CN115473252A

CN115473252A - Power dispatching method of energy storage system and energy storage system

Info

Publication number: CN115473252A
Application number: CN202211192865.3A
Authority: CN
Inventors: 刘少春; 范冬冬; 桂敬杰
Original assignee: Sungrow Energy Storage Technology Co Ltd
Current assignee: Sungrow Energy Storage Technology Co Ltd
Priority date: 2022-09-28
Filing date: 2022-09-28
Publication date: 2022-12-13

Abstract

The application discloses a power dispatching method of an energy storage system and the energy storage system. Wherein, the method comprises the following steps: when the energy storage system normally operates, determining each first difference value between the health degree of each first battery cluster and the first average health degree in the energy storage system, wherein the second battery cluster is provided with a DC/DC voltage converter and a battery, and the DC/DC voltage converter is connected with the battery in series, then is connected into the energy storage system and is connected with the first battery cluster in parallel for use; under the condition that each first difference value is smaller than a first limit value, each second difference value between the charge state value and the average charge state value of each first battery cluster in the energy storage system is obtained; and under the condition that each second difference value is smaller than a second limit value, acquiring a power preset value of the PCS (power converter), and adjusting the output current of the first battery cluster according to the power preset value of the PCS. The technical problems that different degrees of aging exist among different battery clusters due to different charging and discharging rates of the different battery clusters, and the delaying phenomenon cannot be effectively adjusted are solved.

Description

Power dispatching method of energy storage system and energy storage system

Technical Field

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

Background

The energy storage system is a system capable of storing electric energy and supplying power, the battery energy storage system becomes the mainstream of the energy storage technology, and different energy storage system topology schemes are generated along with the development of the energy storage technology.

At present, in the related art, a common energy storage system generally comprises a plurality of groups of battery clusters, a battery collecting cabinet and a power converter, but the capacity and the DOD discharge depth of the energy storage system are limited to a cluster of batteries with the minimum capacity, and different degrees of aging may exist between different battery clusters due to different charging and discharging rates of the different battery clusters, and the aging degree of the battery clusters cannot be delayed.

In view of the above problems, no effective solution has been proposed.

Disclosure of Invention

The embodiment of the application provides a power scheduling method of an energy storage system and the energy storage system, and at least solves the technical problems that different battery clusters age to different degrees due to different charging and discharging rates of different battery clusters, and a delay phenomenon cannot be effectively adjusted.

According to an aspect of an embodiment of the present application, there is provided a power scheduling method for an energy storage system, including: when the energy storage system normally operates, determining each first difference value between the health degree of each first battery cluster and the first average health degree in the energy storage system, wherein the second battery cluster is provided with a DC/DC voltage converter and a battery, and the DC/DC voltage converter is connected with the battery in series, then is connected into the energy storage system and is connected with the first battery cluster in parallel for use; under the condition that each first difference value is smaller than a first limit value, each second difference value between the charge state value and the average charge state value of each first battery cluster in the energy storage system is obtained; and under the condition that each second difference value is smaller than the second limit value, acquiring a power preset value of the power converter PCS, and adjusting the output current of the first battery cluster according to the power preset value of the PCS.

Optionally, obtaining a power predetermined value of the power converter PCS, and switching the second battery cluster to adjust the output current of the first battery cluster according to the power predetermined value of the PCS includes: and calculating the theoretical output power value of each battery cluster according to the power preset value of the PCS, wherein each battery cluster comprises: a first battery cluster and a second battery cluster; obtaining the theoretical output current value of each battery cluster according to the theoretical output power value; acquiring a second average health degree corresponding to the theoretical output power value and the theoretical output current value; and solving a current adjustment value of the primary battery cluster based on the second average health degree, and adjusting the output current of the primary battery cluster based on the current adjustment value.

Optionally, adjusting the output current of the cell cluster based on the current adjustment value comprises: solving the sum of the theoretical output current value and the current adjustment value; and determining the sum value as a current instruction value of the second battery cluster, and controlling the second battery cluster to charge and discharge based on the current magnitude indicated by the current instruction value.

Optionally, according to the power scheduling method of the energy storage system, the method further includes: comparing each first difference value with a first limit value, and screening out first battery clusters larger than the first limit value from each first difference value; and determining the first battery cluster larger than the first limit value as a battery cluster to be replaced, stopping the operation of the battery cluster to be replaced and replacing the battery cluster to be replaced.

Optionally, according to the power scheduling method of the energy storage system, the method further includes: determining each third difference value between the charge state value of the first battery cluster and the average charge state value when the energy storage system is in a standby state; comparing each third difference value with a third limit value, and screening out the first battery clusters larger than the third limit value from each third difference value; and determining the first battery cluster larger than the third limit value as a battery cluster to be discharged, charging the second battery cluster based on the battery cluster to be discharged until the charge state value of the battery cluster to be discharged is equal to the average charge state value of the energy storage system, and stopping charging the second battery cluster.

