Battery charging control method, control device, energy storage system and storage mediumTechnical Field
The present disclosure relates to the field of battery technologies, and in particular, to a battery charging control method, a control device, an energy storage system, and a storage medium.
Background
With the development of rechargeable battery technology, lithium ion batteries are used as batteries which are made of lithium metal or lithium alloy as a negative electrode material and use nonaqueous electrolyte solution, and have the characteristics of long cycle life, no memory effect, high energy density and the like, so that the lithium ion battery energy storage technology is widely applied to the fields of electric automobiles, portable electronic products, mobile devices and the like. The existing battery energy storage system is mostly formed by connecting a plurality of battery clusters in series and/or in parallel, if one battery cluster is in a full-charge state in the charging process of the energy storage system, other unfilled battery clusters can be stopped from being charged, namely the charging performance of a single battery cluster can influence the charging performance of other battery clusters, further the performance of the whole energy storage system is influenced, the consistency among the battery clusters is poorer and worse, and the available capacity and the working efficiency of the energy storage system are reduced.
Disclosure of Invention
Based on the above, it is necessary to provide a battery charging control method, a control device, an energy storage system and a storage medium for solving the problems that in the prior art, the charging performance of a single battery cluster influences the charging performance of other battery clusters during charging, so that the consistency difference between the battery clusters is enlarged, and the available capacity and the working efficiency of the energy storage system are reduced.
In order to achieve the above object, the present application provides a battery charging control method applied to an energy storage system, the energy storage system including a plurality of battery clusters, each of the battery clusters including a plurality of unit batteries, the method comprising:
acquiring battery information of each battery cluster, wherein the battery information comprises voltage values of all the single batteries;
determining the charging priority of each battery cluster according to the battery information of a plurality of battery clusters, so that the maximum voltage value of the battery cluster with high charging priority is smaller than or equal to the maximum voltage value of the battery cluster with low charging priority in the battery clusters with any adjacent charging priority;
and controlling each battery cluster to be sequentially charged from the high charging priority to the low charging priority according to the charging priority.
In one embodiment, the determining the charging priority of each of the battery clusters according to the battery information of the plurality of battery clusters includes:
the battery clusters are initially ordered according to the maximum voltage value of each battery cluster from low to high;
and under the condition that the maximum voltage values of at least two battery clusters are equal, the at least two battery clusters after initial sorting are subjected to secondary sorting from low to high according to the minimum voltage value of the at least two battery clusters, so that the charging priority of each battery cluster is determined.
In one embodiment, the secondary sorting of the at least two initially sorted battery clusters according to the minimum voltage value of the at least two battery clusters from low to high includes:
dividing the battery clusters with the same minimum voltage value into the same charging priority under the condition that the minimum voltage values of the at least two battery clusters are equal;
and under the condition that the minimum voltage values of the at least two battery clusters are not equal, sequencing the at least two battery clusters secondarily from low to high according to the minimum voltage values of the at least two battery clusters.
In one embodiment, the energy storage system further includes a charging module, and the controlling the battery clusters to be sequentially charged from a high charging priority to a low charging priority according to the charging priority includes:
the battery cluster with the highest charging priority is connected to a charging module, and the charging module is controlled to supply power to the connected battery cluster;
under the condition that the currently charged battery cluster meets a first preset condition, simultaneously controlling the battery cluster with the next adjacent charging priority to be connected with the charging module, and controlling the charging module to supply power to the connected battery cluster;
Repeating the steps of controlling the battery cluster with the next adjacent charging priority to be connected with the charging module and controlling the charging module to supply power to the connected battery cluster under the condition that the battery cluster currently being charged meets a first preset condition until all the battery clusters are connected with the charging module;
and under the condition that the maximum value of the charging voltage of the single batteries of each battery cluster meets a second preset condition, controlling each battery cluster to disconnect the charging module.
In one embodiment, the controlling the charging module to supply power to the accessed battery cluster includes:
and controlling the output current of the charging module according to the number of the battery clusters currently being charged so as to supply power to the connected battery clusters.
In one embodiment, when the maximum charging voltage of the unit cells of each battery cluster meets a second preset condition, the controlling the each battery cluster to disconnect the charging module includes:
when a target battery cluster with the maximum charging voltage exceeding the charging cut-off voltage exists, the target battery cluster is controlled to disconnect the charging module;
and correspondingly adjusting the output current of the charging module according to the number of the remaining battery clusters except the target battery cluster so as to continuously charge the remaining battery clusters until the maximum charging voltage of all the single batteries of the battery clusters exceeds the charging cut-off voltage.
In one embodiment, each battery cluster is connected to the charging module through a positive electrode switch unit and a negative electrode switch unit, and when there is a target battery cluster whose maximum charging voltage exceeds a charging cut-off voltage, controlling the target battery cluster to disconnect the charging module includes:
when a target battery cluster with the maximum charging voltage exceeding the charging cut-off voltage exists, controlling a positive electrode switch unit to disconnect the target battery cluster from the charging module;
and after the disconnection time of the positive electrode switch unit is continued to a first preset duration range, controlling the negative electrode switch unit to disconnect the target battery cluster from the charging module.
