CN115692878A

CN115692878A - Battery pack management method for battery system, battery pack and battery system

Info

Publication number: CN115692878A
Application number: CN202211089599.1A
Authority: CN
Inventors: 施海驹; 黄成成
Original assignee: If New Energy Technology Jiangsu Co ltd
Current assignee: If New Energy Technology Jiangsu Co ltd
Priority date: 2022-09-07
Filing date: 2022-09-07
Publication date: 2023-02-03

Abstract

The application relates to a battery pack management method for a battery system, a battery pack, and a battery system. The battery system comprises a first battery pack and a plurality of second battery packs, the management method is applied to the first battery pack, and the management method comprises the following steps: controlling to disconnect the charge-discharge loops of all battery packs in the battery system; the pre-charging circuit is used for controlling the conduction of the first battery pack; the pre-charging circuit is used for sequentially controlling the conduction of the second battery pack; and acquiring a current value between the first battery pack and each second battery pack, and determining whether a parallel error occurs between the first battery pack and each second battery pack according to the current value. By adopting the method, whether the parallel connection between the battery packs in the battery system is abnormal or not can be automatically identified after the battery packs are connected to form the battery system.

Description

Battery pack management method for battery system, battery pack and battery system

Technical Field

The present application relates to the field of new energy technologies, and in particular, to a battery pack management method for a battery system, a battery pack, and a battery system.

Background

With the development of new energy technology, the application range of batteries is wider and wider. At present, many manufacturers manufacture battery packs for production and sale, and after purchasing the battery packs, users perform series-parallel connection on the battery packs so as to meet the requirements of an electric system on battery capacity and output voltage.

Generally speaking, when a user performs series-parallel connection, it is necessary to ensure that the total capacity and the residual capacity of each battery pack and the voltages at two ends of the battery packs are completely consistent, then select a plurality of battery packs to perform parallel connection to form a battery pack string, the capacities after all the battery packs are still consistent after the parallel connection, and finally connect the plurality of battery pack strings in series to obtain a battery system which is composed of a plurality of battery packs and has the rated capacity and the voltage desired by the user.

However, in the practical application process, it cannot be guaranteed that each user reads the operation guide and processes according to the operation guide, and it cannot be guaranteed that each user has certain basic knowledge of electrician theory and necessary electrician tools. Under the normal condition, a user can randomly connect the battery packs in series and/or in parallel, at this time, if the connection between the battery packs is unreasonable or the connection is wrong, the risk that the battery packs cannot be powered on correctly may be caused, and even potential safety hazards may be generated, so that the battery packs are damaged.

Therefore, there is a need for a method capable of automatically recognizing whether or not the connection of the battery packs is abnormal after the battery packs are connected in series and parallel.

The foregoing description is provided for general background information and is not admitted to be prior art.

Disclosure of Invention

In view of the above, it is desirable to provide a battery pack management method for a battery system, a battery pack, and a battery system, which can automatically recognize whether or not there is an abnormal connection between battery packs after the battery packs are connected to form the battery system.

To this end, as a first aspect of the present application, the present application provides a battery pack management method for a battery system. The battery system comprises a first battery pack and a plurality of second battery packs, the management method is applied to the first battery pack, and the method comprises the following steps:

controlling to disconnect the charge-discharge loops of all battery packs in the battery system;

the pre-charging circuit is used for controlling the conduction of the first battery pack;

the pre-charging circuit is used for sequentially controlling the conduction of the second battery pack;

and acquiring a current value between the first battery pack and each second battery pack, and determining whether a parallel error occurs between the first battery pack and each second battery pack according to the current value.

Optionally, with reference to any one of the foregoing aspects, in another implementation manner of this aspect, the determining whether a parallel connection error occurs between the first battery pack and the second battery pack according to the current value includes:

in response to the current value being within a preset first threshold range, determining that no parallel connection error occurs between the first battery pack and the second battery pack; alternatively, the first and second electrodes may be,

and determining that a parallel error occurs between the first battery pack and the second battery pack in response to the current value being within a preset second threshold range.

Optionally, with reference to any one of the foregoing aspects, in another implementation manner of this aspect, the first battery pack and each of the second battery packs are respectively controllably connected to the first signal line through their own first voltage access modules and to the second signal line through their own second voltage access modules, where the management method further includes:

controlling the charging and discharging loops of all battery packs in the battery system to be conducted in response to determining that no parallel connection error occurs between the first battery pack and the second battery pack;

a second voltage access module of the first battery pack is controlled to be connected with the second signal line;

sequentially controlling a first voltage access module of the second battery pack to be connected with the first signal line;

and sequentially acquiring voltage values between the first signal line and the second signal line, and determining whether a series error occurs between the first battery pack and the second battery pack according to the voltage values.

Optionally, with reference to any one of the foregoing aspects, in another implementation manner of this aspect, the determining whether a series error occurs between the first battery pack and the second battery pack according to the voltage value includes:

grouping the voltage values, and acquiring the number of corresponding battery packs in each group;

and determining whether a series error occurs between the first battery pack and the second battery pack according to the number.

Optionally, with reference to any one of the foregoing aspects, in another implementation manner of this aspect, the grouping the voltage values and acquiring the number of corresponding battery packs in each group includes:

dividing the voltage value by the voltage value of the first battery pack and rounding to obtain an integer value;

dividing the same integer value into the same group;

and counting the number of the integer values in each group, and determining the number of the corresponding battery packs in each group according to the number of the integer values.

Optionally, with reference to any one of the foregoing aspects, in another implementation manner of this aspect, the determining whether a series error occurs between the first battery pack and the second battery pack according to the number includes:

if the number of the corresponding battery packs in each group is the same, determining that no series connection error occurs between the first battery pack and the second battery pack; alternatively, the first and second electrodes may be,

and if the number of the corresponding battery packs in each group is different, determining that a series error occurs between the first battery pack and the second battery pack.

Optionally, with reference to any one of the foregoing aspects, in another implementation manner of this aspect, the management method further includes:

responding to the occurrence of a parallel error or a series error between the first battery pack and the second battery pack, and outputting a first reminding message, wherein the first reminding message represents the occurrence of the parallel error or the series error between the first battery pack and the second battery pack.

periodically acquiring the health state and/or the residual capacity of each battery pack in the battery system;

responding to the situation that the health state of the battery pack is smaller than a preset health state threshold value, and outputting a second reminding message, wherein the second reminding message represents that the health state of the corresponding battery pack is abnormal; and/or the presence of a gas in the atmosphere,

and responding to the fact that the difference value of the residual electric quantity between each battery pack is larger than a preset residual electric quantity threshold value, and performing electric quantity balance control.

As a second aspect of the present application, the present application also provides a battery pack. The battery package and a plurality of second battery package are used for forming battery system, the battery package includes at least:

the control module is used for controlling disconnection of a charging and discharging loop of the battery pack and controlling connection of a pre-charging circuit of the battery pack;

the communication module is used for communicating with the second battery pack so as to enable the second battery pack to disconnect a charging and discharging loop of the second battery pack and to connect a pre-charging circuit of the second battery pack;

and the parallel detection module is used for acquiring a current value between the battery pack and each second battery pack and determining whether a parallel error occurs between the battery pack and the second battery pack according to the current value.

As a third aspect of the present application, there is also provided a battery system, which includes a first battery pack and a plurality of second battery packs, wherein the first battery pack is configured to perform the steps of any one of the above method embodiments.

As a fourth aspect of the present application, the present application further provides a battery management system, which includes a memory and a processor, where the memory stores a computer program, and the processor implements the steps in the foregoing method embodiments when executing the computer program.

As a fifth aspect of the present application, the present application further provides a computer-readable storage medium storing a computer program for performing the steps of any one of the above method embodiments when the computer program is executed by a processor.

As a sixth aspect of the present application, the present application also provides a computer program product comprising a computer program that, when being executed by a processor, realizes the steps of any of the above-mentioned method embodiments.

According to the management method, the charging and discharging loops of all the battery packs are disconnected, the pre-charging circuit of the first battery pack is controlled to be conducted, the pre-charging circuits of the second battery packs are sequentially controlled to be conducted, and whether parallel connection errors occur between the first battery pack and the second battery packs is determined according to the current value between the first battery pack and each second battery pack. All the operations are completed by the control host (the first battery pack), so that after a user connects a plurality of battery packs, other operations are not needed, the current value between the first battery pack and each second battery pack can be automatically acquired through the scheme, whether parallel connection errors occur on the second battery pack in the battery system formed by the plurality of battery packs relative to the first battery pack or not is determined according to the current value between the battery packs, the battery packs and the battery system can be better accurately managed, and the service life of the battery packs in the management process and the safety of the user can be guaranteed by using the pre-charging circuit.

The above summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. The above summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. The claimed subject matter is not limited to implementations that solve any or all disadvantages noted in the background.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and together with the description, serve to explain the principles of the application. In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the description of the embodiments will be briefly described below, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise. These drawings and written description are not intended to limit the scope of the inventive concepts in any manner, but rather to illustrate the inventive concepts to those skilled in the art by reference to specific embodiments.

FIG. 1 is a schematic diagram of a battery pack according to an embodiment;

FIG. 2 is a schematic diagram of a control module in one embodiment;

FIG. 3 is a schematic diagram of the first voltage access module, the second voltage access module, the pre-charge circuit, and the charge/discharge circuit according to one embodiment;

FIG. 4 is a schematic diagram of a voltage divider circuit, a first voltage access module, and a second voltage access module according to an embodiment;

FIG. 5 is a schematic diagram of another structure of the voltage divider circuit, the first voltage access module, and the second voltage access module in one embodiment;

FIG. 6 is a schematic diagram of an embodiment of a voltage measurement circuit;

FIG. 7 is a schematic diagram of a circuit configuration for proper connection of a battery pack according to one embodiment;

FIG. 8 is a schematic diagram of an embodiment of a circuit for generating a parallel error in a battery pack;

FIG. 9 is a schematic diagram of an embodiment of a circuit for detecting a series error in a battery pack;

FIG. 10 is a schematic diagram of an embodiment of a circuit configuration for unreasonable battery pack connections;

FIG. 11 is a schematic flow chart diagram illustrating a battery pack management method for a battery system in one embodiment;

FIG. 12 is a flowchart illustrating the steps of determining a host in one embodiment;

FIG. 13 is a flowchart illustrating step S108 according to an embodiment;

FIG. 14 is a schematic diagram of a plurality of battery packs connected in parallel according to one embodiment;

FIG. 15 is a flow diagram illustrating the identification of a concatenation error in one embodiment;

FIG. 16 is a schematic diagram of a series-parallel hybrid configuration of multiple battery packs in one embodiment;

FIG. 17 is a block diagram of a battery pack according to one embodiment;

FIG. 18 is a diagram showing an internal configuration of a computer device according to an embodiment;

fig. 19 is a schematic structural view of a battery system in one embodiment.

