CN117913931A

CN117913931A - Battery pack voltage balance control method and device, energy storage system and storage medium

Info

Publication number: CN117913931A
Application number: CN202211234695.0A
Authority: CN
Inventors: 管帅
Original assignee: Yancheng Dafeng Csi Energy Storage Technology Co ltd; Atlas Energy Storage Technology Co ltd
Current assignee: Yancheng Dafeng Csi Energy Storage Technology Co ltd; Atlas Energy Storage Technology Co ltd
Priority date: 2022-10-10
Filing date: 2022-10-10
Publication date: 2024-04-19

Abstract

The invention discloses a battery pack voltage balance control method, a device, an energy storage system and a storage medium. The battery pack voltage balance control method comprises the following steps: and collecting voltage information in the charging and discharging processes of the battery pack in real time, judging whether the battery cells in the battery pack have voltage inconsistency, and recommending different battery pack maintenance modes according to the type of the voltage inconsistency of the battery cells. If the current battery pack is determined to need balanced maintenance, an active balancing module in the battery pack is controlled to automatically perform balanced control according to set balanced opening conditions and set balanced closing conditions, so that inconsistent battery cell voltages are leveled. The invention realizes the balanced automatic control of the battery pack voltage, does not need personnel intervention, has high reliability and high efficiency, and simultaneously reduces the cost of manpower and materials.

Description

Battery pack voltage balance control method and device, energy storage system and storage medium

Technical Field

The present invention relates to the field of battery management technologies, and in particular, to a battery pack voltage equalization control method, a device, an energy storage system, and a storage medium.

Background

Along with the increase of the number of electric vehicles, the power battery needing to be retired can be applied to an energy storage system, so that not only can the waste of resources be reduced and the pollution to the environment be reduced, but also certain economic value can be generated. In order to improve the energy storage capacity in the energy storage system, a plurality of battery packs are connected in parallel, and if the consistency difference among the plurality of battery packs is large, the balance control of the battery packs needs to be started for a plurality of times before the energy storage system is ready to be electrified so as to level the voltages of the plurality of battery packs.

The voltage balance control of the current battery pack is completed through the battery pack offline charge and discharge test, a tester needs to manually derive charge and discharge test data, a maintenance scheme of the battery pack is judged through fitting a data curve, and if the fact that the charge quantity of the battery in the battery pack is inconsistent is judged, independent charge and discharge treatment is needed for the battery. At present, a conventional treatment scheme for carrying out independent charge and discharge treatment on batteries is to disassemble a battery pack, find out a battery core to be balanced, destroy a certain protection layer, thereby find out a positive and negative electrode lug busbar corresponding to the batteries, and charge and discharge the battery core by clamping a clamp of charge and discharge equipment on the positive and negative electrode lug busbar corresponding to the batteries; if there are multiple cells in the battery pack that need to be balanced, this solution will be extremely inefficient.

Disclosure of Invention

The invention provides a battery pack voltage balance control method, a device, an energy storage system and a storage medium, which are used for solving the problems that the current battery pack voltage balance control is low in automation degree and efficiency, and meanwhile, the battery pack is required to be disassembled, part of protection devices are damaged, and further cost is wasted.

According to an aspect of the present invention, there is provided a battery pack voltage equalization control method including:

Charging and discharging a current battery pack, and collecting current charging terminal voltage and current discharging terminal voltage of each battery cell of the current battery pack;

Determining a first charging end voltage and a corresponding first serial number, a second charging end voltage and a corresponding second serial number, a first discharging end voltage and a corresponding third serial number, and a second discharging end voltage and a corresponding fourth serial number of the current battery pack according to the current charging end voltage and the current discharging end voltage of each battery cell;

Determining whether the current battery pack needs balanced maintenance according to the first charging terminal voltage and the corresponding first serial number, the second charging terminal voltage and the corresponding second serial number, the first discharging terminal voltage and the corresponding third serial number, and the second discharging terminal voltage and the corresponding fourth serial number;

When the current battery pack is determined to need balanced maintenance, determining a charging end voltage average value and a discharging end voltage average value according to the current charging end voltage and the current discharging end voltage of each battery cell, and controlling each battery cell voltage of the current battery pack to be balanced according to the first charging end voltage, the second charging end voltage, the first discharging end voltage, the second discharging end voltage, the charging end voltage average value and the discharging end voltage average value.

Optionally, after the collecting the current charge end voltage and the current discharge end voltage of each battery cell of the current battery pack, the method further includes:

Judging whether the current battery pack is charged or discharged or not to reach the charge-discharge cut-off condition;

collecting a current charge end voltage and a current discharge end voltage of each battery cell of the current battery pack, including:

if the charge and discharge of the current battery pack reach the charge and discharge cut-off condition, recording the current charge terminal voltage and the current discharge terminal voltage of each battery cell of the current battery pack;

And if the charge and discharge of the current battery pack cannot meet the charge and discharge cut-off condition, collecting the current charge terminal voltage and the current discharge terminal voltage of each battery cell of the current battery pack again.

