CN115800423B

CN115800423B - Energy storage system and method for regulating an energy storage system

Info

Publication number: CN115800423B
Application number: CN202211148340.XA
Authority: CN
Inventors: 吴凯; 陈新伟; 颜昱; 李向涛; 但志敏; 潘先喜
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2022-09-20
Filing date: 2022-09-20
Publication date: 2023-11-24
Anticipated expiration: 2042-09-20
Also published as: CN115800423A

Abstract

The embodiment of the application provides an energy storage system and an adjusting method of the energy storage system. The energy storage system includes: n battery clusters, an adjusting switch module and M variable voltage modules, wherein N is a positive integer greater than 1, and M is a positive integer less than N; the N battery clusters are mutually connected in parallel, each battery cluster in the N battery clusters is connected in series with one variable voltage module in the M variable voltage modules through one adjusting switch in the adjusting switch module, and the M variable voltage modules and the adjusting switch module are used for adjusting the electrical parameters of the N battery clusters so as to achieve balance among the electrical parameters of the N battery clusters. The technical scheme can ensure the balance among all battery clusters in the energy storage system, thereby improving the overall performance of the energy storage system.

Description

Energy storage system and method for regulating an energy storage system

Technical Field

Embodiments of the present application relate to the field of energy storage, and more particularly, to an energy storage system and a method of regulating an energy storage system.

Background

In the currently mainstream energy storage system, in order to increase the energy storage capacity, a plurality of batteries are connected in series to form a battery cluster, and the plurality of battery clusters are directly connected in parallel by a wire. With the extension of the working time, the batteries in the energy storage system are gradually different, and the internal circulation can be caused by the voltage difference of the batteries when the batteries are newly added or replaced. This internal circulation can cause further imbalance of the cells in the energy storage system, resulting in reduced performance or even damage to the energy storage system.

In view of this, how to ensure the balance among the battery clusters in the energy storage system so as to improve the overall performance of the energy storage system is a technical problem to be solved.

Disclosure of Invention

The application provides an energy storage system and an adjusting method of the energy storage system, which can ensure balance among all battery clusters in the energy storage system, thereby improving the overall performance of the energy storage system.

In a first aspect, there is provided an energy storage system comprising: n battery clusters, an adjusting switch module and M variable voltage modules, wherein N is a positive integer greater than 1, and M is a positive integer less than N; the N battery clusters are mutually connected in parallel, each battery cluster in the N battery clusters is connected in series with one variable voltage module in the M variable voltage modules through an adjusting switch of the adjusting switch module, and the M variable voltage modules and the adjusting switch module are used for adjusting the electrical parameters of the N battery clusters so as to achieve balance among the electrical parameters of the N battery clusters.

Through the technical scheme of the embodiment of the application, the electrical parameters of N parallel battery clusters in the energy storage system can be regulated and balanced through M variable voltage modules. On the one hand, the technical scheme not only can reduce the circulation between N battery clusters, but also can greatly improve the capacity and the performance of the energy storage system, and on the other hand, at least two battery clusters in the N battery clusters in the technical scheme can share one variable voltage module, so that the quantity of the variable voltage modules in the energy storage system is small, and the cost, the volume and the weight of the energy storage system can be relatively reduced.

In some possible embodiments, the regulating switch module comprises N regulating switches. Through the technical scheme of the embodiment, the N regulating switches are in one-to-one correspondence with the N battery clusters, and reliable control is easily realized on the series connection between the N battery clusters and the variable voltage module through the N regulating switches.

In some possible embodiments, the electrical parameter is SOC or voltage.

Through the technical scheme of the embodiment, the voltage and the SOC of the battery cluster can accurately reflect the state of the battery cluster during charge and discharge, and the battery cluster is easy to monitor by other electrical components such as BMS or BMU. After the voltages or the SOCs of the N battery clusters are regulated to be balanced by the M variable voltage modules, the overall capacity and the performance of the N battery clusters can be effectively and greatly improved.

In some possible embodiments, the N battery clusters include M battery clusters, the M battery clusters are in one-to-one correspondence with the M variable voltage modules, and each of the M battery clusters includes at least one battery cluster.

According to the technical scheme, N battery clusters in the energy storage system are divided into M groups, the M groups of battery clusters are in one-to-one correspondence with the M variable voltage modules, and each variable voltage module can adjust the electrical parameters of a group of corresponding battery clusters.

In some possible embodiments, the energy storage system further comprises: a control module; the control module is used for detecting the electrical parameters of each group of battery clusters in the M groups of battery clusters so as to judge the number of abnormal battery clusters in each group of battery clusters; under the condition that the number of abnormal battery clusters in each group of battery clusters is smaller than or equal to 1, and K groups of battery clusters in M groups of battery clusters are provided with abnormal battery clusters, the control module is used for controlling K variable voltage modules in the M variable voltage modules to operate simultaneously, and the K variable voltage modules are used for adjusting the electrical parameters of the abnormal battery clusters in the K groups of battery clusters, wherein K is a positive integer smaller than or equal to M.

According to the technical scheme of the embodiment, the M variable voltage modules can be fully utilized to adjust the abnormal battery clusters simultaneously according to the number of the abnormal battery clusters in each of the M battery clusters, so that the adjustment efficiency of the abnormal battery clusters in the energy storage system is improved.

In some possible embodiments, in a case that the number of abnormal battery clusters in the ith group of battery clusters of the M groups of battery clusters is greater than 1, the control module is configured to control the ith variable voltage module corresponding to the ith group of battery clusters of the M variable voltage modules to operate, where i is a positive integer less than or equal to M, and the ith variable voltage module is configured to sequentially adjust electrical parameters of the plurality of abnormal battery clusters in the ith group of battery clusters.

According to the technical scheme of the embodiment, for the ith group of battery clusters with the number of the abnormal battery clusters being larger than that of the M group of battery clusters, the control module and the M variable voltage modules can still adjust the abnormal battery clusters in the ith group of battery clusters so as to ensure the capacity and the performance of the energy storage system.

In some possible embodiments, the control module is configured to control the ith variable voltage module to sequentially adjust the electrical parameters of the plurality of abnormal battery clusters in the ith battery cluster according to the difference between the electrical parameters of the plurality of abnormal battery clusters in the ith battery cluster and the preset threshold.

According to the technical scheme, the adjusting performance of the energy storage system to the abnormal battery clusters can be further improved, and the safety of the energy storage system is guaranteed.

In some possible embodiments, the energy storage system further comprises: a bypass switch module and a bus bar, the bypass switch module comprising: each of the N battery clusters is connected in series with a bus bar through one of the N bypass switches, and the bus bar is used for realizing electric energy transmission between the N battery clusters and the outside.

According to the technical scheme provided by the embodiment of the application, the energy storage system can comprise N bypass switches for controlling the transmission of N battery clusters and external electric energy besides N regulating switches for controlling the connection and disconnection of the variable voltage module and the battery clusters. Through the N adjusting switches and the N bypass switches, N battery clusters in the energy storage system can be adjusted and controlled more flexibly.

In some possible embodiments, the N battery clusters include: the first battery cluster, under the condition that a first regulating switch connected in series with the first battery cluster is closed and a first bypass switch is opened, a first variable voltage module in the M variable voltage modules is used for regulating the electrical parameters of the first battery cluster; under the condition that a first regulating switch connected in series with the first battery cluster is opened and a first bypass switch is closed, the first battery cluster transmits electric energy with the outside through a bus bar.

According to the technical scheme of the embodiment, for any one of N battery clusters, for example, the first battery cluster, the first regulating switch and the first bypass switch which are connected in series with the first battery cluster are not closed at the same time, and when the first battery cluster transmits electric energy with the outside through the bus bar, the first variable voltage module connected in series with the first battery cluster can be in an open state, so that the power consumption of the first variable voltage module and the energy storage system is saved.

In some possible embodiments, the energy storage system further comprises: a control module; before a first variable voltage module of the M variable voltage modules is used for adjusting the electrical parameters of the first battery cluster, the control module is used for detecting the electrical parameters of the first battery cluster to determine that the first battery cluster is an abnormal battery cluster; the control module is used for controlling the first regulating switch connected in series with the first battery cluster to be closed, controlling the first bypass switch connected in series with the first battery cluster to be opened and controlling the first variable voltage module to operate so as to regulate the electrical parameters of the first battery cluster; after the electrical parameters of the first battery cluster are adjusted to a preset range, the control module is further used for controlling the first adjusting switch to be opened and the first bypass switch to be closed, so that the first battery cluster can transmit electric energy with the outside through the bus.

Through the technical scheme of the embodiment, the control module can detect and monitor the electrical parameters of the first battery cluster, and can determine that the first battery cluster is an abnormal battery cluster under the condition that the electrical parameters of the first battery cluster exceed a preset range. Further, the control module can control the first regulating switch, the first bypass switch, the first variable voltage module and the like to regulate the abnormal first battery cluster according to the abnormal information of the first battery cluster so as to improve the effectiveness and accuracy of regulation of the first battery cluster. After the first variable voltage module completes the adjustment of the abnormal first battery cluster, the control module controls the first variable voltage module and the first battery cluster to be disconnected with each other, and the first variable voltage module cannot influence the electric energy transmission between the first battery cluster and the outside, so that the charging and discharging performance of the first battery cluster is guaranteed.

In some possible embodiments, the electrical parameter is SOC; the control module is used for controlling the first variable voltage module to operate so as to adjust the SOC of the first battery cluster to a preset SOC range.

Through the technical scheme of the embodiment, the abnormal SOC of the first battery cluster can be directly regulated to the preset SOC range, the capacity of the first battery cluster can be ensured to be the stable capacity most intuitively, and the charge and discharge performance of the first battery cluster is effectively ensured.

In some possible embodiments, the preset SOC range includes: the average value or the median value of the SOCs of the N battery clusters, or the preset SOC range includes: the SOC of any one of the N battery clusters except the first battery cluster.

Through the technical scheme of the embodiment, the average value or the median value of the SOC of the first battery cluster and the SOC of the N battery clusters can be kept balanced, so that capacity balance among the N battery clusters can be realized conveniently, and the overall charge and discharge performance of the N battery clusters is ensured.

In some possible implementations, the control module is configured to send a current command to the first variable voltage module to cause the first variable voltage module to adjust the current of the first battery cluster to a target current that causes the SOC of the first battery cluster to adjust to a target SOC in a preset SOC range.

By the technical scheme of the embodiment, the control module can directly send a current instruction to the first variable voltage module so that the first variable voltage module can output a target current, and the target current can enable the first battery cluster to generate a target SOC which meets expectations. According to the technical scheme, the SOC of the first battery cluster can be adjusted to be the target SOC more efficiently and reliably, and the adjusting efficiency of the energy storage system to the abnormal first battery cluster is improved.