Optionally, according to the power scheduling method of the energy storage system, the method further includes: screening out a first battery cluster smaller than a third limit value from all the third difference values; and determining the first battery cluster smaller than the third limit value as a battery cluster to be charged, charging the battery cluster to be charged based on the second battery cluster until the charge state value of the battery cluster to be charged is equal to the average charge state value of the energy storage system, and stopping charging the battery cluster to be charged.

Optionally, when each of the second difference values is smaller than the second limit value, adjusting the charge-discharge current of the second battery cluster includes: the charge and discharge current of the second battery cluster is increased by the DC/DC converter for reducing the charge and discharge current of the first battery cluster.

According to another aspect of the embodiments of the present application, there is also provided an energy storage system, including: the system comprises a plurality of groups of first battery clusters, wherein the first battery clusters of each group of the plurality of groups of first battery clusters are connected in parallel and then are connected into a main loop of the energy storage system; and the second battery cluster is connected with the plurality of groups of first battery clusters in parallel and is connected into the main loop, wherein the second battery cluster is provided with a DC/DC voltage converter and a battery, and the DC/DC voltage converter is connected with the main loop of the energy storage system after being connected with the battery in series and is connected with the first battery clusters in parallel for use.

Optionally, each group of the first battery clusters in the multiple groups of the first battery clusters is connected with a control switch, where the control switch is used to control the first battery clusters to be connected or disconnected with a main loop of the energy storage system.

Optionally, the energy storage system further comprises: one end of the power converter PCS is connected with the main loop, and the other end of the power converter PCS is connected with a power grid.

Optionally, a controller and an AC/DC bidirectional converter are disposed in the PCS, wherein the controller is configured to receive a control instruction, and control the AC/DC bidirectional converter to charge and discharge the first battery cluster or the second battery cluster according to the control instruction.

Optionally, the controller is further configured to obtain battery state information of the first battery cluster and the second battery cluster, and perform power adjustment on the first battery cluster and the second battery cluster according to the battery state information, where the battery state information at least includes: the health of the first battery cluster and the second battery cluster, and the state of charge value.

Optionally, the AC/DC bidirectional converter is configured to input electric energy of the power grid to the first battery cluster or the second battery cluster through the main loop, so as to charge the first battery cluster or the second battery cluster.

Optionally, the AC/DC bidirectional converter is further configured to input the electric energy stored in the first battery cluster or the second battery cluster to a power grid through the main loop, so as to discharge the first battery cluster or the second battery cluster.

In the embodiment of the application, a mode that a newly added battery cluster and an original battery cluster are used in parallel is adopted, and each first difference value between the health degree of each first battery cluster in an energy storage system and a first average health degree is determined, wherein a second battery cluster is provided with a DC/DC voltage converter and a battery, and the DC/DC voltage converter is connected with the battery in series and then is connected into the energy storage system and is used in parallel with the first battery cluster; under the condition that each first difference value is smaller than a first limit value, each second difference value between the charge state value and the average charge state value of each first battery cluster in the energy storage system is obtained; under the condition that each second difference value is smaller than the second limit value, the power preset value of the power converter PCS is obtained, the output current of the first battery cluster is adjusted according to the power preset value of the PCS, the purpose of adjusting the charging and discharging currents of the original batteries based on the newly added battery clusters is achieved, the technical effects of delaying the aging of the original batteries of the energy storage system, prolonging the service life of the batteries and reducing the energy storage cost are achieved, and the technical problems that different battery clusters are aged to different degrees due to the fact that the charging and discharging rates of different battery clusters are different, and the delaying phenomenon cannot be effectively adjusted are solved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application and not to limit the application. In the drawings:

FIG. 1 is a schematic diagram of an energy storage system according to the related art;

FIG. 2 is a schematic diagram of another energy storage system according to the related art;

FIG. 3 is a schematic diagram of an energy storage system according to an embodiment of the present application;

fig. 4 is a schematic flow chart of a power scheduling method of an energy storage system according to an embodiment of the present application;

FIG. 5 is a schematic diagram of a battery system discharge power flow according to an embodiment of the present application;

FIG. 6 is a control flow diagram of DC/DC during normal operation of the system according to an embodiment of the present application;

FIG. 7 is a schematic flow chart of low power charging and discharging during system standby according to an embodiment of the present application;

FIG. 8 is a schematic diagram of a complementary electrical power flow according to an embodiment of the present application;

FIG. 9 is another complementary power flow schematic according to an embodiment of the present application;

FIG. 10 is a schematic structural diagram of an energy storage system in an embodiment of the present application;

FIG. 11 shows a schematic block diagram of an example electronic device 1100 that may be used to implement embodiments of the present application.