Optionally, the determining whether the current battery pack needs balanced maintenance according to the first charging terminal voltage and the corresponding first serial number, the second charging terminal voltage and the corresponding second serial number, the first discharging terminal voltage and the corresponding third serial number, the second discharging terminal voltage and the corresponding fourth serial number includes:

when the first serial number corresponding to the first charging terminal voltage is different from the fourth serial number corresponding to the second discharging terminal voltage, the second serial number corresponding to the second charging terminal voltage is different from the third serial number corresponding to the first discharging terminal voltage, and the first serial number corresponding to the first charging terminal voltage is the same as the third serial number corresponding to the first discharging terminal voltage, determining that the current battery pack needs balanced maintenance; or alternatively, the first and second heat exchangers may be,

And when the first serial number corresponding to the first charging terminal voltage is different from the fourth serial number corresponding to the second discharging terminal voltage, the second serial number corresponding to the second charging terminal voltage is different from the third serial number corresponding to the first discharging terminal voltage, and the second serial number corresponding to the second charging terminal voltage is the same as the fourth serial number corresponding to the second discharging terminal voltage, determining that the current battery pack needs balanced maintenance.

Optionally, the battery pack voltage equalization control method further includes:

When the first serial number corresponding to the first charging terminal voltage is different from the fourth serial number corresponding to the second discharging terminal voltage, the second serial number corresponding to the second charging terminal voltage is different from the third serial number corresponding to the first discharging terminal voltage, the first serial number corresponding to the first charging terminal voltage is different from the third serial number corresponding to the first discharging terminal voltage, the second serial number corresponding to the second charging terminal voltage is different from the fourth serial number corresponding to the second discharging terminal voltage, and whether the voltage difference between the first discharging terminal voltage and the second discharging terminal voltage is larger than a preset voltage difference threshold value is judged, or whether the discharging capacity of the current battery pack exceeds a standard discharging capacity threshold value is judged;

and if the voltage difference between the first discharge end voltage and the second discharge end voltage is larger than a preset voltage difference threshold value or the discharge capacity of the current battery pack exceeds a standard discharge capacity threshold value, determining that the current battery pack needs balanced maintenance.

Optionally, the controlling the voltage equalization of each battery cell of the current battery pack according to the first charging end voltage, the second charging end voltage, the first discharging end voltage, the second discharging end voltage, the charging end voltage average value and the discharging end voltage average value includes

And if the voltage difference between the first charge end voltage and the average charge end voltage is greater than an equalizing switch threshold, the voltage difference between the second charge end voltage and the average charge end voltage is greater than an equalizing switch threshold, the voltage difference between the first discharge end voltage and the average discharge end voltage is greater than an equalizing switch threshold, the voltage difference between the second discharge end voltage and the average discharge end voltage is greater than an equalizing switch threshold, and the voltage difference between the second discharge end voltage and the average discharge end voltage is greater than an equalizing switch threshold, controlling each battery cell voltage of the current battery pack to be equalized.

acquiring the voltage balance quantity of battery cells to be voltage balanced;

If the voltage equalization quantity is 1, judging whether to control the voltage equalization of each battery cell of the current battery pack according to the first charging terminal voltage, the second charging terminal voltage, the first discharging terminal voltage, the second discharging terminal voltage, the charging terminal voltage average value and the discharging terminal voltage average value;

and if the voltage balancing quantity is larger than 1, controlling the voltage balancing of each battery cell of the current battery pack according to the battery cells corresponding to the voltage balancing quantity.

Optionally, the controlling, by the battery cells corresponding to the voltage balancing number, voltage balancing of each battery cell of the current battery pack includes:

Determining the quantity of the to-be-charged electric cores and the quantity of the to-be-discharged electric cores according to the voltage balance quantity, wherein the quantity of the to-be-charged electric cores and the quantity of the to-be-discharged electric cores are the same or different;

When the number of the battery cells to be charged and the number of the battery cells to be discharged are the same, controlling the battery cells to be charged and the battery cells to be discharged to perform voltage balance control of each battery cell of the current battery pack in a one-to-one correspondence manner;

and when the number of the battery cells to be charged and the number of the battery cells to be discharged are different, screening according to the voltage difference, and performing voltage balance control on each battery cell of the current battery pack.