The components in the drawings are numbered as follows: 100. a battery pack; 120. a battery pack; 140. a first voltage access module; 160. a second voltage access module; 170. a pre-charge circuit; 180. a control module; 190. a charge-discharge loop; 182. a BMS; 184. a voltage measurement circuit; 142. a first switch; 144. a first resistor; 162. a second switch; 164. a second resistor, 172, a third switch; 174. a third resistor; 192. a charging switch; 194. and (4) discharging a switch.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising a … …" does not exclude the presence of another identical element in a process, method, article, or apparatus that comprises the element. It will be further understood that, as used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context indicates otherwise. Also, as used herein, the terms "or," "and/or," "including at least one of the following," and the like, may be construed as being inclusive or meaning any one or any combination. An exception to this definition will occur only when a combination of elements, functions, steps or operations are inherently mutually exclusive in some way.

It should be understood that although the terms first, second, third, etc. may be used herein to describe various parameters or modules, these parameters or modules should not be limited by these terms. These terms are only used to distinguish one type of parameter or module from another. For example, a first parameter may also be referred to as a second parameter, and similarly, a second parameter may also be referred to as a first parameter, without departing from the scope herein. The words "if", as used herein, may be interpreted as "at … …" or "at … …" or "in response to a determination" or "in response to a detection", depending on the context. Similarly, the phrase "if determined" or "if detected (a stated condition or event)" may be interpreted as "upon determining" or "in response to determining" or "upon detecting (a stated condition or event)" or "in response to detecting (a stated condition or event)", depending on the context. Furthermore, the parts, features and elements that have the same name in different embodiments of the application may have the same meaning or may have different meanings, and the specific meaning thereof should be determined by the explanation thereof in the specific embodiment or further by combining the context in the specific embodiment.

It should be understood that, although the steps in the flowcharts in the embodiments of the present application are shown in sequence as indicated by the arrows, the steps are not necessarily performed in sequence as indicated by the arrows. The steps are not performed in the exact order shown and may be performed in other orders unless explicitly stated herein. Moreover, at least some of the steps in the figures may include multiple sub-steps or multiple stages that are not necessarily performed at the same time, but may be performed at different times, in different orders, and may be performed alternately or at least partially with respect to other steps or sub-steps of other steps.

It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

The battery system that this application provided is applicable to multiple application scenario, if grid-connected power generation energy storage field, off-grid light store up the field (be used for supplying power to the consumer in family, car as a house, yacht), wind stores up power generation field, electrical equipment field etc. specifically can confirm according to the practical application scenario, does not do the restriction here. The following description will take the off-network optical storage field as an example, and other application scenarios are basically similar and will not be described again.

Under the application scene of off-grid optical storage, the complete optical storage system at least comprises a photovoltaic power generation system, a power conversion system, a battery system and an electric power utilization system, wherein the photovoltaic power generation system is formed by connecting a plurality of solar panels in series and in parallel and is used for converting solar energy into electric energy, the electric power conversion system injects the electric energy generated by the photovoltaic power generation system into the battery system for storage, and the electric power utilization system adapts the electric energy stored in the battery system to the electric power required by electric equipment. The aforementioned power conversion system can be generally realized by using, for example, a DC/DC converter with MPPT function, and the power utilization system can be generally realized by using a DC/DC converter or a DC/AC converter. The emphasis is placed on a battery system, which is generally formed by connecting a plurality of battery packs with each other, wherein the battery packs are connected in series to increase the output voltage of the battery pack, and the battery packs are connected in parallel to obtain a larger battery capacity. Therefore, in order to obtain a battery system with a target voltage level and capacity, a user may connect a plurality of battery packs in series and parallel with each other, so as to obtain a high-voltage and large-capacity battery system for storing and supplying power. At present, after some users obtain the battery packs, the battery packs are generally randomly connected in series and/or in parallel, or the battery packs are mistakenly operated in the series-parallel connection process, so that the series-parallel connection or the parallel connection is wrong. Therefore, after the battery pack is powered on, due to the possibility of occurrence of a connection error in series or parallel, certain influence may be generated on the battery pack during power-on, so that the battery pack is damaged, normal use of a battery system is influenced, and a potential safety hazard of the battery pack may be generated in a severe case.

Therefore, to solve the above problems, the present application provides a battery pack management method for a battery system, a battery pack, and a battery system.

First, a hardware architecture of a battery pack according to the present application will be described, and it should be noted that, the entire contents of the chinese patent application with application number CN202211004551.6 entitled battery system and battery pack connection state management method are incorporated herein as a part of the contents of the present specification.

In one embodiment, as shown in fig. 1, a battery pack 100 includes: the battery pack 120, the first voltage access module 140, the second voltage access module 160, the pre-charging circuit 170, the control module 180, and the charge and discharge circuit 190. The battery pack 120 is connected to the first voltage access module 140, the second voltage access module 160, the pre-charge circuit 170, the control module 180, and the charge/discharge circuit 190. The first voltage receiving module 140 and the second voltage receiving module 160 are connected to a first signal line (not shown) and a second signal line (not shown) outside, respectively. One end of the battery pack 120 is connected to one terminal of the battery pack 100 through the parallel pre-charge circuit 170 and the charge-discharge circuit 190, and serves as a first output end (which may be a positive output end or a negative output end) of the battery pack 100, and the other end of the battery pack 120 is connected to the other terminal of the battery pack 100, and serves as a second output end (which may be a negative output end or a positive output end) of the battery pack 100.

Optionally, the battery pack 120 is formed by connecting several battery cells in series and parallel, and is used for storing energy and supplying power; the number of battery cells is greater than or equal to 1, and the specific number may be determined by an actual application scenario, which is not limited herein. Types of battery cells may include, but are not limited to, lithium cobalt oxide batteries, lithium manganese batteries, lithium nickel cobalt manganese oxides, lithium nickel cobalt aluminate batteries, lithium iron phosphate batteries, or lithium titanate batteries. The first voltage access module 140 and the second voltage access module 160 are respectively used for controllably connecting the anode and the cathode of the battery pack 120 to a first signal line (not shown) and a second signal line (not shown), which will be specifically explained in the following embodiments. And a control module 180 for detecting performance parameters of the battery pack 120.

In some possible embodiments, as shown in fig. 2, the control module 180 may include a sensing judgment module, which may include a BMS (Battery Management system) 182 and a voltage measurement circuit 184.BMS 182 is connected to battery pack 120 and voltage measuring circuit 184, respectively. The BMS182 is used to intelligently manage and maintain the respective battery cells, monitor the state of the battery, prevent the battery from being overcharged and overdischarged, and prolong the service life of the battery. Specifically, BMS182 may implement one or more of the following functions: cell parameter measurements or monitoring of individual battery cells in battery pack 120, including one or more of: cell voltage, cell remaining capacity (State of Charge, i.e., SOC), cell temperature, cell current, and cell Health (State of Health, i.e., SOH); the energy of the battery cells in the battery pack 120 is balanced, that is, the battery cells are charged and discharged in a balanced manner, so that the battery pack 120 is in a balanced and consistent state; a total voltage measurement of battery pack 120; the total current measurement and SOC calculation of the battery pack 120 accurately estimate the state of charge of the battery pack 120, namely the remaining battery capacity, ensure that the SOC is maintained in a reasonable range, and prevent damage to the battery due to overcharge or overdischarge; dynamically monitoring the operating state of the battery pack 120: during the charging and discharging process of the battery, the voltage and the temperature of the battery pack 120 are collected in real time; the charging and discharging current and the total voltage prevent the battery from being overcharged or overdischarged and display real-time data; data recording and analyzing, and simultaneously selecting the problematic battery to keep the reliability and high efficiency of battery operation; and (5) communication networking function.

The voltage measuring circuit 184 is respectively connected to the output end of the first voltage access module 140 and the output end of the second voltage access module 160, and is configured to measure a voltage between the output end of the first voltage access module 140 and the output end of the second voltage access module 160; when the output terminal of the first voltage access module 140 is connected to the first signal line (not shown), and the output terminal of the second voltage access module 160 is connected to the second signal line (not shown), the voltage value measured by the voltage measurement circuit 184 is equal to the voltage between the first signal line and the second signal line. In actual operation, the voltage measuring circuit 184 is used to collect the voltage between the first signal line and the second signal line, and the BMS182 performs corresponding judgment after obtaining the voltage, which will be described in detail in the following embodiments of the present application.

In some possible embodiments, as shown in fig. 3, the first voltage access module 140 includes at least a first switch, and the second voltage access module 160 includes at least a second switch.

Alternatively, the first voltage access module 140 may be directly a first switch, and the second voltage access module 160 may be directly a second switch, that is, two poles of the battery pack 120 may be directly connected to a first signal line (not shown) and a second signal line (not shown) through the first switch and the second switch, respectively.

Optionally, the first voltage access module 140 may further include a first switch 142 and a first resistor 144, and the battery pack 120 and the first resistor 144 are connected to the first switch 142, or the battery pack 120 may also be connected to the first resistor 144 after being connected to the first switch 142. The second voltage access module 160 may further include a second switch 162 and a second resistor 164, and the battery pack 120 and the second resistor 164 are connected to the second switch 162, or the battery pack 120 may also be connected to the second switch 162 and then connected to the second resistor 164. The number of the first switch 142 and the second switch 162 is not limited in the present embodiment as long as the purpose of controllably connecting both poles of the battery pack 120 to the first signal line (not shown) and the second signal line (not shown) can be achieved. The first switch 142 and the second switch 162 may be implemented by metal oxide semiconductor field effect transistors (MOSFETs or MOS transistors for short), or may be implemented by electronic components such as a triode and a relay, which are not limited herein, as long as the purpose of conducting and disconnecting according to a corresponding driving signal and enabling the battery pack to be controllably connected to a signal line is achieved.

In this embodiment, the first resistor 144 and the second resistor 164 can reduce the problem of excessive current when the battery pack is connected to the signal line, that is, the first resistor 144 and the second resistor 164 can be replaced by a first current limiting element and a second current limiting element, respectively, the number, connection mode, and element type of the current limiting elements are not limited, as long as the purpose of reducing current when the battery pack 120 is connected to the signal line can be achieved, and the implementation modes are within the protection scope of the present application.

In some possible embodiments, continuing with fig. 3, the pre-charge circuit 170 may include at least: a third switch 172 and a third resistor 174. The battery pack 120 and the third switch 172 are connected to a third resistor 174. The pre-charge circuit 170 is used to buffer large current surges during power-up.

The charge and discharge circuit 190 may include a charge switch 192 and a discharge switch 194. Battery pack 120 is connected to charge switch 192, and then to discharge switch 194. The charge and discharge circuit 190 is used to control the charge and discharge of the battery pack according to the control signal of the BMS.