Detailed Description

In order to make the technical solutions better understood by those skilled in the art, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only partial embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It should be noted that the terms "first," "second," and the like in the description and claims of this application and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are capable of operation in sequences other than those illustrated or described herein. Moreover, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

For the convenience of better understanding of the embodiments related to the present application, technical terms or partial terms that may be referred to in the present application are now explained:

the battery charge SOC, which refers to the available state of charge remaining in the battery, is defined by the following equation:

SOC＝Q _{remainder of} /Q _{Rated value} ×100％

Wherein Qrating is the rated charge capacity of the battery, and Qremaining is the remaining charge in the battery.

If Qnominal is considered to be a fixed constant value, i.e., the remaining charge remaining is always considered to be equal to the nominal capacity minus the amount of charge released, then SOC can be represented by the following sub-equation:

SOC＝Q _{remainder of} /(Q _{Remains of} +Q _{Discharge of electricity} )×100％

Where qdischarge represents the amount of charge that the battery has discharged after the last full charge.

SOH refers to battery state of health. When the battery is charged, lithium metal oxide of the positive electrode generates lithium ions through chemical reaction in the battery, the lithium ions pass through the diaphragm by taking an organic electrolyte as a carrier and move to the negative electrode, the graphite of the negative electrode has a laminated structure and a plurality of micropores, the lithium ions reaching the negative electrode can be inserted into the micropores, and the more the number of the inserted lithium ions is, the higher the charging capacity is. The increase in negative electrode lithium ions due to the decrease in internal positive electrode lithium ions during charging of the battery, manifests as a normal terminal voltage rise outside the battery. When the battery is discharged, the internal chemical reaction is opposite, lithium ions are extracted from the negative electrode and return to the positive electrode to be combined with the lithium metal compound, the quantity of the lithium ions at the positive electrode is increased, the quantity of the negative electrode is correspondingly reduced, the energy of the battery is reduced, and the terminal voltage of the battery is externally shown to be reduced. With the repeated charge and discharge of the battery, the active material of the internal electrode and the stored lithium ions are continuously consumed and lost, so that the performances of the capacity, the charge and discharge power and the like are continuously degraded, and the battery is gradually aged until the end of the service life is reached.

DOD refers to the battery depth of discharge. If the change in SOC from fully empty to fully charged is recorded as 0-100%, in practical applications, it is preferred that each cell operates in the 5% -95% interval. A possible overshoot below 5% and a possible overshoot above 95% may result in overcharging, whereby some irreversible chemical reaction occurs and battery life is affected.

Fig. 1 is an energy storage topology structure in the related art, as shown in fig. 1, the topology structure includes a 1# to n # battery cluster, a battery bus Bar (BCP), a PCS (power converter), and the like, and as for a hardware structure thereof, the topology structure has an advantage that initial investment is relatively small, but an energy storage system capacity and a permissible DOD (depth of discharge) under the same dc bus are limited to a battery cluster with a minimum capacity due to a barrel effect.

Fig. 2 is another energy storage topology structure in the related art, as shown in fig. 2, the topology structure includes a 1# to n # battery cluster, a 1# to n # DC/DC converter, a PCS (power converter), and the like, which is equivalent to the topology structure shown in fig. 1, and a bidirectional DC/DC converter is added, obviously, the initial investment of the energy storage system is relatively increased, but the topology structure has the advantages that the DC/DC + PCS two-stage system topology increases the complexity of system control, including but not limited to the complexity of system communication, mode switching, system protection, and the like, and reduces the system reliability to some extent. Meanwhile, in the scheme shown in fig. 2, a DC/DC converter is added to each battery cluster, so that power conversion is increased by one level, the charge-discharge cycle efficiency of the system is reduced, the heat productivity of the system is increased, the customer income is reduced, and the difficulty in heat flow design is increased.

In order to solve the above problems, the present application provides a simplified topology structure of an energy storage system, as shown in fig. 3, compared with the "one cluster one management" shown in fig. 2, the energy storage system according to the present invention can adjust the power flow of the original battery cluster when the system is in normal operation, and can utilize DC/DC to implement a battery cluster level "active equalization" function at the idle time of the system, and complete a short board of a certain battery cluster SOC. The newly added RACK adopts a mode of battery cluster + DC/DC, and new and old batteries can be directly connected in parallel for use; the energy storage system based on this application has not only simplified the complexity of control promptly, and the cost is reduced uses through the parallelly connected of new and old battery can effectively solve moreover because there is ageing of different degrees between the different battery clusters that the charging and discharging speed difference of different battery clusters caused, and to the technical problem that the phenomenon can't effectively be adjusted of delaying.