In one embodiment, the first preset condition includes that a difference between a maximum value of the charge voltage of the unit cells in the currently charging battery cluster and a maximum voltage value of the unit cells of the battery cluster located at the next adjacent charging priority is in a first preset voltage range.
In one embodiment, the first preset condition includes that a charging duration of a battery cluster currently being charged is within a second preset duration range; and/or
The first preset condition includes that the maximum charging voltage of the single batteries in the battery cluster currently being charged is in a second preset voltage range.
The application provides a battery charge control device, including:
the acquisition module is used for acquiring battery information of each battery cluster, wherein the battery information comprises voltage values of all the single batteries;
a determining module, configured to determine a charging priority of each of the battery clusters according to battery information of a plurality of the battery clusters, so that, among battery clusters of any adjacent charging priority, a maximum voltage value of a battery cluster of a high charging priority is less than or equal to a maximum voltage value of a battery cluster of a low charging priority;
and the control module is used for controlling each battery cluster to be sequentially charged from the high charging priority to the low charging priority according to the charging priority.
The present application provides an energy storage system comprising:
a plurality of battery clusters, each of the battery clusters comprising a plurality of unit cells; and
The battery charge control device as described above.
The present application provides a computer readable storage medium having stored thereon a computer program which when executed by a processor implements the steps of the method as described above.
According to the battery charging control method, the control device, the energy storage system and the storage medium, the battery information of each battery cluster is obtained before charging, and the charging priority of each battery cluster is determined according to the battery information of each battery cluster, so that the maximum voltage value of the battery cluster with high charging priority is smaller than or equal to the maximum voltage value of the battery cluster with other charging priority, and the battery clusters are sequentially charged from the high charging priority to the low charging priority, so that the upper voltage limit value of each battery cluster can be leveled, the voltage difference between each battery cluster is effectively reduced, the total voltage consistency difference between the clusters is reduced, the maximization of the capacity of the energy storage system is further realized, and the working efficiency and the service life of the energy storage system are improved.
Drawings
In order to more clearly illustrate the technical solutions of embodiments or conventional techniques of the present application, the drawings required for the descriptions of the embodiments or conventional techniques will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort for a person of ordinary skill in the art.
FIG. 1 is a flow chart of a battery charge control method according to an embodiment;
FIG. 2 is a second flowchart of a battery charge control method according to an embodiment;
FIG. 3 is a third flow chart of a battery charge control method according to an embodiment;
FIG. 4 is a flowchart illustrating a battery charge control method according to an embodiment;
fig. 5 is a flowchart of a battery charge control method according to an embodiment.
Detailed Description
In order to facilitate an understanding of the present application, a more complete description of the present application will now be provided with reference to the relevant figures. Examples of the present application are given in the accompanying drawings. This application may, however, be embodied in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
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 herein in the description of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.
As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," and/or the like, specify the presence of stated features, integers, steps, operations, elements, components, or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or groups thereof. Also, in this specification, the term "and/or" includes any and all combinations of the associated listed items.
The battery energy storage system converts electric energy into chemical energy through a battery for storage, converts the chemical energy into electric energy according to actual demands to supply power to external equipment, adopts a high-energy-density energy storage mode, and has the advantages of high energy utilization efficiency, high integration level, flexible use and the like. In general, a plurality of unit batteries are combined into a battery cluster, and a plurality of battery clusters are combined into a battery module of a system in a serial-parallel connection mode, but even the unit batteries produced in the same batch by the same manufacturer are in the production process, the production process of the battery core enables the unit batteries to have natural differences when leaving the factory, such as inconsistent diaphragm, cathode materials, anode materials and the like, so that the unit batteries have small differences in capacity, internal resistance, voltage and the like. Even though the production and processing of the single batteries are the same, the single batteries cannot always be kept consistent in the electrochemical reaction process of charge and discharge, and as the operation time of the energy storage system is increased, the difference between the single batteries is gradually increased, so that the consistency between the battery clusters is poorer and worse.
The inconsistency of the battery clusters can affect the charging performance of the whole energy storage system, because the energy storage system adopts a mode that all the battery clusters are charged together when being charged, the charging capacity of the system is determined by the battery cell with the smallest capacity, namely, when the highest voltage value of the battery cells in one battery cluster reaches the charging cut-off condition, the battery cell with the smallest capacity is fully charged, and the charging of all the battery clusters is required to be stopped at the moment, so that the battery cells with small capacity are always in a fully charged and discharged state, and the battery cells with large capacity always only use part of the capacity, so that the practical available capacity of the energy storage system is reduced, the service efficiency of the system is affected and the cycle life of other battery cells is reduced.
And with the gradual increase of electricity consumption degree and electricity consumption power demand, the quantity of single batteries needs to be gradually multiplied in the energy storage system to adapt to actual application demands, so the difference between the single batteries is further increased, the consistency among battery clusters is poorer and worse, the system capacity is greatly limited, the service time of the system is shortened, and the experience of a user is influenced and the after-sales maintenance cost of the system is increased.