According to another aspect of the present invention, there is provided a battery pack voltage equalization control device including:

The terminal voltage determining module is used for executing charging and discharging of a current battery pack and collecting current charging terminal voltage and current discharging terminal voltage of each battery cell of the current battery pack;

The serial number information determining module is used for determining a first charging end voltage and a corresponding first serial number, a second charging end voltage and a corresponding second serial number, a first discharging end voltage and a corresponding third serial number, a second discharging end voltage and a corresponding fourth serial number of the current battery pack according to the current charging end voltage and the current discharging end voltage of each battery cell;

The equalization maintenance judging module is used for executing the steps of determining whether the current battery pack needs equalization maintenance according to the first charging terminal voltage and the corresponding first serial number, the second charging terminal voltage and the corresponding second serial number, the first discharging terminal voltage and the corresponding third serial number, the second discharging terminal voltage and the corresponding fourth serial number;

And the voltage balance control module is used for determining a charging end voltage average value and a discharging end voltage average value according to the current charging end voltage and the current discharging end voltage of each battery cell when the current battery pack needs balance maintenance, and controlling each battery cell voltage balance of the current battery pack according to the first charging end voltage, the second charging end voltage, the first discharging end voltage, the second discharging end voltage, the charging end voltage average value and the discharging end voltage average value.

According to another aspect of the present invention, there is provided an energy storage system comprising:

At least one processor; and

A memory communicatively coupled to the at least one processor; wherein,

The memory stores a computer program executable by the at least one processor to enable the at least one processor to perform the battery pack voltage equalization control method according to any of the embodiments of the present invention.

According to another aspect of the present invention, there is provided a computer readable storage medium storing computer instructions for causing a processor to implement the battery pack voltage equalization control method according to any embodiment of the present invention when executed.

According to the technical scheme, the current charging terminal voltage and the current discharging terminal voltage of each battery cell of the current battery pack are collected through charging and discharging of the current battery pack; determining a first charging end voltage and a corresponding first serial number, a second charging end voltage and a corresponding second serial number, a first discharging end voltage and a corresponding third serial number, and a second discharging end voltage and a corresponding fourth serial number of the current battery pack according to the current charging end voltage and the current discharging end voltage of each battery cell; determining whether the current battery pack needs balanced maintenance according to the first charging terminal voltage and the corresponding first serial number, the second charging terminal voltage and the corresponding second serial number, the first discharging terminal voltage and the corresponding third serial number, and the second discharging terminal voltage and the corresponding fourth serial number; when the current battery pack is determined to need balanced maintenance, determining a charging end voltage average value and a discharging end voltage average value according to the current charging end voltage and the current discharging end voltage of each battery cell, and controlling each battery cell voltage of the current battery pack to be balanced according to the first charging end voltage, the second charging end voltage, the first discharging end voltage, the second discharging end voltage, the charging end voltage average value and the discharging end voltage average value. The invention solves the problems of low degree of automation, low efficiency, need to disassemble the battery pack, damage part of protection devices and further cause cost waste in the prior battery pack voltage balance control, so as to realize the battery pack voltage balance automatic control, and has high reliability and high efficiency, and simultaneously, reduces the labor and material cost.

It should be understood that the description in this section is not intended to identify key or critical features of the embodiments of the invention or to delineate the scope of the invention. Other features of the present invention will become apparent from the description that follows.

Drawings

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

Fig. 1 is a flowchart of a battery pack voltage equalization control method according to a first embodiment of the present invention;

fig. 2 is a flowchart of a method for determining battery pack equalization maintenance according to a second embodiment of the present invention;

fig. 3 is a flowchart of a method for performing battery pack voltage equalization control according to a second embodiment of the present invention;

FIG. 4 is a topology of an energy storage system adapted for use in accordance with an embodiment of the present invention;

fig. 5 is a schematic structural diagram of a battery pack voltage balancing control apparatus according to a third embodiment of the present invention;

fig. 6 is a schematic diagram of an energy storage system for implementing a battery pack voltage equalization control method according to an embodiment of the present invention.

Detailed Description

In order that those skilled in the art will better understand the present invention, a technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in which it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present invention without making any inventive effort, shall fall within the scope of the present invention.

It should be noted that the terms "first," "second," and the like in the description and the claims of the present invention and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the invention described herein may be implemented in sequences other than those illustrated or otherwise described herein. Furthermore, 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.

Example 1

Fig. 1 is a flowchart of a battery pack voltage balancing control method according to an embodiment of the present invention, where the method may be applied to a case of performing consistency maintenance determination and active balancing on battery pack voltages, and the method may be performed by a battery pack voltage balancing control device, and the device may be implemented in a hardware and/or software form, and the device may be configured in an energy storage system. As shown in fig. 1, the battery pack voltage equalization control method includes:

s110, charging and discharging the current battery pack, and collecting the current charging terminal voltage and the current discharging terminal voltage of each battery cell of the current battery pack.

The current battery pack can be a battery pack to be subjected to voltage equalization in the energy storage system, and the battery pack voltage equalization control method of the embodiment is applicable to any battery pack in the energy storage system.

In this embodiment, the current battery pack may be charged and discharged by accessing the charging and discharging device, that is, the charging and discharging device is turned on to charge and discharge the current battery pack.

Specifically, after the current battery pack is charged and discharged, the current charging terminal voltage and the current discharging terminal voltage of each battery cell of the current battery pack are actively collected in real time through a battery management system BMS.

