 as an example, battery clusters Rack1, Rack2, and Rack3 respectively correspond to current currents I ₁ , I ₂ , and I ₃ , and corresponding current limits to I _1limit , I _2limit , and I _3limit . Assume that I _1limit , I _2limit , and I _3limit are all 100, and I ₁ =60, I ₂ =50, and I ₃ =40 are obtained in the j-th cycle, and I _total =I ₁ +I ₂ +I ₃ =150.

I _total =150-3*max{(-40), (-50), (-60)}=150+120=270;

I ₁ = 135, I ₂ = 90, I ₃ = 45 are obtained in the j+1th cycle, I _total = I ₁ + I ₂ + I ₃ = 270;

I _total = 270-3*35 = 165.

Make _| _I _k | close to I _klimit , and _| I _q | Clusters of batteries other than clusters.

It can be understood that with the release or storage of potential energy, the battery cluster corresponding to the maximum difference (|I _x |-I _xlimit ) is changing, and the battery cluster that affects _{the total} I is changing, to a certain extent So that each battery cluster can affect the I _total , so that the charging or discharging of each battery cluster can be balanced to a certain extent; the difference in current between different battery clusters is reduced, and the next cycle is adjusted according to the maximum value of the current The charge and discharge current allowed by the battery pack (that is, the PCS rated current), so that the current value in each battery cluster can be fully released, to avoid the situation of insufficient energy release of the battery cluster.

Wherein, the maximum difference is the largest value among |I _x |-I _xlimit .

It can be understood that during the charge and discharge process, each battery cluster is in a parallel state with each other. The voltage of each cell cluster pair is the same. However, with the charging and discharging of currents of different magnitudes, the remaining power of each battery cluster is different, so the potential energy E of each battery cluster is different.

Please refer to the following formula, in charging state: U=E-IR; in discharging state: U=E+IR.

In order to keep the voltage of each battery cluster the same, the corresponding current value of the battery cluster of potential energy E will be reduced. That is, the battery cluster corresponding to the maximum difference (|I _x |-I _xlimit ) is changing.

Referring to FIG. 2 , regarding the composition of the battery manager 103 , the embodiment of the present application also provides a possible implementation manner. As shown in FIG. 2, the battery manager 103 includes at least two groups of battery management units (abbreviated as RBMS) and a group of comprehensive management units (abbreviated as BBMS). The number of battery management units is the same as the number of battery clusters. Each group of batteries The management units are respectively connected to the corresponding battery clusters, each group of battery management units is connected to the comprehensive management unit, and the comprehensive management unit is connected to the energy storage converter 101 .

The battery management unit RBMS is used to obtain the performance parameters of the corresponding battery cluster, such as the current remaining power, the current current, the current limited current, and the current temperature. And transmit the collected performance parameters to the comprehensive management unit BBMS.

The comprehensive management unit BBMS is used to determine the allowable charging and discharging current of the battery pack 102 in the next cycle.

In a possible implementation manner, the energy storage converter 101 is connected to an external main grid through a transformer, so that the energy storage system can complete storage and release of electric energy.

It should be noted that in the embodiment of the present application, the battery clusters are connected in parallel, that is, the voltages at both ends of each battery cluster are the same. Those skilled in the art can know the relationship between power and voltage and current. In the case of the same voltage, the limitation on current can be equivalent to the limitation on power. Therefore, the current current in the embodiment of the present application may be equal to the current power, the current limit may be equal to the power limit, and the charge and discharge current may be equal to the charge and discharge power, which will not be repeated here.

It should be understood that the structures shown in Fig. 1 and Fig. 2 are only partial structural schematic diagrams of the energy storage system, and the energy storage system may also include more or less components than those shown in Fig. 1 and Fig. 2 , or have A different configuration than that shown in Figures 1 and 2. Each component shown in FIG. 1 and FIG. 2 may be implemented by hardware, software or a combination thereof.

An energy storage system management method provided in the embodiment of this application can be applied to, but not limited to, the electronic equipment shown in Figure 1 and Figure 2. For the specific process, please refer to Figure 3. The energy storage system management method includes:

S101, the energy storage converter executes the charging and discharging current transmitted by the battery manager.