It is to be understood that the specific implementation manners of the third switch 172, the charging switch 192 and the discharging switch 194 mentioned above are not limited, as long as the on and off operations according to the corresponding driving signals can be realized.

In some possible embodiments, the battery pack may further include a voltage dividing module connected to the battery pack 120, and the voltage dividing module is configured to divide the output voltage of the battery pack 120, so that when the battery pack 120 is connected to the signal line, the voltage dividing module may reduce the output current of the battery pack 120 and avoid damage or influence on the voltage measuring circuit 184.

Alternatively, the positive electrode of the battery pack 120 is connected to the first access module through the voltage dividing module, the negative electrode of the battery pack 120 is directly connected to the second access module, and the voltage dividing module may include resistors connected in parallel or in series. Fig. 4 and 5 show one possible embodiment of a battery pack including a voltage divider module, where P may be the aforementioned battery pack 120. As shown in FIG. 4 (the charge and discharge circuit and the pre-charge circuit are not shown in FIG. 4), the first voltage access module 140 includes a first voltage access moduleA switch S _{Is just} The second voltage access module 160 includes a second switch S _{Negative pole} The resistor R1 and the resistor R2 are connected in series to constitute a voltage dividing module in the present embodiment. In the present embodiment, the voltage measured by the voltage measurement circuit 184 is the voltage across the voltage dividing resistor R1, rather than the voltage across the battery P, so that the circuit overhead of the voltage measurement circuit can be reduced, and the risk of circuit damage caused by a large current when the voltage measurement circuit is directly connected to the battery P is avoided. As an alternative embodiment, on the basis of the embodiment of the battery pack shown in fig. 4, the voltage access module may further include a resistor, and as shown in fig. 5, the first voltage access module 140 includes a first switch S _{Is just} And a resistance R _{Is just} The second voltage access module 160 includes a second switch S _{Negative pole} And a resistance R _{Negative pole} . Resistance R _{Is just} And a resistance R _{Negative pole} The current level in the overall circuit can be further reduced.

In this embodiment, the battery pack 120 is connected to the signal line after passing through the voltage dividing module, and the voltage dividing is because if the voltage ratio of a single battery pack is high, or the system voltage is too high when a plurality of battery packs are used in series, the voltage measuring circuit 184 is subjected to too much pressure, and the voltage measuring circuit 184 is damaged.

In one embodiment, the detection judging module as described above includes BMS182 and voltage measuring circuit 184 including at least an operational amplifier for acquiring a voltage value between the first signal line and the second signal line; and the microprocessor MCU of the BMS is used for determining the connection mode among the plurality of battery packs and/or the relative position among the plurality of battery packs according to the voltage value.

Specifically, as shown in the schematic diagram of the voltage measuring circuit structure of the detection and judgment module in fig. 6, the microprocessor MCU (Microcontroller Unit) may be an MCU in the BMS of the battery pack. The first input terminal (inverting input terminal) of the operational amplifier is connected to the resistor R3, the resistor R3 is connected to the switch S1, and the switch S1 may be connected to any one of the first signal line and the second signal line and the output terminal of the first voltage access module 140. First of operational amplifierThe two input ends (non-inverting input ends) are connected with a balance resistor R5, the balance resistor R5 is respectively connected with a switch S2 and a pull-down resistor R6, and the switch S2 is connected to the other of the first signal line and the second signal line and the output end of the second voltage access module 160. In a preferred embodiment, the first input of the operational amplifier is controllably connected to the first signal line via a resistor R3 and a first switch S1, and the second input is controllably connected to the second switch S2 via a balancing resistor R5. Pull-down resistor R6 is connected to ground. The output end of the operational amplifier is connected with the microprocessor MCU through a resistor R7 and is used for representing the value V of the voltage difference value between the first signal wire and the second signal wire measured by the voltage measuring circuit _out And outputting to the MCU. MCU is obtaining value V _out Then, whether a series error occurs in the plurality of battery packs can be determined according to the voltage value, and a specific determination method will be specifically described in the subsequent embodiments and will not be described herein again. The detection and judgment module further comprises a feedback resistor R4, one end of the feedback resistor R4 is connected with the first input end of the operational amplifier, and the other end of the feedback resistor R4 is connected with the output end of the operational amplifier.

When a plurality of battery packs are connected with each other, the battery pack of each battery pack is connected with the signal line through the voltage access module, and the voltage value of the signal line is measured, so that the voltage value between the signal lines can be obtained.

Generally, there may be three cases that the battery pack is connected incorrectly or not correctly. The first case is a case of a parallel error, and a battery pack that should be originally connected in parallel with other battery packs becomes connected in series with the other battery packs due to the reverse connection of the positive electrode and the negative electrode. In some exemplary embodiments, as illustrated in fig. 7, two-in-three series battery systems are shown in which 6 battery packs are connected in parallel and then connected in series. On the basis, the situation of parallel connection error can be, for example, as shown in fig. 8, and fig. 8 shows the situation that 6 battery packs are connected in 2-to-3-series (every 2 battery packs are connected in parallel to form a resistance pack group, and then the battery pack groups are connected in series) to form a battery system, wherein the battery packs P ₂ A battery pack determined to be in parallel error due to the reverse polarity of the battery. In this situationUnder the condition of the battery pack P ₁ And a battery pack P ₂ If the voltage difference between the two is large, a large current circulation may be formed to damage the battery pack.

The second condition is a condition of a series error, and originally, the battery pack connected in series with other battery packs is disconnected in a whole battery system loop due to the fact that the positive electrode and the negative electrode are reversely connected. In some exemplary embodiments, the series error may be, for example, as shown in fig. 9, and fig. 9 also shows a case where 6 battery packs are connected in 2-to-3 series (each 2 battery packs are connected in parallel to form a battery pack group, and then the battery pack groups are connected in series) to form a battery system, wherein the battery pack P is used as the battery pack ₃ And a battery pack P ₄ The formed pack group should be connected in series with the other 2 pack groups, but is determined as a series error due to the reversed polarity. In this case, the battery pack P ₃ And a battery pack P ₄ The formed battery pack group forms an open circuit, and the whole battery system cannot supply power.

The third situation is that the battery packs are not connected properly, and the battery pack is formed by connecting a plurality of battery packs in parallel, and then the battery pack is connected in series to form a battery system. In some exemplary embodiments, the series error may be, for example, as shown in fig. 10, and fig. 10 also shows a case where 6 battery packs are connected in 2-to-3 series (each 2 battery packs are connected in parallel to form a battery pack group, and then the battery pack groups are connected in series) to form a battery system, and the battery packs P are connected in series ₅ Should be originally associated with the battery pack P ₆ Are connected in parallel to constitute a battery pack group, but are erroneously connected in parallel to a battery pack P ₃ And a battery pack P ₄ Forming a battery pack P ₆ Are individually formed into a battery pack. In this case, although the entire battery system can operate, the capacity of the entire battery system is determined by the battery pack group having the smallest capacity, i.e., the battery system capacity in this case is only half of that in the case of the normal connection. It should be noted that, as a third case, since when the connection between the battery packs is not reasonable, although the battery system can operate, the performance/capacity thereof is greatly affected ("tub")Effect "), and therefore, in the present embodiment, the case where the connection between the battery packs is not reasonable is also considered to be the case where the connection between the battery packs is erroneous.

The method of the embodiment is intended to automatically recognize whether the connection between the battery packs in the battery system is in error. Generally, it may be determined whether all the battery packs in the battery system have parallel connection errors. This is because if a fault occurs in the parallel connection of the battery packs (i.e., a loop is formed between the battery packs), a large loop current occurs, and the battery may be damaged, and if a series fault occurs, there is no danger of damaging the battery, and therefore it is preferable to determine that the parallel fault is first determined and then the series fault is determined. However, this embodiment is only a preferable embodiment, and the present embodiment is not limited to this, that is, it may be determined whether a series error occurs in all the battery packs in the battery system.

In one embodiment, the present application further provides a battery pack management method for a battery system, the battery system at least including: the management method may be applied to a first battery pack, wherein the first battery pack and a second battery pack may be the battery packs mentioned in some embodiments above, as shown in fig. 11, and the management method includes:

and S102, controlling to disconnect the charge and discharge loops of all the battery packs in the battery system.

And S104, controlling to conduct the pre-charging circuit of the first battery pack.

And S106, sequentially controlling to conduct the pre-charging circuit of the second battery pack.

And S108, acquiring a current value between the first battery pack and each second battery pack, and determining whether a parallel error occurs between the first battery pack and each second battery pack according to the current value.

In this embodiment, the first battery pack and the second battery pack are both provided with a charge-discharge circuit and a pre-charge circuit, where the charge-discharge circuit may be a circuit for controlling on/off of corresponding charge-discharge current, and may be, for example, two metal oxide semiconductor field effect transistors (metal oxide semiconductor) connected in seriesA vector field effect transistor, which may be referred to as a MOSFET or a MOS transistor for short), or may be implemented by using electronic components such as a triode, a relay, etc., where the purpose of controlling the on/off of current is not limited as long as the purpose of controlling the on/off of current is achieved. In a preferred embodiment, the charge and discharge circuit is composed of a charge MOS transistor and a discharge MOS transistor connected in series, and the charge MOS transistor and the discharge MOS transistor are controlled by the BMS of the battery pack, respectively. The pre-charging circuit can be generally connected in parallel with the charging and discharging MOS tubes in the charging and discharging loop, and can be used for buffering large current generated when the battery pack is electrified. Generally, the pre-charging circuit may be formed by a MOS switch tube and a pre-charging resistor connected in series. As a specific embodiment, taking FIG. 14 as an example, M _{1, charging} 、M _{1, placing} And a control switch tube in a charge-discharge loop of the battery pack is formed. K is _{1, preparation of} 、R _{1, preparation} And the pre-charging circuit is connected with the power supply bus after being connected with the charge-discharge loop switch in parallel.

In this embodiment, the first battery pack and the second battery pack may be communicatively connected, for example, each battery pack has an RS485 or CAN communication chip built therein, and the battery packs are connected to each other through an RS485 or CAN communication bus to form a communication connection. The battery packs may be wirelessly connected in a communication manner, and in this embodiment, a specific communication manner between each battery pack is not limited. Through the communication connection, a plurality of functions such as host competition, address allocation, control signal transmission, operation data transmission and the like can be performed among each battery pack.

In this embodiment, for example, the parallel connection error is determined first, and then the series connection error is determined, it can be understood that a person skilled in the art may also determine the series connection error first, and then determine the parallel connection error according to the manner mentioned in this embodiment, and in this embodiment, the order of determining the parallel connection error and the series connection error is not limited. Generally, in some embodiments, the first battery pack may be a control master in a battery system, each second battery pack serves as a slave in the battery system, and the slave battery pack receives a control command of the first battery pack through a communication connection established with the control master and performs a corresponding control action according to the control command.