It is understood that a battery pack (pack) is typically assembled from a plurality of battery packs (Batteries) assembled from a plurality of cell battery cells to provide higher voltage and capacity. In this embodiment, a plurality of battery cells included in the battery pack are collected respectively, so as to obtain a corresponding current charging terminal voltage and a corresponding current discharging terminal voltage.

Further, to ensure accuracy of the battery pack consistency determination, after the collecting the current charge end voltage and the current discharge end voltage of each battery cell of the current battery pack, the method further includes: and judging whether the current battery pack is charged or discharged or not to reach the charge-discharge cut-off condition.

The charge-discharge cut-off condition may be that the charge end voltage and the discharge end voltage reach a certain threshold, or that the temperature reaches a certain threshold in the charge-discharge process of the battery pack, alternatively, the charge-discharge cut-off condition may be that the charge end voltage reaches 3.6v and the discharge end voltage reaches 2.5v, or the charge-discharge cut-off condition may be that the temperature reaches 55 ℃ in the charge-discharge process of the battery pack, or that the temperature is lower than 0 ℃ in the charge-discharge process of the battery pack.

On the basis, if the charge and discharge of the current battery pack reach the charge and discharge cut-off condition, recording the current charge terminal voltage and the current discharge terminal voltage of each battery cell of the current battery pack; and if the charge and discharge of the current battery pack cannot reach the charge and discharge cut-off condition, collecting the current charge end voltage and the current discharge end voltage of each battery cell of the current battery pack again, and judging whether the charge and discharge of the current battery pack reach the charge and discharge cut-off condition again.

And S120, determining the first charge end voltage and the corresponding first serial number, the second charge end voltage and the corresponding second serial number, the first discharge end voltage and the corresponding third serial number, and the second discharge end voltage and the corresponding fourth serial number of the current battery pack according to the current charge end voltage and the current discharge end voltage of each battery cell.

In order to control the battery cells to perform voltage equalization and determine the battery cells in the battery pack in time, serial numbers of each battery cell are written, serial numbers can be sequentially given in sequence, numbers can be given in a specific letter or name mode, and the embodiment is not limited in any way.

Specifically, after the current charging terminal voltage and the current discharging terminal voltage of all battery cells of the battery pack are obtained, the highest charging terminal voltage in all battery cells is used as a first charging terminal voltage, and a first serial number corresponding to the first charging terminal voltage is obtained at the same time; taking the lowest charging terminal voltage in all battery cells as a second charging terminal voltage, and simultaneously obtaining a second serial number corresponding to the second charging terminal voltage; taking the highest discharge end voltage in all battery cells as a first discharge end voltage, and simultaneously obtaining a third serial number corresponding to the first discharge end voltage; and taking the lowest discharge end voltage in all battery cells as a second discharge end voltage, and simultaneously acquiring a fourth serial number corresponding to the second discharge end voltage.

It can be understood that the first serial number, the second serial number, the third serial number and the fourth serial number are respectively corresponding to one of all the battery cells, and the first serial number, the second serial number, the third serial number and the fourth serial number may be the same or different, and are specifically determined according to the actual charge and discharge conditions of the battery cells, that is, the high and low values of the charge and discharge terminal voltages.

S130, determining whether the current battery pack needs balanced maintenance according to the first charging terminal voltage and the corresponding first serial number, the second charging terminal voltage and the corresponding second serial number, the first discharging terminal voltage and the corresponding third serial number, and the second discharging terminal voltage and the corresponding fourth serial number.

On the basis of the above, judging whether the first serial number corresponding to the first charging terminal voltage and the fourth serial number corresponding to the second discharging terminal voltage are the same, if so, prompting that the battery pack needs to be manually unpacked for replacement, and maintaining the corresponding battery cell or maintaining the corresponding busbar; if not, judging whether the second serial number corresponding to the second charging terminal voltage is the same as the third serial number corresponding to the first discharging terminal voltage, if so, prompting that the battery has larger capacity and no maintenance is needed; if not, judging whether the first serial number corresponding to the first charging terminal voltage is the same as the third serial number corresponding to the first discharging terminal voltage, or judging whether the second serial number corresponding to the second charging terminal voltage is the same as the fourth serial number corresponding to the second discharging terminal voltage, and if the first serial number and the third serial number are the same, determining that the current battery pack needs balanced maintenance.

Further, if it is determined that the first serial number corresponding to the first charge end voltage is different from the third serial number corresponding to the first discharge end voltage, and the second serial number corresponding to the second charge end voltage is different from the fourth serial number corresponding to the second discharge end voltage, it is determined whether the voltage difference between the first discharge end voltage and the second discharge end voltage is greater than a preset voltage difference threshold, or whether the discharge capacity of the current battery pack exceeds a standard discharge capacity threshold, and if the voltage difference between the first serial number and the third serial number is any greater than the standard discharge capacity threshold, it is determined that the current battery pack needs balanced maintenance.

If the voltage difference between the first discharging terminal voltage and the second discharging terminal voltage is not greater than a preset voltage difference threshold, and the discharging capacity of the current battery pack does not exceed a standard discharging capacity threshold, the current battery pack is indicated to be normal, and maintenance is not needed.