Based on this, the present application provides a battery charging control method to overcome the above-mentioned drawbacks.
In one embodiment, referring to fig. 1, the battery charging control method is applied to an energy storage system, the energy storage system includes a plurality of battery clusters, each battery cluster includes a plurality of unit batteries, and the battery charging control method includes steps S102 to S106.
Step S102: and acquiring battery information of each battery cluster, wherein the battery information comprises voltage values of all the single batteries.
The battery module can be formed by connecting a plurality of battery cells (single batteries) in series and parallel, a plurality of battery modules are connected in series to form a battery cluster, and a plurality of battery clusters are connected in parallel to form a container type energy storage battery compartment in the energy storage system.
Further, the energy storage system further includes a battery management system (Battery Management System, BMS) for monitoring and managing the battery compartment, and it should be noted that, the battery charging control method provided in this embodiment may be executed by the battery management system BMS, or may be executed by any system having a computing processing capability, and the embodiment is preferably executed by the battery management system BMS. In some embodiments, the battery management system is divided into a multi-layer architecture, for example, the battery management system is divided into three layers, and each battery module may be configured with a first layer management unit to monitor state information of each unit battery in the battery module, for example, collect information of voltage, current, temperature, capacity, etc. of the unit battery; each battery cluster can be provided with a second layer management unit for collecting information such as voltage, current, temperature and the like of the battery cluster, and the second layer management unit of each battery cluster communicates with each first layer management unit below the second layer management unit through a communication link so as to obtain the state information of each single battery in the cluster uploaded by the first layer management unit; the third layer management unit is used as a master control to be in communication connection with the second layer management unit corresponding to each battery cluster, meanwhile, the third layer management unit is also in communication with an energy storage inverter (PCS) and an Energy Management System (EMS) in the energy storage system, the third layer management unit shares data of each single battery to the energy management system and the energy storage inverter in real time, and the energy management system sends control information to the battery management system and the energy storage inverter according to a scheduling decision, for example, the energy storage inverter can be controlled to finish operations such as charging and discharging of a battery compartment.
In other embodiments, the battery management system may be divided into two layers, for example, each battery cluster may be configured with a battery management unit (RBMS) to obtain state information of the corresponding battery cluster and state information of each battery cell in the battery cluster, and each battery management unit uploads the collected information to a comprehensive management unit (BBMS) to make further complex analysis decisions, for example, each battery management unit collects battery information of the corresponding battery cluster, such as voltage, current, temperature and capacity of the battery cells in the cluster, and then each battery management unit transmits the collected battery information to the comprehensive management unit, where the comprehensive management unit may screen out the voltage value of each battery cell in each battery cluster for use in subsequently dividing the charging priority of the battery cluster.
Step S104: and determining the charging priority of each battery cluster according to the battery information of the plurality of battery clusters, so that the maximum voltage value of the battery clusters with high charging priority among the battery clusters with any adjacent charging priority is smaller than or equal to the maximum voltage value of the battery clusters with low charging priority.
Wherein, a single battery cluster or a plurality of battery clusters can exist in a charging priority, and the maximum voltage value of the battery clusters in the charging priority refers to the voltage value corresponding to the single battery with the highest voltage in the battery clusters. Before charging, the charging priority of the battery clusters is divided according to the battery information of each battery cluster, namely the voltage value of each single battery in each battery cluster, so that the maximum single battery voltage value in the battery cluster with high charging priority is smaller than or equal to the maximum single battery voltage value in the battery cluster with low charging priority, and then each battery cluster is charged in stages according to the charging priority, so that the voltage difference between the battery clusters with adjacent charging priorities is reduced. And the voltage value of each single battery in the battery cluster is used as the basis for dividing the charging priority, so that the situation that the single battery is overcharged due to the fact that the battery cluster corresponding to the highest single battery voltage value is firstly accessed to charge can be avoided, the battery cluster corresponding to the lowest single battery voltage value is firstly accessed to charge, and the voltage difference between the clusters can be controlled more accurately.
Step S106: and controlling each battery cluster to be sequentially charged from the high charging priority to the low charging priority according to the charging priority.
It can be understood that by controlling the battery cluster having the highest charging priority to be charged first, the maximum cell voltage value of the battery cluster having the highest charging priority and the maximum cell voltage value of the battery cluster having the next highest charging priority gradually approach each other in the charging process, when the difference between the maximum cell voltage value and the maximum cell voltage value of the battery cluster having the next highest charging priority meets a preset threshold, the battery cluster having the next highest charging priority is accessed again to continue charging, and when the difference between the maximum cell voltage value of the battery cluster having the highest and the battery cluster having the next highest charging priority and the maximum cell voltage value of the battery cluster having the next highest charging priority meets a preset threshold, the above process is repeated until all the battery clusters are accessed to achieve charging. The voltage difference between the battery clusters can be effectively reduced in a mode of sequentially charging the battery clusters according to the charging priority, the total voltage consistency difference between the clusters is reduced, the balance between the clusters is realized, the upper voltage limit value of the single battery of each battery cluster can be leveled to realize the maximization of the capacity of the energy storage system, and the capacity utilization rate of the energy storage system is optimized.
