Battery equalization detection method and device, electronic equipment and storage medium

Abstract

The application discloses a battery equalization detection method and device, electronic equipment and a storage medium. The method comprises the following steps: in response to a battery equalization detection instruction, performing negative pulse discharge on the battery; and determining the unbalance degree of the battery based on the electrical parameters of each cell in the battery after discharging. The embodiment of the application can avoid the detection error caused by DCR when detecting the unbalance degree in the case that the power battery system provides electric energy and the current exists, and can detect the unbalance degree of the battery while detecting the SOH of the battery through the negative pulse, which is beneficial to improving the energy utilization rate and service life of the battery.

Description

Technical Field

[0001] This application relates to the field of batteries, specifically to a battery equalization detection method, apparatus, electronic device, and storage medium. Background Technology

[0002] As a core component of new energy vehicles, the performance of the power battery system directly affects the overall vehicle performance. Among the factors contributing to performance degradation, inconsistency within the battery pack is a significant contributor. This inconsistency is typically caused by differences in the state of charge (SOC) between individual battery cells. An unbalanced battery pack reduces capacity and energy utilization, lowers input and output power levels, and shortens lifespan. To improve battery pack consistency during operation, it is necessary to balance the battery pack based on the degree of imbalance between cells.

[0003] In related technologies, the imbalance of batteries is identified by judging the voltage difference of the power battery system. However, when the power battery system provides electrical energy, there is current. The voltage difference may be caused by the difference in DC impedance (DCR) rather than by the difference in SOC between individual battery cells. Therefore, the above-mentioned scheme will result in low accuracy in detecting the imbalance of batteries in the power battery system. Summary of the Invention

[0004] In view of the above problems, this application provides a battery equalization detection method, apparatus, electronic device and storage medium, which can solve the technical problem of low accuracy in detecting battery imbalance during use.

[0005] In a first aspect, this application provides a battery balancing detection method, comprising: performing a negative pulse discharge on the battery in response to a battery balancing detection command; and determining the degree of imbalance of the battery based on the electrical parameters of each cell in the battery after discharge.

[0006] In the technical solution of this invention embodiment, a negative pulse discharge is performed on the battery, and the battery imbalance is determined based on the electrical parameters of each cell in the battery after discharge. This can avoid the detection error caused by DCR when the power battery system provides power and there is current, thereby improving the accuracy of battery imbalance detection.

[0007] In some embodiments, performing negative pulse discharge on the battery includes: performing negative pulse discharge on the battery to discharge the battery from its current state of charge (SOC) to a target SOC. In this embodiment, by discharging the battery's current SOC to a preset target SOC using negative pulses, the equalization of different types of batteries can be detected quickly and flexibly, with few limitations and high universality.

[0008] In some embodiments, the battery is a plateau battery, and the slope of the SOC-open circuit voltage (OCV) curve corresponding to the plateau battery includes an interval with a slope of zero; the negative pulse discharge of the battery to discharge the battery from the current state of charge (SOC) to the target SOC includes: determining any SOC within the SOC interval of the curve with a slope of non-zero that is less than the current SOC of the battery as the target SOC; and reducing the SOC of the battery to the target SOC based on the negative pulse.

[0009] In this embodiment, when performing balance testing on a battery with a platform, the battery's imbalance can be accurately detected by discharging the battery's SOC to the SOC range where the slope of the SOC-OCV curve is not zero, without having to discharge the battery to the low end, thus avoiding vehicle breakdowns.

[0010] In some embodiments, the battery is a plateau-free battery, and the slope of the SOC-OCV curve corresponding to the plateau-free battery does not include an interval with a slope of zero; the step of performing negative pulse discharge on the battery to discharge the battery from the current state of charge (SOC) to the target SOC includes:

[0011] From the SOC range consisting of the maximum and minimum SOC of the electrical equipment operating conditions within the first preset time period, any SOC smaller than the current SOC of the battery is selected as the target SOC.

[0012] The SOC of the battery is reduced to the target SOC based on the negative pulse.

[0013] In this embodiment, when performing balance testing on a battery without a platform, the SOC of this type of battery is discharged to the SOC range corresponding to the operating conditions of the electrical equipment. Balance testing can be performed without discharging this type of battery to a low level. This not only avoids vehicle breakdowns but also prevents situations where the battery cannot be balanced in time after a breakdown, thus improving the user experience of the vehicle.

[0014] In some embodiments, after performing negative pulse discharge on the battery, the method further includes: allowing the discharged battery to rest for a second preset time. In this embodiment, by allowing the discharged battery to rest, the battery can be depolarized to the open circuit voltage, avoiding the polarization phenomenon after battery discharge from affecting the battery balance detection and improving the accuracy of battery balance detection.

[0015] In some embodiments, determining the battery imbalance based on the electrical parameters of each cell in the battery after discharge includes:

[0016] Based on the voltage values ​​of each cell in the battery after discharge, the SOC value of each cell is determined.

[0017] The imbalance of the battery is determined based on the SOC value of each cell.

[0018] In this embodiment, the SOC value of each cell is obtained by measuring the voltage value of each cell in the battery, and the battery imbalance is determined based on the SOC value. This method avoids the detection error caused by DCR when the power battery system is providing power and there is current, thus improving the accuracy of battery imbalance detection.

[0019] In some embodiments, determining the SOC value of each cell based on the voltage value of each cell in the battery after discharge includes:

[0020] Determine the current temperature of the battery; based on the current temperature and the voltage value of each cell, obtain the current SOC value of each cell from the preset mapping relationship between battery temperature, SOC and voltage.