In accordance with an embodiment of the present application, there is provided an embodiment of a power scheduling method for an energy storage system, where the steps illustrated in the flowchart of the drawings may be implemented in a computer system, such as a set of computer-executable instructions, and where, although a logical order is illustrated in the flowchart, in some cases, the steps illustrated or described may be performed in an order different than the order presented herein.

Fig. 4 is a power scheduling method of an energy storage system according to an embodiment of the present application, and as shown in fig. 4, the method includes the following steps:

step S402, when the energy storage system normally runs, determining each first difference value between the health degree of each first battery cluster in the energy storage system and the first average health degree, wherein the second battery cluster is provided with a DC/DC voltage converter and a battery, and the DC/DC voltage converter is connected with the battery in series, then is connected into the energy storage system and is connected with the first battery cluster in parallel for use;

it should be noted that the first battery cluster is an original battery cluster, the second battery cluster is a newly added battery cluster, and the first difference is a difference between the health degree of each original battery cluster in the energy storage system and the average health degree of the original battery clusters in the energy storage system.

In the related art, each battery cluster can be additionally provided with a bidirectional DC/DC converter, but the initial cost of the energy storage system is increased, and the system topology of the DC/DC + PCS two-stage system increases the complexity of system control and reduces the reliability of the system to a certain extent. After the DC/DC converter is added, the power conversion of the energy storage system is increased by one level, the charge-discharge cycle efficiency of the system is reduced, the heat productivity of the system is increased, the income of customers is reduced, and the difficulty in heat flow design is increased. Compared with the related technology, the control complexity is simplified, and therefore the system circulation efficiency is higher, the cost is reduced, and the technical goal of one cluster and one management is also achieved.

Step S404, acquiring each second difference value between the charge state value and the average charge state value of each first battery cluster in the energy storage system under the condition that each first difference value is smaller than a first limit value;

it should be noted that the first limit value is an error limit value 1, and the second difference value is a difference value between a charge state value of each original battery cluster in the energy storage system and an average charge state value of the original battery cluster in the energy storage system.

Step S406, acquiring a power predetermined value of the power converter PCS under the condition that each second difference is smaller than the second limit value, and adjusting the output current of the first battery cluster according to the power predetermined value of the PCS. It should be noted that the second limit value can be expressed as an error limit value 2.

In some embodiments of the present application, a manner of adding a battery cluster is adopted, and each first difference value between the health degree of each first battery cluster in the energy storage system and the first average health degree is determined, wherein the second battery cluster is provided with a DC/DC voltage converter and a battery, and the DC/DC voltage converter is connected in series with the battery, then is connected to the energy storage system, and is used in parallel with the first battery cluster; under the condition that each first difference value is smaller than a first limit value, each second difference value between the charge state value and the average charge state value of each first battery cluster in the energy storage system is obtained; under the condition that each second difference value is smaller than the second limit value, the power preset value of the power converter PCS is obtained, the output current of the first battery cluster is adjusted according to the power preset value of the PCS, the purpose of reducing the charging and discharging currents of the aged batteries is achieved, the technical effect of delaying the battery aging of the energy storage system is achieved, and the technical problems that different battery clusters are aged at different degrees due to different charging and discharging rates of different battery clusters, and the delay phenomenon cannot be effectively adjusted are solved.

In some embodiments of the present application, the predetermined value of the power converter PCS may be obtainedAnd the second battery cluster is input to adjust the output current of the first battery cluster according to the power preset value of the PCS, and the method can be realized by the following steps: and calculating theoretical output power values of the battery clusters according to the power preset value of the PCS, wherein each battery cluster comprises: a first battery cluster and a second battery cluster; calculating the theoretical output current value of each battery cluster according to the theoretical output power value; acquiring a second average health degree corresponding to the theoretical output power value and the theoretical output current value; and solving a current adjustment value of the primary battery cluster based on the second average health degree, and adjusting the output current of the primary battery cluster based on the current adjustment value. Wherein the current adjustment value is: delta I _x1 ＝I _avg *K _SOH *(SOH _X /SOH _avg )；

Optionally, adjusting the output current of the cell cluster based on the current adjustment value comprises: calculating the sum of the theoretical output current value and the current adjustment value; and determining the sum value as a current instruction value of the second battery cluster, and controlling the second battery cluster to charge and discharge based on the current indicated by the current instruction value.