In the above example, the battery information of each battery cluster is obtained before charging, and the charging priority of each battery cluster is determined according to the battery information of each battery cluster, so that the maximum voltage value of the battery cluster with high charging priority is smaller than or equal to the maximum voltage value of the battery cluster with other charging priority, and the battery clusters are sequentially charged from the high charging priority to the low charging priority, so that the upper voltage limit value of each battery cluster can be leveled, the voltage difference between each battery cluster is effectively reduced, the total voltage consistency difference between the clusters is reduced, the capacity maximization of the energy storage system is further realized, the working efficiency and the service life of the energy storage system are improved, the experience feeling of users is improved, and the after-sales maintenance cost of the system is reduced.
In one embodiment, as shown in fig. 2, step S104 determines the charging priority of each battery cluster according to the battery information of the plurality of battery clusters, including steps S202 to S204.
Step S202: and initially sequencing the battery clusters according to the maximum voltage value of each battery cluster from low to high.
The battery management system may screen out a maximum voltage value of the unit battery in each battery cluster according to the obtained unit battery voltage values of the battery clusters, and perform initial sorting from low to high on each battery cluster according to the magnitude of the unit battery maximum voltage values of the battery clusters, that is, if the unit battery maximum voltage value of one battery cluster is at a lowest value compared with other clusters, the battery cluster has the highest charging priority, and if the unit battery maximum voltage value of one battery cluster is at a highest value compared with other clusters, the battery cluster has the lowest charging priority.
For example, if the energy storage system includes three battery clusters, each battery cluster includes four battery cells, the battery clusters are respectively denoted as A1, A2, and A3, and the voltage values of the battery cells in the A1 battery cluster are respectively 1V/2V/3V/4V, the voltage values of the battery cells in the A2 battery cluster are respectively 1V/2V/3V/5V, the voltage values of the battery cells in the A3 battery cluster are respectively 1V/3V/4V/6V, so that the battery cells in the A1 battery cluster are 4V, the battery cells in the A2 battery cluster are 5V, the battery cells in the A3 battery cluster are 6V, the A1 battery cluster has the highest charge priority, the maximum voltage value of the A3 battery cluster is the highest among the three battery clusters, the A3 battery cluster has the lowest charge priority, and the initial result is the battery clusters A1, A2 battery cluster, and A3 battery cluster.
Step S204: and under the condition that the maximum voltage values of the at least two battery clusters are equal, the at least two battery clusters after initial sorting are subjected to secondary sorting from low to high according to the minimum voltage value of the at least two battery clusters, so that the charging priority of each battery cluster is determined.
In the process of sorting the battery clusters according to the maximum voltage values of the single batteries, it is necessary to determine whether at least two battery clusters with equal maximum voltage values exist, if no battery clusters with equal maximum voltage values exist, sorting the battery clusters according to the maximum voltage values of each battery cluster from low to high, if at least two battery clusters with equal maximum voltage values exist, further sorting the battery clusters according to the minimum voltage values of the single batteries of the at least two battery clusters, that is, if the minimum voltage value of a certain battery cluster is at the lowest value among the battery clusters with equal maximum voltage values, the battery cluster has the highest charging priority among the battery clusters with equal maximum voltage values, so that the battery clusters with equal maximum voltage values can be sorted secondarily according to the minimum voltage values from low to high, and the battery clusters with equal maximum voltage values after sorting are inserted into the original initial sorting, so as to form the final charging priority sorting of the battery clusters.
In one embodiment, as shown in fig. 3, step S204 performs secondary sorting on the at least two battery clusters after the initial sorting according to the minimum voltage value of the at least two battery clusters from low to high, and includes steps S302 to S304.
Step S302: and dividing the battery clusters with the same minimum voltage value into the same charging priority under the condition that the minimum voltage values of the at least two battery clusters are equal.
In the process of sorting at least two battery clusters with equal maximum voltage values according to the minimum voltage values of the single batteries, the battery clusters with equal minimum voltage values may occur, so it is necessary to determine whether there are battery clusters with equal minimum voltage values among the at least two battery clusters with equal maximum voltage values, if there are battery clusters with equal minimum voltage values, that is, if there are at least two battery clusters with equal maximum voltage values and equal minimum voltage values, at least two battery clusters with equal maximum voltage values and equal minimum voltage values are defined as the same charging priority, that is, each battery cluster in the same charging priority is simultaneously connected for charging in the charging process.