[0021] In this embodiment, the SOC value of each cell is obtained through the mapping relationship between battery temperature, SOC and voltage, and the imbalance of the battery is determined based on the SOC value. This method can accurately obtain the SOC value of each cell of the current battery. The battery can be conveniently tested for imbalance at any temperature. It has a wide range of applicable scenarios, few limitations and high accuracy.

[0022] In some embodiments, after determining the imbalance of the battery, the method further includes: if the imbalance of the battery is greater than a preset threshold, then using a preset active balancing module or passive balancing module to perform balancing operation on the battery.

[0023] In this embodiment, balancing is activated based on the imbalance detection result, which allows the battery capacity of the device to be utilized to a greater extent, improves the battery capacity and energy utilization rate, increases the battery input and output power level, and extends the battery life.

[0024] In some embodiments, the response to the battery equalization detection command further includes:

[0025] When the battery is detected to meet the first preset abnormal condition, a battery equalization detection command is triggered. The first preset abnormal condition includes the battery experiencing a cell drop or the battery not undergoing battery equalization detection for more than a third preset time period.

[0026] In this embodiment, when the control module detects that the battery meets a first preset abnormal condition, it triggers a battery balancing detection command. This allows the battery balancing detection process to be automatically initiated when abnormal conditions occur in the electrical equipment or battery, improving the automation level of equipment maintenance. Timely battery balancing detection when abnormal conditions occur in the electrical equipment or battery can improve the accuracy of calculations such as battery state of charge estimation, power estimation, and charging rate determination, reducing the possibility of battery or electrical equipment failures caused by SOC imbalance among the battery cells. Specifically, triggering a battery balancing detection command when a cell dip is detected allows for timely detection and calibration of the battery's balancing degree, aiding in diagnosing the cause of the cell dip based on the balanced battery and enabling more accurate battery control. Furthermore, if the battery has not undergone balancing detection for an extended period, it indicates that the battery balancing degree recorded in the control module may not match the actual situation of the battery. In this case, triggering a battery balancing detection command can calibrate the battery balancing degree recorded in the control module, improving the accuracy of the recorded battery balancing degree and thus improving the accuracy of battery control based on battery balancing degree.

[0027] In some embodiments, the response to the battery equalization detection command further includes:

[0028] Receive battery balancing detection commands sent by the user; or,

[0029] The receiving server sends a battery balancing detection command when it detects that a second preset abnormal condition is met. The second preset abnormal condition includes the battery cell dropping phenomenon, or the deviation between the imbalance detected by the server and the device where the battery is located exceeds a preset value.

[0030] In this embodiment, when a user needs to perform battery balancing detection, they can send a battery balancing detection command through the user terminal or directly submit the command on the electric device. This meets the user's need to detect battery balancing in any scenario, improving the convenience of triggering battery balancing detection. It allows users to promptly grasp the battery balancing status and perform balancing. Simultaneously, it can calibrate the battery balancing recorded in the control module, improving the accuracy of the recorded battery balancing and thus enhancing the accuracy of battery control based on battery balancing. Alternatively, when the server detects that the deviation between battery imbalances exceeds a preset value, it issues a battery balancing detection command. This allows the server to trigger battery balancing detection when it detects abnormalities in the electrical device or battery, improving the automation of equipment maintenance. Timely battery balancing detection in abnormal situations can reduce the possibility of battery or electrical device failures due to excessive battery imbalance. It also helps ensure consistency between the battery balancing recorded by the electrical device and the server, improving the accuracy of server-side control of the electrical device based on battery balancing and the accuracy of data analysis based on battery balancing.

[0031] In some embodiments, it is determined that the electrical device containing the battery is connected to a charging / discharging device. In this embodiment, by determining that the electrical device containing the battery is connected to the charging / discharging device, it is possible to determine whether the charging / discharging device is malfunctioning or not connected to the electrical device. This can automatically or actively calibrate the imbalance of the battery pack in the vehicle, improve the automation level of battery balance detection, thereby maximizing the capacity of the cells in the battery pack and improving the user experience of the vehicle.

[0032] Secondly, an embodiment of the present invention provides a battery equalization detection device, characterized in that it includes:

[0033] The discharge unit is used to perform negative pulse discharge on the battery in response to the battery equalization detection command;

[0034] The determining unit is used to determine the degree of imbalance of the battery based on the electrical parameters of each cell in the battery after discharge.

[0035] Thirdly, an embodiment of the present invention provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, it implements the method described in the first aspect.

[0036] Fourthly, embodiments of the present invention provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method described in the first aspect.

[0037] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0038] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0039] Figure 1 This is a flowchart of a battery equalization detection method provided in an embodiment of the present invention;

[0040] Figure 2 This is a schematic diagram of the SOC-OCV curve of a platform cell provided in an embodiment of the present invention;

[0041] Figure 3 This is a schematic diagram of the SOC-OCV curve of a platformless battery cell provided in an embodiment of the present invention;

[0042] Figure 4 This is another flowchart of a battery equalization detection method provided in an embodiment of the present invention;

[0043] Figure 5 This is a schematic diagram of the structure of a battery equalization detection device provided in an embodiment of the present invention;

[0044] Figure 6 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0045] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0047] In the description of the embodiments of this invention, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this invention, "multiple" means two or more, unless otherwise explicitly defined.

[0048] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0049] In the description of the embodiments of this invention, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0050] In the description of the embodiments of the present invention, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0051] In the description of the embodiments of the present invention, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention.

[0052] In the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention according to the specific circumstances.

[0053] Currently, judging from market trends, the application of power batteries is becoming increasingly widespread. Power batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. In electric transportation, military equipment, and aerospace, batteries are typically used to provide power.