Before executing the embodiment, a user may design a battery pack connection scheme according to requirements of an application scenario and a rated voltage of each battery pack, then keep a charge-discharge loop of each battery pack in a disconnected state, and perform connection between the battery packs according to the battery pack connection scheme. It should be noted that the connection between the battery packs described herein includes the connection between the voltage access module of each battery pack and the signal line, and also includes the communication connection and the power line connection (forming the series connection or the parallel connection between the battery packs). As a possible implementation, if each battery pack has a master loop control switch, as shown in FIG. 14, switch K _{1, is turning to} Arranged between the fuse and P ₁ And the battery packs of the battery pack are used as a main loop control switch for controlling the connection with a power bus. Before the battery pack is connected, the switch K is controlled _{1, positive} Remains in the off state. If each battery pack does not have a main loop control switch, the charging and discharging MOS tube in the charging and discharging loop is controlled (such as M in fig. 11) _{1, charging} And M _{1, placing} ) Remains in the off state. Therefore, when the user is connected with the battery packs, the user can not be hurt because of the possibility of discharging between the battery packs.

After the battery pack is connected, the master loop control switch may be turned on to wake up the battery pack, and the power-on self-test step and the management method step in this embodiment are performed to determine whether there is a connection error in the battery system. A specific embodiment of the battery pack management method in the present embodiment will be described below.

In this step, the first battery pack controls to disconnect its own charge and discharge loop, for example, the BMS of the first battery pack controls to turn off the charge and discharge MOS transistor of the first battery pack. Meanwhile, the first battery pack sends control information to each second battery pack through communication connection established between the first battery pack and each second battery pack, so that each second battery pack controls to disconnect the charging and discharging loop of the first battery pack according to the control information. In this step, the charging and discharging loops of all the battery packs are disconnected, so that the battery packs can be prevented from being directly connected with each other before the connection state of the battery packs is judged, because the battery packs can be damaged unrecoverably if the connection between the battery packs is in the above-described parallel connection error. It should be noted that, in general, a new battery pack may keep the charge and discharge loop in a disconnected state when the battery pack leaves a factory, and the battery pack is usually kept in a disconnected state in both the connection stage and the power-on self-test stage, so as to be an optional implementation manner, if all the battery packs in the battery system are new battery packs that have just left the factory, step S102 may be omitted, and implementation of subsequent steps in this embodiment is not affected.

In this step, the first battery pack controls its own precharge circuit to be accessed into the circuit, for example, the BMS of the first battery pack controls to close a switch in its own precharge circuit, so that the first battery pack is connected to an external power supply line through its own precharge circuit. In this step, taking the battery pack 100 of fig. 3 as an example, the BMS182 may control the switch 172 to be closed such that one end of the battery pack 120 of the battery pack 100 is connected to an external power supply line through the pre-charge circuit. The other end of the battery pack 120 is always connected to an external power supply line.

In this step, it has been mentioned above that the first battery pack and each second battery pack have already established communication connection, so that the first battery pack may send first control information to each second battery pack, so that each second battery pack in turn controls to turn on a switch in its own precharge circuit according to the first control information, so as to complete connection of each second battery pack in turn with an external power line. In addition, in this step, the pre-charging circuit of the first battery pack and the pre-charging circuit of each second battery pack are sequentially turned on, so that a loop between the first battery pack and each second battery pack can be established through the external power line, and at this time, the relationship between the first battery pack and the second battery pack can be determined according to information in the loop. In addition, each second battery pack is independently conducted, so that when one battery pack has a connection error, the other second battery packs are not influenced, and the stability and the reliability of the battery system can be ensured.

It should be noted that when the number of the second battery packs is greater than or equal to 2, the precharge circuits of each second battery pack need to be controlled to be turned on in sequence, so as to ensure that only one precharge circuit of one second battery pack is in a turned-on state at the same time.

In this step, after the precharge circuits of the first battery pack and the second battery pack are turned on for each second battery pack, the first battery pack and the second battery pack form a circuit. Therefore, the current between the first battery pack and each of the second battery packs may be obtained by the BMS in the first battery pack, and then it may be determined whether a parallel connection error between the first battery pack and each of the second battery packs occurs according to the magnitude of the current value.

In this step, in the actual use process, even though the structures and specifications of the first battery pack and each second battery pack are completely the same, a loss or SOC of each battery pack may be different, and a certain voltage difference may still exist between the two battery packs, so that when the two battery packs are correctly connected in parallel to form a loop, a slight current exists between the two battery packs, which is generally called a loop current, and the current value of the loop current is generally relatively small. It can be determined that a parallel error does not occur between the two battery packs (the first battery pack and the second battery pack) in the case where the current value is relatively small. In contrast, if a parallel error occurs in two battery packs, that is, the second battery pack is erroneously connected to the first battery pack in a series state by the user (see the battery pack P in fig. 8) ₁ And a battery pack P ₂ ) Then the first battery pack and the second battery pack are in the momentThe pre-charging circuit of one battery pack, the second battery pack and the pre-charging circuit of the second battery pack form a series circuit, the voltage value in the circuit is equal to the sum of the voltages of the first battery pack and the second battery pack, and the current value in the circuit can be very large in the case. Therefore, whether a parallel connection error occurs between the two battery packs can be determined by detecting the current value. Meanwhile, in the process of judging whether parallel connection errors occur among the battery packs, the charging and discharging circuit is disconnected, and the pre-charging circuit is connected into the circuit.

It should be noted that, when the number of the second battery packs is greater than or equal to 2, because only one pre-charge circuit of one second battery pack is in a conducting state at the same time in step S106, in this step, it is necessary to sequentially obtain a current value between the first battery pack and the second battery pack and determine whether a parallel error occurs according to the current value, that is, it is only determined whether a parallel error occurs between one second battery pack and the first battery pack at a time, after the determination, it is necessary to control to disconnect the pre-charge circuit of the second battery pack and control to conduct the pre-charge circuit of the next second battery pack, continue to obtain the current value between the first battery pack and the second battery pack and determine whether a parallel error occurs according to the current value, repeat the above steps until all the second battery packs are traversed, and after the determination of whether a parallel error occurs between each second battery pack and the first battery pack is completed, the present step is ended.

In this embodiment, the charging and discharging loops of all the battery packs are disconnected, the precharge circuit of the first battery pack is controlled to be turned on, the precharge circuits of the second battery packs are sequentially controlled to be turned on, and whether a parallel connection error occurs between the first battery pack and each second battery pack is determined according to a current value between the first battery pack and each second battery pack. All the operations are completed by the control host (the first battery pack), so that after a user connects a plurality of battery packs, other operations are not needed, the current value between the first battery pack and each second battery pack can be automatically acquired through the scheme, whether parallel connection errors occur on the second battery pack in the battery system formed by the plurality of battery packs relative to the first battery pack or not is determined according to the current value between the battery packs, the battery packs and the battery system can be better accurately managed, and the service life of the battery packs in the management process and the safety of the user can be guaranteed by using the pre-charging circuit.

Optionally, in the process of determining whether a parallel error occurs between the first battery pack and the second battery pack, if a small loop current is detected, the management method may further include: the first battery pack queries the voltage of the corresponding second battery pack, and if the voltage of the first battery pack is substantially identical or identical to the voltage of the second battery pack, but there is still current between the two battery packs, it is determined that there is a parallel connection error between the first battery pack and the corresponding second battery pack. If the voltage values of the two battery packs have certain differences, whether the current value is the loop current caused by the voltage inconsistency of the two parallel battery packs is determined by calculating the current value, and the specific calculation mode is specifically explained in the following embodiment. It should be noted that the preset current range may be generally determined according to the voltage values of the first battery pack and the second battery pack, and the resistance values in the pre-charging circuits of the first battery pack and the second battery pack, however, the present embodiment does not limit the manner of determining the preset current range, as long as the preset current range can determine that the current value is relatively small.

In addition, the current value between the first battery pack and each of the second battery packs may be acquired in the present embodiment as follows: the control host (first battery pack) determines the magnitude of the current value through the BMS of the control host, and the control host can actively acquire the current value of each second battery pack as the second battery packs (slave battery packs) are sequentially connected into an external power line; or, the slave battery pack actively reports the current value obtained by the slave battery pack to the control host, and similarly, the slave battery pack (second battery pack) may determine the current value through its BMS.

It is understood that the first battery pack and the second battery pack mentioned above are relative terms, and in practical operation, any one battery pack in the battery system may be selected as the first battery pack according to some situations, and the rest of the battery packs may be selected as the second battery pack.

In one possible embodiment, before controlling to disconnect the charge and discharge loops of all the battery packs in the battery system, the method further includes:

and determining a control host according to a preset rule, and distributing the slave address of each battery pack.

In the embodiment, after the connection of the battery system is completed and the communication connection is established, each battery pack is started up, power-on self-test is performed, and whether the battery pack has a problem or not is checked. After the battery pack completes power-on self-test, a plurality of battery packs need to compete for the host and allocate addresses. A specific method of competing for the host is shown in fig. 12, and determines whether a control box exists, where the control box may be a control box with a display screen or a control box without a display screen. In the present embodiment, the control box is provided in the battery system as an independent module, and can control the first battery pack and the second battery pack. If the control box exists, the control box is used as a control host. Alternatively, in the present embodiment, the step of determining whether or not the control box exists may be omitted, and when the control box exists in the battery system, the control box may directly perform communication through a communication connection with each battery pack and notify each battery pack that the control box serves as the control master. Further, if there is no control box, the control host may be determined according to a preset rule, where the specific preset rule includes any one of the following modes: and determining the control host according to the data transmission sequence of the battery packs, or determining the control host according to the theoretical SOC or the maximum value of the current SOC of each battery, or selecting the maximum or minimum ID as the control host according to the factory ID number of each battery pack. The factory ID numbers of the battery packs are unique and are sequentially increased according to the factory dates. In a preferred embodiment, the battery pack with the largest theoretical SOC or the battery pack with the largest factory ID number is selected as the control master, that is, the latest battery pack is selected as the control master, so that the stability and sustainability of the operation of the entire battery system can be ensured.

In some embodiments of the present application, it is typically the case that the first battery pack is the host. It will be appreciated that the method as referred to in the embodiments of the present application may also be implemented if the control box acts as a host.

When a plurality of battery packs are connected with each other, if it is desired to implement RS485 or CAN bus communication between the plurality of battery packs, an address is required for each battery pack. Therefore, after the control master is determined, slave addresses can be sequentially allocated to other battery packs through the factory ID number of each battery pack.

In addition, when a plurality of battery packs are connected with each other, the battery packs can be connected when the SOC and/or the voltage of each battery pack are basically consistent, so that the situation that large circulation current is generated due to overlarge voltage difference between the battery packs to cause unexpected danger can be avoided, and the performance of a connected battery system can be optimal.