Specifically, the current command value can be obtained as follows:

I _X ＝I _avg *(1+K _SOH (SOH _X /SOH _avg ))。

fig. 5 is a schematic diagram of discharge power flow of an optional energy storage system according to an embodiment of the present application, as shown in fig. 5, an original battery cluster may discharge to an external device through a PCS, and fig. 6 is a control flow chart of DC/DC when the system in this embodiment operates normally, as shown in fig. 6, the specific steps are as follows:

(1) Acquiring the health degree of the original battery cluster, and acquiring the difference value between the health degree of the original battery cluster and the average health degree;

(2) If the health degree difference is smaller than the error limit value 1, continuously acquiring the difference between the charge quantity of the original battery cluster and the average charge quantity;

(3) If the difference value of the electric charge is smaller than the error limit value 2, setting a power value according to the actual operation requirement of the system, and calculating the theoretical output power of each cluster of batteries and the theoretical output current of each cluster of batteries;

(4) The difference value between the health degree of the original battery cluster and the average health degree is recalculated again;

(5) Calculating the current adjustment value of the primary battery cluster according to the recalculated difference value;

(6) And calculating the sum of the theoretical output current value and the current adjustment value, determining the sum as a current instruction value, and controlling the newly added battery cluster to charge and discharge based on the current indicated by the current instruction value.

Wherein the variables have the following meanings:

in other optional embodiments of the present application, each of the first difference values may be further compared with a first limit value, and a first cell cluster larger than the first limit value is selected from each of the first difference values; and determining the first battery cluster larger than the first limit value as a battery cluster to be replaced, stopping the operation of the battery cluster to be replaced and replacing the battery cluster to be replaced. It can be understood that batteries with the health degree not meeting the requirements can be replaced in time through the scheme, and normal use of the whole energy storage system is ensured.

As an alternative embodiment, when the energy storage system is in a standby state, each third difference value between the state of charge value of the first battery cluster and the average state of charge value may be determined; comparing each third difference value with a third limit value, and screening out the first battery clusters larger than the third limit value from each third difference value; and determining the first battery cluster larger than the third limit value as a battery cluster to be discharged, charging the second battery cluster based on the battery cluster to be discharged until the charge state value of the battery cluster to be discharged is equal to the average charge state value of the energy storage system, and stopping charging the second battery cluster.

Fig. 7 is a schematic diagram of a charging/discharging adjustment process in an embodiment of the present application, as shown in fig. 7 (see left half), when a difference between a state of charge value of an original battery cluster and an average state of charge value is greater than a third limit value (i.e., limit 2), the original battery cluster is used to charge a newly added battery cluster until the original battery cluster is equal to the average state of charge value, fig. 8 is a schematic diagram of a complementary power in an embodiment, as shown in fig. 8, a power flow can flow from the original battery cluster (BT 1) to the newly added battery cluster (BTX). It should be noted that, when the energy storage system is in a standby state, the third limit value may be the same as the second limit value (i.e., both limit 2).

In other optional embodiments of the present application, a first battery cluster smaller than a third limit value may be further screened from each third difference value; and determining the first battery cluster smaller than the third limit value as a battery cluster to be charged, charging the battery cluster to be charged based on the second battery cluster until the charge state value of the battery cluster to be charged is equal to the average charge state value of the energy storage system, and stopping charging the battery cluster to be charged.

As shown in the right part of fig. 7, when the difference between the soc value of an original cluster and the average soc value is smaller than the third limit value (i.e., limit 2), the new cluster is used to charge the original cluster until the original cluster is equal to the average soc value, fig. 9 is a schematic diagram of the supplementary power in this embodiment, and as shown in fig. 9, the power flow can flow from the new cluster (BTX) to the original cluster (BT 2) for charging the original cluster until the soc value is equal to the average soc value of the energy storage system.

Fig. 10 is an energy storage system in an embodiment of the present application, and as shown in fig. 10, the energy storage system includes:

the system comprises a plurality of groups of first battery clusters, wherein the first battery clusters of each group of the plurality of groups of first battery clusters are connected in parallel and then are connected into a main loop of the energy storage system;

and the second battery cluster is connected with the plurality of groups of first battery clusters in parallel and is connected into the main loop, wherein the second battery cluster is provided with a DC/DC voltage converter and a battery, and the DC/DC voltage converter is connected with the main loop of the energy storage system after being connected with the battery in series and is connected with the first battery clusters in parallel for use.

In the energy storage system, a plurality of groups of first battery clusters are connected in parallel, and then the first battery clusters of each group of the plurality of groups of first battery clusters are connected into a main loop of the energy storage system; the second battery cluster is connected with the multiple groups of first battery clusters in parallel and enters the main loop, wherein the second battery cluster is provided with a DC/DC voltage converter and batteries, the DC/DC voltage converter is connected with the batteries in series and then is connected into the main loop of the energy storage system and is used in parallel with the first battery clusters, and the purpose of reducing the charging and discharging currents of aged batteries is achieved, so that the technical effect of delaying the aging of the batteries of the energy storage system is achieved, and the technical problems that different battery clusters are aged to different degrees due to different charging and discharging rates of different battery clusters and the delay phenomenon cannot be effectively adjusted are solved.