For example, if the energy storage system includes four battery clusters, each battery cluster includes four battery cells, the battery clusters are respectively recorded as A1, A2, A3, and A4, and the voltage values of the battery cells in the A1 battery cluster are respectively 1V/2V/3V/4V, the voltage values of the battery cells in the A2 battery cluster are respectively 1V/2V/3V/5V, the voltage values of the battery cells in the A3 battery cluster are respectively 2V/3V/4V/5V, the voltage values of the battery cells in the A4 battery cluster are respectively 2V/3V/4V/5V, the battery clusters are initially sorted according to the battery cell values of the battery clusters, and the initial sorting results are the battery clusters A1, the battery clusters A2, and the battery clusters A4, that is, since the maximum voltage values of the battery cells in the A2, the battery clusters A3, and the battery clusters A4 are equal, the three battery clusters are classified in the same charge priority when initially sorted, and the battery cell values of the battery cell clusters in the four battery clusters are at the lowest value when the initial sorting has the highest priority when the battery cluster has the highest charge priority. Further, since there are three battery clusters (A2, A3, A4) with equal maximum voltage values, it is necessary to perform secondary ranking according to the minimum voltage values of the three battery clusters, wherein the minimum voltage value in the A2 battery cluster is 1V, the minimum voltage value in the A3 battery cluster is 2V, the minimum voltage value in the A4 battery cluster is 2V, the A3 battery cluster and the A4 battery cluster are still divided into the same charge priority in the secondary ranking due to the equality of the minimum voltage values of the A3 battery cluster and the A4 battery cluster, and the minimum voltage value of the A2 battery cluster is at the lowest value in the A2, A3, A4, the A2 battery cluster has the highest charge priority in the A2, A3, A4, whereby the secondary ranking results are the A2 battery cluster, A3 battery cluster and A4 battery cluster, and the secondary ranking results are interspersed into the initial ranking to form the final charge priority: the A1 battery cluster, the A2 battery cluster, the A3 battery cluster, and the A4 battery cluster, i.e., the A1 battery cluster has the highest charging priority, the A2 battery cluster has the next highest charging priority, and the A3 battery cluster and the A4 battery cluster are the same charging priority and have the lowest charging priority.
Step S304: and under the condition that the minimum voltage values of the at least two battery clusters are not equal, sequencing the at least two battery clusters secondarily from low to high according to the minimum voltage values of the at least two battery clusters.
Further, if no battery cluster with the same minimum voltage value exists in at least two battery clusters with the same maximum voltage value, the at least two battery clusters are secondarily ordered from low to high according to the minimum voltage value, and the at least two battery clusters after the secondary ordering are inserted into the initial ordering to form the charging priority. For example, if the energy storage system includes four battery clusters, each battery cluster includes four battery cells, the battery clusters are respectively recorded as A1, A2, A3, and A4, and the voltage values of the battery cells in the A1 battery cluster are respectively 1V/2V/3V/4V, the voltage values of the battery cells in the A2 battery cluster are respectively 1V/3V/4V/5V, the voltage values of the battery cells in the A3 battery cluster are respectively 2V/3V/4V/5V, the voltage values of the battery cells in the A4 battery cluster are respectively 3V/4V/5V, the battery clusters are initially sorted according to the maximum voltage values of the battery clusters, and the initial sorting results are that the battery clusters A1, A2 battery cluster, A3 battery cluster, and A4 battery cluster, that is, since the maximum voltage values of the battery cells in the initial sorting are equal, the two battery clusters are classified into the same charging priority, and since the maximum voltage values of the battery clusters A1 battery is at the lowest of the four battery clusters initially sorted, the battery clusters have the highest charging priority when the battery cluster is the initial sorting. Further, since there are two battery clusters (A2, A3) with equal maximum voltage values, it is necessary to perform secondary sorting according to the minimum voltage values of the two battery clusters, wherein the minimum voltage value in the A2 battery cluster is 1V, the minimum voltage value in the A3 battery cluster is 2V, and since the minimum voltage value of the A2 battery cluster is smaller than the minimum voltage value of the A3 battery cluster, the charging priority of the A2 battery cluster at the time of secondary sorting is higher than the charging priority of the A3 battery cluster, whereby the secondary sorting result is the A2 battery cluster, the A3 battery cluster, and the secondary sorting result is interspersed into the initial sorting to form the final charging priority in order from high to low: the A1 battery cluster, the A2 battery cluster, the A3 battery cluster and the A4 battery cluster, namely the A1 battery cluster has the highest charging priority, the A4 battery cluster has the lowest charging priority, and the A4 battery cluster has the last charging priority.
In one embodiment, the energy storage system further includes a charging module, and step S206 controls each battery cluster to be sequentially charged from a high charging priority to a low charging priority according to the charging priority, including the following steps: and accessing the battery cluster with the highest charging priority to the charging module, controlling the charging module to supply power to the accessed battery cluster, simultaneously controlling the battery cluster with the next adjacent charging priority to be accessed to the charging module and controlling the charging module to supply power to the accessed battery cluster under the condition that the battery cluster with the current charging priority meets the first preset condition, and repeating the steps of simultaneously controlling the battery cluster with the next adjacent charging priority to be accessed to the charging module and controlling the charging module to supply power to the accessed battery cluster until all the battery clusters are accessed to the charging module. And under the condition that the maximum charging voltage of the single batteries of each battery cluster meets a second preset condition, controlling each battery cluster to disconnect the charging module.