In addition, when a plurality of battery packs are connected in series and/or in parallel, the operation must be performed under any one of the following conditions:

(1) All battery packs enter a shutdown (or sleep) state;

(2) Under the normal working state of starting up, the communication line needs to be connected first, and after the communication is established between the battery packs, the series-parallel connection operation is carried out.

If any of the above conditions is not met, that is, if a communication line is not connected first (based on communication establishment) and a connection error occurs in a power-on state, the battery pack performs overcurrent or short-circuit protection by itself. Therefore, by the mode, when the misoperation occurs, the potential safety hazard can be eliminated and the loss can be reduced as much as possible.

In one embodiment, as shown in fig. 13, the determining whether a parallel connection error occurs between the first battery pack and the second battery pack according to the current value includes:

s202, judging that the current value is in a preset first threshold range or a preset second threshold range.

In this step, the preset first threshold range is determined by dividing a voltage value obtained by subtracting the second voltage value from the first voltage value by a resistance value of the first pre-charge resistor and a resistance value of the second pre-charge resistor;

the preset second threshold range is determined by dividing a voltage value obtained by adding the second voltage value to the first voltage value by the resistance value of the first pre-charging resistor and the resistance value of the second pre-charging resistor;

the first voltage value characterizes a voltage value of the first battery pack, the second voltage value characterizes a voltage value of the second battery pack, the first pre-charge resistance characterizes a resistance in the pre-charge circuit of the first battery pack, and the second pre-charge resistance characterizes a resistance in a pre-charge circuit of the second battery pack.

In this embodiment, although the voltage values of each battery pack in the battery system are substantially the same or similar, there is still a non-negligible voltage difference, and therefore the first threshold range is usually a threshold interval. When determining the first threshold range, the first standard current value within the first threshold range may be determined, and then the first threshold range may be determined according to the first standard current value. Similarly, the second threshold range is also typically a threshold interval, and the second standard current value of the second threshold range may be determined first.

In an alternative embodiment, the first standard current value is calculated by:

y ₁ ＝|U _p1 -U _p2 |/(R _{1 preparation of} +R _{2 preparation} )

The second standard current value is calculated by:

y ₂ ＝|U _p1 +U _p2 |/(r _{1 preparation} +R _{2 preparation} )

Wherein, y ₁ Is a standard current value, U _p1 Is a first voltage value (voltage value of the first battery pack), U _p2 And is the second voltage value (the voltage value of the second battery pack). R _{1 preparation of} Is the resistance value, R, in the pre-charge circuit of the first battery pack _{2 preparation} For the second battery packThe resistance value in the precharge circuit. After the first standard current value and the second standard current value are calculated, the first threshold range and the second threshold range may be finally determined by selecting the first standard current value and the second standard current value within a certain range before and after the first standard current value and the second standard current value. It will be appreciated that a range may be selectively set by one skilled in the art depending on the circumstances in different battery systems, typically the first threshold range being much smaller than the second threshold range. For example, if the voltage of the first battery pack is 12.8V, the voltage of the second battery pack is 13.2V, and the resistance values of the pre-charging circuits of the first battery pack and the second battery pack are both 100 Ω, when the first battery pack and the second battery pack are correctly connected in parallel, the measured current value is |12.8-13.2 |/(100 + 100) =0.002A; if the first battery pack and the second battery pack are incorrectly connected in parallel (i.e., connected in series), the measured current value is |12.8+13.2 |/(100 + 100) =0.13A. It can be seen that the two current values are significantly different in magnitude, and therefore, the first threshold range and the second threshold range can be set to a wide range, for example, the first threshold range is set to 0 to 0.01A, and the second threshold range is set to 0.05 to 1A, so that the accuracy and the applicable range of the determination are improved.

S204, in response to the current value being within a preset first threshold range, it is determined that no parallel connection error occurs between the first battery pack and the second battery pack.

In this step, after the first and second threshold ranges are determined and the current value between the first and second battery packs has been measured by the BMS of the first battery pack, it may be determined whether the above-obtained current value is within the first threshold range. If the current value is within the first threshold range, it may be determined that the current value between the first battery pack and the second battery pack is small, and there is no error in the parallel connection between the first battery pack and the second battery pack, and the small current value is a loop current formed due to a voltage difference between the two battery packs.

S206, in response to the current value being within a preset second threshold range, it is determined that a parallel connection error occurs between the first battery pack and the second battery pack.

In this step, if the current value measured between the first battery pack and the second battery pack is not within the preset first threshold range, it is determined whether the current value is within the second threshold range. If the current value is within the second threshold range, the current value can be determined to be relatively large, and a parallel error between the first battery pack and the second battery pack can be determined. In the present embodiment, the pre-charge resistance in the pre-charge circuit is usually about several tens Ω to several hundreds Ω, so the measured current value after the parallel connection error is significantly larger than the measured current value in the normal parallel connection state, that is, the measured current value is in the second threshold range.

In other possible embodiments, if the measured current value is neither within the first threshold range nor within the second threshold range, it may be that the set threshold range is relatively small and losses in the circuit or other factors affect the current value. At this time, the measured current value may be compared with a first standard current value in a first threshold range to obtain a first difference value. The measured current value may be compared to a second standard current value in a second threshold range to obtain a second difference value. The first difference and the second difference are compared. If the first difference is larger than the second difference, the measured current value can be proved to be close to the second standard current value, and the fact that the parallel connection error occurs between the first battery pack and the second battery pack at the moment can be determined. If the first difference is smaller than the second difference, the measured current value is proved to be close to the first standard current value, and it can be determined that no parallel connection error occurs between the first battery pack and the second battery pack at the moment. If the first difference is equal to the second difference, this will not normally occur, and if this occurs it is necessary to check whether the battery system is malfunctioning.

In some exemplary embodiments, as shown in fig. 14, a battery pack in a parallel circuit is exemplified. In the figure P ₁ 、P ₂ ...P _n The battery pack is a battery pack, and two dotted lines connected with the isolation communication module are communication lines, such as a CAN bus; the battery packs can communicate with each other through the isolation communication module. With voltage access module (switch and resistor structure for each battery pack)Yes) are signal lines; and two thick solid lines connected with the fuse are power supply buses. With P ₁ The battery pack is exemplified, wherein the BMS is a battery management system for the slave current sensor (and the charge-discharge loop switch M of the battery pack) _{1, charging} 、M _{1, placing} In series) and a voltage detection unit (not shown) to obtain various parameters of the battery pack and perform corresponding control; m _{1, charging} 、M _{1, placing} A charge and discharge circuit for the battery pack, which controls the charge and discharge of the battery pack according to the control signal of the BMS; k _{1, preparation of} 、R _{1, preparation of} The pre-charging circuit is used for buffering large current impact during power-on, and is connected with the power supply bus after being connected with the charge-discharge loop in parallel; k _{1, is turning to} Arranged between fuse and P ₁ Between the battery packs of the battery pack, as a main loop control switch for connecting with the power bus, in some embodiments, the main loop control switch K _{1, is turning to} May be omitted; s _{1, is turning to} And R _{1, is turning to} The first voltage access module is used for enabling the positive electrode of the battery pack to be in controllable connection with the first signal line; s _{1, negative} And R _{1, negative} The second voltage access module is used for enabling the negative electrode of the battery pack to be in controllable connection with the second signal line; an isolated communication unit connected to a communication bus (two dotted lines in the drawing) so as to establish communication connection with other battery packs through the communication bus; the voltage measuring circuit and the BMS form a detection and judgment module of the battery pack, and the voltage measuring circuit is used for measuring a voltage value between the first signal line and the second signal line. Other Battery pack Structure and Battery pack P ₁ The structures of the battery packs are completely the same, and the difference is only that the connection modes of the battery packs are different (in series or in parallel), and the description is omitted. Suppose P ₁ Is the master, then P ₁ Disconnecting its own charge-discharge circuit (M) _{1, charging} And M _{1, placing} ) Then closing K _{1, is turning to} And K _{1, preparation of} Then control P ₂ ...P _n Close its corresponding K in turn _{n is positive} Switch and K _{n, pre} And the switch detects the current value through the current sensor in turn to judge whether the parallel connection is wrong. If there is no error in parallel (to)P ₂ Slave for example), the magnitude of the measured current value should be | U _P1 -U _P2 |/(R _{1, preparation of} +R _{2, pre} ) (ii) a If parallel connection is faulty (e.g. slave P) ₂ Is connected into a host P ₁ Series connection), the magnitude of the measured current value should be | U | _P1 +U _P2 |/(R _{1, preparation of} +R _{2, pre} ). From the measured current it can be determined whether a parallel fault has occurred.

In one embodiment, as shown in fig. 15, the first battery pack and each of the second battery packs are respectively and controllably connected to the first signal line through their own first voltage access module and to the second signal line through their own second voltage access module, and the management method further includes:

s302, in response to the fact that the first battery pack and the second battery pack are not in parallel connection, controlling to conduct the charging and discharging loops of all battery packs in the battery system.

In this step, after it is confirmed that no parallel connection error occurs between the first battery pack and each of the second battery packs, it may be further determined whether a series connection error occurs between the first battery pack and each of the second battery packs. In the step, because the parallel connection error does not occur, the hidden danger of large-current discharge caused by the parallel connection error is eliminated. Therefore, at this time, the first battery pack can control to conduct the charging and discharging loop of the first battery pack. For example, the BMS of the first battery pack turns on the charge and discharge MOS transistor of the first battery pack. Meanwhile, the first battery pack sends control information to each second battery pack through communication connection established between the first battery pack and each second battery pack, so that each second battery pack controls and conducts a charging and discharging loop of the first battery pack according to the control information. In this step, since no parallel error occurs, the charge and discharge loops of all the battery packs can be conducted to form connection between the battery packs.

Optionally, before or after step S302, further comprising: and controlling to disconnect the pre-charging circuit of the first battery pack and each second battery pack. After determining that no parallel connection error occurs between the first battery pack and each second battery pack, the pre-charging circuit is not required to be connected into the circuit any more, and therefore the pre-charging circuit of all the battery packs in the battery system is controlled to be disconnected. The step is an optional implementation step, because the charge-discharge loop control switch and the pre-charging circuit in the battery pack are connected in parallel, when the charge-discharge loop control switch is controlled to be switched on, the corresponding pre-charging circuit is automatically disconnected with the loop due to short circuit.

And S304, controlling a second voltage access module of the first battery pack to be connected with the second signal line.