[0054] Battery inconsistency (balance) is one of the important parameters of a battery. Due to the imbalance of individual cells, during the charging phase, some cells may overcharge earlier than others, and during the discharging phase, some cells may over-discharge earlier than others. Therefore, battery balance plays a very important role in both efficiency and safety. Thus, battery balance is frequently monitored during the use of electrical devices. In related technologies, when the detected battery inconsistency reaches a certain threshold, balancing operations are performed on the battery based on the inconsistency between each cell to improve battery consistency during use.

[0055] In the process of researching battery balancing detection methods, the inventors of this application discovered that when a power battery system provides electrical energy and there is current, the voltage difference may be caused by the difference in DC impedance (DCR), rather than by the difference in SOC between individual battery cells. Therefore, judging the voltage difference of the power battery system to identify the battery imbalance will result in low accuracy in detecting battery imbalance, and the above detection method has a limited scope of application.

[0056] To provide a battery balancing detection method applicable to various operating conditions and different battery types under different aging paths, the inventors of this application, through in-depth research, designed a battery balancing detection method. This method responds to a battery balancing detection command by performing a negative pulse discharge on the battery; based on the electrical parameters of each cell in the battery after discharge, the degree of imbalance of the battery is determined.

[0057] This method designs different target detection conditions for battery balancing detection commands under different application scenarios. Upon receiving a battery balancing detection command triggered in a specific application scenario, it first performs a negative pulse discharge on the battery. Then, based on the electrical parameters of each cell in the battery after discharge, it determines the battery's imbalance degree. This avoids detection errors caused by DCR (Discharge Calibration) when the power battery system provides power and current is present, improving the accuracy of battery imbalance detection. Furthermore, it can simultaneously detect battery imbalance degree while detecting the battery's SOH (State of Health) through negative pulses, meeting the battery imbalance detection needs under various operating conditions. This allows for greater utilization of the cell capacity within the battery pack, improving the vehicle's user experience. This method is not only applicable to energy storage systems but also to detection requests from the vehicle, server, or user end, exhibiting minimal limitations and high universality.

[0058] The battery equalization detection method provided in this invention can be applied to any battery, which can be a single cell, a battery pack, or a battery array composed of multiple single cells. Electrical devices that can utilize the method provided in this invention can include, but are not limited to, battery-powered toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0059] The aforementioned electrical equipment can communicate with a server, which can be a single physical server device, a server cluster consisting of multiple devices, or a cloud server in a public or private cloud. The electrical equipment can receive battery balancing detection commands sent by the server and detect the battery's balancing degree using the method of this embodiment. The aforementioned electrical equipment can also communicate with user terminals such as mobile phones, tablets, and laptops. The electrical equipment can receive battery balancing detection commands sent by the user through the user terminal and detect the battery's balancing degree using the method of this embodiment. Alternatively, the control module in the electrical equipment can provide an interface for the user to trigger battery balancing detection commands, allowing the user to submit battery balancing detection commands to the electrical equipment through this interface. For example, a button to start battery balancing detection can be displayed on the center console of an electric vehicle, allowing the user to click the button to submit a battery balancing detection command to the electric vehicle. The electrical equipment can also connect to charging and discharging equipment in charging stations or battery swapping stations, receiving battery balancing detection commands triggered by the charging and discharging equipment. This charging and discharging equipment can be a charging pile, a charging / discharging machine, etc. The aforementioned electrical equipment can also connect to maintenance equipment, receiving battery balancing detection commands triggered by the maintenance equipment.

[0060] The above lists various application scenarios in which the electrical device is connected to other devices and receives battery equalization detection commands triggered by other devices. However, this application is not limited to the application scenarios listed above. Any other application scenario that can trigger battery equalization detection can detect the battery balance according to the method provided in the embodiments of this invention, including battery equalization detection actively triggered by the control module of the electrical device itself based on the state of the electrical device and / or the battery.

[0061] The following detailed description of the specific process for detecting battery balance in this application is provided through specific embodiments. This invention provides a battery balance detection method. This method performs negative pulse discharge on the battery, and determines the battery's imbalance based on the electrical parameters of each cell in the battery after discharge. This avoids detection errors caused by DCR (Discharge-Resistant Cycle) when performing imbalance detection under current conditions during power battery system power supply. Furthermore, it can detect battery imbalance while simultaneously detecting the battery's state of equilibrium (SOH) through negative pulse discharge, meeting the battery imbalance detection requirements under various operating conditions. This method is not only applicable to energy storage systems but also suitable for detection requests at the vehicle, server, or user ends, exhibiting minimal limitations and high universality.

[0062] See Figure 1 The flowchart shown illustrates a battery equalization detection method, which specifically includes the following steps:

[0063] Step S101: In response to the battery equalization detection command, perform negative pulse discharge on the battery.

[0064] In this embodiment of the invention, the executing entity is an electrical device or a control module within the electrical device. This control module can be a BMS (Battery Management System), a VCU (Vehicle Control Unit), a DC (Domain Controller), etc. This embodiment of the invention will be described in detail using a control module as the executing entity.

[0065] The battery equalization detection method of this invention can be applied to various application scenarios that require detection of battery equalization. According to the different sources of detection instructions, this invention divides various application scenarios into three categories: the power equipment end, the user end, and the server end. This division method is only an example. In actual applications, there may be other division methods, as well as application scenarios from sources other than these three ends. These will not be listed here.

[0066] For detection commands originating from the electrical equipment containing the battery, the control module of the equipment can monitor in real time. When the battery meets a first preset abnormal condition, a battery equalization detection command is triggered. The first preset abnormal condition includes battery cell degradation or failure to perform battery equalization detection for a preset period. The preset period can be 5 months, 6 months, or 1 year, etc.