Optionally, the charging module may be an energy storage inverter (PCS), and the battery management system may first access the battery cluster with the highest charging priority to the charging module for charging, during which the battery management system may send a charging current request to the energy management system EMS, and the energy management system EMS may send charging control information to the energy storage inverter PCS to control the energy storage inverter PCS to charge the battery cluster with the highest charging priority, where the more the number of battery clusters in a charging priority, the greater the required charging current.
Further, when the battery cluster with the highest charging priority meets the first preset condition during charging, the battery cluster with the next highest charging priority is controlled to be connected to the charging module at the same time so as to charge the battery clusters with the highest charging priority and the next highest charging priority at the same time, the battery management system then sends a charging current request to the energy management system EMS according to the number of the battery clusters with the two charging priorities connected to the battery management system, the energy management system EMS sends the charging control information after decision to the energy storage inverter PCS so as to control the energy storage inverter PCS to supply power to the battery clusters with the highest charging priority and the next highest charging priority, when the battery clusters with the highest charging priority and the next highest charging priority meet the first preset condition during charging, the battery clusters with the next highest charging priority are continuously controlled to be connected to the charging module, and the battery management system further continues to send charging requests according to the number of the connected battery clusters to charge the three battery clusters with the charging priority connected to the battery clusters, and the process is repeated until all the battery clusters are connected to the charging module for charging. The upper voltage limit value of each battery cluster is leveled in a mode that each battery cluster is charged in a staged way, so that the voltage difference among the battery clusters is reduced, the total voltage consistency difference among the battery clusters is reduced, and capacity balance among the clusters is realized.
And further, in the process that each battery cluster is connected to charge, if it is judged that a certain battery cluster has the condition that the maximum value of the charging voltage of the single battery meets the second preset condition, the battery cluster needs to stop charging based on the barrel effect so as to avoid overcharging of the single battery, namely, the connection between the battery cluster and the charging module is disconnected, but the rest battery clusters which do not meet the second preset condition still remain to be charged, so that the condition that the other battery clusters stop charging due to the fact that the full charge of the certain battery cluster is avoided, and the capacity utilization rate of the system is reduced is avoided. And the battery management system also needs to correspondingly send a charging current request to the energy management system according to the number of the rest battery clusters so as to update the current magnitude input to the battery clusters.
In one embodiment, in the step of controlling the charging module to supply power to the accessed battery cluster, the method further comprises the steps of: and controlling the output current of the charging module according to the number of the battery clusters currently being charged so as to supply power to the connected battery clusters.
When the battery management system is sequentially connected to the charging modules from the high charging priority to the low charging priority for charging, a request for charging current needs to be sent to the energy management system EMS according to the number of the connected battery clusters, the energy management system controls the charging modules to charge each connected battery cluster again, and the larger the number of the battery clusters is, the larger the current output by the charging modules is. Specifically, the battery management system may store a preset charging current corresponding to each battery cluster, for example, the current required by the A1 battery cluster is 100mA, the current required by the A2 battery cluster is 100mA, if the first charging priority includes only the A1 battery cluster connected to the charging module, the output current of the charging module is adjusted to be 100mA, and if the first charging priority includes two battery clusters A1 and A2, the output current of the charging module is adjusted to be 200mA.
In one embodiment, the first preset condition includes that a difference between a maximum value of the charge voltage of the battery cells in the battery cluster currently being charged and a maximum voltage value of the battery cells of the battery cluster located at the next adjacent charge priority is within a first preset voltage range.
When a part of battery clusters with charging priority are in a charging state, judging whether a difference value between a maximum value of a single battery charging voltage in the battery clusters with charging priority and a maximum voltage value of a single battery which is not connected to a charging module for charging is in a first preset voltage range, if the difference value is not in the first preset voltage range, indicating that a larger difference still exists between the voltage difference between the battery clusters with charging priority and the battery clusters with charging priority, continuously charging the battery clusters with charging priority, and if the difference value is in the first preset voltage range, indicating that a voltage difference between the battery clusters with charging priority and the battery clusters with charging priority is small, achieving a consistency requirement between the two, and controlling the battery clusters with charging priority to be connected to the charging module for charging.
Optionally, the first preset voltage range may be [ -5mv,5mv ], and it should be noted that, during the charging control, the desired optimal state is that the voltage difference between the battery cluster being charged and the battery cluster of the next charging priority is 0, but there is a certain error during the actual operation, so that the error range is set in the first preset voltage range to achieve the effect that the voltage difference between clusters is significantly reduced.
In one embodiment, the first preset condition includes a charging duration of the currently charging battery cluster being in a second preset duration range.
When the charging time length of the battery cluster being charged reaches a second preset time length range, the voltage difference between the battery cluster being charged and the battery cluster with the next charging priority is small, and then the battery cluster with the next charging priority is controlled to be connected into the charging module for charging. The second preset duration range may be determined according to an actual application scenario.
In one embodiment, the first preset condition includes that a maximum value of the charging voltages of the unit cells in the battery cluster currently being charged is within a second preset voltage range.