In this step, the currents flowing through each of the battery packs in the series circuit are identical to each other, and it cannot be determined whether or not a series error occurs by the current values, and therefore it can be determined whether or not a series error occurs between the first battery pack and the second battery pack by the voltage values, that is, whether or not a series error occurs between the first battery pack and the second battery pack is determined by the relative voltage values between the first battery pack and the second battery pack. For a two-in-three string battery system formed of 6 battery packs, referring to fig. 7, assume that a battery pack P ₁ For controlling the host, the battery pack P ₃ And a battery pack P ₄ Relative to the battery pack P ₁ Have the same voltage value, and the battery pack P ₅ And a battery pack P ₆ Relative to the battery pack P ₁ Is also the same, and the battery pack P ₅ And a battery pack P ₆ Relative to the battery pack P ₁ Voltage value of, battery pack P ₃ And a battery pack P ₄ Relative to the battery pack P ₁ Voltage value of, and battery pack P ₂ Relative to the battery pack P ₁ The voltage values of the slave battery packs are different, so that whether errors occur in series connection between the battery packs can be determined by judging the voltage values of the slave battery packs relative to the control master battery pack. In this embodiment, through being connected different battery package and different signal lines respectively to make things convenient for the battery package to judge the relation of connection between the different battery packages through the voltage value between the measurement signal line. Optionally, the first battery pack may control to turn on the second voltage access module, that is, to close a switch in the second voltage access module, so that the first battery pack is connected to the second signal line. It should be noted that, in this embodiment, the second voltage access module of the first battery pack may be electrically connected with the first battery packThe positive electrode of the battery pack may be connected to the negative electrode of the battery pack of the first battery pack, and this embodiment is not limited thereto.

And S306, sequentially controlling the first voltage access module of the second battery pack to be connected with the first signal line.

In this step, the first battery pack needs to acquire the voltage between each of the second battery packs that need to determine whether a series error occurs, and thus the second battery pack needs to be connected to another signal line. Specifically, the first battery pack sequentially sends second control information to each second battery pack, so that each second battery pack controls to turn on the first voltage access module according to the second control information, that is, a switch in the first voltage access module is closed, so that the second battery pack is connected to the first signal line. In this embodiment, the first voltage access module of the second battery pack may be connected to the negative electrode of the battery pack of the second battery pack, or may be connected to the positive electrode of the battery pack of the first battery pack, and this embodiment is not limited, so long as the polarity of the first voltage access module is different from the polarity of the first voltage access module of the first battery pack into the first signal line in step S304, so as to achieve the purpose of this embodiment.

It should be noted that, when the number of the second battery packs is greater than or equal to 2, the first voltage access modules of the second battery packs need to be sequentially controlled to be connected to the first signal line, that is, it is ensured that only the first voltage access module of one second battery pack is connected to the first signal line in a conducting manner at the same time.

S308, sequentially obtaining voltage values between the first signal line and the second signal line, and determining whether a series error occurs between the first battery pack and the second battery pack according to the voltage values.

In this step, the voltage values between the first signal line and the second signal line may be sequentially acquired by the voltage detection circuit in the first battery pack. It should be noted that, when the number of the second battery packs is greater than or equal to 2, because only the first voltage access module of one second battery pack is in conductive connection with the first signal line in the same time in step S306, in this step, the voltage value between the first signal line and the second signal line needs to be sequentially acquired, after the acquisition, the disconnection between the first voltage access module of the second battery pack and the first signal line needs to be controlled, the first voltage access module of the next second battery pack is controlled to be connected to the first signal line, the voltage value between the first signal line and the second signal line continues to be acquired, the above steps are repeated until all the second battery packs are traversed, the voltage value between the power lines when each second battery pack is connected to the first signal line is completed, whether a series error occurs between the first battery pack and each second battery pack is determined according to the plurality of voltage values, and this step may be ended.

In this embodiment, after it is determined that no parallel connection error occurs between the first battery pack and each second battery pack, the charging and discharging loops of all the battery packs in the battery system are controlled to be turned on; controlling a second voltage access module of the first battery pack to be connected with the second signal line; sequentially controlling a first voltage access module of the second battery pack to be connected with the first signal line; and sequentially acquiring voltage values between the first signal line and the second signal line, and determining whether a series error occurs between the first battery pack and the second battery pack according to the voltage values. All the above operations are completed by the control host (the first battery pack), so after the user connects the plurality of battery packs, no other operation is needed, and whether a series error occurs in each second battery pack in the battery system formed by the plurality of battery packs relative to the first battery pack can be automatically determined through the embodiment, so that the battery packs and the battery system can be better and precisely managed.

In one embodiment, the determining whether a series error occurs between the first battery pack and the second battery pack according to the voltage value includes:

and grouping the voltage values, and acquiring the number of corresponding battery packs in each group.

In this step, in the case where there are a plurality of battery packs connected in series-parallel hybrid, then each of the first battery packs composed of a plurality of parallel battery packs should theoretically be the same with respect to the first voltage value of the control host battery pack (first battery pack), each of the second battery packs composed of another plurality of parallel battery packs should also theoretically be the same with respect to the second voltage value of the control host battery pack (first battery pack), and the first voltage value and the second voltage value should be different, and the difference between the first voltage value and the second voltage value should be equal to or close to an integral multiple of the voltage value of a single battery pack; and the like, the similar characteristics are also applied to other battery packs. Therefore, if each battery pack in the battery system is correctly connected, the number of parallel battery packs in each battery pack should be consistent (the number of battery packs in the battery pack where the control host (first battery pack) is located should be added by one (first battery pack itself)), and the number of parallel battery packs can be determined according to the number of the same or close voltage values.

Based on the characteristic, after all the second battery packs are traversed and voltage values between the first signal lines and the second signal lines corresponding to the plurality of second battery packs are obtained, the second battery packs corresponding to the same or close voltage values can be divided into one group (battery pack group) according to the voltage values, and the number of the battery packs in each group is counted. Since the battery pack group is composed of a plurality of battery packs connected in parallel, the number of battery packs in the battery pack group can be determined according to the same or close voltage value number.

Further, whether a series error occurs between the first battery pack and the second battery pack is determined according to the number.

In this step, if the number of the battery packs in the group corresponding to each voltage value is the same and the voltage values corresponding to each battery pack group are different, it may be determined that no series connection error occurs between the battery pack groups. If the number of battery packs in the battery pack group is different, it may be determined that a series error occurs between the battery pack groups or between the battery pack group and the battery pack, and the type of the series error may be a wrong connection type as shown in fig. 9 or fig. 10. In addition, in the case where all the battery packs in the battery system are directly connected in series (that is, there is no battery pack formed by parallel battery packs), the number of the same or close voltage values can be directly counted without grouping. If the same voltage value exists (the number of the same voltage values is greater than or equal to 2), it can be determined that the battery packs corresponding to the same voltage value have a series connection error.

In this embodiment, the battery packs are grouped according to the voltage values, whether a series error occurs can be judged according to the number of the battery packs, whether a series error occurs between the battery packs and/or the battery pack group can be accurately determined, and the accuracy of judging the series error is improved.

In one embodiment, the grouping the voltage values and obtaining the number of corresponding battery packs in each group includes:

in the embodiment described above, it is necessary to sequentially obtain the voltage values between the first signal line and the second signal line, perform grouping according to the voltage values, and determine whether a series error occurs between the battery packs according to the number of the battery packs in each grouping. However, there may be a slight deviation in the voltage value of each battery pack for a variety of different reasons, and thus there may be a deviation in grouping, and the present embodiment proposes a further solution to this problem.

In this step, after the voltage value between the first signal line and the second signal line is obtained, the voltage value may be divided by the voltage value of the first battery pack, and usually, considering that circuit loss may occur and a voltage difference may occur, so that the voltage may not be exactly equal to an integral multiple of a voltage of one battery pack, the calculated value may be rounded to obtain an integer value. Taking a 12V lithium battery pack as an example, the voltage range is usually 10 to 14.4V, that is, the maximum voltage difference is 4.4V according to the difference of the remaining power, so even if the maximum voltage difference of 4.4V exists in the battery pack in the battery system, the voltage value is divided by the voltage value of the first battery pack (assuming that the minimum value is 10V as an example) and rounded to obtain an integer value, and 4.4/10=0.44 ≈ 0, the battery error can still be eliminated. In the actual use process, because a battery system usually adopts a passive or active equalization control strategy, the actual differential pressure between the battery packs can not generate the differential pressure of 4.4V (generally, the differential pressure is less than 1V, even less than 0.1V), and therefore, the accuracy of the grouping process according to the voltage value can be ensured by the step.

Dividing the same integer value into the same group; and counting the number of the integer values in each group, and determining the number of the corresponding battery packs in each group according to the number of the integer values.

In this step, after obtaining the integer value corresponding to each voltage value, the same integer values may be grouped together, so that the number of battery packs in each group is determined according to the number of integer values. When the battery system is in a correct series-parallel state, the number of battery packs in each group indicates the number of battery packs in a parallel state, and therefore the number of battery packs in each group should be the same. On the contrary, if the number of the battery packs is different, the situation that the slave battery pack and the control master battery pack are connected in series incorrectly in the battery system is described. In a possible case, if the anodes of the first battery pack and the second battery pack are respectively and controllably connected with a first signal line through a first voltage access module, and the cathodes of the first battery pack and the second battery pack are respectively and controllably connected with a second signal line through a second voltage access module, when the second voltage access module of the first battery pack is accessed into the second signal line and the first voltage access module of the second battery pack is accessed into the first signal line, the measured voltage value between the first signal line and the second signal line corresponds to the voltage value between the cathode of the first battery pack and the anode of the second battery pack; since the number of battery pack groups in which the battery packs of the control host are located needs to be added to the control host, the number obtained in the group of which the corresponding integer value is 1 needs to be added by one (that is, the battery pack of the control host is added), so as to obtain the number of the battery packs in the group of which the integer value is 1. In another possible situation, if the cathodes of the first battery pack and the second battery pack are respectively and controllably connected to the first signal line through their first voltage access modules, and the anodes of the first battery pack and the second battery pack are respectively and controllably connected to the second signal line through their second voltage access modules, when the second voltage access module of the first battery pack is connected to the second signal line and the first voltage access module of the second battery pack is connected to the first signal line, the measured voltage value between the first signal line and the second signal line corresponds to the voltage value between the anode of the first battery pack and the cathode of the second battery pack, so that it is necessary to add one to the number of integer values in a group whose integer value is-1 (i.e. add the control host battery pack itself), and further obtain the number of battery packs in a group whose integer value is-1.

In this embodiment, the number of the corresponding battery packs in each group can be determined according to the condition that the positive and negative electrodes of different battery packs are connected to the signal lines and the corresponding integer values, whether a series error occurs between the first battery pack and the second battery pack can be accurately determined according to different connection conditions, the integer values obtained by dividing the measured voltage value by the voltage value of the first battery pack and rounding off the voltage value are adopted for grouping, the risk of misjudgment caused by the voltage difference between different battery packs can be eliminated, and the accuracy of the execution of the management method is ensured.

In one embodiment, the determining whether a series error occurs between the first battery pack and the second battery pack according to the number includes:

and if the number of the corresponding battery packs in each group is the same, determining that no series connection error occurs between the first battery pack and the second battery pack.