[0067] For example, if the BMS detects a rapid drop in battery cell charge within a short period, it confirms a cell charge depletion phenomenon and triggers a battery balancing detection command. Alternatively, the BMS may be pre-configured with preset calculation conditions that the battery must meet to trigger battery balancing detection. These conditions may include a certain state of charge (SOC) and a specific battery temperature. If the BMS detects that the battery has not met these preset calculation conditions for a preset period of time, it will trigger a battery balancing detection command.

[0068] The first preset abnormal condition may also include any other situation in which the electric device itself actively triggers the battery equalization detection command, such as when the VCU detects that the electric vehicle has a reduced driving range, it triggers the battery equalization detection command, etc. The embodiments of the present invention will not be listed one by one here.

[0069] The aforementioned control module triggers a battery balancing detection command when it detects that the battery meets a first preset abnormal condition. This allows for automatic initiation of the battery balancing detection process when abnormal conditions occur in the equipment or battery, improving the automation level of equipment maintenance. Timely battery balancing detection when abnormal conditions occur improves the accuracy of calculations such as state of charge estimation, power estimation, and charging rate determination based on battery balancing, reducing the likelihood of battery or equipment failures due to inaccurate battery balancing. Specifically, triggering a battery balancing detection command when a cell temperature drop is detected allows for timely detection and balancing of the battery, reducing inconsistencies between cells. This helps diagnose the cause of cell temperature drops based on calibrated battery balancing and enables more accurate battery control based on battery balancing. Furthermore, if a battery has not undergone balancing detection for an extended period, it indicates that the battery balancing recorded in the control module may not reflect the actual battery condition. In this case, triggering a battery balancing detection command monitors and balances the battery, thereby improving the accuracy of battery control based on battery balancing. In addition, it can improve the consistency of the battery cells during use, and improve the energy utilization rate and lifespan of the battery.

[0070] For situations where battery balancing detection commands originate from the user's end, this applies when the user finds that the device cannot accurately display the battery's balancing status; when the user has not used the device for an extended period, causing a prolonged power outage in the BMS; when the user observes range degradation in electric vehicles; or when the user needs to assess battery balancing when buying or selling a used electric vehicle. The situations where battery balancing detection commands originate from the user's end are not limited to those listed here; any other user-triggered situation applies.

[0071] Users can install an application associated with the electrical device on their mobile phones or computers. This application includes an interface for triggering battery balancing detection commands. Whenever a user needs to check battery balancing, they trigger a battery balancing detection command through the interface provided by the application on their user terminal. The user terminal then sends this command to the electrical device.

[0072] Alternatively, the electrical device may have a mechanical button for triggering battery balancing detection, or the device's display screen may include a button for triggering battery balancing detection. Whenever a user needs to check battery balancing, they trigger the detection by pressing these buttons. When the electrical device detects these button press events, it confirms that it has received the user's battery balancing detection command.

[0073] When users need to perform battery balancing tests, they can send a battery balancing test command through the user terminal or directly submit the command on the electric device. This meets users' needs for testing battery balancing in any scenario, improving the convenience of triggering battery balancing tests. Timely detection and balancing of the battery when needed allows users to promptly grasp the actual battery balancing level, contributing to improved battery energy utilization and lifespan. Simultaneously, it enables timely calibration of the battery balancing level recorded in the control module, improving the accuracy of the recorded battery balancing level and thus enhancing the accuracy of battery control based on battery balancing.

[0074] When the battery balancing detection command originates from the server, the server sends the battery balancing detection command to the device when it detects that a second preset abnormal condition is met. The device receives the battery balancing detection command sent by the server. The second preset abnormal condition includes situations such as the battery cell experiencing a drop in battery level, the deviation between the imbalance detected by the server and the device containing the battery exceeding a preset threshold, or the state of charge (SOC) of some cells in the battery exhibiting outlier behavior under certain operating conditions, etc.

[0075] In this embodiment of the invention, for batteries of the same model used in similar electrical devices, the server statistically analyzes the SOC values ​​of these batteries under various operating conditions. Under the same operating conditions, the SOC values ​​of these batteries tend to cluster within a relatively small range. If the server detects that the SOC value of a battery in a certain electrical device is outside the SOC range of similar batteries under that operating condition, the server determines that the SOC of that battery under that operating condition has become an outlier.

[0076] The second preset abnormal condition may also include any other situation in which the server issues a battery balancing detection command, such as when the server detects that the electric vehicle has a reduced driving range, etc. The embodiments of the present invention will not be listed one by one here.

[0077] When the server detects that the second preset abnormal condition is met, it issues a battery balancing detection command. This allows the server to trigger a battery balancing check when it detects an anomaly in the powered device or battery, improving the automation of equipment maintenance. Timely battery balancing detection in case of anomalies reduces the likelihood of battery or powered device failures caused by excessive battery imbalance. It also helps ensure consistency between the battery balancing recorded by the powered device and the server, improving the accuracy of server-side control of powered devices based on battery balancing, and enhancing the accuracy of server-side data analysis based on battery balancing.

[0078] For any battery balancing detection command triggered in any scenario, such as the electric device end, server end, or user end, the control module of the electric device responds to the battery balancing detection command and initiates the detection of the current battery balancing degree. In this embodiment of the invention, the operating condition refers to the battery's working state, and the operating condition parameters include parameters such as battery temperature, current, voltage, and SOC when the battery is operating under the detection condition.