In some possible implementations, the control module is configured to determine the target current based on a difference between the SOC of the first battery cluster and the target SOC and an average current of the N battery clusters.

According to the technical scheme, the target current comprehensively considers the difference between the SOC of the first battery cluster and the target SOC and the average current of the N battery clusters, so that the target current can be used for adjusting the SOC of the first battery cluster to the target SOC more quickly and accurately, and the first battery cluster and other battery clusters can be balanced.

In some possible embodiments, the target current I' satisfies the following relation:

I’=I _ave + f(ΔSOC)；

f(ΔSOC)=k ₁ *((1+ΔSOC) ⁿ -1)，ΔSOC＞0；

f(ΔSOC)=-k ₁ *((1+ΔSOC) ⁿ -1)，ΔSOC＜0；

wherein I is _ave Delta SOC is the difference between the SOC of the first battery cluster and the target SOC, k, which is the average current of N battery clusters ₁ And n is a preset coefficient.

According to the technical scheme of the embodiment, the target current I 'and the target SOC which are calculated by using the formula can have higher correspondence, so that the energy storage system can quickly adjust the SOC of the first battery cluster to the target SOC according to the target current I', and the adjustment efficiency of the energy storage system to the abnormal battery cluster is improved.

In some possible embodiments, k ₁ And n is related to the power regulation capability of the first variable voltage module; and/or, k ₁ And N is related to the overcurrent capability of the N clusters.

By the technical scheme of the embodiment, the system k is preset in the formula ₁ And N considers the power regulation capability of the first variable voltage module and/or the overcurrent capability of the N battery clusters, so that the first variable voltage module can effectively regulate the target current on one hand, and the safety performance of the energy storage system can be ensured on the other hand.

in case Δsoc > 0 and the energy storage system is in a charged state, I' =k ₂ *I _ave ，0＜k ₂ ≤1；

In case Δsoc < 0 and the energy storage system is in a charged state, I' =k ₂ *I _ave ，1＜k ₂ ≤10；

In case Δsoc > 0 and the energy storage system is in a discharged state, I' =k ₂ *I _ave ，1＜k ₂ ≤10；

At delta SOC < 0, and under the condition that the energy storage system is in a discharge state, I' =k ₂ *I _ave ，0＜k ₂ ≤1；

Wherein ΔSOC is the difference between the SOC of the first battery cluster and the target SOC, I _ave Average current, k, for N clusters ₂ Is a preset coefficient.

According to the technical scheme of the embodiment, under the condition that the difference delta SOC between the SOC of the abnormal battery cluster and the target SOC is different in value and the energy storage system is in different states, the control module can determine different target currents I' according to different formulas, the formulas are easy to realize, and the average current I of N battery clusters is considered as well _ave Therefore, the abnormal first battery cluster can be quickly regulated and balanced, and the regulation efficiency of the energy storage system on the first battery cluster is improved.

In some possible embodiments, the energy storage system further comprises: a control module; the control module is further configured to detect an electrical parameter of the first battery cluster before the first battery cluster is connected in parallel with the other battery clusters of the N battery clusters, so as to determine whether to connect the first battery cluster in parallel with the other battery clusters.

According to the technical scheme of the embodiment, before the first battery cluster is connected in parallel with other battery clusters, the control module can also judge whether the first battery cluster is connected in parallel or not according to the electrical parameters of the first battery cluster, so that the overall performance of the energy storage system is guaranteed. In addition, the regulation capability of the first variable voltage module can be designed within a relatively suitable range without requiring a particularly large design to accommodate the abnormally severe regulation of the first battery cluster, which can be relatively low cost, thereby facilitating the production and manufacture of the energy storage system.

In some possible embodiments, the electrical parameter is voltage; the control module is used for connecting the first battery cluster in parallel with other battery clusters under the condition that the voltage difference between the voltage of the first battery cluster and the preset voltage is smaller than or equal to a first preset voltage value; and under the condition that the voltage difference between the voltage of the first battery cluster and the preset voltage is larger than a first preset voltage value, the control module is used for not connecting the first battery cluster in parallel with other battery clusters.

In this embodiment, by detecting the voltage of the first battery cluster, it can be intuitively and rapidly determined and controlled whether the first battery cluster can be connected in parallel with other battery clusters.

In some possible embodiments, when the voltage difference between the voltage of the first battery cluster and the preset voltage is smaller than or equal to the first preset voltage value and larger than or equal to the second preset voltage value, the control module is used for controlling the first regulating switch to be closed and controlling the first variable voltage module to operate, so that the first variable voltage module regulates the voltage of the first battery cluster to a target voltage range; the control module is used for connecting the adjusted first battery cluster in parallel with other battery clusters, controlling the first bypass switch to be closed and controlling the first adjusting switch to be opened so that the first battery cluster can transmit electric energy with the outside through the bus.

According to the technical scheme of the embodiment, on the basis that the control module detects the voltage of the first battery cluster, the control module can further control the first variable voltage module to adjust the voltage of the first battery cluster, so that the first variable voltage module can be connected with other battery clusters in the N battery clusters in parallel, and the capacity and performance of the energy storage system are guaranteed.

In some possible embodiments, the first preset voltage value is related to a voltage adjustment range of the first variable voltage module; and/or the target voltage range is related to an average voltage value of the battery clusters which are already connected in parallel with each other among the N battery clusters.

By the technical solution of this embodiment, the first preset voltage value may be related to the voltage adjustment range of the first variable voltage module, so that the first variable voltage module may support voltage adjustment of the first battery cluster. The target voltage range can be related to the average voltage value of the battery clusters which are connected in parallel in the N battery clusters, so that the first battery cluster can be ensured to be connected in parallel with other battery clusters in the N battery clusters, and the voltage of each battery cluster is in an equilibrium state, thereby being beneficial to the subsequent normal operation of each battery cluster.

In some possible embodiments, the power sources of the M variable voltage modules are any one of: at least one cell of the N clusters; a bus bar of N battery clusters; a power supply battery; or, a supply capacitor.

According to the technical scheme provided by the embodiment of the application, various power sources can be adopted to provide power for the variable voltage module, so that the variable voltage module is convenient to adapt to more application scenes, and the popularization and the use of the energy storage system are facilitated.

In some possible embodiments, the M variable voltage modules are isolated DC/DC converters or non-isolated DC/DC converters, and/or; the M variable voltage modules are used for outputting positive voltage and/or negative voltage.

Through the technical scheme of the embodiment, the variable voltage module can be adapted to more application scenes and has better voltage regulation performance.

In a second aspect, a method for regulating an energy storage system is provided, the energy storage system comprising: n battery clusters, an adjusting switch module and M variable voltage modules, wherein the N battery clusters are mutually connected in parallel, each battery cluster in the N battery clusters is connected in series with one variable voltage module in the M variable voltage modules through one adjusting switch in the adjusting switch module, N is a positive integer larger than 1, M is a positive integer smaller than N, and the adjusting method comprises the following steps: and controlling the adjusting switch module and the M variable voltage modules to adjust the electrical parameters of the N battery clusters, so that the electrical parameters of the N battery clusters are balanced.

In some possible embodiments, the regulating switch module comprises N regulating switches.

In some possible embodiments, the electrical parameter is SOC or voltage.

In some possible embodiments, the adjusting method further comprises: detecting electrical parameters of each group of battery clusters in the M groups of battery clusters to judge the number of abnormal battery clusters in each group of battery clusters; the controlling and adjusting the switch module and the M variable voltage modules to adjust the electrical parameters of the N battery clusters includes: under the condition that the number of abnormal battery clusters in each group of battery clusters is smaller than or equal to 1, and K groups of battery clusters in M groups of battery clusters are provided with K abnormal battery clusters, K regulating switches connected in series with the K abnormal battery clusters are controlled to be closed, and K variable voltage modules in the M variable voltage modules are controlled to operate simultaneously, so that the K variable voltage modules regulate electrical parameters of the K abnormal battery clusters, wherein K is a positive integer smaller than or equal to M.

In some possible embodiments, the controlling and adjusting the switch module and the M variable voltage modules to adjust the electrical parameters of the N battery clusters further includes: and under the condition that the number of the abnormal battery clusters in the ith battery cluster of the M battery clusters is larger than 1, controlling a plurality of regulating switches connected in series with the plurality of abnormal battery clusters in the ith battery cluster to be sequentially closed, and operating the ith variable voltage module corresponding to the ith battery cluster in the M variable voltage modules so as to sequentially regulate the electrical parameters of the plurality of abnormal battery clusters in the ith battery cluster, wherein i is a positive integer smaller than or equal to M.

In some possible embodiments, the controlling the operation of the ith variable voltage module corresponding to the ith battery cluster in the M variable voltage modules includes: and controlling a plurality of regulating switches connected in series with a plurality of abnormal battery clusters in the ith group of battery clusters to be sequentially closed according to the difference value between the electrical parameters of the plurality of abnormal battery clusters in the ith group of battery clusters and a preset threshold value.

In some possible embodiments, the energy storage system further comprises: a bypass switch module and a bus bar, the bypass switch module comprising: each of the N battery clusters is connected in series with the bus bar through one of the N bypass switches; the adjusting method further comprises the following steps: the N bypass switches are controlled so that the N battery clusters perform electric energy transmission with the outside through the bus bars.

In some possible embodiments, the N battery clusters include: a first battery cluster; wherein, the controlling and adjusting the switch module and the M variable voltage modules to adjust the electrical parameters of the N battery clusters includes: a first regulating switch connected in series with a first battery cluster in the regulating switch module is controlled to be closed, and a first bypass switch connected in series with the first battery cluster in the N bypass switches is controlled to be opened; controlling a first variable voltage module in the M variable voltage modules to operate so as to adjust the electrical parameters of the first battery cluster; the controlling of the N bypass switches to enable the N battery clusters to output electric energy through the bus bar includes: and the first regulating switch connected in series with the first battery cluster in the control regulating switch module is opened, and the first bypass switch connected in series with the first battery cluster in the N bypass switches is closed, so that the first battery cluster performs electric energy transmission with the outside through the bus bar.

In some possible embodiments, before controlling the operation of the first variable voltage module of the M variable voltage modules to adjust the electrical parameter of the first battery cluster, the adjusting method further includes: and detecting the electrical parameters of the first battery cluster to determine that the first battery cluster is an abnormal battery cluster.

In some possible embodiments, the electrical parameter is SOC; wherein, the controlling the operation of the first variable voltage module of the M variable voltage modules to adjust the electrical parameters of the first battery cluster includes: and controlling the first variable voltage module to operate so as to adjust the SOC of the first battery cluster to a preset SOC range.

In some possible embodiments, the controlling the operation of the first variable voltage module to adjust the SOC of the first battery cluster to a preset SOC range includes: and sending a current instruction to the first variable voltage module so that the first variable voltage module adjusts the current of the first battery cluster to a target current, and the target current adjusts the SOC of the first battery cluster to a target SOC in a preset SOC range.