It should be noted that, step S120 and step S130 are implemented by further determining after the battery management system BMS obtains the voltage information of all the battery cells of the battery pack.

And S140, when the current battery pack is determined to need balanced maintenance, determining a charging end voltage average value and a discharging end voltage average value according to the current charging end voltage and the current discharging end voltage of each battery cell, and controlling the voltage balance of each battery cell of the current battery pack according to the first charging end voltage, the second charging end voltage, the first discharging end voltage, the second discharging end voltage, the charging end voltage average value and the discharging end voltage average value.

It can be understood that when the battery management system BMS determines that the current battery pack needs balanced maintenance, the battery management system BMS obtains a preset balanced switch threshold, and the balanced switch threshold can be selectively set by a person skilled in the art according to the actual situation through the battery management system BMS.

Specifically, if the voltage difference between the first charging end voltage and the average value of the charging end voltage is greater than an equalization switch threshold, and the voltage difference between the second charging end voltage and the average value of the charging end voltage is greater than an equalization switch threshold, and the voltage difference between the first discharging end voltage and the average value of the discharging end voltage is greater than an equalization switch threshold, and the voltage difference between the second discharging end voltage and the average value of the discharging end voltage is greater than an equalization switch threshold, each battery cell voltage of the current battery pack is controlled to be equalized. If the conditions are not met, stopping controlling the voltage balancing operation of the current battery pack, and indicating that the voltage balancing control is finished.

Further, on the basis of the above embodiment, after determining to control the voltage balance of each battery cell of the current battery pack, the number of voltage balances of the battery cells to be voltage-balanced is obtained; if the voltage equalization quantity is 1, judging whether to control the voltage equalization of each battery cell of the current battery pack according to the first charging terminal voltage, the second charging terminal voltage, the first discharging terminal voltage, the second discharging terminal voltage, the charging terminal voltage average value and the discharging terminal voltage average value; and if the voltage balancing quantity is larger than 1, controlling the voltage balancing of each battery cell of the current battery pack according to the battery cells corresponding to the voltage balancing quantity.

On the basis, determining the quantity of the to-be-charged battery cores and the quantity of the to-be-discharged battery cores according to the voltage balance quantity, wherein the quantity of the to-be-charged battery cores and the quantity of the to-be-discharged battery cores are the same or different; when the number of the battery cells to be charged and the number of the battery cells to be discharged are the same, controlling the battery cells to be charged and the battery cells to be discharged to perform voltage balance control of each battery cell of the current battery pack in a one-to-one correspondence manner; and when the number of the battery cells to be charged and the number of the battery cells to be discharged are different, screening according to the voltage difference, and performing voltage balance control on each battery cell of the current battery pack.

Example two

Fig. 2 is a flowchart of a method for determining battery pack balancing maintenance according to a second embodiment of the present invention, and fig. 3 is a flowchart of a method for performing battery pack voltage balancing control according to a second embodiment of the present invention, where the flow of the battery pack voltage balancing control method is further refined on the basis of the foregoing embodiment, and meanwhile, a topology structure diagram of an energy storage system shown in fig. 4 is provided, which details an information interaction schematic process of a battery pack, the energy storage system and a remote monitoring platform. As shown in fig. 1, 2 and 4, the method for determining battery pack equalization maintenance includes:

With continued reference to fig. 4, the battery pack is the current battery pack according to this embodiment, the battery pack includes a plurality of battery packs (B1-, b1+ … … b11+, b12+, … …, b61-, b61+327b71+, b72+) formed by parallel connection of bus bars, temperature sensors (T1 … T3, … …, T16 … T18) are arranged on the battery packs, and information is collected into an active equalization module (BMU-1 … BMU-6) through voltage and temperature sampling lines, the active equalization module (BMU-1 … BMU-6) includes a plurality of bidirectional DCDC modules, a voltage input end (DC 2-5V) of each DCDC module is connected with each battery cell managed by the battery packs through a switch matrix, and an output end (DC 24V) of each battery pack is connected with a power supply of the active equalization module (BMU-1 …) and each battery pack includes a plurality of active equalization modules (BMU-1 … BMU-6).

For example, if the voltage of a certain single battery managed by the active equalization module BMU-1 is too high, the voltage of a certain single battery managed by the active equalization module BMU-6 is too low, the active equalization module BMU-1 and the active equalization module BMU-6 are connected with the DCDC through the switch matrix, and the active equalization module BMU-1 controls bidirectional discharging, and the active equalization module BMU-6 controls bidirectional charging, that is, is equivalent to transferring the power from the high-voltage battery cell in the active equalization module BMU-1 to the low-voltage battery cell in the active equalization module BMU-6 through two bidirectional DCDC. Otherwise, if the battery cell voltage managed by the active equalization module BMU-6 is high, the battery cell voltage managed by the active equalization module BMU-1 is low, and the high-voltage battery cell in the active equalization module BMU-6 can also transfer electricity to the low-voltage battery cell in the active equalization module BMU-1 through two bidirectional DCDC.