[0079] In this embodiment of the invention, before performing battery equalization testing, the control module first determines whether the current electrical device is connected to the charging / discharging device. Both the charging / discharging device and the electrical device support negative pulse functionality. By determining that the electrical device containing the battery is connected to the charging / discharging device, it can be determined whether the charging / discharging device has malfunctioned or is not connected to the electrical device. When the charging / discharging device malfunctions, the cause of the malfunction and the disconnection between the electrical device and the charging / discharging device can be displayed on the device's screen. This allows for timely reminders to inspect and replace the charging / discharging device. Furthermore, once the control module determines that the current electrical device is connected to the charging / discharging device, it can automatically or actively calibrate the imbalance of the battery pack within the vehicle. This not only improves the automation level of battery equalization testing but also allows the capacity of the battery cells within the battery pack to be utilized to a greater extent, improving the user experience of the vehicle.

[0080] Optionally, in one or more embodiments, performing negative pulse discharge on the battery includes: performing negative pulse discharge on the battery to discharge the battery from its current state of charge (SOC) to a target SOC. Specifically, the target SOC here depends on the type of battery. By discharging the battery's current SOC to a preset target SOC through negative pulse discharge, the equalization of different types of batteries can be detected quickly and flexibly. The detection method has few limitations and high universality.

[0081] Specifically, when the battery is a platform battery, the step of performing negative pulse discharge on the battery to discharge the battery from the current state of charge (SOC) to the target SOC includes: determining any SOC within the SOC interval of the curve with a slope that is not zero that is less than the current SOC of the battery as the target SOC; and reducing the SOC of the battery to the target SOC based on the negative pulse.

[0082] like Figure 3 As shown, the slope of the SOC-OV curve corresponding to a platform battery contains intervals with a slope of zero (75% SOC-95% SOC, 40% SOC-65% SOC), such as lithium iron phosphate (LFP) batteries. During the discharge process of this type of battery, assuming the current battery SOC is 70%, any SOC less than 70% within the SOC interval of the SOC-OCV curve with a slope of non-zero is determined as the target SOC, such as 35% SOC. Then, based on a negative pulse, the battery is reduced from 70% SOC to 35% SOC.

[0083] In related technologies, battery imbalance identification methods have significant limitations on operating conditions. For example, for cells with a plateau area, they must be discharged to a low level (below 25% SOC) to accurately identify the ΔSOC (imbalance) between cells. In this embodiment, when performing balance detection on batteries without a plateau, the SOC of this type of battery can be discharged to the SOC range corresponding to the operating conditions of the electrical equipment. It is not necessary to discharge this type of battery to a low level, which can avoid vehicle breakdowns and improve the safety of battery use.

[0084] Optionally, in one embodiment, when the battery is a platformless battery, the step of performing negative pulse discharge on the battery to discharge the battery from the current state of charge (SOC) to the target SOC includes: selecting any SOC lower than the current SOC of the battery from the SOC interval formed by the maximum and minimum SOC of the operating conditions of the electrical equipment within a first preset time period as the target SOC; and reducing the SOC of the battery to the target SOC based on the negative pulse.

[0085] Specifically, such as Figure 4As shown, the slope of the SOC-OCV curve corresponding to the platformless battery does not include the interval with a slope of zero, such as the lithium nickel cobalt manganese oxide (NCM) battery. During the discharge process of this type of battery, assuming the current battery SOC is 70%, the SOC interval is formed by the maximum and minimum SOC of the electrical equipment operating conditions within one month (e.g., ...). Figure 4 Within the range of 30% SOC-80% SOC within the dashed line, any SOC lower than the current SOC of the battery is selected as the target SOC. For example, if the target SOC is 50% SOC, the battery is then reduced from 70% SOC to the 50% SOC based on a negative pulse.

[0086] In this embodiment, when performing equalization testing on a battery without a platform, the SOC of this type of battery can be discharged to the SOC range corresponding to the operating conditions of the electrical equipment. It is not necessary to discharge this type of battery to a low end to perform equalization testing. This not only avoids vehicle breakdowns, but also avoids situations where the battery cannot be equalized in time after a breakdown, thus improving the user experience of the vehicle.

[0087] Optionally, in one or more embodiments, after performing negative pulse discharge on the battery, the battery is allowed to stand for a second preset time after the discharge is completed in the above battery equalization detection method.

[0088] In related technologies, after a battery is discharged, polarization occurs, causing fluctuations in the State of Charge (SOC) of the battery cells, which can affect battery equalization detection. Therefore, to avoid the effects of battery polarization, the battery is left to stand for a period of time after discharge to allow the charge of each cell to stabilize. It should be noted that this second preset time can be obtained by repeatedly measuring the time it takes for the cells to depolarize to the open-circuit voltage.

[0089] By allowing the discharged battery to stand still, the battery can be depolarized to the open circuit voltage, thus avoiding the impact of the polarization phenomenon after battery discharge on the battery balance detection and improving the accuracy of battery balance detection.

[0090] Step S102: Determine the battery imbalance based on the electrical parameters of each cell in the battery after discharge.

[0091] In this embodiment of the invention, the battery cell parameters include the battery current, voltage, current SOC and current battery temperature. After the battery is discharged with a preset requested negative pulse current, the battery imbalance is determined by acquiring electrical parameters such as the battery current, voltage, current SOC and current battery temperature.

[0092] Specifically, for example, based on the mapping relationship between cell voltage and SOC, the current SOC value of each cell in the battery is obtained, and then the battery imbalance is determined based on the current SOC value of each cell. Alternatively, based on the mapping relationship between cell voltage, SOC, and battery temperature, the current SOC value of each cell in the battery is obtained, and then the battery imbalance is determined based on the current SOC value of each cell. For example, if the current battery includes four cells A, B, and C, and cell A has an SOC of 40%, 30%, and 60%, then the current battery imbalance can be obtained by averaging the differences in SOC among the three cells, finally yielding a battery imbalance ΔSOC of 20%.