In this step, after the battery packs with the same voltage value are grouped, the number of the corresponding battery packs in each group can be counted. If the number of the battery packs in each group is the same, it can be determined that no series error occurs between the first battery pack and the second battery pack in the battery system. For example, after grouping, a total of 3 groups are found, and the number of the corresponding battery packs in each group is 2, which indicates that a total of 6 battery packs are found, and each battery pack is connected in series and parallel in a 2-to-3 series manner to form a battery system. For another example, after grouping, a total of 4 groups are found, and the number of the corresponding battery packs in each group is 1, which indicates that a total of 4 battery packs are formed, and each battery pack is directly connected in series to form the battery system. For example, only 1 group is found after grouping, and the number of the corresponding battery packs in the group is 3, which indicates that there are 3 battery packs in total, and each battery pack is directly connected in parallel to form a battery system. It should be noted that the control host battery pack (i.e., the first battery pack) is added to the group in which the control host battery pack is located (corresponding to the calculated integer value of 1 or-1 (depending on the polarity of the connection between the battery pack and the voltage access module)).

As another possibility, if the number of corresponding battery packs in each grouping is different, it is determined that a series error occurs between the first battery pack and the second battery pack.

In this step, if the number of battery packs in each group is different, it may be determined that a series error occurs between the first battery pack and the second battery pack in the battery system.

Further, the method may further include: and determining the type of the series errors and the positions of the series errors according to the specific number of the battery packs in each group.

In some exemplary embodiments, the principle of the present embodiment is explained in a structure in which a plurality of battery packs are mixed in series and parallel as shown in fig. 16. Various elements of each battery pack in fig. 16 correspond to those of each battery pack in fig. 14, like reference numerals indicate like elements, and repeated description is omitted here. When it is determined that there is no parallel error, controlling to disconnect all the battery packs P ₁ -P _n Middle K _{1, preparation of} -K _{n, pre} Control to close all the battery packs P ₁ -P _n Middle K _{1, is turning to} -K _{n is positive} (may be omitted), M _{1, charging} -M _{n, charging} And M _{1, placing} -M _{n, to put} . With battery pack P ₁ As an example of a controlling master, P ₁ The battery pack can close the second voltage access module (corresponding to S in FIG. 16) _{1, negative} ) Let P stand in ₁ The negative pole of the battery pack is connected with the second signal line. Then, the battery pack P ₁ In turn with other battery packs (slave battery pack P) ₂ -P _n I.e. a plurality of second battery packs) to control other battery packs to close the first voltage connection of the battery packs in sequenceGo to module (corresponding to S in FIG. 16) _{2, positive} -S _{n is positive} ) And the anodes of other battery packs are sequentially connected into the first signal line. Then when the positive electrode of each of the other battery packs is connected to the first signal line, the battery pack P ₁ The voltage value between the first signal line and the second signal line is obtained by the voltage detection circuit of the battery pack, and the voltage value is divided by the first battery pack P ₁ Rounding to get integer value, and repeating the steps until all other battery packs are traversed to obtain n-1 integer values. Grouping the n-1 integer values, dividing the same integer value into the same group, and counting the number of integer values in each group (the count value corresponds to the number of battery packs in the group), wherein the number of groups with an integer value of 1 needs to be increased by one (corresponding to the number of battery packs P) ₁ The group of the battery pack P ₁ Taken into account by itself). Then, the counting value of each group is compared, and whether other battery packs and the battery pack P exist in the whole battery system or not is further determined ₁ In case of series errors. The determination of the type of the tandem error and the position where the tandem error occurs are described below by way of example of possible scenarios (assuming n = 10):

the first situation is that:

group number	Grouping corresponding integer values	Number of integer values in a packet
			1#	1	2
2#	0	4
			3#	-1	2
4#	-2	2

For the first case, it can be found that the integer values are divided into 4 groups, where the number of integer values in 1#, 3# and 4# groups is 2, and the number of integer values in 2# group is 4. Based on the detection result, it can be confirmed that an error has occurred in connection of 4 battery packs in the # 2 packet, and the main reason is that the polarity in which 2 battery packs are connected in the battery system is reversed. At this time, the control host (the first battery pack) may send an error report message to the user to remind the user that the connection error occurs in the corresponding battery pack, and whether the connection condition of the corresponding battery pack meets the design expectation of the user needs to be checked.

The second case:

group number	Grouping corresponding integer values	Number of integer values in a packet
			1#	1	2
2#	0	2
			3#	-1	3
4#	-2	2
			5#	-3	1

For the second case, it can be found that the integer value is divided into 5 groups, indicating that the user desires to construct the battery system in a 2-by-5 string manner. The number of the integer values in the groups of 1#, 2# and 4# is 2, which indicates that the three groups adopt 2 battery packs connected in parallel, and meets the design expectation of users. And if the number of the integer values in the 3# and 5# groups is not 2, the connection errors of the battery packs corresponding to the two groups are indicated, at this time, the control host (the first battery pack) can send error reporting information to a user to remind the user that the connection errors of the battery packs corresponding to the user occur, the error type is a battery pack which is originally required to be connected in parallel with the battery packs in the 5# group, and the user mistakenly connects the battery packs in parallel to the battery packs in the 3# group, so that the number of the parallel battery packs in each group is different. Since the performance of the battery system has a "barrel effect," such a situation may affect the battery capacity and performance of the entire battery system, and it is also necessary to remind the user to check whether the connection situation of the corresponding battery pack meets the design expectations of the user.

The third situation:

group number	Grouping corresponding integer values	Number of integer values in a packet
			1#	1	2
2#	0	2
			3#	-1	2

For the third case, it can be found that the integer values are divided into 3 groups, and the number of integer values in each group is 2. If a user desires to construct a battery system with 10 battery packs in 2-5 strings, there is an open circuit in the circuit, so that the voltage values of other battery packs cannot be detected, and the position of the open circuit is located at the third battery pack position of the negative terminal of the battery pack of the control host. At this time, the control host (the first battery pack) may send an error report message to the user to remind the user that the connection error occurs in the corresponding battery pack, and whether the connection condition of the corresponding battery pack meets the design expectation of the user needs to be checked.

It will be understood by those skilled in the art that the above three cases are only exemplary three cases for explaining the representative possible judgment manner when error occurs in tandem, but do not mean that the management method given in the embodiment of the present application can be used in only the three cases. In fact, all possible tandem error situations can be detected based on the same method and principle.

In one embodiment, after the step of sequentially acquiring the voltage values between the first signal line and the second signal line, the management method further includes:

determining the connection mode among all the battery packs in the battery system according to the voltage value;

and outputting preset information, wherein the preset information is used for representing the connection mode among all the battery packs in the battery system.

In this embodiment, after the first voltage access module controlling each second battery pack is connected to the first signal line, the voltage value between each first signal line and each second signal line is sequentially obtained, and based on the voltage values, the connection mode between all the battery packs in the entire battery system can be determined, and the specific determination method is completely disclosed in the chinese patent application with the application number of CN202211004551.6 and the invention name of a battery system and a battery pack connection state management method, and is not repeated herein.

After the connection modes between all the battery packs in the battery system are determined, in order to facilitate the user to intuitively compare the difference between the actual connection mode and the connection mode used for expectation, the control host battery pack (the first battery pack) can output preset information which is used for representing the connection modes between all the battery packs in the battery system, so that the user can know the actual connection modes of all the battery packs in the current battery system by looking over the preset information. If the control host battery pack is provided with a display screen, preset information can be directly displayed on the display screen. If the battery pack of the control host does not have a display screen, the control host outputs the preset information to a mobile terminal (a mobile phone, a tablet, a control panel and the like) of a user, and the mobile terminal displays the preset information on a UI (user interface) of an application program. In this case, the control host battery pack needs to establish a communication connection with the mobile terminal of the user, for example, the battery pack is connected with the mobile phone of the user through bluetooth, wi-Fi or through a cloud server, so that the user can view the connection states of all the battery packs in the battery system directly on the application program interface of the mobile phone.

In one embodiment, the management method further comprises:

In this embodiment, when it is determined that a parallel error or a series error occurs in the first battery pack and the second battery pack, a first prompting message may be output, where the first prompting message may be sent through an APP interface of the mobile phone, for example, in a manner of flashing/graying/popping a window on an interface component (e.g., a battery pack icon) corresponding to the battery pack that needs to be charged, so as to prompt a user that the parallel error or the series error occurs in the battery pack. If the control host battery pack is provided with a display screen, the first reminding message can be directly displayed on the display screen. If the battery pack of the control host does not have a display screen, the control host outputs the first reminding message to a mobile terminal (a mobile phone, a tablet, a control panel and the like) of a user, and the mobile terminal displays the first reminding message on a UI (user interface) of an application program. In this case, the control host battery pack needs to establish a communication connection with the mobile terminal of the user, for example, the battery pack is connected with the mobile phone of the user through bluetooth, wi-Fi or through a cloud server, so that the user can view the connection states of all the battery packs in the battery system directly on the application program interface of the mobile phone. As another possible embodiment, the LED lamp of the battery pack with the connection error (parallel connection error and/or series connection error) may be controlled to light up or flash, so as to alert the user that the connection of the battery pack may be incorrect and the connection condition needs to be checked.

In one embodiment, the management method further comprises:

in this step, the State of Health may be a State of Health (SOH) in which the battery capacity is degraded, and the remaining capacity may be generally a State of Charge (SOC). The periodicity may be set selectively according to actual conditions, such as 1 day, 3 days, etc., and the specific time is not limited in this embodiment. The state of health and/or the remaining capacity of each battery pack of the battery system may be periodically acquired using the BMS in each battery pack.

Responding to the situation that the health state of the battery pack is smaller than a preset health state threshold value, and outputting a second reminding message, wherein the second reminding message represents that the health state of the battery pack is abnormal; and/or the presence of a gas in the gas,

In this embodiment, it is determined whether the health status of each battery pack is less than a preset health status threshold, and if so, the BMS in the battery pack outputs a second warning message. The second reminding message is used for reminding that the health state of the battery pack is abnormal. The second reminding message can also be sent out through an APP interface of the mobile phone, for example, in a manner of flashing/graying/popup an interface component (a battery pack icon) corresponding to the battery pack to be charged; the second reminding message can also be sent out in modes of LED light reminding, buzzing alarm and the like. The preset state of health threshold may be determined according to the rated capacity of each battery pack, for example, assuming that the rated capacity of the battery pack is 100Ah, the state of health threshold is set to 60%. After each battery pack is used for a period of time, the rated capacity is generally reduced due to an increase in the internal resistance of the battery, and the like, for example, the rated capacity becomes 95Ah after 1 year of use, and the corresponding state of health is 95%. After the battery pack is used for a longer time, when the health state is lower than 60%, the battery pack can be considered to be abnormal in health state, a second reminding message needs to be output, and a user is reminded that the battery pack needs to be replaced.