Some optional embodiments of the present application include: each group of first battery clusters in the multiple groups of first battery clusters is connected with a control switch, wherein the control switch is used for controlling the first battery clusters to be connected or disconnected with a main loop of the energy storage system.

As an optional implementation manner, a controller and an AC/DC bidirectional converter are disposed in the PCS, and the controller is configured to receive a control instruction, and control the AC/DC bidirectional converter to charge and discharge the first battery cluster or the second battery cluster according to the control instruction. It should be noted that the control command includes, but is not limited to: the sign and value of the power command may control a certain battery cluster to be discharged when the power command is negative, or may control a certain battery cluster to be charged when the power command is positive, for example.

Optionally, the controller is further configured to obtain battery state information of the first battery cluster and the second battery cluster, and perform power adjustment on the first battery cluster and the second battery cluster according to the battery state information, where the battery state information at least includes: the health of the first battery cluster and the second battery cluster, and the state of charge value. As can be seen from the embodiments related to the present application, the power regulation is realized by the current transfer between the plurality of first battery clusters and the plurality of second battery clusters.

In an exemplary embodiment of the present application, the AC/DC bidirectional converter is configured to input electric energy of a power grid to the first battery cluster or the second battery cluster through the main loop, so as to charge the first battery cluster or the second battery cluster.

It can be understood that, by charging and discharging the second battery cluster to the first battery cluster, the charge state between the first battery clusters can be balanced, for example, the charge and discharge current of the newly added battery cluster is appropriately increased, and the charge and discharge current of the other battery clusters is reduced, so as to slow down the capacity fading of the other batteries.

It is readily noted that this embodiment provides an energy storage system that does not require excessive system hardware modifications relative to conventional energy storage solutions; by operating the power scheduling method in the related embodiment, the charging and discharging current of the aging battery can be properly reduced, and the aging speed of the system is delayed.

According to another aspect of the embodiments of the present application, there is also provided a non-volatile storage medium, where the non-volatile storage medium includes a stored program, and a device in which the non-volatile storage medium is located is controlled to execute any power scheduling method of an energy storage system when the program runs.

Specifically, the storage medium is used for storing program instructions of the following functions, and the following functions are realized:

determining each first difference value between the health degree of each first battery cluster in the energy storage system and the first average health degree, wherein the energy storage system further comprises: the second battery cluster is opposite to the first battery cluster, the second battery cluster is provided with a DC/DC voltage converter and a battery, the DC/DC voltage converter is connected with the battery in series and then is connected into an energy storage system, and the DC/DC voltage converter is connected with the first battery cluster in parallel for use; under the condition that each first difference value is smaller than a first limit value, each second difference value between the charge state value and the average charge state value of each first battery cluster in the energy storage system is obtained; and under the condition that each second difference value is smaller than the second limit value, acquiring a power preset value of the power converter PCS, and adjusting the output current of the first battery cluster according to the power preset value of the PCS.

Alternatively, in the present embodiment, the storage medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the aforementioned storage medium would include an electrical connection based on one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the aforementioned.

An embodiment according to the present application provides an electronic device including: at least one processor; and a memory communicatively coupled to the at least one processor; the storage stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform any one of the above power scheduling methods for an energy storage system.

Optionally, the electronic device may further include a transmission device and an input/output device, wherein the transmission device is connected to the processor, and the input/output device is connected to the processor.

FIG. 11 shows a schematic block diagram of an example electronic device 1100 that may be used to implement embodiments of the present application. Electronic devices are intended to represent various forms of digital computers, such as laptops, desktops, workstations, personal digital assistants, servers, blade servers, mainframes, and other appropriate computers. Electronic devices may also represent various forms of mobile devices, such as personal digital processors, cellular telephones, smart phones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions, are meant to be examples only, and are not meant to limit implementations of the present application that are described and/or claimed herein.

As shown in fig. 11, the device 1100 comprises a computing unit 1101, which may perform various appropriate actions and processes according to a computer program stored in a Read Only Memory (ROM) 1102 or a computer program loaded from a storage unit 1108 into a Random Access Memory (RAM) 1103. In the RAM 1103, various programs and data necessary for the operation of the device 1100 may also be stored. The calculation unit 1101, the ROM 1102, and the RAM 1103 are connected to each other by a bus 1104. An input/output (I/O) interface 1105 is also connected to bus 1104.