[0093] Optionally, in one or more embodiments, determining the battery imbalance based on the electrical parameters of each cell in the battery after discharge includes: determining the SOC value of each cell based on the voltage value of each cell in the battery after discharge; and determining the battery imbalance based on the SOC value of each cell. This embodiment of the invention, by determining the SOC value of each cell based on the voltage value of each cell in the battery after discharge, and then determining the battery imbalance based on the SOC value of each cell, can avoid detection errors caused by DCR when performing imbalance detection in a power battery system with current supplying electrical energy, thereby improving the accuracy of battery imbalance detection.

[0094] Optionally, in one or more embodiments, determining the SOC value of each cell based on the voltage value of each cell in the battery after discharge includes:

[0095] Determine the current temperature of the battery; based on the current temperature and the voltage value of each cell, obtain the current SOC value of each cell from the preset mapping relationship between battery temperature, SOC and voltage.

[0096] This invention provides a pre-defined SOC lookup set that stores the mapping relationship between SOC, battery temperature, and cell voltage. When the discharged battery is allowed to rest at its open-circuit voltage, the SOC associated with the first preset temperature and voltage is retrieved from the pre-defined SOC lookup set. This allows for accurate acquisition of the SOC value of each cell in the current battery. This method can be conveniently and quickly used to detect battery balance at any temperature, making it applicable to a wide range of scenarios, offering fast detection speed and high accuracy.

[0097] As an example, a SOC query set can be a data collection in tabular form. For example, as shown in Table 1 below:

[0098] Table 1

[0099]

[0100] As another example, the SOC lookup set can also be a data set in formula form. That is, the SOC data set records the calculation formulas for each SOC and its corresponding temperature and voltage values. This allows the BMS to calculate the corresponding SOC value using the given battery temperature and voltage value, and then use the corresponding formulas.

[0101] Optionally, in one or more embodiments, after determining the imbalance of the battery, the method further includes: if the imbalance of the battery is greater than a preset threshold, then using a preset active balancing module or passive balancing module to perform balancing operations on the battery.

[0102] Specifically, the preset threshold here can be obtained based on the battery's operating conditions. For example, when the power consumption of an electrical device is significantly reduced during use, the battery's imbalance is high, meaning there is a large difference in the State of Charge (SOC) between the cells within the battery, requiring battery equalization.

[0103] The passive equalization module used in this embodiment of the invention discharges the higher-voltage cells through resistor discharge, releasing electrical energy as heat. By discharging the relatively higher-voltage individual cells (such as battery cells) through resistors, the charge level of these cells is kept equal to or nearly equal to that of the lower-voltage individual cells. This is because the energy in the higher-charged cells is dissipated as heat. The active equalization module transfers energy from the higher-voltage individual cells in the battery module to the lower-voltage individual cells, achieving energy redistribution and thus equalizing the energy among the cells.

[0104] In this embodiment of the invention, by activating the balancing method based on the battery imbalance detection results, the battery capacity of the device can be utilized to a greater extent, thereby improving the battery capacity and energy utilization rate, increasing the battery input and output power levels, and enhancing the battery's safety and lifespan.

[0105] The following example illustrates how to detect battery balance based on battery SOC during charging and discharging of an electric vehicle. When the electric vehicle is located within a battery swapping station or charging station, it establishes a connection with the station's charging / discharging machine and main unit:

[0106] Step S401: Determine whether the battery has not undergone imbalance detection within a preset time period. If yes, proceed to step S402; otherwise, proceed to step S408.

[0107] Step S402: Detect whether the current vehicle supports negative pulse charging. If yes, proceed to step S403; otherwise, proceed to step S408.

[0108] Step S403: Discharge the current vehicle's battery pack system to the SOC region where the slope of the SOC-OCV curve is greater than a preset value, where the preset value is any value greater than zero. If the cells in the current battery pack system are platform cells, such as lithium iron phosphate (LFP) cells, discharge the battery pack system to any value below 25% SOC. If the cells in the current battery pack system are non-platform cells, such as nickel-cobalt-manganese (NCM) cells, then it is necessary to discharge the battery pack system to any SOC value lower than the current SOC value within the vehicle's driving conditions, based on the maximum / minimum SOC under the vehicle's driving conditions.

[0109] Step S404: Let the battery pack system that has been discharged in step S403 stand still for a preset time. The preset time is determined according to the time it takes for the cells in the battery pack system to depolarize to open circuit voltage.

[0110] Step S405: Query the SOC-OCV correspondence from the current vehicle's BMS, obtain the SOC of each cell based on the current voltage of each cell, calculate the difference ΔSOC between cells, and calculate the imbalance of the battery pack system based on ΔSOC.

[0111] Step S406: Based on the balance determined in step S405, determine the difference between the balance and the preset threshold. If the imbalance is greater than the preset threshold, proceed to step S407; otherwise, proceed to step S408.

[0112] Step S407: Perform active or passive balancing on the battery pack system.

[0113] Step S408: End battery equalization detection operation.

[0114] By applying the technical solution of this application, negative pulse discharge is performed on the battery. Based on the electrical parameters of each cell in the battery after discharge, the battery imbalance is determined. This avoids the detection error caused by DCR when performing imbalance detection under the condition that current is present when the power battery system is providing power. Moreover, it can detect battery imbalance while detecting the battery's State of Health (SOH) through negative pulses, meeting the battery imbalance detection requirements under various operating conditions. This method can automatically or actively calibrate the imbalance of the battery pack in the vehicle, thereby maximizing the capacity of the cells in the battery pack and improving the user experience.