S302. The battery manager acquires the current current of each battery cluster.

S303. The battery manager determines the allowable charging and discharging current of the battery pack according to the current current of each battery cluster and the corresponding limit current of each battery cluster.

S304, transmitting the acquired charging and discharging current allowed by the battery pack to the energy storage converter.

In a possible implementation manner, after S304 is executed, S101 may be repeatedly executed, so that the current flowing through each group of battery clusters in the next cycle is smaller than the corresponding limited current.

In a possible implementation manner, S303, the battery manager determines the allowable charging and discharging current of the battery pack in the next cycle according to the current current of each battery cluster and the corresponding limit current of each battery cluster. S304, transmitting the acquired charge and discharge current allowed by the battery pack in the next cycle to the energy storage converter.

Please continue to refer to Figure 3. In a possible implementation, the energy storage system management method further includes:

S301. The battery manager acquires the current limited current of each battery cluster.

It should be noted that the embodiment of the present application does not limit the execution order of S302 and S301, and the two may be executed simultaneously or separately.

On the basis of Figure 3, regarding the content in S103, this embodiment of the present application also provides a possible implementation, please refer to Figure 4, S103 includes:

S103-1. When the current current of any group of battery clusters is greater than the corresponding limit current, the battery manager reduces the total current of the current cycle to determine the allowable charging and discharging current of the battery group in the next cycle.

S103-2. When the current current of each battery group is lower than the corresponding limit current, the battery manager increases the total current of the current cycle to determine the allowable charging and discharging current of the battery group in the next cycle.

In a possible implementation, the battery manager determines the allowable charging and discharging current of the battery pack in the next cycle through the following formula;

I _pre-total =|I _total |—n*max{|I ₁ |-I _1limit ,|I ₂ |-I _2limit ,...,|I _n |-I _nlimit };

In a possible implementation, the battery manager includes at least two groups of battery management units and a group of integrated management units, the number of battery management units is the same as the number of battery clusters, and each group of battery management units is connected to the corresponding battery cluster Each group of battery management units is connected to the integrated management unit, and the integrated management unit is connected to the energy storage converter.

It should be noted that the energy storage system management method provided in this embodiment can perform the functions and purposes of each part in the above energy storage system embodiments to achieve corresponding technical effects. For brief description, for parts not mentioned in this embodiment, reference may be made to the corresponding content in the foregoing embodiments.

The above descriptions are only preferred embodiments of the present application, and are not intended to limit the present application. For those skilled in the art, various modifications and changes may be made to the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application shall be included within the protection scope of this application.

It will be apparent to those skilled in the art that the present application is not limited to the details of the exemplary embodiments described above, but that the present application can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be regarded as exemplary and not restrictive in all points of view, and the scope of the application is defined by the appended claims rather than the foregoing description, and it is intended that the scope of the present application be defined by the appended claims rather than by the foregoing description. All changes within the meaning and range of equivalents of the elements are embraced in this application. Any reference sign in a claim should not be construed as limiting the claim concerned.

Claims

An energy storage system, characterized in that the energy storage system includes an energy storage converter, a battery manager, and a battery pack, and the battery pack includes at least two groups of battery clusters, and the positive terminals of each battery cluster are connected to At the first end of the energy storage converter, the negative terminals of each set of battery clusters are connected to the second end of the energy storage converter, and each set of battery clusters is connected to the battery manager, The battery manager is connected to the energy storage converter;

The energy storage converter is used to execute the charging and discharging current transmitted by the battery manager;

The battery manager is also used to obtain the current limited current of each group of battery clusters, and determine the current limited current according to the current remaining power of each group of battery clusters;

The battery manager is used to obtain the current current of each group of battery clusters, determine the allowable charging and discharging current of the battery group according to the current current of each group of battery clusters and the corresponding limit current of each group of battery clusters, and obtain The received charge and discharge current allowed by the battery pack is transmitted to the energy storage converter, so that the current flowing through each battery cluster is less than the corresponding limit current;

The battery manager is also used to repeatedly determine the allowable charging and discharging current of the battery pack in the next cycle according to the current current of each battery cluster and the current limit corresponding to each battery cluster, so that in the next cycle The current flowing through each group of battery clusters is less than the corresponding limit current, and the acquired charging and discharging current allowed by the battery group in the next cycle is transmitted to the energy storage converter;