A number of components in device 1100 connect to I/O interface 1105, including: an input unit 1106 such as a keyboard, a mouse, and the like; an output unit 1107 such as various types of displays, speakers, and the like; a storage unit 1108, such as a magnetic disk, optical disk, or the like; and a communication unit 1109 such as a network card, a modem, a wireless communication transceiver, and the like. The communication unit 1109 allows the device 1100 to exchange information/data with other devices via a computer network such as the internet and/or various telecommunication networks.

The computing unit 1101 can be a variety of general purpose and/or special purpose processing components having processing and computing capabilities. Some examples of the computing unit 1001 include, but are not limited to, a Central Processing Unit (CPU), a Graphics Processing Unit (GPU), various dedicated Artificial Intelligence (AI) computing chips, various computing units running machine learning model algorithms, a Digital Signal Processor (DSP), and any suitable processor, controller, microcontroller, and so forth. The computing unit 1101 performs the various methods and processes described above, such as the power scheduling method of the energy storage system. For example, in some embodiments, the power scheduling method of the energy storage system may be implemented as a computer software program tangibly embodied in a machine-readable medium, such as the storage unit 1108. In some embodiments, part or all of the computer program may be loaded and/or installed onto device 1100 via ROM 1102 and/or communications unit 1109. When the computer program is loaded into the RAM 1103 and executed by the computing unit 1101, one or more steps of the power scheduling method of the energy storage system described above may be performed. Alternatively, in other embodiments, the computing unit 1101 may be configured to perform the power scheduling method of the energy storage system by any other suitable means (e.g., by means of firmware).

Various implementations of the systems and techniques described here above may be implemented in digital electronic circuitry, integrated circuitry, field Programmable Gate Arrays (FPGAs), application Specific Integrated Circuits (ASICs), application Specific Standard Products (ASSPs), system on a chip (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and/or combinations thereof. These various embodiments may include: implemented in one or more computer programs that are executable and/or interpretable on a programmable system including at least one programmable processor, which may be special or general purpose, receiving data and instructions from, and transmitting data and instructions to, a storage system, at least one input device, and at least one output device.

Program code for implementing the methods of the present application may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program codes, when executed by the processor or controller, cause the functions/operations specified in the flowchart and/or block diagram to be performed. The program code may execute entirely on the machine, partly on the machine, as a stand-alone software package partly on the machine and partly on a remote machine or entirely on the remote machine or server.

In the context of this application, a machine-readable medium may be a tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. The machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of a machine-readable storage medium would include an electrical connection based on one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

To provide for interaction with a user, the systems and techniques described here can be implemented on a computer having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to a user; and a keyboard and a pointing device (e.g., a mouse or a trackball) by which a user may provide input to the computer. Other kinds of devices may also be used to provide for interaction with a user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form, including acoustic, speech, or tactile input.

The systems and techniques described here can be implemented in a computing system that includes a back-end component (e.g., as a data server), or that includes a middleware component (e.g., an application server), or that includes a front-end component (e.g., a user computer having a graphical user interface or a web browser through which a user can interact with an implementation of the systems and techniques described here), or any combination of such back-end, middleware, or front-end components. The components of the system can be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: local Area Networks (LANs), wide Area Networks (WANs), and the Internet.

The computer system may include clients and servers. A client and server are generally remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other. The server may be a cloud server, a server of a distributed system, or a server with a combined blockchain.

The above-mentioned serial numbers of the embodiments of the present application are merely for description and do not represent the merits of the embodiments.

In the above embodiments of the present application, the descriptions of the respective embodiments have respective emphasis, and for parts that are not described in detail in a certain embodiment, reference may be made to related descriptions of other embodiments.

In the embodiments provided in the present application, it should be understood that the disclosed technology can be implemented in other ways. The above-described embodiments of the apparatus are merely illustrative, and for example, the division of the units may be a logical division, and in actual implementation, there may be another division, for example, multiple units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, units or modules, and may be in an electrical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one position, or may be distributed on a plurality of units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application may be substantially implemented or contributed to by the prior art, or all or part of the technical solution may be embodied in a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a removable hard disk, a magnetic disk, or an optical disk, and various media capable of storing program codes.

The foregoing is only a preferred embodiment of the present application and it should be noted that those skilled in the art can make several improvements and modifications without departing from the principle of the present application, and these improvements and modifications should also be considered as the protection scope of the present application.