[0115] This invention also provides a battery balancing detection device, which is used to execute the battery balancing detection methods provided in the above embodiments, such as... Figure 5 As shown, the device includes:

[0116] The discharge unit 501 is used to perform negative pulse discharge on the battery in response to the battery equalization detection command;

[0117] The determining unit 502 is used to determine the degree of imbalance of the battery based on the electrical parameters of each cell in the battery after discharge.

[0118] In the technical solution of this invention, by performing negative pulse discharge on the battery, the battery imbalance is determined based on the electrical parameters of each cell in the battery after discharge. This avoids the detection error caused by DCR when performing imbalance detection under the condition that current is present when the power battery system is providing power, thus improving the accuracy of battery imbalance detection. Moreover, while detecting the battery's state of health (SOH) through negative pulses, it can also detect the battery imbalance, meeting the battery imbalance detection needs under various operating conditions. This method is not only applicable to energy storage systems, but also to detection requests at the vehicle end, server end, or user end, exhibiting minimal limitations and high universality.

[0119] In another embodiment of this application, the discharge unit 501 includes:

[0120] The discharge module is used to perform negative pulse discharge on the battery, discharging the battery from its current state of charge (SOC) to the target SOC.

[0121] In another embodiment of this application, the battery is a plateau battery, and the slope of the SOC-open circuit voltage (OCV) curve corresponding to the plateau battery includes an interval with a slope of zero; the discharge module includes:

[0122] The first determining subunit is used to determine any SOC that is less than the current SOC of the battery within the SOC interval of the curve where the slope is not zero as the target SOC.

[0123] The first adjustment unit is used to reduce the SOC of the battery to the target SOC based on a negative pulse.

[0124] In another embodiment of this application, the battery is a plateau-free battery, and the slope of the SOC-OCV curve corresponding to the plateau-free battery does not include an interval with a slope of zero; the discharge module further includes:

[0125] The selection subunit is used to select any SOC that is smaller than the current SOC of the battery from the SOC range formed by the maximum SOC and minimum SOC of the electrical equipment operating conditions within the first preset time period as the target SOC.

[0126] The second adjustment unit is used to reduce the SOC of the battery to the target SOC based on a negative pulse.

[0127] In another embodiment of this application, the battery balancing detection device further includes:

[0128] A settling unit is used to set the battery, after the discharge has ended, for a second preset time.

[0129] In another embodiment of this application, the determining unit 502 includes:

[0130] The first determining module is used to determine the SOC value of each cell based on the voltage value of each cell in the battery after discharge.

[0131] The second determining module is used to determine the imbalance of the battery based on the SOC value of each cell.

[0132] In another embodiment of this application, the first determining module includes:

[0133] The second determining subunit is used to determine the current temperature of the aforementioned battery;

[0134] The acquisition sub-unit is used to obtain the current SOC value of each cell from the preset mapping relationship between battery temperature, SOC and voltage, based on the current temperature and the voltage value of each cell.

[0135] In another embodiment of this application, the battery balancing detection device further includes:

[0136] The balancing unit is used to perform balancing operations on the battery using a preset active balancing module or a passive balancing module if the imbalance of the battery exceeds a preset threshold.

[0137] In another embodiment of this application, the battery balancing detection device further includes:

[0138] The first triggering unit is used to trigger a battery equalization detection command when the battery meets the first preset abnormal conditions. The first preset abnormal conditions include the battery experiencing a cell drop or the battery not undergoing battery equalization detection for more than a third preset time period.

[0139] In another embodiment of this application, the battery balancing detection device further includes:

[0140] The first receiving unit is used to receive a battery equalization detection command sent by the user; or,

[0141] The second receiving unit is used to receive a battery balancing detection command sent by the server when it detects that a second preset abnormal condition is met. The second preset abnormal condition includes the battery cell dropping phenomenon, or the deviation between the imbalance detected by the server and the device where the battery is located exceeds a preset value.

[0142] In another embodiment of this application, the battery balancing detection device further includes:

[0143] The connection unit is used to determine the connection between the electrical equipment containing the battery and the charging / discharging equipment.

[0144] The battery charging device provided in the above embodiments of this application and the battery charging method provided in the embodiments of this invention are based on the same inventive concept and have the same beneficial effects as the methods adopted, run or implemented by the applications stored therein.

[0145] Figure 6 This is a logical structure block diagram of an electronic device according to an exemplary embodiment. For example, electronic device 600 may be an electronic device installed inside an electrical device, such as a BMS, vehicle controller, motor controller, or domain controller.

[0146] In an exemplary embodiment, a non-transitory computer-readable storage medium including instructions is also provided, such as a memory including instructions, which can be executed by a battery processor to complete a battery charging method, the method including: performing a negative pulse discharge on the battery in response to a battery equalization detection instruction; and determining the degree of imbalance of the battery based on the electrical parameters of each cell in the battery after discharge. Optionally, the instructions can also be executed by a battery processor to complete other steps involved in the exemplary embodiment. For example, the non-transitory computer-readable storage medium may be a ROM, random access memory (RAM), CD-ROM, magnetic tape, floppy disk, and optical data storage device, etc.

[0147] In an exemplary embodiment, an application / computer program product is also provided, including one or more instructions that can be executed by a battery processor to complete the battery charging method described above. The method includes: performing a negative pulse discharge on the battery in response to a battery equalization detection instruction; and determining the degree of imbalance of the battery based on the electrical parameters of each cell in the battery after discharge. Optionally, the instructions can also be executed by the battery processor to complete other steps involved in the exemplary embodiment described above.