It should be noted that, with continued reference to fig. 4, the energy storage system further includes a switching power supply, and the switching power supply is plugged into a 220V plug, and outputs 24V voltage at the other end to supply power to an active equalization module (BMU-1 … BMU-6) and a battery management system BMS in the battery pack respectively.

And S210, judging whether the current battery pack is charged or discharged or not, if so, executing the step S120, and if not, executing the step S110.

S230, judging whether the first sequence number corresponding to the first charging terminal voltage and the fourth sequence number corresponding to the second discharging terminal voltage are the same, if so, executing step S231, and if not, executing step S240.

S231, the battery pack can be prompted to be manually unpacked and replaced, and corresponding battery cells are maintained or corresponding bus bars are maintained.

As can be seen from fig. 2 and fig. 4, the upper computer of the PC computer can prompt that the battery pack needs to be manually unpacked for replacement, and maintain the corresponding battery cells or repair the corresponding busbar.

S240, judging whether the second sequence number corresponding to the second charging terminal voltage is the same as the third sequence number corresponding to the first discharging terminal voltage, if so, executing step S241, and if not, executing step S250.

S241, the battery can be prompted to have larger capacity and maintenance is not needed.

As can be seen from fig. 2 and fig. 4, the upper computer of the PC computer can prompt that the battery pack has a larger capacity, and maintenance is not required.

S250, judging whether the first sequence number corresponding to the first charging terminal voltage and the third sequence number corresponding to the first discharging terminal voltage are the same, or judging whether the second sequence number corresponding to the second charging terminal voltage and the fourth sequence number corresponding to the second discharging terminal voltage are the same, if any, executing step S251, otherwise, executing step S260.

S251, determining that the current battery pack needs balanced maintenance.

As can be seen from fig. 2 and fig. 4, the upper computer of the PC computer can determine that the current battery pack needs to be balanced for maintenance, and automatically perform voltage balance control of the battery pack.

And S260, judging whether the voltage difference between the first discharge end voltage and the second discharge end voltage is larger than a preset voltage difference threshold or not, or judging whether the discharge capacity of the current battery pack exceeds a standard discharge capacity threshold, if any of the two exceeds the threshold, executing the step S261, and if not, executing the step S270.

S261, determining that the current battery pack needs balanced maintenance.

S270, prompting that the current battery pack is normal, and no maintenance is needed.

In addition, referring to fig. 4, the battery management system BMS performs information interaction with the active equalization module (BMU-1 … BMU-6) in the battery pack through the CAN communication line to obtain all battery voltage and temperature information; on the other hand, the battery is electrically connected with the PC computer through the CAN to USB, and then various information (including the voltage, the temperature, the highest and lowest voltage, the highest and lowest temperature and the like) obtained in the embodiment are displayed on a monitoring upper computer of the PC computer.

It is known that the BMS can identify the state of the battery pack during the charge and discharge process, and display the result of determining the battery pack balancing maintenance method on the monitoring host computer of the PC, and specifically determine the workflow of the battery pack balancing maintenance method as in steps S110 to S270. In addition, when it is determined that the current battery pack needs to be balanced for maintenance, the battery management system BMS controls automatic balanced operation according to a balanced switch threshold set by the PC computer, and the specific workflow is as follows.

On the basis of the above embodiment, if it is determined that the current battery pack needs equalization maintenance, step S140 is specifically explained, and as shown in fig. 3, the method for performing battery pack voltage equalization control specifically includes:

And S310, acquiring a preset equalization switch threshold value through the battery management system BMS.

S320, judging whether the voltage difference between the first charging end voltage, the second charging end voltage, the first discharging end voltage and the second discharging end voltage and the average value of the charging end voltage and the average value of the discharging end voltage are larger than an equalizing switch threshold, if yes, executing step S340, and if not, executing step S330.

S330, stopping controlling the voltage balancing operation of the current battery pack.

And S340, acquiring the voltage balancing quantity of the battery cells to be voltage balanced, and executing step S350.

S350, judging whether the voltage balance number is 1, if so, executing the step S320, and if not, executing the step S360.

It will be understood that when the number of voltage equalizations is 1, the decision is restarted after waiting for the next execution of step S320, and the decision is generally restarted within a certain time, and the specific time interval may be selectively set by those skilled in the art, and optionally, step S320 is executed again every one minute.

And S360, controlling the voltage balance of each battery cell of the current battery pack according to the battery cells corresponding to the voltage balance quantity, and executing the step S320 again to judge the balanced switch threshold again.