In some possible embodiments, before the sending of the current command to the first variable voltage module, the adjusting method includes: and determining the target current according to the difference between the SOC of the first battery cluster and the target SOC and the average current of the N battery clusters.

I’=I _ave + f(ΔSOC)；

f(ΔSOC)=k ₁ *((1+ΔSOC) ⁿ -1)，ΔSOC＞0；

f(ΔSOC)= -k ₁ *((1+ΔSOC) ⁿ -1)，ΔSOC＜0；

In case Δsoc < 0 and the energy storage system is in a discharged state, I' =k ₂ *I _ave ，0＜k ₂ ≤1；

In some possible embodiments, the conditioning method further comprises, before the first battery cluster is connected in parallel with the other battery clusters of the N battery clusters: detecting an electrical parameter of the first battery cluster; and judging whether the first battery cluster is connected with other battery clusters in parallel according to the electrical parameters of the first battery cluster.

In some possible embodiments, the electrical parameter is a voltage, where determining whether to connect the first battery cluster in parallel with other battery clusters according to the electrical parameter of the first battery cluster includes: when the voltage difference between the voltage of the first battery cluster and the preset voltage is smaller than or equal to a first preset voltage value, connecting the first battery cluster in parallel with other battery clusters; and under the condition that the voltage difference between the voltage of the first battery cluster and the preset voltage is larger than a first preset voltage value, the first battery cluster is not connected in parallel with other battery clusters.

In some possible embodiments, in the case that the voltage difference between the voltage of the first battery cluster and the preset voltage is less than or equal to the first preset voltage value, the connecting the first battery cluster in parallel to the other battery clusters includes: when the voltage difference between the voltage of the first battery cluster and the preset voltage is smaller than or equal to a first preset voltage value and larger than or equal to a second preset voltage value, the first regulating switch is controlled to be closed, and the first variable voltage module is controlled to operate, so that the first variable voltage module regulates the voltage of the first battery cluster to a target voltage range; and connecting the adjusted first battery cluster with other battery clusters in parallel, and controlling the first bypass switch to be closed and the first adjusting switch to be opened so that the first battery cluster can transmit electric energy with the outside through the bus.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments of the present application will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present application, and other drawings may be obtained according to the drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic block diagram of an energy storage system according to an embodiment of the present application.

Fig. 2 is a schematic diagram of a variable voltage module connected in series with a battery cluster through a regulating switch according to an embodiment of the present application.

Fig. 3 illustrates several power source versions of a variable voltage module provided by an embodiment of the present application.

Fig. 4 is another schematic block diagram of an energy storage system provided by an embodiment of the present application.

Fig. 5 is another schematic block diagram of an energy storage system provided by an embodiment of the present application.

Fig. 6 is another schematic block diagram of an energy storage system provided by an embodiment of the present application.

Fig. 7 is another schematic block diagram of an energy storage system provided by an embodiment of the present application.

Fig. 8 is a graph showing the SOC of the first battery cluster and the second battery cluster according to the time variation in the energy storage system according to the embodiment of the present application.

Fig. 9 is a schematic flow chart diagram of a method for adjusting an energy storage system according to an embodiment of the present application.

Fig. 10 is a schematic flow diagram of another method for regulating an energy storage system according to an embodiment of the present application.

Fig. 11 is a schematic flow diagram of another method for regulating an energy storage system according to an embodiment of the present application.

Fig. 12 is a schematic flow diagram of another method for regulating an energy storage system according to an embodiment of the present application.

Fig. 13 is a schematic flow diagram of another method for regulating an energy storage system according to an embodiment of the present application.

In the drawings, the drawings are not drawn to scale.

Detailed Description

Embodiments of the present application are described in further detail below with reference to the accompanying drawings and examples. The following detailed description of the embodiments and the accompanying drawings are provided to illustrate the principles of the application and are not intended to limit the scope of the application, i.e., the application is not limited to the embodiments described.

In the description of the present application, it is to be noted that, unless otherwise indicated, the meaning of "plurality" is two or more; the terms "upper," "lower," "left," "right," "inner," "outer," and the like are merely used for convenience in describing the present application and to simplify the description, and do not denote or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus are not to be construed as limiting the present application. Furthermore, the terms "first," "second," "third," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. The "vertical" is not strictly vertical but is within the allowable error range. "parallel" is not strictly parallel but is within the tolerance of the error.

The directional terms appearing in the following description are those directions shown in the drawings and do not limit the specific structure of the application. In the description of the present application, it should also be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be directly connected or indirectly connected through an intermediate medium. The specific meaning of the above terms in the present application can be understood as appropriate by those of ordinary skill in the art.

The term "and/or" in the present application is merely an association relation describing the association object, and indicates that three kinds of relations may exist, for example, a and/or B may indicate: there are three cases, a, B, a and B simultaneously. In the present application, the character "/" generally indicates that the front and rear related objects are an or relationship.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having" and any variations thereof in the description of the application and the claims and the description of the drawings above are intended to cover a non-exclusive inclusion. The terms first, second and the like in the description and in the claims or in the above-described figures, are used for distinguishing between different objects and not necessarily for describing a particular sequential or chronological order.

Reference in the specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly appreciate that the described embodiments of the application may be combined with other embodiments.

The battery cluster in the application refers to a battery assembly formed by connecting batteries in a serial, parallel or series-parallel mode, wherein series-parallel refers to a mixture of serial and parallel. For example, the battery cluster in the present application may be formed of a plurality of batteries connected in series or in parallel. For another example, the battery cluster in the present application may be formed by connecting a plurality of batteries in parallel and then in series. A battery refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery may be a battery module or a battery pack.

Alternatively, the battery in the embodiment of the present application may be a lithium ion battery, a lithium metal battery, a lead-acid battery, a nickel-metal separator battery, a nickel-metal hydride battery, a lithium sulfur battery, a lithium air battery, or a sodium ion battery, which is not specifically limited in the embodiment of the present application.

Currently, in most energy storage systems, it is necessary to boost the system capacity by connecting the battery clusters in parallel. Different battery clusters are directly connected in parallel to generate a circulation phenomenon in the charge and discharge process, the voltage of each battery cluster is forced to be balanced, and when the electric quantity of the battery cluster with smaller internal resistance is full or empty, other battery clusters must stop charge and discharge, so that other battery clusters are not full or empty, capacity loss and performance reduction of the battery are caused, attenuation of the battery is accelerated, and the available capacity of an energy storage system is reduced.

In some related technologies, direct parallel connection of the battery clusters is generally achieved by raising a current protection value, that is, under the condition that the current of the battery clusters does not exceed the current protection value, direct parallel connection of the battery clusters can be achieved. However, this approach has the following disadvantages: firstly, the voltage difference of the battery clusters to be connected in parallel must be made as small as possible, if the voltage difference is too large, the impact current is larger than the set overcurrent protection value during parallel connection, and the parallel connection failure is caused; and secondly, a large circulation current still exists between the parallel battery clusters, so that the risk of damaging the battery clusters is high.

In view of the above, the embodiment of the application provides an energy storage system, which comprises a variable voltage module in addition to the parallel battery clusters, wherein the variable voltage module is connected in series with the battery clusters and can adjust the electrical parameters of the battery clusters so as to balance the electrical parameters of the parallel battery clusters, reduce the circulation between the battery clusters and further improve the capacity and performance of the energy storage system to a greater extent.

Fig. 1 illustrates a schematic block diagram of an energy storage system 100 provided in an embodiment of the present application.

As shown in fig. 1, the energy storage system 100 includes: n battery clusters 110, a regulating switch module (e.g., including regulating switch 130 shown in fig. 1), and M variable voltage modules 120. Wherein N is a positive integer greater than 1, and M is a positive integer less than N. The N battery clusters 110 are connected in parallel, and each of the N battery clusters 110 is connected in series to one of the M variable voltage modules 120 through one of the adjusting switches 130 of the adjusting switch modules, and the M variable voltage modules 120 and the adjusting switch modules are used for adjusting the electrical parameters of the N battery clusters 110, so that the electrical parameters of the N battery clusters 110 are balanced.

Specifically, each of the N battery clusters 110 may include at least one battery, which may be connected in series or in series-parallel with each other. After each of the M variable voltage modules 120 is connected in series with one of the battery clusters 110 through an adjusting switch 130, it can adjust the current of the battery cluster 110, so as to adjust other electrical parameters such as the voltage of the battery cluster 110.

By way of example and not limitation, the variable voltage module 120 may be a Direct Current/Direct Current (DC/DC) converter, an alternating Current/Direct Current (AC/DC) converter, a variable resistor, or the like. Alternatively, the variable voltage module 120 may include at least one DC/DC converter, or the variable voltage module 120 may include both an AC/DC converter and a DC/DC converter, or the like.

Alternatively, as shown in fig. 1, the regulating switch module may include N regulating switches 130, where the N regulating switches 130 are in one-to-one correspondence with the N battery clusters 110. Optionally, in addition to the N adjustment switches 130, the adjustment switch module may further include other components of the user-assisted adjustment switch 130, such as: capacitance, resistance, etc., the specific structure of the regulating switch module is not limited in the embodiment of the application. In addition, the adjusting switch 130 includes, but is not limited to, a switch structure such as a relay, and the specific type of the adjusting switch 130 is not limited in the embodiment of the present application. Each of the N battery clusters 110 may be connected in series to one variable voltage module 120 of the M variable voltage modules 120 through one of the N regulating switches 130. Each of the M variable voltage modules 120 may be connected in series with at least one battery cluster 110.

Since M is smaller than N, at least two of the N battery clusters 110 are connected in series to the same variable voltage module 120 through at least two regulating switches 130. In this case, the at least two adjustment switches 130 may be sequentially closed such that the variable voltage module 120 sequentially performs power conversion on the at least two battery clusters 110, thereby adjusting the electrical parameter of each of the at least two battery clusters 110.

For the energy storage system 100 provided in the embodiment of the present application, the electrical parameters of each of the N parallel-connected battery clusters 110 may be adjusted by one variable voltage module 120 of the M variable voltage modules 120, so that the electrical parameters of the N battery clusters 110 are balanced. For example, after the adjustment of the variable voltage module 120, the electrical parameters of the N battery clusters 110 may be within a preset range. Alternatively, the difference in electrical parameters of the N clusters 110 may be small or even zero.

In summary, according to the technical solution of the embodiment of the present application, the electrical parameters of the N parallel battery clusters 110 in the energy storage system 100 can be adjusted and balanced by the M variable voltage modules 120. On one hand, the technical scheme not only can reduce the circulation between the N battery clusters, but also can greatly improve the capacity and the performance of the energy storage system 100, and on the other hand, at least two battery clusters 110 in the N battery clusters 110 in the technical scheme can share one variable voltage module 120, so that the number of the variable voltage modules 120 in the energy storage system 100 is small, and the cost, the volume and the weight of the energy storage system 100 can be relatively reduced.