[0148] Figure 6 This is an example diagram of an electronic device 600. Those skilled in the art will understand that it is illustrative. Figure 6 This is merely an example of electronic device 600 and does not constitute a limitation on electronic device 600. It may include more or fewer components than shown, or combine certain components, or different components. For example, electronic device 600 may also include input / output devices, network access devices, buses, etc.

[0149] The processor 602 may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor, or processor 602 may be any conventional processor. Processor 602 is the control center of electronic device 600, connecting all parts of electronic device 600 via various interfaces and lines.

[0150] The memory 601 can be used to store computer-readable instructions. The processor 602 implements various functions of the electronic device 600 by running or executing the computer-readable instructions or modules stored in the memory 601 and by calling the data stored in the memory 601. The memory 601 may mainly include a program storage area and a data storage area. The program storage area may store the operating system, application programs required for at least one function (such as sound playback function, image playback function, etc.), etc.; the data storage area may store data created according to the use of the electronic device 600, etc. In addition, the memory 601 may include a hard disk, memory, plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, at least one disk storage device, flash memory device, read-only memory (ROM), random access memory (RAM), or other non-volatile / volatile storage devices.

[0151] If the modules integrated in the electronic device 600 are implemented as software functional modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the present invention can implement all or part of the processes in the methods of the above embodiments. Alternatively, computer-readable instructions that instruct related hardware can be stored in a computer-readable storage medium. When executed by a processor, these computer-readable instructions can implement the steps of the various method embodiments described above.

[0152] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0153] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A battery equalization detection method, characterized in that, include: In response to the battery equalization detection command, a negative pulse discharge is performed on the battery to discharge the battery from the current state of charge (SOC) to the target SOC. The battery is a plateau battery, and the slope of the SOC-open circuit voltage (OCV) curve corresponding to the plateau battery includes an interval with a slope of zero. The degree of imbalance of the battery is determined based on the electrical parameters of each cell in the battery after discharge. The step of performing negative pulse discharge on the battery to discharge the battery from the current state of charge (SOC) to the target SOC includes: Any SOC within the SOC interval of the curve where the slope is not zero that is less than the current SOC of the battery is determined as the target SOC; The SOC of the battery is reduced to the target SOC based on the negative pulse.

2. The method according to claim 1, characterized in that, The battery is a plateau-free battery, and the slope of the SOC-OCV curve corresponding to the plateau-free battery does not include the interval with a slope of zero. The step of performing negative pulse discharge on the battery to discharge the battery from the current state of charge (SOC) to the target SOC includes: From the SOC range consisting of the maximum and minimum SOC of the electrical equipment operating conditions within the first preset time period, any SOC smaller than the current SOC of the battery is selected as the target SOC. The SOC of the battery is reduced to the target SOC based on the negative pulse.

3. The method according to claim 1 or 2, characterized in that, After performing a negative pulse discharge on the battery, the method further includes: The battery is left to stand for a second preset time after the discharge is complete.

4. The method according to claim 1, characterized in that, The determination of the battery imbalance based on the electrical parameters of each cell in the battery after discharge includes: Based on the voltage values ​​of each cell in the battery after discharge, the SOC value of each cell is determined. The imbalance of the battery is determined based on the SOC value of each cell.

5. The method according to claim 4, characterized in that, The determination of the SOC value of each cell based on the voltage value of each cell in the battery after discharge includes: Determine the current temperature of the battery; Based on the current temperature and the voltage value of each cell, the current SOC value of each cell is obtained from the preset mapping relationship between battery temperature, SOC and voltage.

6. The method according to claim 1, characterized in that, After determining the imbalance of the battery, the method further includes: If the imbalance of the battery is greater than a preset threshold, the battery will be balanced using a preset active balancing module or passive balancing module.

7. The method according to claim 1, characterized in that, The response prior to the battery equalization detection command also includes: When the battery is detected to meet the first preset abnormal condition, a battery equalization detection command is triggered. The first preset abnormal condition includes the battery experiencing a cell drop or the battery not undergoing battery equalization detection for more than a third preset time period.

8. The method according to claim 1, characterized in that, The response prior to the battery equalization detection command also includes: Receive battery balancing detection commands sent by the user; or, The receiving server sends a battery balancing detection command when it detects that a second preset abnormal condition is met. The second preset abnormal condition includes the battery cell dropping phenomenon, or the deviation between the imbalance detected by the server and the device where the battery is located exceeds a preset value.

9. The method according to claim 1, characterized in that, The response prior to the battery equalization detection command also includes: Determine the connection between the electrical device containing the battery and the charging / discharging device.

10. A battery equalization detection device, characterized in that, include: The discharge unit is used to perform negative pulse discharge on the battery in response to the battery equalization detection command, and discharge the battery from the current state of charge (SOC) to the target SOC. The battery is a plateau battery, and the slope of the SOC-open circuit voltage (OCV) curve corresponding to the plateau battery includes an interval with a slope of zero. A determining unit is used to determine the degree of imbalance of the battery based on the electrical parameters of each cell in the battery after discharge. The step of performing negative pulse discharge on the battery to discharge the battery from the current state of charge (SOC) to the target SOC includes: Any SOC within the SOC interval of the curve where the slope is not zero that is less than the current SOC of the battery is determined as the target SOC; The SOC of the battery is reduced to the target SOC based on the negative pulse.

11. An electronic device comprising a memory and a processor, characterized in that, The memory stores a computer program, and the processor is configured to execute the method described in any one of claims 1 to 9 through the computer program.

12. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein the program, when executed, performs the method according to any one of claims 1 to 9.

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