Claims

1. A power scheduling method of an energy storage system, comprising:

when the energy storage system normally operates, determining each first difference value between the health degree of each first battery cluster in the energy storage system and the first average health degree, wherein a second battery cluster is provided with a DC/DC voltage converter and a battery, and the DC/DC voltage converter is connected with the battery in series and then is connected into the energy storage system and is connected with the first battery cluster in parallel for use;

under the condition that each first difference value is smaller than a first limit value, each second difference value between the charge state value and the average charge state value of each first battery cluster in the energy storage system is obtained;

and under the condition that each second difference value is smaller than a second limit value, acquiring a power preset value of a power converter PCS, and adjusting the output current of the first battery cluster according to the power preset value of the PCS.

2. The method of claim 1, wherein obtaining a predetermined value of power for a Power Converter (PCS), and switching the second battery cluster to adjust the output current of the first battery cluster according to the predetermined value of power for the PCS, comprises:

calculating theoretical output power values of the battery clusters according to the power preset value of the PCS, wherein the battery clusters comprise: the first battery cluster and the second battery cluster;

obtaining the theoretical output current value of each battery cluster according to the theoretical output power value;

acquiring a second average health degree corresponding to the theoretical output power value and the theoretical output current value;

and solving a current adjustment value of the primary battery cluster based on the second average health degree, and adjusting the output current of the primary battery cluster based on the current adjustment value.

3. The method of claim 2, wherein adjusting the output current of the battery cell cluster based on the current adjustment value comprises:

calculating the sum of the theoretical output current value and the current adjustment value;

and determining the sum as a current instruction value of the second battery cluster, and controlling the second battery cluster to charge and discharge based on the current indicated by the current instruction value.

4. The method of claim 1, further comprising:

comparing each first difference value with the first limit value, and screening the first battery clusters which are greater than the first limit value from each first difference value;

and determining the first battery cluster larger than the first limit value as a battery cluster to be replaced, stopping the operation of the battery cluster to be replaced and replacing the battery cluster to be replaced.

5. The method of claim 1, further comprising:

determining each third difference value between the charge state value of the first battery cluster and the average charge state value when the energy storage system is in a standby state;

comparing each third difference value with a third limit value, and screening the first battery cluster which is greater than the third limit value from each third difference value;

and determining the first battery cluster which is larger than the third limit value as a battery cluster to be discharged, charging the second battery cluster based on the battery cluster to be discharged until the charge state value of the battery cluster to be discharged is equal to the average charge state value of the energy storage system, and stopping charging the second battery cluster.

6. The method of claim 5, further comprising:

screening out the first battery cluster smaller than the third limit value from the various third difference values;

and determining the first battery cluster smaller than the third limit value as a battery cluster to be charged, charging the battery cluster to be charged based on the second battery cluster until the charge state value of the battery cluster to be charged is equal to the average charge state value of the energy storage system, and stopping charging the battery cluster to be charged.

7. The power dispatching method of the energy storage system according to claim 1, wherein when each second difference is smaller than a second limit value, adjusting the charging and discharging current of the second battery cluster comprises:

increasing, by the DC/DC converter, a charge-discharge current of the second battery cluster for reducing the charge-discharge current of the first battery cluster.

8. An energy storage system, comprising:

and the second battery cluster and the plurality of groups of first battery clusters are connected into the main loop in parallel, wherein the second battery cluster is provided with a DC/DC voltage converter and a battery, and the DC/DC voltage converter is connected with the battery in series and then is connected into the main loop of the energy storage system and is connected with the first battery clusters in parallel for use.

9. The energy storage system of claim 8, comprising:

each group of first battery clusters in the multiple groups of first battery clusters is connected with a control switch, wherein the control switch is used for controlling the connection or disconnection of the first battery clusters and a main loop of the energy storage system.

10. The energy storage system of claim 8, further comprising:

and one end of the PCS is connected with the main loop, and the other end of the PCS is connected with a power grid.

11. The energy storage system according to claim 10, wherein a controller and an AC/DC bidirectional converter are disposed in the PCS, and wherein the controller is configured to receive a control command and control the AC/DC bidirectional converter to charge and discharge the first battery cluster or the second battery cluster according to the control command.

12. The energy storage system of claim 11, wherein the controller is further configured to obtain battery status information of the first battery cluster and the second battery cluster, and perform power adjustment on the first battery cluster and the second battery cluster according to the battery status information, wherein the battery status information at least includes: a health of the first battery cluster and the second battery cluster, and a state of charge value.

13. The energy storage system of claim 11, wherein the AC/DC bidirectional converter is configured to input the electric energy of the grid to the first battery cluster or the second battery cluster through the main loop for charging the first battery cluster or the second battery cluster.

14. The system of claim 11, wherein the AC/DC bi-directional converter is further configured to input the stored electrical energy of the first battery cluster or the second battery cluster to the grid through the main loop for discharging the first battery cluster or the second battery cluster.