Optionally, in some embodiments, the electrical parameters of the battery cluster 110 regulated by the variable voltage module 120 include, but are not limited to: the voltage or State of Charge (SOC) of the battery cluster 110.

Specifically, the voltage of the variable voltage module 120 is adjustable, and when the voltage of the variable voltage module 120 is adjusted, the current of the battery cluster 110 connected in series with the variable voltage module is adjustable, so that the voltage, the SOC and other electrical parameters of the battery cluster 110 are changed correspondingly.

Fig. 2 shows a schematic diagram of a variable voltage module 120 connected in series with a battery cluster 110 via a regulating switch 130.

As shown in fig. 2, the voltage of the variable voltage module 120 is denoted as U _dcdc The voltage of the battery cluster 110 is denoted as U _bat The variable voltage module 120 and the battery cluster 110 may be connected in series between bus bars, the bus voltage being denoted as U _bus 。

When the regulating switch 130 is closed, the current i= (U) of the battery cluster 110 during the charging of the energy storage system 100 _bus -U _dcdc -U _bat ) R; during discharging of the energy storage system 100, the current i= (U) of the battery cluster 110 _dcdc +U _bat -U _bus ) R. Where R is the total resistance of the series branch formed by the variable voltage module 120 and the battery cluster 110. The total resistance R may include the resistance of the battery cluster 110, the resistance of the variable voltage module 120, the resistance of the regulating switch 130, the resistance of the connecting lines, etc., wherein the resistance of the battery cluster 110 is large.

Accordingly, when the voltage of the variable voltage module 120 is adjusted, the current of the battery cluster 110 is correspondingly adjusted and changed, and other electrical parameters of the battery cluster 110, such as voltage and SOC, etc., are correspondingly adjusted and changed.

The voltage and SOC of the battery cluster 110 can more accurately reflect the state of the battery cluster 110 when charged and discharged, and can be easily monitored by other electrical components, such as a battery management system (Battery Management System, BMS) or a battery management unit (Battery Management Unit, BMU). After the voltages or SOCs of the N battery clusters 110 are adjusted to be balanced by the M variable voltage modules 120, the overall capacity and performance of the N battery clusters 110 can be effectively and greatly improved in the charge and discharge process of the energy storage system 100.

Optionally, in some embodiments, the variable voltage module 120 is an isolated DC/DC converter or a non-isolated DC/DC converter, and/or the variable voltage module 120 is configured to output a positive voltage and/or a negative voltage.

By the technical scheme of the embodiment, the variable voltage module 120 can be adapted to more application scenes and has better voltage regulation performance.

Optionally, in some embodiments, the power source of the variable voltage module 120 is any one of: at least one cell of the N cell clusters 110; a bus bar of N battery clusters; a power supply battery; or, a supply capacitor.

Fig. 3 illustrates several power source versions of the variable voltage module 120 in an embodiment of the application.

As shown in fig. 3 (a), the power source of the variable voltage module 120 may be at least one battery 111 of the battery clusters 110 in series. For example, the two voltage inputs of the variable voltage module 120 may be connected to the positive and negative poles of the battery cluster 110, respectively. Alternatively, in other alternative embodiments, the two voltage inputs of the variable voltage module 120 may be connected to the positive and negative poles, respectively, of at least one cell 111 in the battery cluster 110.

As shown in fig. 3 (b), the power source of the variable voltage module 120 may be a power module 121 independent of the battery cluster 110, and the power module 121 may be a power supply battery other than the battery cluster 110, which is dedicated to supply power to the variable voltage module 120. Alternatively, the power module 121 may be a power supply capacitor. In addition to the power supply battery and the power supply capacitor, the power module 121 may be a power source of another type, and the embodiment of the present application is not limited to the specific type.

As shown in fig. 3 (c), the power source of the variable voltage module 120 may also be a bus bar of the N battery clusters 110. For example, the N battery clusters 110 are connected to a first bus bar 1601 and a second bus bar 1602, and the first bus bar 1601 and the second bus bar 1602 are respectively connected to two voltage input terminals of the variable voltage module 120 to supply power to the variable voltage module 120.

According to the technical scheme provided by the embodiment of the application, various power sources can be adopted to provide power for the variable voltage module 120, so that the variable voltage module 120 is convenient to adapt to more application scenes, and popularization and use of the energy storage system 100 are facilitated.

Fig. 4 illustrates another schematic block diagram of an energy storage system 100 provided by an embodiment of the present application.

As shown in fig. 4, in the embodiment of the present application, the N battery clusters 110 include M battery clusters, or, the N battery clusters 110 are composed of M battery clusters, the M battery clusters are in one-to-one correspondence with the M variable voltage modules 120, and each of the M battery clusters includes at least one battery cluster 110.

Alternatively, as shown in fig. 4, for any one of the M groups of battery clusters 110, at least one of the battery clusters 110 may be connected in series to one of the M variable voltage modules 120 through at least one regulating switch 130 in a one-to-one correspondence.

According to the technical scheme provided by the embodiment of the application, N battery clusters 110 in the energy storage system 100 are divided into M groups, the M groups of battery clusters are in one-to-one correspondence with the M variable voltage modules 120, and each variable voltage module 120 can adjust the electrical parameters of the corresponding group of battery clusters 110.

Fig. 5 illustrates another schematic block diagram of an energy storage system 100 provided by an embodiment of the present application.

As shown in fig. 5, in an embodiment of the present application, the energy storage system 100 further includes: and the control module 150 is used for detecting the electrical parameters of each group of battery clusters in the M groups of battery clusters so as to judge the number of abnormal battery clusters in each group of battery clusters. In the case that the number of abnormal battery clusters in each group of battery clusters is less than or equal to 1, and K groups of battery clusters in the M groups of battery clusters have abnormal battery clusters, the control module 150 is configured to control K variable voltage modules 120 of the M variable voltage modules 120 to operate simultaneously, where K is a positive integer less than or equal to M, and the K variable voltage modules 120 are configured to adjust electrical parameters for the abnormal battery clusters in the K groups of battery clusters.

Specifically, in an embodiment of the present application, the M groups of battery clusters in the energy storage system 100 may be in an operational state, for example, the M groups of battery clusters may be in a charged state or a discharged state.

The control module 150 may be configured to detect in real-time an operating parameter of each of the M groups of battery clusters, which may include an operating electrical parameter of the battery cluster 110, such as voltage, current, or SOC, among others. Based on the operation electrical parameters of each group of battery clusters in the M groups of battery clusters, the number of abnormal battery clusters in each group of battery clusters can be judged, wherein the abnormal battery clusters can be battery clusters with the operation electrical parameters exceeding a preset threshold.

In the case where the number of abnormal battery clusters in each of the M battery clusters is less than or equal to 1, it is illustrated that the M variable voltage modules 120 can be operated simultaneously to adjust the abnormal battery clusters in the M battery clusters.

Specifically, among the M groups of battery clusters, the K groups of battery clusters have an abnormal battery cluster therein, and each group of battery clusters has one abnormal battery cluster therein. The control module 150 may control the operation of the K variable voltage modules 120 corresponding to the K battery clusters to adjust the electrical parameters of the K abnormal battery clusters in the K battery clusters.

It is understood that the control module 150 may not only control the operation of the K variable voltage modules 120, but also control the closing of the K regulating switches 130 connected in series to the K abnormal battery clusters, so that the K variable voltage modules 120 regulate the K abnormal battery clusters.

Alternatively, the control module 150 includes, but is not limited to, a BMS or BMU. The BMS or BMU may monitor operating parameters of the various battery clusters 110 and other components in the energy storage system 100 and control the regulating switch 130, the variable voltage module 120, etc. in the energy storage system 100 based on the operating parameters.

According to the technical scheme provided by the embodiment of the application, the abnormal battery clusters can be adjusted by fully utilizing the M variable voltage modules 120 according to the number of the abnormal battery clusters in each of the M battery clusters, so that the adjustment efficiency of the abnormal battery clusters in the energy storage system 100 is improved.

Optionally, in the case that the number of abnormal battery clusters in the ith battery cluster of the M battery clusters is greater than 1, the control module 150 is configured to control the ith variable voltage module corresponding to the ith battery cluster of the M variable voltage modules 120 to operate, where i is a positive integer less than or equal to M, and the ith variable voltage module is configured to sequentially adjust the electrical parameters of the plurality of abnormal battery clusters in the ith battery cluster.

Specifically, the ith group of battery clusters may be any one group of battery clusters in the M group of battery clusters, and when the number of abnormal battery clusters in the ith group of battery clusters is greater than 1, the ith variable voltage module corresponding to the ith group of battery clusters cannot adjust a plurality of abnormal battery clusters in the ith group of battery clusters at the same time, and the plurality of abnormal battery clusters need to be sequentially adjusted.

Optionally, the control module 150 may be configured to control the ith variable voltage module to sequentially adjust the electrical parameters of the plurality of abnormal battery clusters in the ith battery cluster according to the difference between the electrical parameters of the plurality of abnormal battery clusters in the ith battery cluster and the preset threshold.

In some embodiments, the ith variable voltage module first adjusts an abnormally more severe battery cluster of the plurality of abnormal battery clusters. For example, if the deviation between the electrical parameter of an abnormal battery cluster and the preset threshold is the largest among the abnormal battery clusters, the abnormal battery cluster is the most serious abnormal battery cluster among the abnormal battery clusters.

By the technical scheme of the embodiment, the adjusting performance of the energy storage system 100 to a plurality of abnormal battery clusters can be further improved, and the safety of the energy storage system 100 can be guaranteed.

In addition to the ith battery cluster, for the jth battery cluster having the number of abnormal battery clusters equal to 1 among the M battery clusters, the control module 150 may control the operation of the jth variable voltage module corresponding to the jth battery cluster, where j is a positive integer less than M. The j-th battery cluster is any one of the M-th battery clusters except the i-th battery cluster.

It can be appreciated that, in the embodiment of the present application, the control module 150 may not only control the variable voltage module 120 to operate, but also control the adjusting switch 130 connected in series to the abnormal battery cluster to be closed, so that the variable voltage module 120 adjusts the abnormal battery cluster.

According to the technical scheme provided by the embodiment of the application, for the ith group of battery clusters, the number of the abnormal battery clusters in the ith group of battery clusters is greater than 1, the control module 150 and the M variable voltage modules 120 can still adjust the abnormal battery clusters in the ith group of battery clusters so as to ensure the capacity and the performance of the energy storage system 100.

Fig. 6 illustrates another schematic block diagram of an energy storage system 100 provided by an embodiment of the present application.