In this embodiment, the battery cells in one active equalization module determine which is started first according to the voltage, and different active equalization modules can be started simultaneously, but some active equalization modules need to be charged and some active equalization modules need to be discharged, at this time, it can be understood that the battery cells in the active equalization modules cannot be fully charged or discharged. The detected voltage balance number is determined to be 6, wherein 4 cells to be charged and 2 cells to be discharged can only be opened first, and the 4 cells to be charged can be opened first to 3 cells to be charged, and the 3 cells to be charged are not opened first with the minimum voltage difference according to the voltage difference, so that voltage balance control of each battery cell of the current battery pack is correspondingly performed.

According to the technical scheme provided by the embodiment of the invention, the energy storage system is built according to the topological structure diagram of fig. 4, the switching power supply and the PC are turned on, and the charging and discharging equipment is connected to charge and discharge the current battery pack. After the current battery pack is charged and discharged, the battery management system BMS determines whether the current battery pack needs balanced maintenance according to the battery pack balancing maintenance determination method shown in fig. 2, and displays the current battery pack on an upper computer of the PC. If the current battery pack needs manual maintenance, the person skilled in the art performs unpacking treatment; if the current battery pack needs automatic equalization maintenance, the energy storage system executes battery pack voltage equalization control according to the diagram shown in fig. 3; and if the current battery pack does not need maintenance, the offline operation can be completed. The automatic balance control system has the advantages that the automation degree is high, the misjudgment of manual intervention is avoided, the reliability is high, the labor cost can be reduced, the automatic balance control of the battery pack voltage can avoid opening a box and damaging part of devices, the materials and labor cost are saved, in addition, the balance quantity of battery cells is large when the automatic balance control of the battery pack voltage is performed, and the automatic balance control system is higher than the manual charge and discharge efficiency.

Example III

Fig. 5 is a schematic structural diagram of a battery pack voltage balancing control device according to a third embodiment of the present invention. As shown in fig. 5, the battery pack voltage equalization control device includes:

The terminal voltage determining module 510 is configured to perform charging and discharging of a current battery pack, and collect a current charging terminal voltage and a current discharging terminal voltage of each battery cell of the current battery pack;

The serial number information determining module 520 is configured to determine a first charging end voltage and a corresponding first serial number, a second charging end voltage and a corresponding second serial number, a first discharging end voltage and a corresponding third serial number, and a second discharging end voltage and a corresponding fourth serial number of the current battery pack according to the current charging end voltage and the current discharging end voltage of each battery cell;

The equalization maintenance judging module 530 is configured to determine whether the current battery pack requires equalization maintenance according to the first charging terminal voltage and the corresponding first sequence number, the second charging terminal voltage and the corresponding second sequence number, the first discharging terminal voltage and the corresponding third sequence number, and the second discharging terminal voltage and the corresponding fourth sequence number;

the voltage balancing control module 540 is configured to determine, when it is determined that the current battery pack requires balancing maintenance, a charging end voltage average value and a discharging end voltage average value according to a current charging end voltage and a current discharging end voltage of each battery cell, and control voltage balancing of each battery cell of the current battery pack according to the first charging end voltage, the second charging end voltage, the first discharging end voltage, the second discharging end voltage, the charging end voltage average value and the discharging end voltage average value.

Optionally, the battery pack voltage equalization control device further includes:

the charge and discharge cut-off condition judging module is used for executing judgment on whether the current battery pack is charged or discharged or not and reaches the charge and discharge cut-off condition;

Optionally, the equalization maintenance judging module 530 is specifically configured to:

The voltage balance quantity acquisition module is used for executing the acquisition of the voltage balance quantity of the battery cells to be voltage balanced;

The voltage balance judging module is used for executing the judgment whether to control the voltage balance of each battery cell of the current battery pack according to the first charging terminal voltage, the second charging terminal voltage, the first discharging terminal voltage, the second discharging terminal voltage, the charging terminal voltage average value and the discharging terminal voltage average value again if the voltage balance number is 1;

The battery pack voltage balance control device provided by the embodiment of the invention can execute the battery pack voltage balance control method provided by any embodiment of the invention, and has the corresponding functional modules and beneficial effects of executing the battery pack voltage balance control method.

Example IV

Fig. 6 illustrates a schematic diagram of an energy storage system 610 that may be used to implement an embodiment of the present invention. As shown in fig. 6, the energy storage system 610 includes at least one processor 611, and a memory, such as a Read Only Memory (ROM) 612, a Random Access Memory (RAM) 613, etc., communicatively coupled to the at least one processor 611, where the memory stores computer programs executable by the at least one processor, and the processor 611 may perform various suitable actions and processes according to the computer programs stored in the Read Only Memory (ROM) 612 or the computer programs loaded from the storage unit 618 into the Random Access Memory (RAM) 613. In RAM 613, various programs and data required for the operation of energy storage system 610 may also be stored. The processor 611, the ROM 612, and the RAM 613 are connected to each other by a bus 614. An input/output (I/O) interface 615 is also connected to bus 614.