The battery manager is also used to reduce the total current of the current cycle when the current current of any group of battery clusters is greater than the corresponding limit current, so as to determine the charge and discharge current allowed by the battery group in the next cycle;

The battery manager is also used to increase the total current of the current cycle when the current current of each group of battery clusters is less than the corresponding current limit, so as to determine the allowable charging and discharging current of the battery group in the next cycle;

The battery manager determines the allowable charging and discharging current of the battery pack in the next cycle through the following formula;

I total = ∣I total ∣-n*max{∣I 1 ∣-I 1limit ，∣I 2 ∣-I 2limit ，…，∣I n ∣-I nlimit };

Among them, Itotal represents the total current of the current cycle, Ipretotal represents the charge and discharge current allowed by the battery pack in the next cycle, Ix represents the current current of the xth battery cluster, and Ixlimit represents the limit of the xth battery cluster Current, n represents the total number of battery clusters.
The energy storage system according to claim 1, wherein the battery manager includes at least two groups of battery management units and a group of comprehensive management units, the number of the battery management units is the same as the number of the battery clusters, Each group of battery management units is respectively connected to the corresponding battery cluster, each group of battery management units is connected to the comprehensive management unit, and the comprehensive management unit is connected to the energy storage converter.
A management method for an energy storage system, characterized in that it is applied to an energy storage system, the energy storage system includes an energy storage converter, a battery manager, and a battery pack, and the battery pack includes at least two groups of battery clusters, each The positive terminals of the battery clusters are all connected to the first terminal of the energy storage converter, the negative terminals of each battery cluster are connected to the second terminal of the energy storage converter, and each battery cluster is connected with the battery manager, and the battery manager is connected with the energy storage converter;

The energy storage converter executes the charging and discharging current transmitted by the battery manager;

The battery manager obtains the current limiting current of each group of battery clusters, and determines its current limiting current according to the current remaining power of each group of battery clusters;

The battery manager acquires the current current of each battery cluster, determines the allowable charge and discharge current of the battery pack according to the current current of each battery cluster and the current limit corresponding to each battery cluster, and obtains The charge and discharge current allowed by the battery pack is transmitted to the energy storage converter, so that the current flowing through each battery cluster is less than the corresponding limit current;

The battery manager repeatedly determines the allowable charging and discharging current of the battery pack in the next cycle based on the current current of each battery cluster and the corresponding limit current of each battery cluster, so that each battery cluster will flow in the next cycle. The currents of a group of battery clusters are all less than the corresponding limit current, and the obtained charging and discharging current allowed by the battery group in the next cycle is transmitted to the energy storage converter;

The step of determining the allowable charging and discharging current of the battery pack in the next cycle according to the current current of each battery cluster and the corresponding limit current of each battery cluster includes:

When the current current of any group of battery clusters is greater than the corresponding limit current, the battery manager reduces the total current of the current cycle to determine the allowable charge and discharge current of the battery group in the next cycle;

When the current current of each group of battery clusters is less than the corresponding current limit, the battery manager increases the total current of the current cycle to determine the allowable charge and discharge current of the battery group in the next cycle;

The battery manager determines the allowable charging and discharging current of the battery pack in the next cycle through the following formula;

I total = ∣I total ∣-n*max{∣I 1 ∣-I 1limit ，∣I 2 ∣-I 2limit ，…，∣I n ∣-I nlimit };

Among them, Itotal represents the total current of the current cycle, Ipretotal represents the charge and discharge current allowed by the battery pack in the next cycle, Ix represents the current current of the xth battery cluster, and Ixlimit represents the limit of the xth battery cluster Current, n represents the total number of battery clusters.
The energy storage system management method according to claim 3, wherein the battery manager includes at least two groups of battery management units and a group of comprehensive management units, and the number of the battery management units is the same as the number of the battery clusters Similarly, each group of battery management units is connected to the corresponding battery cluster, each group of battery management units is connected to the comprehensive management unit, and the comprehensive management unit is connected to the energy storage converter.