As shown in fig. 6, in the embodiment of the present application, in addition to the N battery clusters 110, the N regulating switches 130, and the M variable voltage modules 120 in the above embodiment, the energy storage system 100 further includes: a bypass switch module and a bus bar 160, the bypass switch module comprising: each of the N battery clusters 110 is connected in series to a bus bar 160 through one of the N bypass switches 140, and the bus bar 160 is used to realize power transmission between the N battery clusters 110 and the outside.

Specifically, in the embodiment shown in fig. 6, the positive and negative electrodes of the N battery clusters 110 are connected to two bus bars 160, respectively. The two bus bars 160 may be the first bus bar 1601 and the second bus bar 1602, respectively, in the embodiment shown in fig. 3 above. The N battery clusters 110 may be discharged to the outside through the two bus bars 160, or an external power source may charge the N battery clusters 110 through the two bus bars.

Alternatively, as shown in fig. 6, the energy storage system 100 includes a bypass switch module in addition to the regulation switch module, the bypass switch module including: and N bypass switches 140, wherein the N bypass switches 140 are in one-to-one correspondence with the N battery clusters 110. Optionally, in the bypass switch module, the bypass switch module may further include other components of the user-assisted bypass switch 140, such as: capacitance, resistance, etc., the specific structure of the regulating switch module is not limited in the embodiment of the application. In addition, the bypass switch 140 includes, but is not limited to, a switch structure such as a relay, and the specific type of the bypass switch 140 is not limited in the embodiment of the present application.

Alternatively, the N battery clusters 110 may be connected to any one bus bar 160 of the two bus bars 160 through the N bypass switches 140. For example, each bypass switch 140 of the N bypass switches 140 is connected in series between one bus bar 160 and the positive electrode of one battery cluster 110, or each bypass switch 140 is connected in series between one bus bar 160 and the negative electrode of one battery cluster 110, or each bypass switch 140 is connected in series between two adjacent batteries of one battery cluster 110.

Alternatively, in an embodiment of the present application, the N battery clusters 110 may include a first battery cluster, and the first battery cluster may be any one of the N battery clusters 110. For convenience of description, in the embodiment of the present application, the adjusting switch 130 connected in series to the first battery cluster is referred to as a first adjusting switch, the bypass switch 140 connected in series to the first battery cluster is referred to as a first bypass switch, and the variable voltage module connected in series to the first battery cluster is referred to as a first variable voltage module.

Under the condition that a first regulating switch connected in series with the first battery cluster is closed and a first bypass switch is opened, a first variable voltage module connected in series with the first battery cluster is used for regulating the electrical parameters of the first battery cluster. After the adjustment is completed, the first adjusting switch connected in series with the first battery cluster is opened, the first bypass switch is closed, and at this time, the first battery cluster can transmit electric energy with the outside through the bus 160.

According to the technical scheme of the embodiment of the application, the energy storage system 100 may include N bypass switches 140 for controlling the transmission of electric energy between the N battery clusters 110 and the outside, in addition to the N regulating switches 130 for controlling the connection and disconnection of the variable voltage module 120 and the battery clusters 110. The N number of the battery clusters 110 in the energy storage system 100 can be more flexibly adjusted and controlled through the N number of the adjusting switches 130 and the N number of the bypass switches 140.

Further, for any one of the N battery clusters 110, for example, the first battery cluster, the first regulating switch and the first bypass switch connected in series therewith are not closed at the same time, and when the first battery cluster transmits electric energy to the outside through the bus bar 160, the first variable voltage module connected in series therewith may be in an open state, thereby saving power consumption of the first variable voltage module and the energy storage system 100.

In some embodiments, when the N battery clusters 110 of the energy storage system 100 are all in a normal operation state, the N bypass switches 140 in the energy storage system 100 may be all closed, the N regulation switches 130 may be all open, and then when the N battery clusters 110 transmit electric energy with the outside through the bus bar, the M variable voltage modules 120 may be all in an open state.

Alternatively, in the embodiment shown in fig. 6, for any one variable voltage module 120 of the M variable voltage modules 120, one end thereof may be connected to any one bus bar, and the other end thereof may be connected to the positive electrode or the negative electrode of one battery cluster 110 through one regulating switch 130. Alternatively, in some alternative embodiments, for any one variable voltage module 120 of the M variable voltage modules 120, it may be connected in series between two adjacent cells in one cell cluster 110 through one regulating switch 130.

On the basis of the embodiment shown in fig. 6 above, fig. 7 shows a schematic block diagram of another energy storage system 100 provided by an embodiment of the present application.

As shown in fig. 6, in an embodiment of the present application, the energy storage system 100 may include the control module 150 of the embodiment shown in fig. 5 above.

Specifically, before the first variable voltage module of the M variable voltage modules 120 is used to adjust the electrical parameters of the first battery cluster, the control module 150 is configured to detect the electrical parameters of the first battery cluster to determine that the first battery cluster is an abnormal battery cluster. The control module 150 is configured to control the first adjusting switch connected in series with the first battery cluster to be closed, the first bypass switch connected in series with the first battery cluster to be opened, and control the first variable voltage module to operate so as to adjust the electrical parameters of the first battery cluster.

In the embodiment of the present application, detection and monitoring of the electrical parameter of the first battery cluster can be implemented by the control module 150, and the first battery cluster can be determined to be an abnormal battery cluster when the electrical parameter of the first battery cluster exceeds a preset range. Further, the control module 150 may further control the first adjusting switch, the first bypass switch, the first variable voltage module, etc. to adjust the abnormal first battery cluster according to the abnormal information of the first battery cluster, so as to improve the effectiveness and accuracy of the adjustment of the first battery cluster.

After the electrical parameters of the first battery cluster are adjusted to the preset range, the control module 150 is further configured to control the first adjusting switch connected in series to the first battery cluster to be opened and the first bypass switch to be closed, so that the first battery cluster transmits electrical energy with the outside through the bus bar 160.

Through the technical scheme of the embodiment, after the first variable voltage module completes the adjustment of the abnormal first battery cluster, the first variable voltage module is mutually disconnected with the first battery cluster, and the first variable voltage module cannot influence the electric energy transmission between the first battery cluster and the outside, so that the charging and discharging performance of the first battery cluster is guaranteed.

In some possible embodiments, the electrical parameter may be SOC, and the control module 150 may be configured to control the first variable voltage module to operate to adjust the SOC of the first battery cluster to a preset SOC range.

Optionally, in some examples, the preset SOC range may include: average or median of the SOC of the N battery clusters. Alternatively, the central value of the preset SOC range may be an average value or a median value of the SOCs of the N battery clusters.

Through the technical scheme of the example, the average value or the median value of the SOC of the first battery cluster and the SOC of the N battery clusters 110 can be kept balanced, so that capacity balance among the N battery clusters 110 can be realized more conveniently, and the overall charge and discharge performance of the N battery clusters 110 is ensured.

Alternatively, in other examples, the preset SOC range may include: the SOC of any one of the N battery clusters except the first battery cluster. Alternatively, the central value of the preset SOC range may be the SOC of any one of the N battery clusters other than the first battery cluster.

Through the technical scheme of the example, the SOC of the first battery cluster and the SOCs of other battery clusters can be kept balanced, and the charge and discharge performance of the first battery cluster and the other battery clusters is ensured.

Alternatively, the control module 150 may be configured to send a current command to the first variable voltage module to cause the first variable voltage module to adjust the current of the first battery cluster to a target current that causes the SOC of the first battery cluster to adjust to a target SOC in a preset SOC range.

As an example, the target SOC may be an average value or a median value of the SOCs of the N battery clusters 110, or the target SOC may be the SOC of any one of the N battery clusters other than the first battery cluster.

In particular, the control module 150 may send a current command to a first variable voltage module that may adjust its own voltage and current based on the current command, thereby adjusting the current of a first cluster of cells in series with the first variable voltage module. Because of the current change of the first battery cluster, the SOC of the first battery cluster also changes to a certain extent, and the control module 150 can monitor the SOC of the first battery cluster in real time to determine whether to adjust the SOC to the target SOC.

According to the technical scheme provided by the embodiment of the application, the control module 150 can directly send the current command to the first variable voltage module so that the first variable voltage module can output the target current, and the target current can enable the first battery cluster to generate the target SOC which meets the expectations. According to the technical scheme, the SOC of the first battery cluster can be adjusted to be the target SOC more efficiently and reliably, and the adjusting efficiency of the energy storage system 100 to the abnormal first battery cluster is improved.

In some embodiments, the control module 150 may be further configured to determine the target current based on a difference between the SOC of the first battery cluster and the target SOC and an average current of the N battery clusters 110 before the control module 150 sends the current command to the first variable voltage module.

In this embodiment, the target current comprehensively considers the difference between the SOC of the first battery cluster and the target SOC and the average current of the N battery clusters 110, so that the target current can more quickly and accurately adjust the SOC of the first battery cluster to the target SOC, so that the first battery cluster and other battery clusters reach equilibrium.

As an example, the target current I' may satisfy the following relation:

I’=I _ave + f(ΔSOC)；

f(ΔSOC)=k ₁ *((1+ΔSOC) ⁿ -1)，ΔSOC＞0；

f(ΔSOC)= -k ₁ *((1+ΔSOC) ⁿ -1)，ΔSOC＜0；

wherein I is _ave The ΔSOC is the difference between the SOC of the first battery cluster and the target SOC, k, which is the average current of N battery clusters 110 ₁ And n is a preset coefficient.

In the solution of this embodiment, the control module 150 may determine the target current I' according to the above formula, which determines the current variation f (Δsoc) by using the exponential function and Δsoc, and then determine the average current I of the N battery clusters 110 according to the average current I _ave The target current I' is determined from the current variation f (Δsoc).

The target current I 'and the target SOC obtained by calculation through the above formula may have a higher correspondence, so that the energy storage system 100 may quickly adjust the SOC of the first battery cluster to the target SOC according to the target current I', thereby improving the adjustment efficiency of the energy storage system 100 for the abnormal battery cluster.

Alternatively, in the above formula, the coefficient k is preset ₁ And n is related to the power regulation capability of the first variable voltage module, and/or the preset coefficient k ₁ And N is related to the overcurrent capability of the N battery clusters 110.

In particular, the power regulation capability of the first variable voltage module may depend on the maximum output power and the minimum output power of the first variable voltage module. The overcurrent capability of the N battery clusters 110 may depend on the maximum current that each of the N battery clusters 110 can withstand.

Optionally with a preset coefficient k ₁ And n, the following two conditions are included: (1) The first variable voltage module is required to meet the power regulation capability of the corresponding current variation. (2) When the total power of the energy storage system 100 in a specific mode is constant, the current of the first battery cluster is adjusted individually, and the current of other battery clusters can be adjusted passively to meet the total power, and when the current of the first battery cluster is adjusted, not only the current overflow capacity of the first battery cluster but also the current overflow capacity of the other battery clusters after being influenced is needed to be noted.