A number of components in the energy storage system 610 are connected to the I/O interface 615, including: an input unit 616 such as a keyboard, mouse, etc.; an output unit 617 such as various types of displays, speakers, and the like; a storage unit 618, such as a magnetic disk, optical disk, etc.; and a communication unit 619 such as a network card, modem, wireless communication transceiver, etc. The communication unit 619 allows the energy storage system 610 to exchange information/data with other devices via a computer network, such as the internet, and/or various telecommunication networks.

Processor 611 may be a variety of general and/or special purpose processing components having processing and computing capabilities. Some examples of processor 611 include, but are not limited to, a Central Processing Unit (CPU), a Graphics Processing Unit (GPU), various specialized Artificial Intelligence (AI) computing chips, various processors running machine learning model algorithms, digital Signal Processors (DSPs), and any suitable processor, controller, microcontroller, etc. The processor 611 performs the various methods and processes described above, such as the battery pack voltage equalization control method.

In some embodiments, the battery pack voltage equalization control method may be implemented as a computer program tangibly embodied on a computer-readable storage medium, such as the storage unit 618. In some embodiments, some or all of the computer program may be loaded and/or installed onto the energy storage system 610 via the ROM 612 and/or the communication unit 619. When the computer program is loaded into RAM 613 and executed by processor 611, one or more steps of the battery pack voltage equalization control method described above may be performed. Alternatively, in other embodiments, the processor 611 may be configured to perform the battery pack voltage balancing control method in any other suitable manner (e.g., by means of firmware).

Various implementations of the systems and techniques described here above may be implemented in digital electronic circuitry, integrated circuit systems, field Programmable Gate Arrays (FPGAs), application Specific Integrated Circuits (ASICs), application Specific Standard Products (ASSPs), systems On 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, the one or more computer programs may be executed and/or interpreted on a programmable system including at least one programmable processor, which may be a special purpose or general-purpose programmable processor, that may receive data and instructions from, and transmit data and instructions to, a storage system, at least one input device, and at least one output device.

A computer program for carrying out methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the computer programs, when executed by the processor, cause the functions/acts specified in the flowchart and/or block diagram block or blocks to be implemented. The computer program 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 the present invention, a computer-readable storage medium may be a tangible medium that can contain, or store a computer program for use by or in connection with an instruction execution system, apparatus, or device. The computer readable 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. Alternatively, the computer readable storage medium may be a machine readable signal medium. 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 portable 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 an energy storage system 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 pointing device (e.g., a mouse or trackball) through which a user may provide input to the energy storage system. Other kinds of devices may also be used to provide for interaction with a user; for example, feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user may be received in any form, including acoustic input, speech input, or tactile input.

The systems and techniques described here can be implemented in a computing system that includes a background 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 background, 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), blockchain networks, and the internet.

The computing system may include clients and servers. The client and server are typically 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 can be a cloud server, also called a cloud computing server or a cloud host, and is a host product in a cloud computing service system, so that the defects of high management difficulty and weak service expansibility in the traditional physical hosts and VPS service are overcome.

It should be appreciated that various forms of the flows shown above may be used to reorder, add, or delete steps. For example, the steps described in the present invention may be performed in parallel, sequentially, or in a different order, so long as the desired results of the technical solution of the present invention are achieved, and the present invention is not limited herein.

The above embodiments do not limit the scope of the present invention. It will be apparent to those skilled in the art that various modifications, combinations, sub-combinations and alternatives are possible, depending on design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of the present invention.

Claims

1. A battery pack voltage equalization control method, comprising:

2. The battery pack voltage equalization control method of claim 1, further comprising, after said collecting a current charge end voltage and a current discharge end voltage of each battery cell of said current battery pack:

3. The battery pack voltage equalization control method of claim 1, wherein said determining whether the current battery pack requires equalization maintenance based on the first charge end voltage and the corresponding first sequence number, the second charge end voltage and the corresponding second sequence number, the first discharge end voltage and the corresponding third sequence number, the second discharge end voltage and the corresponding fourth sequence number comprises:

4. The battery pack voltage equalization control method of claim 1, further comprising:

5. The battery pack voltage equalization control method of claim 1, wherein said controlling each cell voltage equalization of said current battery pack based on said first charge end voltage, said second charge end voltage, said first discharge end voltage, said second discharge end voltage, said charge end voltage average value, and said discharge end voltage average value comprises

6. The battery pack voltage equalization control method of claim 5, further comprising:

acquiring the voltage balance quantity of battery cells to be voltage balanced;

7. The battery pack voltage equalization control method of claim 6, wherein said controlling each battery cell voltage equalization of said current battery pack according to said corresponding number of battery cells comprises:

8. A battery pack voltage equalization control device, comprising:

9. An energy storage system, the energy storage system comprising:

At least one processor; and

A memory communicatively coupled to the at least one processor; wherein,

The memory stores a computer program executable by the at least one processor to enable the at least one processor to perform the battery pack voltage equalization control method of any of claims 1-7.

10. A computer readable storage medium storing computer instructions for causing a processor to implement the battery pack voltage equalization control method of any of claims 1-7 when executed.