Optionally, this embodiment may further include determining whether a difference between remaining power amounts of each battery pack is greater than a preset remaining power threshold, and if the difference is greater than the preset remaining power threshold, it may be proved that the difference between remaining power amounts of the battery packs is too large, and power equalization control needs to be performed. The electric quantity balance control can be realized by independently supplementing electricity to the battery pack with the minimum SOC or independently discharging the battery pack with the maximum SOC, so that the electric quantity among the batteries is balanced. For example, the remaining power threshold may be set to 3%, the remaining power after a certain battery pack is used for a period of time is 35%, and the remaining power after a battery pack is used for the same period of time is 39%, where the difference value of 39% -35% =4% is greater than the remaining power threshold, and at this time, power balance control is required. The battery packs with the residual electric quantity of 39% can be automatically and independently discharged for a period of time, so that the residual electric quantity gradually approaches 35%, after the residual electric quantity difference value between every two battery packs is smaller than the residual electric quantity threshold value, all the battery packs are controlled to be charged or discharged together. According to the method, the electric quantity of each battery pack can be always in a balanced state, the capacity and the performance of the battery system are improved, and the service life of each battery pack is prolonged.

It should be understood that, although the steps in the flowcharts related to the embodiments described above are shown in sequence as indicated by the arrows, the steps are not necessarily performed in sequence as indicated by the arrows. The steps are not performed in the exact order shown and described, and may be performed in other orders, unless explicitly stated otherwise. Moreover, at least a part of the steps in the flowcharts related to the embodiments described above may include multiple steps or multiple stages, which are not necessarily performed at the same time, but may be performed at different times, and the execution order of the steps or stages is not necessarily sequential, but may be rotated or alternated with other steps or at least a part of the steps or stages in other steps.

Based on the same inventive concept, the embodiment of the present application further provides a battery pack for implementing the battery pack management method for a battery system. The implementation scheme for solving the problem provided by the battery pack is similar to the implementation scheme described in the above method, so specific limitations in one or more battery pack embodiments provided below can be referred to as limitations on a battery pack management method for a battery system in the foregoing, and details are not described here.

In one embodiment, a battery pack 100 is provided, in which in addition to the above-mentioned structure shown in fig. 1 to 6, the battery pack and a plurality of second battery packs are used to form a battery system, as shown in fig. 17, the battery pack includes: a control module 402, a communication module 404, and a parallel detection module 404, wherein:

a control module 402, configured to control to disconnect a charge and discharge circuit of the battery pack and control to connect a pre-charge circuit of the battery pack;

a communication module 404, configured to communicate with the second battery pack, so that the second battery pack disconnects a charge and discharge circuit of the second battery pack and connects a pre-charge circuit of the second battery pack;

a parallel detection module 404, configured to obtain a current value between the battery pack and each second battery pack, and determine whether a parallel error occurs between the battery pack and the second battery pack according to the current value.

In one embodiment of the battery pack, the parallel detection module 404 is further configured to: in response to the current value being within a preset first threshold range, determining that no parallel connection error occurs between the battery pack and the second battery pack; alternatively, the first and second electrodes may be,

and the current value is within a preset second threshold range, and the parallel connection error between the battery pack and the second battery pack is determined.

In an optional embodiment of the battery pack, the control module 402 is further configured to control the charging and discharging loops of all battery packs in the battery system to be conducted in response to determining that no parallel connection error occurs between the battery pack and the second battery pack; the second voltage access module is used for controlling the battery pack and is connected with the second signal line;

the communication module 404 is further configured to sequentially communicate with the second battery pack, and sequentially control the first voltage access module of the second battery pack to be connected to the first signal line;

and the series detection module is used for sequentially acquiring voltage values between the first signal line and the second signal line and determining whether a series error occurs between the battery pack and the second battery pack according to the voltage values.

In one embodiment of the battery pack, the series detection module includes: and the voltage grouping module is used for grouping the voltage values and acquiring the number of the corresponding battery packs in each group.

And the series detection submodule is used for determining whether series errors occur between the battery pack and the second battery pack according to the number.

In one embodiment of the battery pack, the voltage grouping module includes: the numerical value calculation module is used for dividing the voltage value by the voltage value of the battery pack and rounding the voltage value to obtain an integer value;

a numerical grouping module for grouping the same integer values into the same group;

and the battery pack number determining module is used for counting the number of the integer values in each group and determining the number of the corresponding battery packs in each group according to the number of the integer values.

In one embodiment of the battery pack, the series detection submodule includes:

the first detection module is used for determining that no series connection error occurs between the battery pack and the second battery pack if the number of the corresponding battery packs in each group is the same. Alternatively, the first and second electrodes may be,

the second detection module is used for determining that a series error occurs between the battery pack and the second battery pack if the number of the corresponding battery packs in each group is different.

In one embodiment of the battery pack, the battery pack further comprises: the first reminding module responds to the occurrence of a parallel error or a series error between the battery pack and the second battery pack and outputs a first reminding message, and the first reminding message represents the occurrence of a parallel error or a series error between the battery pack and the second battery pack.

In one embodiment of the battery pack, the battery pack further comprises: and the information acquisition module is used for periodically acquiring the health state and/or the residual electric quantity of each battery pack in the battery system.

The second prompting module is used for responding to the situation that the health state of the battery pack is smaller than a preset health state threshold value and outputting a second prompting message, wherein the second prompting message represents that the health state of the corresponding battery pack is abnormal;

and the balance control module is used for responding to the situation that the difference value of the residual electric quantity between each battery pack is larger than a preset residual electric quantity threshold value, and performing electric quantity balance control.

It is understood that the above-mentioned various modules may be provided in the battery pack alone or in the BMS of the battery pack.

The various modules in the battery pack described above may be implemented in whole or in part by software, hardware, and combinations thereof. The modules can be embedded in a hardware form or independent from a processor in the computer device, and can also be stored in a memory in the computer device in a software form, so that the processor can call and execute operations corresponding to the modules.

In one embodiment, a computer device is provided, which may be a server, and its internal structure diagram may be as shown in fig. 18. The computer device includes a processor, a memory, and a network interface connected by a system bus. Wherein the processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of an operating system and computer programs in the non-volatile storage medium. The database of the computer device is used for storing current values and voltage values. The network interface of the computer device is used for communicating with an external terminal through a network connection. The computer program is executed by a processor to implement a battery pack management method for a battery system.

Those skilled in the art will appreciate that the architecture shown in fig. 18 is merely a block diagram of some of the structures associated with the disclosed aspects and is not intended to limit the computing devices to which the disclosed aspects apply, as particular computing devices may include more or less components than those shown, or may combine certain components, or have a different arrangement of components.

In one embodiment, as shown in fig. 19, the present application further provides a battery system including a first battery pack and a plurality of second battery packs, wherein the first battery pack is configured to perform the steps of any of the above method embodiments.

In one embodiment of the battery system, the first battery pack and the plurality of second battery packs are connected with a power bus bar, and the first battery pack and the plurality of second battery packs are directly or indirectly connected with each other.

In one embodiment, a battery management system is further provided, which includes a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the above method embodiments when executing the computer program.

In an embodiment, a computer-readable storage medium is also provided, on which a computer program is stored, which, when being executed by a processor, carries out the steps of the above-mentioned method embodiments.

In an embodiment, a computer program product is also provided, comprising a computer program which, when executed by a processor, carries out the steps in the above-described method embodiments.

The arrangement sequence of the embodiments of the present application is merely for description, and does not represent the advantages and disadvantages of the embodiments.

It should be understood that, although the steps in the flowcharts related to the embodiments as described above are sequentially displayed as indicated by arrows, the steps are not necessarily performed sequentially as indicated by the arrows. The steps are not performed in the exact order shown and described, and may be performed in other orders, unless explicitly stated otherwise. Moreover, at least a part of the steps in the flowcharts related to the embodiments described above may include multiple steps or multiple stages, which are not necessarily performed at the same time, but may be performed at different times, and the execution order of the steps or stages is not necessarily sequential, but may be performed alternately or alternately with other steps or at least a part of the steps or stages in other steps.

In the present application, the same or similar descriptions of terms, technical solutions and/or application scenarios will generally be described in detail only when they occur for the first time, and when they occur repeatedly later, they will not be repeated again for brevity, and in understanding the technical solutions and the like of the present application, reference may be made to the related detailed descriptions and the like before the same or similar descriptions of terms, technical solutions and/or application scenarios and the like which are not described in detail later.

The technical features of the technical solution of the present application may be arbitrarily combined, and for brevity of description, all possible combinations of the technical features in the embodiments are not described, however, as long as there is no contradiction between the combinations of the technical features, the scope of the present application should be considered as being described in the present application.

The above description is only a preferred embodiment of the present application, and not intended to limit the scope of the present application, and all modifications of equivalent structures and equivalent processes, which are made by the contents of the specification and the drawings of the present application, or which are directly or indirectly applied to other related technical fields, are included in the scope of the present application.

Claims

1. A battery pack management method for a battery system, wherein the battery system comprises a first battery pack and a plurality of second battery packs, the management method applied to the first battery pack comprises:

the pre-charging circuit is used for sequentially controlling and conducting the second battery pack;

2. The method for managing according to claim 1, wherein the determining whether a parallel error occurs between the first battery pack and the second battery pack according to the current value comprises:

3. The management method according to claim 1 or 2, wherein the first battery pack and each of the second battery packs are respectively and controllably connected to the first signal line through a first voltage access module and to the second signal line through a second voltage access module, and the management method further comprises:

4. The method for managing according to claim 3, wherein the determining whether a series error occurs between the first battery pack and the second battery pack according to the voltage value comprises:

5. The method for managing according to claim 4, wherein the grouping the voltage values and obtaining the number of corresponding battery packs in each group comprises:

dividing the same integer value into the same group;

6. The method for managing according to claim 5, wherein the determining whether a series error occurs between the first battery pack and the second battery pack according to the number comprises:

7. The management method according to claim 4, wherein the management method further comprises:

8. The method of managing of claim 1, further comprising:

periodically acquiring the health state and/or the residual electric quantity of each battery pack in the battery system;

responding to the situation that the health state of the battery pack is smaller than a preset health state threshold value, and outputting a second reminding message, wherein the second reminding message represents that the health state of the corresponding battery pack is abnormal; and/or the presence of a gas in the gas,

and performing power balance control in response to the fact that the difference value of the residual power between each battery pack is larger than a preset residual power threshold value.

9. A battery pack, wherein the battery pack and a plurality of second battery packs are used to form a battery system, the battery pack comprising:

10. A battery system, comprising a first battery pack and a plurality of second battery packs, wherein the first battery pack is configured to perform the battery pack management method according to any one of claims 1 to 8.