By the technical scheme of the embodiment, the system k is preset in the formula ₁ And N considers the power regulation capability of the first variable voltage module and/or the overcurrent capability of the N battery clusters, so that on one hand, the first variable voltage module can effectively regulate the target current, and on the other hand, the safety performance of the energy storage system 100 can also be ensured.

As another example, the target current I' may satisfy the following relation:

in the case where Δsoc > 0, and energy storage system 100 is in a charged state, I' =k ₂ *I _ave ，0＜k ₂ ≤1；

In the case where Δsoc < 0, and energy storage system 100 is in a charged state, I' =k ₂ *I _ave ，1＜k ₂ ≤10；

In the case where Δsoc > 0 and energy storage system 100 is in a discharged state, I' =k ₂ *I _ave ，1＜k ₂ ≤10；

In the case where Δsoc < 0 and energy storage system 100 is in a discharged state, I' =k ₂ *I _ave ，0＜k ₂ ≤1；

By the technical scheme of the embodiment of the application, the method comprises the following steps ofUnder the condition that the difference Δsoc between the SOC of the abnormal battery cluster and the target SOC is different and the energy storage system 100 is in different states, the control module 150 can determine different target currents I' according to different formulas, which are easy to implement and consider the average current I of the N battery clusters 110 _ave Therefore, the abnormal first battery cluster can be quickly regulated and balanced, and the regulation efficiency of the energy storage system 100 on the first battery cluster is improved.

By adjusting the current in the above two ways, when the energy storage system 100 is charged, the charging of the battery cluster 110 with higher capacity can be slowed down or the charging of the battery cluster 110 with lower capacity can be slowed down. When the energy storage system 100 is discharging, the higher capacity battery cluster 110 may be discharged faster or the lower capacity battery cluster 110 may be discharged slower.

Fig. 8 shows a graph of SOC of a first battery cluster versus a second battery cluster in the energy storage system 100 over time.

Specifically, the energy storage system 100 may be in a state of charge, wherein the SOC of the first and second battery clusters may gradually increase over time.

In the case that the control module 150 detects that the first battery cluster is an abnormal battery cluster, and the charging rate of the first battery cluster is relatively fast, the control module 150 may at t ₁ The first battery cluster is adjusted at the moment so that the charging rate of the first battery cluster is slow, that is, the rate of increase of the SOC of the first battery cluster over time is slow. The SOC of the first battery cluster and the SOC of the second battery cluster can be both at t ₂ The time reaches 80%.

In the embodiment shown in fig. 8, if no adjustment is made to the abnormal first battery cluster, the charging time of the energy storage system 100 is determined by the charging time of the first battery cluster, which is at t ₃ When the time SOC reaches 80%, if the charging of the energy storage system 100 is stopped at this time, the second battery cluster is at t ₃ The SOC at time is much less than 80% affecting the charge capacity of the energy storage system 100.

It can be appreciated that, for the energy storage system 100 in a discharging state, the abnormal battery clusters may also affect the discharge capacity of the energy storage system 100, such that the electric quantity of at least some battery clusters in the energy storage system 100 cannot be completely released, and the service time of the energy storage system 100 is affected.

By the adjustment method for the abnormal battery clusters in the energy storage system 100 provided by the embodiment of the application, the battery clusters 110 with higher capacity in the energy storage system 100 can be slowly charged or the battery clusters 110 with lower capacity can be quickly charged, or the battery clusters 110 with higher capacity can be quickly discharged or the battery clusters 110 with lower capacity can be slowly discharged, so that the capacities of the battery clusters 110 in the energy storage system 100 are balanced, and the charge and discharge performance of the energy storage system 100 is ensured.

In the above embodiments, the control module 150 may adjust the electrical parameters of the first battery cluster in the operational state. Optionally, the control module 150 may also control the first battery cluster connected in parallel to the other battery clusters, that is, control the first battery cluster in the non-operating state.

Optionally, before the first battery cluster is connected in parallel with the other battery clusters of the N battery clusters 110, the control module 150 is further configured to detect an electrical parameter of the first battery cluster to determine whether to connect the first battery cluster in parallel with the other battery clusters.

Specifically, before the first battery cluster is connected in parallel with other battery clusters, the first battery cluster may be powered on separately, and the control module 150 may detect electrical parameters such as voltage and current of the first battery cluster, where the difference between the first battery cluster and the other battery clusters is greater when the electrical parameters of the first battery cluster exceed a preset range. Considering the regulation capability of the first variable voltage module connected in series with the first battery cluster, the first variable voltage module may not be able to perform good regulation even if the first battery cluster is connected in parallel to other battery clusters, so that the first battery cluster is balanced with the other battery clusters.

In view of this, in the embodiment of the present application, before the first battery cluster is connected in parallel with other battery clusters, the control module may further determine whether to connect the first battery cluster in parallel according to the electrical parameters of the first battery cluster, so as to ensure the overall performance of the energy storage system 100. In addition, the tuning capability of the first variable voltage module may be designed within a relatively suitable range without requiring a particularly large design to accommodate the tuning of the abnormally severe first battery cluster, which may be relatively low cost, thereby facilitating the production and manufacture of the energy storage system 100.

Optionally, in some embodiments, the electrical parameter is voltage, and the control module 150 is configured to connect the first battery cluster in parallel with other battery clusters when a voltage difference between the voltage of the first battery cluster and the preset voltage is less than or equal to a first preset voltage value; in the case that the voltage difference between the voltage of the first battery cluster and the preset voltage is greater than the first preset voltage value, the control module 150 is configured to not connect the first battery cluster in parallel with other battery clusters.

Optionally, when the voltage difference between the voltage of the first battery cluster and the preset voltage is smaller than or equal to the first preset voltage value and greater than or equal to the second preset voltage value, the control module 150 is configured to control the first adjusting switch connected in series to the first battery cluster to be closed, and control the first variable voltage module to operate, so that the first variable voltage module adjusts the voltage of the first battery cluster to the target voltage range. After the adjustment is completed, the control module 150 is configured to connect the adjusted first battery cluster in parallel with other battery clusters, and control the first bypass switch connected in series with the first battery cluster to be closed and the first adjustment switch to be opened, where the first battery cluster transmits electric energy with the outside through the bus 160.

In this embodiment, when the voltage difference between the voltage of the first battery cluster and the preset voltage is less than or equal to the first preset voltage value and greater than or equal to the second preset voltage value, the first battery cluster generates an abnormality, but the abnormality may be regulated by the first adjustable voltage module connected in series to the first battery cluster. Specifically, the control module 150 may be configured to control the voltage of the first variable voltage module, so as to adjust the voltage of the first battery cluster, and after the voltage of the first battery cluster is adjusted to the target voltage range, the first battery cluster may be connected in parallel to the other battery clusters 110 of the N battery clusters 110.

According to the technical scheme of the embodiment, on the basis that the control module 150 detects the voltage of the first battery cluster, the control module 150 can further control the first variable voltage module to adjust the voltage of the first battery cluster, so that the first variable voltage module can be connected with other battery clusters 110 in the N battery clusters 110 in parallel, and the capacity and performance of the energy storage system 100 are ensured.

Alternatively, the first preset voltage value may be related to a voltage adjustment range of the first variable voltage module, so that the first variable voltage module can support voltage adjustment of the first battery cluster.

Alternatively, the above target voltage range may be related to an average voltage value of the battery clusters that have been connected in parallel with each other among the N battery clusters. For example, the target voltage range may include average voltage values of the battery clusters that have been connected in parallel with each other among the N battery clusters.

Through the technical scheme, the first battery cluster and other battery clusters 110 in the N battery clusters 110 can be ensured to be connected in parallel, and the voltage of each battery cluster 110 is in an equilibrium state, so that the subsequent normal operation of each battery cluster 110 is facilitated.

In the above embodiments, the energy storage system 100 provided by the embodiments of the present application is described with reference to fig. 1 to 8, and the method for adjusting the energy storage system provided by the embodiments of the present application is described with reference to fig. 9 to 13. It will be appreciated that the method embodiments described below correspond to the apparatus embodiments described above, and that similar descriptions are provided with reference to the embodiments described above.

Fig. 9 shows a schematic flow diagram of a method 200 for adjusting an energy storage system according to an embodiment of the present application. The energy storage system includes: n battery clusters, an adjusting switch module and M variable voltage modules 120, wherein the N battery clusters are mutually connected in parallel, each battery cluster in the N battery clusters is connected in series with one variable voltage module in the M variable voltage modules through one adjusting switch in the adjusting switch module, N is a positive integer greater than 1, and M is a positive integer smaller than N.

As shown in fig. 9, the adjustment method 200 may include the following steps.

S210: and controlling the adjusting switch module and the M variable voltage modules to adjust the electrical parameters of the N battery clusters, so that the electrical parameters of the N battery clusters are balanced.

Specifically, the adjustment method 200 provided in the embodiment of the present application may be applied to the energy storage system 100 in the embodiment of the application. The subject of the conditioning method 200 may be the control module 150 in the energy storage system 100.

In some possible embodiments, the above-mentioned regulating switch module includes N regulating switches.

In some possible embodiments, the electrical parameter may be SOC or voltage.

In this case, fig. 10 shows a schematic flow diagram of another energy storage system adjustment method 300 according to an embodiment of the present application.

As shown in fig. 10, the adjustment method 300 may include the following steps.

S310: and detecting the electrical parameters of each group of battery clusters in the M groups of battery clusters to judge the number of abnormal battery clusters in each group of battery clusters.

S320: under the condition that the number of abnormal battery clusters in each group of battery clusters is smaller than or equal to 1, and K groups of battery clusters in M groups of battery clusters are provided with K abnormal battery clusters, K regulating switches connected in series with the K abnormal battery clusters are controlled to be closed, and K variable voltage modules in the M variable voltage modules are controlled to operate simultaneously, so that the K variable voltage modules regulate electrical parameters of the K abnormal battery clusters, wherein K is a positive integer smaller than or equal to M.

S330: and under the condition that the number of the abnormal battery clusters in the ith battery cluster of the M battery clusters is larger than 1, controlling a plurality of regulating switches connected in series with the plurality of abnormal battery clusters in the ith battery cluster to be sequentially closed, and operating the ith variable voltage module corresponding to the ith battery cluster in the M variable voltage modules so as to sequentially regulate the electrical parameters of the plurality of abnormal battery clusters in the ith battery cluster, wherein i is a positive integer smaller than or equal to M.

Specifically, the execution subject of steps S310 to S330 may also be the control module 150 in the energy storage system 100. The control module 150 may detect battery clusters in the energy storage system 100 and control the adjustment switches and the variable voltage modules to adjust for abnormal battery clusters in the energy storage system 100.

Alternatively, the steps S320 to S330 may be an implementation of the step S210 in the embodiment of fig. 9.