When the maximum value of the charging voltages of the single batteries in the battery cluster being charged is in the second preset voltage range, it is indicated that the maximum value of the charging voltages of the battery cluster being charged is close to the maximum voltage value of the single batteries of the next charging priority, that is, the voltage difference between the battery cluster being charged and the battery cluster of the next charging priority is small, and therefore the battery cluster of the next charging priority is controlled to be connected to the charging module for charging. The second preset voltage range may be determined according to an actual application scenario.
In one embodiment, as shown in fig. 4, the step of controlling the charging module to be disconnected from each battery cluster further includes steps S402 to S404 when the maximum value of the charging voltage of the single battery of each battery cluster meets a second preset condition.
Step S402: and in the case that the target battery cluster with the maximum charging voltage exceeding the charging cut-off voltage exists, controlling the target battery cluster to disconnect the charging module.
When each battery cluster is connected to the charging module for charging, whether the maximum charging voltage of the single battery of a certain battery cluster triggers the charging cut-off voltage is required to be judged, if the maximum charging voltage does not exist, the charging state of each battery cluster is kept continuously, if the maximum charging voltage does not exist, the current output by the charging module can be firstly regulated to be reduced to the lowest current which can be provided by the current system, or the current output by the charging module is regulated to be 0-10% of the current charging current, then the target battery cluster triggering the charging cut-off voltage is disconnected from the charging module, and the current impact on a switching unit of the battery cluster when the target battery cluster is disconnected can be reduced by firstly reducing the charging current and then disconnecting the target battery cluster.
Step S404: and correspondingly adjusting the output current of the charging module according to the number of the remaining battery clusters except the target battery cluster so as to continuously charge the remaining battery clusters until the maximum charging voltage of the single batteries of all the battery clusters is at the charging cut-off voltage.
After disconnecting the target battery cluster triggering the charge cut-off voltage, the battery management system needs to send a charge current request to the energy management system again according to the number of the battery clusters currently being charged, so that the charge module updates the current input to the battery clusters, and also needs to judge whether the maximum value of the charge voltage of all the battery clusters is at the charge cut-off voltage, if so, the battery management system indicates that all the battery clusters are charged, and sets the state of charge (SOC) of the energy storage system as 100%; if the maximum charging voltage of all the battery clusters is not in the charging cut-off voltage, the charging and judging process is continuously maintained.
In one embodiment, as shown in fig. 5, step S402 controls the target battery cluster to disconnect the charging module when there is a target battery cluster whose charging voltage maximum exceeds the charging cutoff voltage, and further includes steps S502 to S504. Each battery cluster is connected with the charging module through a positive electrode switch unit and a negative electrode switch unit respectively.
Step S502: and when the maximum value of the charging voltage exceeds the target battery cluster of the charging cut-off voltage, controlling the positive electrode switch unit to disconnect the target battery cluster from the charging module.
Alternatively, the switching unit may be a relay. When it is determined that the maximum charging voltage of the target battery cluster triggers the charging cut-off voltage, it is indicated that the target battery cluster reaches a full-charge state, and the target battery cluster needs to be disconnected at the moment to avoid overcharging, so that the positive electrode switch unit of the target battery cluster is disconnected first, and then the negative electrode switch unit of the target battery cluster is disconnected, so that damage to the switch unit caused by current impact is avoided. After the target battery cluster is disconnected, the charging of the remaining battery clusters which are not fully charged is continuously controlled, and the situation that the whole system stops charging due to the fact that a certain battery cluster is fully charged can be avoided by disconnecting the battery clusters in a fully charged state and keeping the continuous charging of the remaining battery clusters.
Step S504: and after the disconnection time of the positive electrode switch unit is continued to a first preset time range, controlling the negative electrode switch unit to disconnect the target battery cluster from the charging module.
When the off time of the positive electrode switch unit of the target battery cluster is continued to a first preset duration range (for example, about five seconds), the battery management system sends a charging current request to the energy management system EMS again according to the number of the battery clusters currently being charged, so that the charging module reduces the current input to the battery cluster, and further reduces the current impact on the switch unit of the target battery cluster when the switch unit of the target battery cluster is turned off.
In one embodiment, a battery charging control method is provided, and the method includes steps S601 to S608.
Step S601: and acquiring battery information of each battery cluster, wherein the battery information comprises voltage values of all the single batteries.
Step S602: and initially sequencing the battery clusters according to the maximum voltage value of each battery cluster from low to high.
Step S603: in the case where the maximum voltage values of at least two battery clusters are equal and the minimum voltage values of the at least two battery clusters are also equal, the battery clusters having the same minimum voltage value are classified into the same charge priority.
Step S604: and when the maximum voltage values of at least two battery clusters are equal and the minimum voltage values of the at least two battery clusters are not equal, sequencing the at least two battery clusters from low to high according to the minimum voltage values of the at least two battery clusters to determine the charging priority of each battery cluster.
Step S605: the battery cluster with the highest charging priority is connected to the charging module, the charging module is controlled to supply power to the connected battery cluster, under the condition that the battery cluster currently being charged meets a first preset condition, the battery cluster with the next adjacent charging priority is simultaneously controlled to be connected to the charging module, the charging module is controlled to supply power to the connected battery cluster, and the steps are repeated until all the battery clusters are connected to the charging module; and under the condition that the maximum charging voltage of the single batteries of each battery cluster meets a second preset condition, controlling each battery cluster to disconnect the charging module.