Optionally, in the step S330, the control module 150 may control the plurality of adjustment switches connected in series to the plurality of abnormal battery clusters in the ith battery cluster to be sequentially closed and the ith variable voltage module to operate according to the difference between the electrical parameters of the plurality of abnormal battery clusters in the ith battery cluster and the preset threshold, so that the ith variable voltage module sequentially adjusts the electrical parameters of the plurality of abnormal battery clusters in the ith battery cluster. In this case, an i-th variable voltage module corresponding to the i-th group of battery clusters among the M variable voltage modules operates such that the i-th variable voltage module sequentially adjusts electrical parameters of a plurality of abnormal battery clusters among the i-th group of battery clusters.

In some possible embodiments, the energy storage system further comprises: a bypass switch module and a bus bar, the bypass switch module comprising: and each of the N battery clusters is connected in series with the bus bar through one of the N bypass switches.

In this case, fig. 11 shows a schematic flow diagram of another energy storage system adjustment method 400 according to an embodiment of the present application.

As shown in fig. 11, the adjustment method 400 may include the following steps.

S210: and controlling the N adjusting switches and the M variable voltage modules to adjust the electrical parameters of the N battery clusters, so that the electrical parameters of the N battery clusters are balanced.

S410: the N bypass switches are controlled so that the N battery clusters perform electric energy transmission with the outside through the bus bars.

Specifically, the execution body of the step S410 may be the control module 150 in the energy storage system 100. The control module 150 may control the N bypass switches 140 in the energy storage system 100 in addition to the N regulation switches 130 in the energy storage system 100.

In some possible embodiments, the N battery clusters include: a first battery cluster, in this case, fig. 12 shows a schematic flow diagram of another energy storage system conditioning method 500 provided by an embodiment of the present application.

As shown in fig. 12, the adjustment method 500 may include the following steps.

S520: and controlling a first regulating switch connected in series with the first battery cluster in the N regulating switches to be closed, and controlling a first bypass switch connected in series with the first battery cluster in the N bypass switches to be opened.

S530: and controlling the operation of a first variable voltage module in the M variable voltage modules to adjust the electrical parameters of the first battery cluster.

S540: and controlling the first regulating switch connected in series with the first battery cluster in the N regulating switches to be opened, and controlling the first bypass switch connected in series with the first battery cluster in the N bypass switches to be closed so that the first battery cluster can perform electric energy transmission with the outside through the bus bar.

Alternatively, the steps S520 to S530 may be an implementation of the step S210 in the embodiment shown in fig. 11. The step S540 may be an implementation of the step S410 in the embodiment shown in fig. 11.

In some possible embodiments, as shown in fig. 12, before step S520, the adjusting method 500 may further include:

s510: and detecting the electrical parameters of the first battery cluster to determine that the first battery cluster is an abnormal battery cluster.

In some possible embodiments, the electrical parameter is SOC, in which case the step S530 may include: and controlling the first variable voltage module to operate so as to adjust the SOC of the first battery cluster to a preset SOC range.

In some possible embodiments, controlling the operation of the first variable voltage module to adjust the SOC of the first battery cluster to the preset SOC range may include: and sending a current command to the first variable voltage module so that the first variable voltage module adjusts the current of the first battery cluster to a target current, and the target current enables the SOC of the first battery cluster to be adjusted to a target SOC in a preset SOC range.

In some possible implementations, the regulation method 500 may further include, prior to sending the current command to the first variable voltage module: and determining the target current according to the difference between the SOC of the first battery cluster and the target SOC and the average current of the N battery clusters.

I’=I _ave + f(ΔSOC)；

f(ΔSOC)=k ₁ *((1+ΔSOC) ⁿ -1)，ΔSOC＞0；

f(ΔSOC)= -k ₁ *((1+ΔSOC) ⁿ -1)，ΔSOC＜0；

Alternatively, k ₁ And n is related to the power regulation capability of the first variable voltage module; and/or, k ₁ And N is related to the overcurrent capability of the N clusters.

In other possible embodiments, the target current I' satisfies the following relation:

At delta SOC > 0, and the energy storage system is dischargingIn the case of state, I' =k ₂ *I _ave ，1＜k ₂ ≤10；

Fig. 13 shows a schematic flow diagram of another energy storage system conditioning method 600 provided by an embodiment of the present application. The conditioning method 600 may be performed before the first cluster is connected in parallel with the other clusters of the N clusters.

As shown in fig. 13, the adjustment method 600 may include the following steps.

S610: detecting an electrical parameter of the first battery cluster;

s620: and judging whether the first battery cluster is connected with other battery clusters in parallel according to the electrical parameters of the first battery cluster.

Specifically, the execution subject of steps S610 to S620 may also be the control module 150 in the energy storage system 100. The control module 150 may detect an electrical parameter of the first battery cluster before being connected in parallel with the other battery clusters in addition to detecting an electrical parameter of the first battery cluster after being connected in parallel with the other battery clusters.

In some possible embodiments, the electrical parameter is voltage, in which case the step S620 may include: when the voltage difference between the voltage of the first battery cluster and the preset voltage is smaller than or equal to a first preset voltage value, connecting the first battery cluster in parallel with other battery clusters; and under the condition that the voltage difference between the voltage of the first battery cluster and the preset voltage is larger than a first preset voltage value, the first battery cluster is not connected in parallel with other battery clusters.

In some possible embodiments, the power sources of the M variable voltage modules in the energy storage system are any one of the following: at least one cell of the N clusters; a bus bar of N battery clusters; a power supply battery; or a supply capacitor.

While the application has been described with reference to a preferred embodiment, various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the application. In particular, the technical features mentioned in the respective embodiments may be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions falling within the scope of the claims.

Claims

1. An energy storage system, comprising: n battery clusters, an adjusting switch module and M variable voltage modules, wherein N is a positive integer greater than 1, and M is a positive integer less than N;

the N battery clusters are mutually connected in parallel, each battery cluster in the N battery clusters is connected in series with one variable voltage module in the M variable voltage modules through one regulating switch in the regulating switch module, and the M variable voltage modules and the regulating switch module are used for regulating the electrical parameters of the N battery clusters so as to achieve balance among the electrical parameters of the N battery clusters;

the N battery clusters comprise M battery clusters, the M battery clusters are in one-to-one correspondence with the M variable voltage modules, and each battery cluster in the M battery clusters comprises at least one battery cluster;

the energy storage system further comprises: a control module;

the control module is used for detecting the electrical parameters of each group of battery clusters in the M groups of battery clusters so as to judge the number of abnormal battery clusters in each group of battery clusters;

and under the condition that the number of the abnormal battery clusters in the ith battery cluster of the M battery clusters is larger than 1, the control module is used for controlling the ith variable voltage module corresponding to the ith battery cluster in the M variable voltage modules to operate, and the ith variable voltage module is used for sequentially adjusting the electrical parameters of the abnormal battery clusters in the ith battery cluster, wherein i is a positive integer smaller than or equal to M.

2. The energy storage system of claim 1, wherein the regulating switch module comprises N regulating switches.

3. The energy storage system of claim 1 or 2, wherein the electrical parameter is SOC or voltage.

4. The energy storage system of claim 1, wherein the energy storage system comprises,

and under the condition that the number of the abnormal battery clusters in each group of battery clusters is smaller than or equal to 1 and K groups of battery clusters in the M groups of battery clusters are provided with abnormal battery clusters, the control module is used for controlling K variable voltage modules in the M variable voltage modules to operate simultaneously, and the K variable voltage modules are used for adjusting the electrical parameters of the abnormal battery clusters in the K groups of battery clusters, wherein K is a positive integer smaller than or equal to M.

5. The energy storage system of claim 1, wherein the control module is configured to control the i-th variable voltage module to sequentially adjust the electrical parameters of the plurality of abnormal battery clusters in the i-th battery cluster according to a difference between the electrical parameters of the plurality of abnormal battery clusters in the i-th battery cluster and a preset threshold.

6. The energy storage system of any of claims 1 to 5, further comprising: a bypass switch module and a bus bar, the bypass switch module comprising: each of the N battery clusters is connected in series with a bus bar through one of the N bypass switches, and the bus bar is used for realizing electric energy transmission between the N battery clusters and the outside.

7. The energy storage system of claim 6, wherein the N battery clusters comprise: the first battery cluster, under the condition that a first regulating switch connected in series with the first battery cluster is closed and a first bypass switch is opened, a first variable voltage module in the M variable voltage modules is used for regulating the electrical parameters of the first battery cluster;

and under the condition that a first regulating switch connected in series with the first battery cluster is opened and a first bypass switch is closed, the first battery cluster transmits electric energy with the outside through the bus bar.

8. The energy storage system of claim 7, further comprising: a control module;

before a first variable voltage module of the M variable voltage modules is used for adjusting the electrical parameters of the first battery cluster, the control module is used for detecting the electrical parameters of the first battery cluster to determine that the first battery cluster is an abnormal battery cluster;

the control module is used for controlling a first regulating switch connected in series with the first battery cluster to be closed, a first bypass switch connected in series with the first battery cluster to be opened and controlling the first variable voltage module to operate so as to regulate the electrical parameters of the first battery cluster;

After the electrical parameters of the first battery cluster are adjusted to a preset range, the control module is further used for controlling the first adjusting switch to be opened and the first bypass switch to be closed, so that the first battery cluster can transmit electric energy with the outside through the bus bar.

9. The energy storage system of claim 8, wherein the electrical parameter is SOC;

the control module is used for controlling the first variable voltage module to operate so as to adjust the SOC of the first battery cluster to a preset SOC range.

10. The energy storage system of claim 9, wherein the preset SOC range includes: the average value or the median value of the SOCs of the N battery clusters, or the preset SOC range includes: and the SOC of any one battery cluster except the first battery cluster in the N battery clusters.

11. The energy storage system of claim 9 or 10, wherein the control module is configured to send a current command to the first variable voltage module to cause the first variable voltage module to adjust the current of the first battery cluster to a target current that causes the SOC of the first battery cluster to adjust to a target SOC in the preset SOC range.

12. The energy storage system of claim 11, wherein the control module is further configured to determine the target current based on a difference between the SOC of the first battery cluster and the target SOC and an average current of the N battery clusters before the control module is configured to send a current command to the first variable voltage module.

13. The energy storage system of claim 12, wherein the target current I' satisfies the following relationship:

I’=I _ave + f(ΔSOC)；

f(ΔSOC)=k ₁ *((1+ΔSOC) ⁿ -1)，ΔSOC＞0；

f(ΔSOC)=-k ₁ *((1+ΔSOC) ⁿ -1)，ΔSOC＜0；

wherein I is _ave Delta SOC is the difference between the SOC of the first battery cluster and the target SOC, k, which is the average current of the N battery clusters ₁ And n is a preset coefficient.

14. The energy storage system of claim 13, wherein k ₁ And n is related to the power regulation capability of the first variable voltage module; and/or, k ₁ And N is related to the overcurrent capability of the N battery clusters.

15. The energy storage system of claim 12, wherein the target current I' satisfies the following relationship:

Wherein ΔSOC is the difference between the SOC of the first battery cluster and the target SOC, I _ave K is the average current of the N battery clusters ₂ Is a preset coefficient.

16. The energy storage system of any of claims 7 to 15, further comprising: a control module;

the control module is further configured to detect an electrical parameter of the first battery cluster before the first battery cluster is connected in parallel with other battery clusters of the N battery clusters, so as to determine whether to connect the first battery cluster in parallel with the other battery clusters.

17. The energy storage system of claim 16, wherein the electrical parameter is voltage;

the control module is used for connecting the first battery cluster in parallel with other battery clusters under the condition that the voltage difference between the voltage of the first battery cluster and the preset voltage is smaller than or equal to a first preset voltage value;

and the control module is used for not connecting the first battery cluster in parallel with other battery clusters under the condition that the voltage difference between the voltage of the first battery cluster and the preset voltage is larger than the first preset voltage value.

18. The energy storage system of claim 17, wherein the control module is configured to control the first regulation switch to close and control the first variable voltage module to operate such that the first variable voltage module regulates the voltage of the first battery cluster to a target voltage range if a voltage difference between the voltage of the first battery cluster and the preset voltage is less than or equal to a first preset voltage value and greater than or equal to a second preset voltage value;

the control module is used for connecting the adjusted first battery cluster in parallel with other battery clusters, and controlling the first bypass switch to be closed and the first adjusting switch to be opened so that the first battery cluster can transmit electric energy with the outside through the bus.

19. The energy storage system of claim 18, wherein the first preset voltage value is related to a voltage regulation range of the first variable voltage module; and/or the number of the groups of groups,

the target voltage range is related to an average voltage value of the battery clusters that have been connected in parallel with each other among the N battery clusters.

20. The energy storage system of any one of claims 1 to 19, wherein the power source of the M variable voltage modules is any one of:

At least one cell of the N clusters;

a bus bar of the N battery clusters;

a power supply battery; or alternatively

And a power supply capacitor.

21. The energy storage system of any of claims 1 to 20, wherein the M variable voltage modules are isolated DC/DC converters or non-isolated DC/DC converters, and/or;

the M variable voltage modules are used for outputting positive voltage and/or negative voltage.

22. A method of conditioning an energy storage system, the energy storage system comprising: the device comprises N battery clusters, an adjusting switch module and M variable voltage modules, wherein the N battery clusters are mutually connected in parallel, each battery cluster in the N battery clusters is connected in series with one variable voltage module in the M variable voltage modules through one adjusting switch in the adjusting switch module, N is a positive integer greater than 1, M is a positive integer less than N, and the adjusting method comprises the following steps:

controlling the adjusting switch module and the M variable voltage modules to adjust the electrical parameters of the N battery clusters so as to achieve balance among the electrical parameters of the N battery clusters;

The adjustment method further comprises the following steps:

detecting electrical parameters of each group of battery clusters in the M groups of battery clusters to judge the number of abnormal battery clusters in each group of battery clusters;

the controlling the adjusting switch module and the M variable voltage modules to adjust the electrical parameters of the N battery clusters further includes:

and under the condition that the number of the abnormal battery clusters in the ith battery cluster of the M battery clusters is larger than 1, controlling a plurality of regulating switches connected in series with the plurality of abnormal battery clusters in the ith battery cluster to be sequentially closed, and operating the ith variable voltage module corresponding to the ith battery cluster in the M variable voltage modules so that the ith variable voltage module sequentially regulates the electrical parameters of the plurality of abnormal battery clusters in the ith battery cluster, wherein i is a positive integer smaller than or equal to M.

23. The method of claim 22, wherein the conditioning switch module comprises N conditioning switches.

24. The method of claim 22 or 23, wherein the electrical parameter is SOC or voltage.

25. The method of claim 22, wherein the adjusting means comprises,

The controlling the adjusting switch module and the M variable voltage modules to adjust the electrical parameters of the N battery clusters includes:

and under the condition that the number of the abnormal battery clusters in each group of battery clusters is smaller than or equal to 1 and K groups of battery clusters in the M groups of battery clusters are provided with K abnormal battery clusters, controlling K regulating switches connected in series with the K abnormal battery clusters to be closed and simultaneously operating K variable voltage modules in the M variable voltage modules so that the K variable voltage modules regulate the electrical parameters of the K abnormal battery clusters, wherein K is a positive integer smaller than or equal to M.

26. The adjustment method according to claim 22, wherein the controlling the plurality of adjustment switches connected in series to the plurality of abnormal battery clusters in the i-th group of battery clusters sequentially closes and the i-th variable voltage module corresponding to the i-th group of battery clusters among the M variable voltage modules operates such that the i-th variable voltage module sequentially adjusts the electrical parameters of the plurality of abnormal battery clusters in the i-th group of battery clusters, includes:

and controlling a plurality of regulating switches connected in series with a plurality of abnormal battery clusters in the ith battery cluster to be sequentially closed and the ith variable voltage module to operate according to the difference value between the electrical parameters of the plurality of abnormal battery clusters in the ith battery cluster and a preset threshold value, so that the ith variable voltage module sequentially regulates the electrical parameters of the plurality of abnormal battery clusters in the ith battery cluster.

27. The conditioning method according to any one of claims 22 to 26, wherein the energy storage system further comprises: a bypass switch module and a bus bar, the bypass switch module comprising: each of the N battery clusters is connected in series with the bus bar through one bypass switch of the N bypass switches;

the adjustment method further comprises the following steps: and controlling the N bypass switches to enable the N battery clusters to conduct electric energy transmission with the outside through the bus bars.

28. The conditioning method of claim 27, wherein the N battery clusters comprise: a first battery cluster;

wherein the controlling the adjusting switch module and the M variable voltage modules to adjust the electrical parameters of the N battery clusters includes:

controlling a first regulating switch connected in series with the first battery cluster in the regulating switch module to be closed, and controlling a first bypass switch connected in series with the first battery cluster in the N bypass switches to be opened;

controlling a first variable voltage module of the M variable voltage modules to operate so as to adjust electrical parameters of the first battery cluster;

the controlling the N bypass switches such that the N battery clusters output electric power through the bus bar includes:

And controlling a first regulating switch connected in series with the first battery cluster in the regulating switch module to be opened, and controlling a first bypass switch connected in series with the first battery cluster in the N bypass switches to be closed so that the first battery cluster can transmit electric energy with the outside through the bus.

29. The conditioning method according to claim 28, wherein before said controlling operation of a first variable voltage module of said M variable voltage modules to adjust an electrical parameter of said first battery cluster, said conditioning method further comprises:

and detecting the electrical parameters of the first battery cluster to determine that the first battery cluster is an abnormal battery cluster.

30. The conditioning method of claim 29, wherein the electrical parameter is SOC;

wherein said controlling operation of a first variable voltage module of said M variable voltage modules to adjust an electrical parameter of said first battery cluster comprises:

and controlling the first variable voltage module to operate so as to adjust the SOC of the first battery cluster to a preset SOC range.

31. The adjustment method according to claim 30, characterized in that the preset SOC range includes: the average value or the median value of the SOCs of the N battery clusters, or the preset SOC range includes: and the SOC of any one battery cluster except the first battery cluster in the N battery clusters.

32. The adjustment method according to claim 30 or 31, characterized in that the controlling the first variable voltage module to operate to adjust the SOC of the first battery cluster to a preset SOC range includes:

and sending a current instruction to the first variable voltage module so that the first variable voltage module adjusts the current of the first battery cluster to a target current, and the target current adjusts the SOC of the first battery cluster to a target SOC in the preset SOC range.

33. The regulation method of claim 32, wherein prior to said sending a current command to the first variable voltage module, the regulation method comprises:

and determining the target current according to the difference between the SOC of the first battery cluster and the target SOC and the average current of the N battery clusters.

34. The regulation method of claim 33, wherein the target current I' satisfies the following relationship:

I’=I _ave + f(ΔSOC)；

f(ΔSOC)=k ₁ *((1+ΔSOC) ⁿ -1)，ΔSOC＞0；

f(ΔSOC)= -k ₁ *((1+ΔSOC) ⁿ -1)，ΔSOC＜0；

35. The tuning method of claim 34, wherein k ₁ And n is related to the power regulation capability of the first variable voltage module; and/or, k ₁ And N is related to the overcurrent capability of the N battery clusters.

36. The regulation method of claim 33, wherein the target current I' satisfies the following relationship:

At ΔSOC < 0, and the reservoirIn the case where the energy system is in a charged state, I' =k ₂ *I _ave ，1＜k ₂ ≤10；

37. The conditioning method according to any one of claims 28 to 36, characterized in that before the first battery cluster is connected in parallel to the other battery clusters of the N battery clusters, the conditioning method further comprises:

detecting an electrical parameter of the first battery cluster;

and judging whether the first battery cluster is connected with other battery clusters in parallel according to the electrical parameters of the first battery cluster.

38. The method of claim 37, wherein the electrical parameter is a voltage, and wherein the determining whether to connect the first cluster in parallel with other clusters based on the electrical parameter of the first cluster comprises:

when the voltage difference between the voltage of the first battery cluster and the preset voltage is smaller than or equal to a first preset voltage value, connecting the first battery cluster in parallel with other battery clusters;

and under the condition that the voltage difference between the voltage of the first battery cluster and the preset voltage is larger than the first preset voltage value, the first battery cluster is not connected with other battery clusters in parallel.

39. The method according to claim 38, wherein the connecting the first battery cluster in parallel with other battery clusters in the case where a voltage difference between the voltage of the first battery cluster and a preset voltage is less than or equal to a first preset voltage value, comprises:

when the voltage difference between the voltage of the first battery cluster and the preset voltage is smaller than or equal to a first preset voltage value and larger than or equal to a second preset voltage value, the first regulating switch is controlled to be closed, and the first variable voltage module is controlled to operate, so that the first variable voltage module regulates the voltage of the first battery cluster to a target voltage range;

And connecting the regulated first battery cluster with other battery clusters in parallel, and controlling the first bypass switch to be closed and the first regulating switch to be opened so that the first battery cluster can transmit electric energy with the outside through the bus.

40. The method of claim 39, wherein the first predetermined voltage value is related to a voltage adjustment range of the first variable voltage module; and/or the number of the groups of groups,

41. The method of any one of claims 22 to 40, wherein the power sources of the M variable voltage modules are any one of:

at least one cell of the N clusters;

a bus bar of the N battery clusters;

a power supply battery; or alternatively

And a power supply capacitor.

42. The regulation method of any one of claims 22 to 41, wherein the M variable voltage modules are isolated DC/DC converters or non-isolated DC/DC converters, and/or;