The first preset condition includes that a difference value between a maximum value of charging voltages of the single batteries in the battery cluster currently being charged and a maximum voltage value of single batteries in the battery cluster positioned at the next adjacent charging priority is in a first preset voltage range. The first preset condition further comprises that the charging duration of the battery cluster currently being charged is in a second preset duration range; and/or the first preset condition further comprises that the maximum charging voltage of the single batteries in the battery cluster currently being charged is in a second preset voltage range.
Step S606: and controlling the output current of the charging module according to the number of the battery clusters currently being charged so as to supply power to the connected battery clusters.
Step S607: when a target battery cluster with the maximum charging voltage exceeding the charging cut-off voltage exists, the positive electrode switch unit is controlled to disconnect the target battery cluster from the charging module; and after the disconnection time of the positive electrode switch unit is continued to a first preset time range, controlling the negative electrode switch unit to disconnect the target battery cluster from the charging module. Each battery cluster is connected with the charging module through a positive electrode switch unit and a negative electrode switch unit respectively.
Step S608: and correspondingly adjusting the output current of the charging module according to the number of the remaining battery clusters except the target battery cluster so as to continuously charge the remaining battery clusters until the maximum charging voltage of the single batteries of all the battery clusters exceeds the charging cut-off voltage.
The steps in this embodiment are the same as those in the previous embodiment, and are not described herein.
In one embodiment, a battery charge control device is provided that includes an acquisition module, a determination module, and a control module. The acquisition module is used for acquiring battery information of each battery cluster, wherein the battery information comprises voltage values of all the single batteries. The determining module is used for determining the charging priority of each battery cluster according to the battery information of the plurality of battery clusters, so that the maximum voltage value of the battery cluster with the high charging priority is smaller than or equal to the maximum voltage value of the battery cluster with the low charging priority in the battery clusters with any adjacent charging priority. The control module is used for controlling each battery cluster to be sequentially charged from the high charging priority to the low charging priority according to the charging priority. Therefore, the upper voltage limit value of each battery cluster is leveled, the total voltage consistency difference between the clusters is reduced, the capacity maximization of the energy storage system is realized, and the working efficiency and the service life of the energy storage system are improved.
In one embodiment, an energy storage system is provided, including a plurality of battery clusters, and a battery charging control device as described in the foregoing embodiments, where each battery cluster includes a plurality of unit batteries. The energy storage system provided by the embodiment is based on the battery charging control method described in the above embodiment, so that the difference of the total voltage consistency among all battery clusters in the energy storage system is reduced, the utilization rate of the system capacity and the whole service life of the system can be effectively improved, the experience of a user is improved, and the maintenance cost of the system after sale is reduced.
In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored which, when being executed by a processor, implements the steps of the method as described in the above embodiments.
In one embodiment, there is also provided a computer program product containing instructions which, when run on a computer, cause the computer to perform the steps of the method described in the above embodiments.
Any reference to memory, storage, database, or other medium used herein may include non-volatile and/or volatile memory. Suitable nonvolatile memory can include Read Only Memory (ROM), programmable ROM (PROM), electrically Programmable ROM (EPROM), electrically Erasable Programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RM), which acts as external cache memory. By way of illustration and not limitation, RMs are available in a variety of forms, such as Static RMs (SRMs), dynamic RMs (DRMs), synchronous DRMs (SDRMs), double data rates SDRM (DDR SDRM), enhanced SDRMs (ESDRMs), synchronous link (synchronous) DRMs (SLDRMs), memory bus (Rmbus) direct RMs (RDRMs), direct memory bus dynamic RMs (DRDRMs), and memory bus dynamic RMs (RDRMs).
It should be understood that, although the steps in the flowcharts of fig. 1 to 5 are sequentially shown as indicated by arrows, these steps are not necessarily sequentially performed in the order indicated by the arrows. The steps are not strictly limited to the order of execution unless explicitly recited herein, and the steps may be executed in other orders. Moreover, at least a portion of the steps in fig. 1 to 5 may include a plurality of steps or a plurality of stages, which are not necessarily performed at the same time, but may be performed at different times, and the order of performing the steps or stages is not necessarily sequential, but may be performed in turn or alternately with at least a portion of the steps or stages in other steps or other steps.
In the description of the present specification, reference to the terms "some embodiments," "other embodiments," "ideal embodiments," and the like, means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, schematic descriptions of the above terms do not necessarily refer to the same embodiment or example.
The technical features of the above embodiments may be arbitrarily combined, and for brevity, all of the possible combinations of the technical features of the above embodiments are not described, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.
The above examples only represent a few embodiments of the present application, which are described in more detail and are not to be construed as limiting the scope of the claims. It should be noted that it would be apparent to those skilled in the art that various modifications and improvements could be made without departing from the spirit of the present application, which would be within the scope of the present application. Accordingly, the scope of protection of the present application is to be determined by the claims appended hereto.